truffle: src/share/vm/memory/referenceProcessor.cpp annotate

annotate src/share/vm/memory/referenceProcessor.cpp @ 3938:e6b1331a51d2

7086585: make Java field injection more flexible Reviewed-by: jrose, twisti, kvn, coleenp

author	never
date	Sat, 10 Sep 2011 17:29:02 -0700
parents	eca1193ca245
children	4dfb2df418f2

rev	line source
0 a61af66fc99e Initial load duke parents: diff changeset	1 /*
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
0 a61af66fc99e Initial load duke parents: diff changeset	3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
a61af66fc99e Initial load duke parents: diff changeset	4 *
a61af66fc99e Initial load duke parents: diff changeset	5 * This code is free software; you can redistribute it and/or modify it
a61af66fc99e Initial load duke parents: diff changeset	6 * under the terms of the GNU General Public License version 2 only, as
a61af66fc99e Initial load duke parents: diff changeset	7 * published by the Free Software Foundation.
a61af66fc99e Initial load duke parents: diff changeset	8 *
a61af66fc99e Initial load duke parents: diff changeset	9 * This code is distributed in the hope that it will be useful, but WITHOUT
a61af66fc99e Initial load duke parents: diff changeset	10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
a61af66fc99e Initial load duke parents: diff changeset	11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
a61af66fc99e Initial load duke parents: diff changeset	12 * version 2 for more details (a copy is included in the LICENSE file that
a61af66fc99e Initial load duke parents: diff changeset	13 * accompanied this code).
a61af66fc99e Initial load duke parents: diff changeset	14 *
a61af66fc99e Initial load duke parents: diff changeset	15 * You should have received a copy of the GNU General Public License version
a61af66fc99e Initial load duke parents: diff changeset	16 * 2 along with this work; if not, write to the Free Software Foundation,
a61af66fc99e Initial load duke parents: diff changeset	17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
a61af66fc99e Initial load duke parents: diff changeset	18 *
1552 c18cbe5936b8 6941466: Oracle rebranding changes for Hotspot repositories trims parents: 1190 diff changeset	19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
c18cbe5936b8 6941466: Oracle rebranding changes for Hotspot repositories trims parents: 1190 diff changeset	20 * or visit www.oracle.com if you need additional information or have any
c18cbe5936b8 6941466: Oracle rebranding changes for Hotspot repositories trims parents: 1190 diff changeset	21 * questions.
0 a61af66fc99e Initial load duke parents: diff changeset	22 *
a61af66fc99e Initial load duke parents: diff changeset	23 */
a61af66fc99e Initial load duke parents: diff changeset	24
1972 f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	25 #include "precompiled.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	26 #include "classfile/javaClasses.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	27 #include "classfile/systemDictionary.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	28 #include "gc_interface/collectedHeap.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	29 #include "gc_interface/collectedHeap.inline.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	30 #include "memory/referencePolicy.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	31 #include "memory/referenceProcessor.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	32 #include "oops/oop.inline.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	33 #include "runtime/java.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	34 #include "runtime/jniHandles.hpp"
0 a61af66fc99e Initial load duke parents: diff changeset	35
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	36 ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	37 ReferencePolicy* ReferenceProcessor::_default_soft_ref_policy = NULL;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	38 const int subclasses_of_ref = REF_PHANTOM - REF_OTHER;
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	39 bool ReferenceProcessor::_pending_list_uses_discovered_field = false;
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	40
0 a61af66fc99e Initial load duke parents: diff changeset	41 // List of discovered references.
a61af66fc99e Initial load duke parents: diff changeset	42 class DiscoveredList {
a61af66fc99e Initial load duke parents: diff changeset	43 public:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	44 DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	45 oop head() const {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	46 return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) :
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	47 _oop_head;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	48 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	49 HeapWord* adr_head() {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	50 return UseCompressedOops ? (HeapWord*)&_compressed_head :
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	51 (HeapWord*)&_oop_head;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	52 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	53 void set_head(oop o) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	54 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	55 // Must compress the head ptr.
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	56 _compressed_head = oopDesc::encode_heap_oop(o);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	57 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	58 _oop_head = o;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	59 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	60 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	61 bool empty() const { return head() == NULL; }
0 a61af66fc99e Initial load duke parents: diff changeset	62 size_t length() { return _len; }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	63 void set_length(size_t len) { _len = len; }
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	64 void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); }
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	65 void dec_length(size_t dec) { _len -= dec; }
0 a61af66fc99e Initial load duke parents: diff changeset	66 private:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	67 // Set value depending on UseCompressedOops. This could be a template class
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	68 // but then we have to fix all the instantiations and declarations that use this class.
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	69 oop _oop_head;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	70 narrowOop _compressed_head;
0 a61af66fc99e Initial load duke parents: diff changeset	71 size_t _len;
a61af66fc99e Initial load duke parents: diff changeset	72 };
a61af66fc99e Initial load duke parents: diff changeset	73
a61af66fc99e Initial load duke parents: diff changeset	74 void referenceProcessor_init() {
a61af66fc99e Initial load duke parents: diff changeset	75 ReferenceProcessor::init_statics();
a61af66fc99e Initial load duke parents: diff changeset	76 }
a61af66fc99e Initial load duke parents: diff changeset	77
a61af66fc99e Initial load duke parents: diff changeset	78 void ReferenceProcessor::init_statics() {
a61af66fc99e Initial load duke parents: diff changeset	79 // Initialize the master soft ref clock.
a61af66fc99e Initial load duke parents: diff changeset	80 java_lang_ref_SoftReference::set_clock(os::javaTimeMillis());
a61af66fc99e Initial load duke parents: diff changeset	81
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	82 _always_clear_soft_ref_policy = new AlwaysClearPolicy();
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	83 _default_soft_ref_policy = new COMPILER2_PRESENT(LRUMaxHeapPolicy())
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	84 NOT_COMPILER2(LRUCurrentHeapPolicy());
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	85 if (_always_clear_soft_ref_policy == NULL \|\| _default_soft_ref_policy == NULL) {
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	86 vm_exit_during_initialization("Could not allocate reference policy object");
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	87 }
0 a61af66fc99e Initial load duke parents: diff changeset	88 guarantee(RefDiscoveryPolicy == ReferenceBasedDiscovery \|\|
a61af66fc99e Initial load duke parents: diff changeset	89 RefDiscoveryPolicy == ReferentBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	90 "Unrecongnized RefDiscoveryPolicy");
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	91 _pending_list_uses_discovered_field = JDK_Version::current().pending_list_uses_discovered_field();
0 a61af66fc99e Initial load duke parents: diff changeset	92 }
a61af66fc99e Initial load duke parents: diff changeset	93
a61af66fc99e Initial load duke parents: diff changeset	94 ReferenceProcessor::ReferenceProcessor(MemRegion span,
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	95 bool mt_processing,
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	96 int mt_processing_degree,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	97 bool mt_discovery,
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	98 int mt_discovery_degree,
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	99 bool atomic_discovery,
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	100 BoolObjectClosure* is_alive_non_header,
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	101 bool discovered_list_needs_barrier) :
0 a61af66fc99e Initial load duke parents: diff changeset	102 _discovering_refs(false),
a61af66fc99e Initial load duke parents: diff changeset	103 _enqueuing_is_done(false),
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	104 _is_alive_non_header(is_alive_non_header),
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	105 _discovered_list_needs_barrier(discovered_list_needs_barrier),
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	106 _bs(NULL),
0 a61af66fc99e Initial load duke parents: diff changeset	107 _processing_is_mt(mt_processing),
a61af66fc99e Initial load duke parents: diff changeset	108 _next_id(0)
a61af66fc99e Initial load duke parents: diff changeset	109 {
a61af66fc99e Initial load duke parents: diff changeset	110 _span = span;
a61af66fc99e Initial load duke parents: diff changeset	111 _discovery_is_atomic = atomic_discovery;
a61af66fc99e Initial load duke parents: diff changeset	112 _discovery_is_mt = mt_discovery;
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	113 _num_q = MAX2(1, mt_processing_degree);
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	114 _max_num_q = MAX2(_num_q, mt_discovery_degree);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	115 _discoveredSoftRefs = NEW_C_HEAP_ARRAY(DiscoveredList, _max_num_q * subclasses_of_ref);
0 a61af66fc99e Initial load duke parents: diff changeset	116 if (_discoveredSoftRefs == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	117 vm_exit_during_initialization("Could not allocated RefProc Array");
a61af66fc99e Initial load duke parents: diff changeset	118 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	119 _discoveredWeakRefs = &_discoveredSoftRefs[_max_num_q];
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	120 _discoveredFinalRefs = &_discoveredWeakRefs[_max_num_q];
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	121 _discoveredPhantomRefs = &_discoveredFinalRefs[_max_num_q];
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	122 // Initialized all entries to NULL
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	123 for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	124 _discoveredSoftRefs[i].set_head(NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	125 _discoveredSoftRefs[i].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	126 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	127 // If we do barriers, cache a copy of the barrier set.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	128 if (discovered_list_needs_barrier) {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	129 _bs = Universe::heap()->barrier_set();
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	130 }
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	131 setup_policy(false /* default soft ref policy */);
0 a61af66fc99e Initial load duke parents: diff changeset	132 }
a61af66fc99e Initial load duke parents: diff changeset	133
a61af66fc99e Initial load duke parents: diff changeset	134 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	135 void ReferenceProcessor::verify_no_references_recorded() {
a61af66fc99e Initial load duke parents: diff changeset	136 guarantee(!_discovering_refs, "Discovering refs?");
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	137 for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	138 guarantee(_discoveredSoftRefs[i].empty(),
a61af66fc99e Initial load duke parents: diff changeset	139 "Found non-empty discovered list");
a61af66fc99e Initial load duke parents: diff changeset	140 }
a61af66fc99e Initial load duke parents: diff changeset	141 }
a61af66fc99e Initial load duke parents: diff changeset	142 #endif
a61af66fc99e Initial load duke parents: diff changeset	143
a61af66fc99e Initial load duke parents: diff changeset	144 void ReferenceProcessor::weak_oops_do(OopClosure* f) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	145 // Should this instead be
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	146 // for (int i = 0; i < subclasses_of_ref; i++_ {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	147 // for (int j = 0; j < _num_q; j++) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	148 // int index = i * _max_num_q + j;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	149 for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	150 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	151 f->do_oop((narrowOop*)_discoveredSoftRefs[i].adr_head());
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	152 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	153 f->do_oop((oop*)_discoveredSoftRefs[i].adr_head());
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	154 }
0 a61af66fc99e Initial load duke parents: diff changeset	155 }
a61af66fc99e Initial load duke parents: diff changeset	156 }
a61af66fc99e Initial load duke parents: diff changeset	157
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	158 void ReferenceProcessor::update_soft_ref_master_clock() {
0 a61af66fc99e Initial load duke parents: diff changeset	159 // Update (advance) the soft ref master clock field. This must be done
a61af66fc99e Initial load duke parents: diff changeset	160 // after processing the soft ref list.
a61af66fc99e Initial load duke parents: diff changeset	161 jlong now = os::javaTimeMillis();
a61af66fc99e Initial load duke parents: diff changeset	162 jlong clock = java_lang_ref_SoftReference::clock();
a61af66fc99e Initial load duke parents: diff changeset	163 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	164 if (now < clock) {
a61af66fc99e Initial load duke parents: diff changeset	165 warning("time warp: %d to %d", clock, now);
a61af66fc99e Initial load duke parents: diff changeset	166 }
a61af66fc99e Initial load duke parents: diff changeset	167 )
a61af66fc99e Initial load duke parents: diff changeset	168 // In product mode, protect ourselves from system time being adjusted
a61af66fc99e Initial load duke parents: diff changeset	169 // externally and going backward; see note in the implementation of
a61af66fc99e Initial load duke parents: diff changeset	170 // GenCollectedHeap::time_since_last_gc() for the right way to fix
a61af66fc99e Initial load duke parents: diff changeset	171 // this uniformly throughout the VM; see bug-id 4741166. XXX
a61af66fc99e Initial load duke parents: diff changeset	172 if (now > clock) {
a61af66fc99e Initial load duke parents: diff changeset	173 java_lang_ref_SoftReference::set_clock(now);
a61af66fc99e Initial load duke parents: diff changeset	174 }
a61af66fc99e Initial load duke parents: diff changeset	175 // Else leave clock stalled at its old value until time progresses
a61af66fc99e Initial load duke parents: diff changeset	176 // past clock value.
a61af66fc99e Initial load duke parents: diff changeset	177 }
a61af66fc99e Initial load duke parents: diff changeset	178
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	179 void ReferenceProcessor::process_discovered_references(
0 a61af66fc99e Initial load duke parents: diff changeset	180 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	181 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	182 VoidClosure* complete_gc,
a61af66fc99e Initial load duke parents: diff changeset	183 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load duke parents: diff changeset	184 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	185
a61af66fc99e Initial load duke parents: diff changeset	186 assert(!enqueuing_is_done(), "If here enqueuing should not be complete");
a61af66fc99e Initial load duke parents: diff changeset	187 // Stop treating discovered references specially.
a61af66fc99e Initial load duke parents: diff changeset	188 disable_discovery();
a61af66fc99e Initial load duke parents: diff changeset	189
a61af66fc99e Initial load duke parents: diff changeset	190 bool trace_time = PrintGCDetails && PrintReferenceGC;
a61af66fc99e Initial load duke parents: diff changeset	191 // Soft references
a61af66fc99e Initial load duke parents: diff changeset	192 {
a61af66fc99e Initial load duke parents: diff changeset	193 TraceTime tt("SoftReference", trace_time, false, gclog_or_tty);
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	194 process_discovered_reflist(_discoveredSoftRefs, _current_soft_ref_policy, true,
0 a61af66fc99e Initial load duke parents: diff changeset	195 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	196 }
a61af66fc99e Initial load duke parents: diff changeset	197
a61af66fc99e Initial load duke parents: diff changeset	198 update_soft_ref_master_clock();
a61af66fc99e Initial load duke parents: diff changeset	199
a61af66fc99e Initial load duke parents: diff changeset	200 // Weak references
a61af66fc99e Initial load duke parents: diff changeset	201 {
a61af66fc99e Initial load duke parents: diff changeset	202 TraceTime tt("WeakReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	203 process_discovered_reflist(_discoveredWeakRefs, NULL, true,
a61af66fc99e Initial load duke parents: diff changeset	204 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	205 }
a61af66fc99e Initial load duke parents: diff changeset	206
a61af66fc99e Initial load duke parents: diff changeset	207 // Final references
a61af66fc99e Initial load duke parents: diff changeset	208 {
a61af66fc99e Initial load duke parents: diff changeset	209 TraceTime tt("FinalReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	210 process_discovered_reflist(_discoveredFinalRefs, NULL, false,
a61af66fc99e Initial load duke parents: diff changeset	211 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	212 }
a61af66fc99e Initial load duke parents: diff changeset	213
a61af66fc99e Initial load duke parents: diff changeset	214 // Phantom references
a61af66fc99e Initial load duke parents: diff changeset	215 {
a61af66fc99e Initial load duke parents: diff changeset	216 TraceTime tt("PhantomReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	217 process_discovered_reflist(_discoveredPhantomRefs, NULL, false,
a61af66fc99e Initial load duke parents: diff changeset	218 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	219 }
a61af66fc99e Initial load duke parents: diff changeset	220
a61af66fc99e Initial load duke parents: diff changeset	221 // Weak global JNI references. It would make more sense (semantically) to
a61af66fc99e Initial load duke parents: diff changeset	222 // traverse these simultaneously with the regular weak references above, but
a61af66fc99e Initial load duke parents: diff changeset	223 // that is not how the JDK1.2 specification is. See #4126360. Native code can
a61af66fc99e Initial load duke parents: diff changeset	224 // thus use JNI weak references to circumvent the phantom references and
a61af66fc99e Initial load duke parents: diff changeset	225 // resurrect a "post-mortem" object.
a61af66fc99e Initial load duke parents: diff changeset	226 {
a61af66fc99e Initial load duke parents: diff changeset	227 TraceTime tt("JNI Weak Reference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	228 if (task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	229 task_executor->set_single_threaded_mode();
a61af66fc99e Initial load duke parents: diff changeset	230 }
a61af66fc99e Initial load duke parents: diff changeset	231 process_phaseJNI(is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	232 }
a61af66fc99e Initial load duke parents: diff changeset	233 }
a61af66fc99e Initial load duke parents: diff changeset	234
a61af66fc99e Initial load duke parents: diff changeset	235 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	236 // Calculate the number of jni handles.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	237 uint ReferenceProcessor::count_jni_refs() {
0 a61af66fc99e Initial load duke parents: diff changeset	238 class AlwaysAliveClosure: public BoolObjectClosure {
a61af66fc99e Initial load duke parents: diff changeset	239 public:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	240 virtual bool do_object_b(oop obj) { return true; }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	241 virtual void do_object(oop obj) { assert(false, "Don't call"); }
0 a61af66fc99e Initial load duke parents: diff changeset	242 };
a61af66fc99e Initial load duke parents: diff changeset	243
a61af66fc99e Initial load duke parents: diff changeset	244 class CountHandleClosure: public OopClosure {
a61af66fc99e Initial load duke parents: diff changeset	245 private:
a61af66fc99e Initial load duke parents: diff changeset	246 int _count;
a61af66fc99e Initial load duke parents: diff changeset	247 public:
a61af66fc99e Initial load duke parents: diff changeset	248 CountHandleClosure(): _count(0) {}
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	249 void do_oop(oop* unused) { _count++; }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	250 void do_oop(narrowOop* unused) { ShouldNotReachHere(); }
0 a61af66fc99e Initial load duke parents: diff changeset	251 int count() { return _count; }
a61af66fc99e Initial load duke parents: diff changeset	252 };
a61af66fc99e Initial load duke parents: diff changeset	253 CountHandleClosure global_handle_count;
a61af66fc99e Initial load duke parents: diff changeset	254 AlwaysAliveClosure always_alive;
a61af66fc99e Initial load duke parents: diff changeset	255 JNIHandles::weak_oops_do(&always_alive, &global_handle_count);
a61af66fc99e Initial load duke parents: diff changeset	256 return global_handle_count.count();
a61af66fc99e Initial load duke parents: diff changeset	257 }
a61af66fc99e Initial load duke parents: diff changeset	258 #endif
a61af66fc99e Initial load duke parents: diff changeset	259
a61af66fc99e Initial load duke parents: diff changeset	260 void ReferenceProcessor::process_phaseJNI(BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	261 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	262 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	263 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	264 if (PrintGCDetails && PrintReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	265 unsigned int count = count_jni_refs();
a61af66fc99e Initial load duke parents: diff changeset	266 gclog_or_tty->print(", %u refs", count);
a61af66fc99e Initial load duke parents: diff changeset	267 }
a61af66fc99e Initial load duke parents: diff changeset	268 #endif
a61af66fc99e Initial load duke parents: diff changeset	269 JNIHandles::weak_oops_do(is_alive, keep_alive);
a61af66fc99e Initial load duke parents: diff changeset	270 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	271 }
a61af66fc99e Initial load duke parents: diff changeset	272
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	273
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	274 template <class T>
1123 167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	275 bool enqueue_discovered_ref_helper(ReferenceProcessor* ref,
167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	276 AbstractRefProcTaskExecutor* task_executor) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	277
0 a61af66fc99e Initial load duke parents: diff changeset	278 // Remember old value of pending references list
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	279 T* pending_list_addr = (T*)java_lang_ref_Reference::pending_list_addr();
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	280 T old_pending_list_value = *pending_list_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	281
a61af66fc99e Initial load duke parents: diff changeset	282 // Enqueue references that are not made active again, and
a61af66fc99e Initial load duke parents: diff changeset	283 // clear the decks for the next collection (cycle).
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	284 ref->enqueue_discovered_reflists((HeapWord*)pending_list_addr, task_executor);
0 a61af66fc99e Initial load duke parents: diff changeset	285 // Do the oop-check on pending_list_addr missed in
a61af66fc99e Initial load duke parents: diff changeset	286 // enqueue_discovered_reflist. We should probably
a61af66fc99e Initial load duke parents: diff changeset	287 // do a raw oop_check so that future such idempotent
a61af66fc99e Initial load duke parents: diff changeset	288 // oop_stores relying on the oop-check side-effect
a61af66fc99e Initial load duke parents: diff changeset	289 // may be elided automatically and safely without
a61af66fc99e Initial load duke parents: diff changeset	290 // affecting correctness.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	291 oop_store(pending_list_addr, oopDesc::load_decode_heap_oop(pending_list_addr));
0 a61af66fc99e Initial load duke parents: diff changeset	292
a61af66fc99e Initial load duke parents: diff changeset	293 // Stop treating discovered references specially.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	294 ref->disable_discovery();
0 a61af66fc99e Initial load duke parents: diff changeset	295
a61af66fc99e Initial load duke parents: diff changeset	296 // Return true if new pending references were added
a61af66fc99e Initial load duke parents: diff changeset	297 return old_pending_list_value != *pending_list_addr;
a61af66fc99e Initial load duke parents: diff changeset	298 }
a61af66fc99e Initial load duke parents: diff changeset	299
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	300 bool ReferenceProcessor::enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	301 NOT_PRODUCT(verify_ok_to_handle_reflists());
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	302 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	303 return enqueue_discovered_ref_helper<narrowOop>(this, task_executor);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	304 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	305 return enqueue_discovered_ref_helper<oop>(this, task_executor);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	306 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	307 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	308
0 a61af66fc99e Initial load duke parents: diff changeset	309 void ReferenceProcessor::enqueue_discovered_reflist(DiscoveredList& refs_list,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	310 HeapWord* pending_list_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	311 // Given a list of refs linked through the "discovered" field
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	312 // (java.lang.ref.Reference.discovered), self-loop their "next" field
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	313 // thus distinguishing them from active References, then
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	314 // prepend them to the pending list.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	315 // BKWRD COMPATIBILITY NOTE: For older JDKs (prior to the fix for 4956777),
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	316 // the "next" field is used to chain the pending list, not the discovered
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	317 // field.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	318
0 a61af66fc99e Initial load duke parents: diff changeset	319 if (TraceReferenceGC && PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	320 gclog_or_tty->print_cr("ReferenceProcessor::enqueue_discovered_reflist list "
a61af66fc99e Initial load duke parents: diff changeset	321 INTPTR_FORMAT, (address)refs_list.head());
a61af66fc99e Initial load duke parents: diff changeset	322 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	323
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	324 oop obj = NULL;
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	325 oop next_d = refs_list.head();
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	326 if (pending_list_uses_discovered_field()) { // New behaviour
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	327 // Walk down the list, self-looping the next field
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	328 // so that the References are not considered active.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	329 while (obj != next_d) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	330 obj = next_d;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	331 assert(obj->is_instanceRef(), "should be reference object");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	332 next_d = java_lang_ref_Reference::discovered(obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	333 if (TraceReferenceGC && PrintGCDetails) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	334 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	335 obj, next_d);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	336 }
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	337 assert(java_lang_ref_Reference::next(obj) == NULL,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	338 "Reference not active; should not be discovered");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	339 // Self-loop next, so as to make Ref not active.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	340 java_lang_ref_Reference::set_next(obj, obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	341 if (next_d == obj) { // obj is last
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	342 // Swap refs_list into pendling_list_addr and
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	343 // set obj's discovered to what we read from pending_list_addr.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	344 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	345 // Need oop_check on pending_list_addr above;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	346 // see special oop-check code at the end of
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	347 // enqueue_discovered_reflists() further below.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	348 java_lang_ref_Reference::set_discovered(obj, old); // old may be NULL
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	349 }
0 a61af66fc99e Initial load duke parents: diff changeset	350 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	351 } else { // Old behaviour
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	352 // Walk down the list, copying the discovered field into
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	353 // the next field and clearing the discovered field.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	354 while (obj != next_d) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	355 obj = next_d;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	356 assert(obj->is_instanceRef(), "should be reference object");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	357 next_d = java_lang_ref_Reference::discovered(obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	358 if (TraceReferenceGC && PrintGCDetails) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	359 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	360 obj, next_d);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	361 }
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	362 assert(java_lang_ref_Reference::next(obj) == NULL,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	363 "The reference should not be enqueued");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	364 if (next_d == obj) { // obj is last
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	365 // Swap refs_list into pendling_list_addr and
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	366 // set obj's next to what we read from pending_list_addr.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	367 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	368 // Need oop_check on pending_list_addr above;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	369 // see special oop-check code at the end of
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	370 // enqueue_discovered_reflists() further below.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	371 if (old == NULL) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	372 // obj should be made to point to itself, since
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	373 // pending list was empty.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	374 java_lang_ref_Reference::set_next(obj, obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	375 } else {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	376 java_lang_ref_Reference::set_next(obj, old);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	377 }
0 a61af66fc99e Initial load duke parents: diff changeset	378 } else {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	379 java_lang_ref_Reference::set_next(obj, next_d);
0 a61af66fc99e Initial load duke parents: diff changeset	380 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	381 java_lang_ref_Reference::set_discovered(obj, (oop) NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	382 }
a61af66fc99e Initial load duke parents: diff changeset	383 }
a61af66fc99e Initial load duke parents: diff changeset	384 }
a61af66fc99e Initial load duke parents: diff changeset	385
a61af66fc99e Initial load duke parents: diff changeset	386 // Parallel enqueue task
a61af66fc99e Initial load duke parents: diff changeset	387 class RefProcEnqueueTask: public AbstractRefProcTaskExecutor::EnqueueTask {
a61af66fc99e Initial load duke parents: diff changeset	388 public:
a61af66fc99e Initial load duke parents: diff changeset	389 RefProcEnqueueTask(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	390 DiscoveredList discovered_refs[],
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	391 HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	392 int n_queues)
a61af66fc99e Initial load duke parents: diff changeset	393 : EnqueueTask(ref_processor, discovered_refs,
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	394 pending_list_addr, n_queues)
0 a61af66fc99e Initial load duke parents: diff changeset	395 { }
a61af66fc99e Initial load duke parents: diff changeset	396
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	397 virtual void work(unsigned int work_id) {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	398 assert(work_id < (unsigned int)_ref_processor.max_num_q(), "Index out-of-bounds");
0 a61af66fc99e Initial load duke parents: diff changeset	399 // Simplest first cut: static partitioning.
a61af66fc99e Initial load duke parents: diff changeset	400 int index = work_id;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	401 // The increment on "index" must correspond to the maximum number of queues
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	402 // (n_queues) with which that ReferenceProcessor was created. That
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	403 // is because of the "clever" way the discovered references lists were
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	404 // allocated and are indexed into.
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	405 assert(_n_queues == (int) _ref_processor.max_num_q(), "Different number not expected");
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	406 for (int j = 0;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	407 j < subclasses_of_ref;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	408 j++, index += _n_queues) {
0 a61af66fc99e Initial load duke parents: diff changeset	409 _ref_processor.enqueue_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	410 _refs_lists[index], _pending_list_addr);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	411 _refs_lists[index].set_head(NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	412 _refs_lists[index].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	413 }
a61af66fc99e Initial load duke parents: diff changeset	414 }
a61af66fc99e Initial load duke parents: diff changeset	415 };
a61af66fc99e Initial load duke parents: diff changeset	416
a61af66fc99e Initial load duke parents: diff changeset	417 // Enqueue references that are not made active again
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	418 void ReferenceProcessor::enqueue_discovered_reflists(HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	419 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load duke parents: diff changeset	420 if (_processing_is_mt && task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	421 // Parallel code
a61af66fc99e Initial load duke parents: diff changeset	422 RefProcEnqueueTask tsk(*this, _discoveredSoftRefs,
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	423 pending_list_addr, _max_num_q);
0 a61af66fc99e Initial load duke parents: diff changeset	424 task_executor->execute(tsk);
a61af66fc99e Initial load duke parents: diff changeset	425 } else {
a61af66fc99e Initial load duke parents: diff changeset	426 // Serial code: call the parent class's implementation
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	427 for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	428 enqueue_discovered_reflist(_discoveredSoftRefs[i], pending_list_addr);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	429 _discoveredSoftRefs[i].set_head(NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	430 _discoveredSoftRefs[i].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	431 }
a61af66fc99e Initial load duke parents: diff changeset	432 }
a61af66fc99e Initial load duke parents: diff changeset	433 }
a61af66fc99e Initial load duke parents: diff changeset	434
a61af66fc99e Initial load duke parents: diff changeset	435 // Iterator for the list of discovered references.
a61af66fc99e Initial load duke parents: diff changeset	436 class DiscoveredListIterator {
a61af66fc99e Initial load duke parents: diff changeset	437 public:
a61af66fc99e Initial load duke parents: diff changeset	438 inline DiscoveredListIterator(DiscoveredList& refs_list,
a61af66fc99e Initial load duke parents: diff changeset	439 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	440 BoolObjectClosure* is_alive);
a61af66fc99e Initial load duke parents: diff changeset	441
a61af66fc99e Initial load duke parents: diff changeset	442 // End Of List.
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	443 inline bool has_next() const { return _ref != NULL; }
0 a61af66fc99e Initial load duke parents: diff changeset	444
a61af66fc99e Initial load duke parents: diff changeset	445 // Get oop to the Reference object.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	446 inline oop obj() const { return _ref; }
0 a61af66fc99e Initial load duke parents: diff changeset	447
a61af66fc99e Initial load duke parents: diff changeset	448 // Get oop to the referent object.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	449 inline oop referent() const { return _referent; }
0 a61af66fc99e Initial load duke parents: diff changeset	450
a61af66fc99e Initial load duke parents: diff changeset	451 // Returns true if referent is alive.
a61af66fc99e Initial load duke parents: diff changeset	452 inline bool is_referent_alive() const;
a61af66fc99e Initial load duke parents: diff changeset	453
a61af66fc99e Initial load duke parents: diff changeset	454 // Loads data for the current reference.
a61af66fc99e Initial load duke parents: diff changeset	455 // The "allow_null_referent" argument tells us to allow for the possibility
a61af66fc99e Initial load duke parents: diff changeset	456 // of a NULL referent in the discovered Reference object. This typically
a61af66fc99e Initial load duke parents: diff changeset	457 // happens in the case of concurrent collectors that may have done the
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	458 // discovery concurrently, or interleaved, with mutator execution.
0 a61af66fc99e Initial load duke parents: diff changeset	459 inline void load_ptrs(DEBUG_ONLY(bool allow_null_referent));
a61af66fc99e Initial load duke parents: diff changeset	460
a61af66fc99e Initial load duke parents: diff changeset	461 // Move to the next discovered reference.
a61af66fc99e Initial load duke parents: diff changeset	462 inline void next();
a61af66fc99e Initial load duke parents: diff changeset	463
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	464 // Remove the current reference from the list
0 a61af66fc99e Initial load duke parents: diff changeset	465 inline void remove();
a61af66fc99e Initial load duke parents: diff changeset	466
a61af66fc99e Initial load duke parents: diff changeset	467 // Make the Reference object active again.
a61af66fc99e Initial load duke parents: diff changeset	468 inline void make_active() { java_lang_ref_Reference::set_next(_ref, NULL); }
a61af66fc99e Initial load duke parents: diff changeset	469
a61af66fc99e Initial load duke parents: diff changeset	470 // Make the referent alive.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	471 inline void make_referent_alive() {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	472 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	473 _keep_alive->do_oop((narrowOop*)_referent_addr);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	474 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	475 _keep_alive->do_oop((oop*)_referent_addr);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	476 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	477 }
0 a61af66fc99e Initial load duke parents: diff changeset	478
a61af66fc99e Initial load duke parents: diff changeset	479 // Update the discovered field.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	480 inline void update_discovered() {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	481 // First _prev_next ref actually points into DiscoveredList (gross).
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	482 if (UseCompressedOops) {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	483 if (!oopDesc::is_null((narrowOop)_prev_next)) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	484 _keep_alive->do_oop((narrowOop*)_prev_next);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	485 }
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	486 } else {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	487 if (!oopDesc::is_null((oop)_prev_next)) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	488 _keep_alive->do_oop((oop*)_prev_next);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	489 }
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	490 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	491 }
0 a61af66fc99e Initial load duke parents: diff changeset	492
a61af66fc99e Initial load duke parents: diff changeset	493 // NULL out referent pointer.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	494 inline void clear_referent() { oop_store_raw(_referent_addr, NULL); }
0 a61af66fc99e Initial load duke parents: diff changeset	495
a61af66fc99e Initial load duke parents: diff changeset	496 // Statistics
a61af66fc99e Initial load duke parents: diff changeset	497 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	498 inline size_t processed() const { return _processed; }
a61af66fc99e Initial load duke parents: diff changeset	499 inline size_t removed() const { return _removed; }
a61af66fc99e Initial load duke parents: diff changeset	500 )
a61af66fc99e Initial load duke parents: diff changeset	501
a61af66fc99e Initial load duke parents: diff changeset	502 inline void move_to_next();
a61af66fc99e Initial load duke parents: diff changeset	503
a61af66fc99e Initial load duke parents: diff changeset	504 private:
a61af66fc99e Initial load duke parents: diff changeset	505 DiscoveredList& _refs_list;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	506 HeapWord* _prev_next;
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	507 oop _prev;
0 a61af66fc99e Initial load duke parents: diff changeset	508 oop _ref;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	509 HeapWord* _discovered_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	510 oop _next;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	511 HeapWord* _referent_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	512 oop _referent;
a61af66fc99e Initial load duke parents: diff changeset	513 OopClosure* _keep_alive;
a61af66fc99e Initial load duke parents: diff changeset	514 BoolObjectClosure* _is_alive;
a61af66fc99e Initial load duke parents: diff changeset	515 DEBUG_ONLY(
a61af66fc99e Initial load duke parents: diff changeset	516 oop _first_seen; // cyclic linked list check
a61af66fc99e Initial load duke parents: diff changeset	517 )
a61af66fc99e Initial load duke parents: diff changeset	518 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	519 size_t _processed;
a61af66fc99e Initial load duke parents: diff changeset	520 size_t _removed;
a61af66fc99e Initial load duke parents: diff changeset	521 )
a61af66fc99e Initial load duke parents: diff changeset	522 };
a61af66fc99e Initial load duke parents: diff changeset	523
a61af66fc99e Initial load duke parents: diff changeset	524 inline DiscoveredListIterator::DiscoveredListIterator(DiscoveredList& refs_list,
a61af66fc99e Initial load duke parents: diff changeset	525 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	526 BoolObjectClosure* is_alive)
a61af66fc99e Initial load duke parents: diff changeset	527 : _refs_list(refs_list),
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	528 _prev_next(refs_list.adr_head()),
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	529 _prev(NULL),
0 a61af66fc99e Initial load duke parents: diff changeset	530 _ref(refs_list.head()),
a61af66fc99e Initial load duke parents: diff changeset	531 #ifdef ASSERT
a61af66fc99e Initial load duke parents: diff changeset	532 _first_seen(refs_list.head()),
a61af66fc99e Initial load duke parents: diff changeset	533 #endif
a61af66fc99e Initial load duke parents: diff changeset	534 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	535 _processed(0),
a61af66fc99e Initial load duke parents: diff changeset	536 _removed(0),
a61af66fc99e Initial load duke parents: diff changeset	537 #endif
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	538 _next(NULL),
0 a61af66fc99e Initial load duke parents: diff changeset	539 _keep_alive(keep_alive),
a61af66fc99e Initial load duke parents: diff changeset	540 _is_alive(is_alive)
a61af66fc99e Initial load duke parents: diff changeset	541 { }
a61af66fc99e Initial load duke parents: diff changeset	542
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	543 inline bool DiscoveredListIterator::is_referent_alive() const {
0 a61af66fc99e Initial load duke parents: diff changeset	544 return _is_alive->do_object_b(_referent);
a61af66fc99e Initial load duke parents: diff changeset	545 }
a61af66fc99e Initial load duke parents: diff changeset	546
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	547 inline void DiscoveredListIterator::load_ptrs(DEBUG_ONLY(bool allow_null_referent)) {
0 a61af66fc99e Initial load duke parents: diff changeset	548 _discovered_addr = java_lang_ref_Reference::discovered_addr(_ref);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	549 oop discovered = java_lang_ref_Reference::discovered(_ref);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	550 assert(_discovered_addr && discovered->is_oop_or_null(),
0 a61af66fc99e Initial load duke parents: diff changeset	551 "discovered field is bad");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	552 _next = discovered;
0 a61af66fc99e Initial load duke parents: diff changeset	553 _referent_addr = java_lang_ref_Reference::referent_addr(_ref);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	554 _referent = java_lang_ref_Reference::referent(_ref);
0 a61af66fc99e Initial load duke parents: diff changeset	555 assert(Universe::heap()->is_in_reserved_or_null(_referent),
a61af66fc99e Initial load duke parents: diff changeset	556 "Wrong oop found in java.lang.Reference object");
a61af66fc99e Initial load duke parents: diff changeset	557 assert(allow_null_referent ?
a61af66fc99e Initial load duke parents: diff changeset	558 _referent->is_oop_or_null()
a61af66fc99e Initial load duke parents: diff changeset	559 : _referent->is_oop(),
a61af66fc99e Initial load duke parents: diff changeset	560 "bad referent");
a61af66fc99e Initial load duke parents: diff changeset	561 }
a61af66fc99e Initial load duke parents: diff changeset	562
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	563 inline void DiscoveredListIterator::next() {
0 a61af66fc99e Initial load duke parents: diff changeset	564 _prev_next = _discovered_addr;
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	565 _prev = _ref;
0 a61af66fc99e Initial load duke parents: diff changeset	566 move_to_next();
a61af66fc99e Initial load duke parents: diff changeset	567 }
a61af66fc99e Initial load duke parents: diff changeset	568
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	569 inline void DiscoveredListIterator::remove() {
0 a61af66fc99e Initial load duke parents: diff changeset	570 assert(_ref->is_oop(), "Dropping a bad reference");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	571 oop_store_raw(_discovered_addr, NULL);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	572
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	573 // First _prev_next ref actually points into DiscoveredList (gross).
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	574 oop new_next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	575 if (_next == _ref) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	576 // At the end of the list, we should make _prev point to itself.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	577 // If _ref is the first ref, then _prev_next will be in the DiscoveredList,
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	578 // and _prev will be NULL.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	579 new_next = _prev;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	580 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	581 new_next = _next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	582 }
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	583
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	584 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	585 // Remove Reference object from list.
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	586 oopDesc::encode_store_heap_oop((narrowOop*)_prev_next, new_next);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	587 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	588 // Remove Reference object from list.
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	589 oopDesc::store_heap_oop((oop*)_prev_next, new_next);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	590 }
0 a61af66fc99e Initial load duke parents: diff changeset	591 NOT_PRODUCT(_removed++);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	592 _refs_list.dec_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	593 }
a61af66fc99e Initial load duke parents: diff changeset	594
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	595 inline void DiscoveredListIterator::move_to_next() {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	596 if (_ref == _next) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	597 // End of the list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	598 _ref = NULL;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	599 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	600 _ref = _next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	601 }
0 a61af66fc99e Initial load duke parents: diff changeset	602 assert(_ref != _first_seen, "cyclic ref_list found");
a61af66fc99e Initial load duke parents: diff changeset	603 NOT_PRODUCT(_processed++);
a61af66fc99e Initial load duke parents: diff changeset	604 }
a61af66fc99e Initial load duke parents: diff changeset	605
a61af66fc99e Initial load duke parents: diff changeset	606 // NOTE: process_phase*() are largely similar, and at a high level
a61af66fc99e Initial load duke parents: diff changeset	607 // merely iterate over the extant list applying a predicate to
a61af66fc99e Initial load duke parents: diff changeset	608 // each of its elements and possibly removing that element from the
a61af66fc99e Initial load duke parents: diff changeset	609 // list and applying some further closures to that element.
a61af66fc99e Initial load duke parents: diff changeset	610 // We should consider the possibility of replacing these
a61af66fc99e Initial load duke parents: diff changeset	611 // process_phase*() methods by abstracting them into
a61af66fc99e Initial load duke parents: diff changeset	612 // a single general iterator invocation that receives appropriate
a61af66fc99e Initial load duke parents: diff changeset	613 // closures that accomplish this work.
a61af66fc99e Initial load duke parents: diff changeset	614
a61af66fc99e Initial load duke parents: diff changeset	615 // (SoftReferences only) Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	616 // referents are not alive, but that should be kept alive for policy reasons.
a61af66fc99e Initial load duke parents: diff changeset	617 // Keep alive the transitive closure of all such referents.
a61af66fc99e Initial load duke parents: diff changeset	618 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	619 ReferenceProcessor::process_phase1(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	620 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	621 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	622 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	623 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	624 assert(policy != NULL, "Must have a non-NULL policy");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	625 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	626 // Decide which softly reachable refs should be kept alive.
a61af66fc99e Initial load duke parents: diff changeset	627 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	628 iter.load_ptrs(DEBUG_ONLY(!discovery_is_atomic() /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	629 bool referent_is_dead = (iter.referent() != NULL) && !iter.is_referent_alive();
a61af66fc99e Initial load duke parents: diff changeset	630 if (referent_is_dead && !policy->should_clear_reference(iter.obj())) {
a61af66fc99e Initial load duke parents: diff changeset	631 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	632 gclog_or_tty->print_cr("Dropping reference (" INTPTR_FORMAT ": %s" ") by policy",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	633 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	634 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	635 // Remove Reference object from list
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	636 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	637 // Make the Reference object active again
a61af66fc99e Initial load duke parents: diff changeset	638 iter.make_active();
a61af66fc99e Initial load duke parents: diff changeset	639 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	640 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	641 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	642 } else {
a61af66fc99e Initial load duke parents: diff changeset	643 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	644 }
a61af66fc99e Initial load duke parents: diff changeset	645 }
a61af66fc99e Initial load duke parents: diff changeset	646 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	647 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	648 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	649 if (PrintGCDetails && TraceReferenceGC) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	650 gclog_or_tty->print_cr(" Dropped %d dead Refs out of %d "
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	651 "discovered Refs by policy, from list " INTPTR_FORMAT,
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	652 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	653 }
a61af66fc99e Initial load duke parents: diff changeset	654 )
a61af66fc99e Initial load duke parents: diff changeset	655 }
a61af66fc99e Initial load duke parents: diff changeset	656
a61af66fc99e Initial load duke parents: diff changeset	657 // Traverse the list and remove any Refs that are not active, or
a61af66fc99e Initial load duke parents: diff changeset	658 // whose referents are either alive or NULL.
a61af66fc99e Initial load duke parents: diff changeset	659 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	660 ReferenceProcessor::pp2_work(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	661 BoolObjectClosure* is_alive,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	662 OopClosure* keep_alive) {
0 a61af66fc99e Initial load duke parents: diff changeset	663 assert(discovery_is_atomic(), "Error");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	664 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	665 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	666 iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	667 DEBUG_ONLY(oop next = java_lang_ref_Reference::next(iter.obj());)
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	668 assert(next == NULL, "Should not discover inactive Reference");
0 a61af66fc99e Initial load duke parents: diff changeset	669 if (iter.is_referent_alive()) {
a61af66fc99e Initial load duke parents: diff changeset	670 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	671 gclog_or_tty->print_cr("Dropping strongly reachable reference (" INTPTR_FORMAT ": %s)",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	672 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	673 }
a61af66fc99e Initial load duke parents: diff changeset	674 // The referent is reachable after all.
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	675 // Remove Reference object from list.
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	676 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	677 // Update the referent pointer as necessary: Note that this
a61af66fc99e Initial load duke parents: diff changeset	678 // should not entail any recursive marking because the
a61af66fc99e Initial load duke parents: diff changeset	679 // referent must already have been traversed.
a61af66fc99e Initial load duke parents: diff changeset	680 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	681 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	682 } else {
a61af66fc99e Initial load duke parents: diff changeset	683 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	684 }
a61af66fc99e Initial load duke parents: diff changeset	685 }
a61af66fc99e Initial load duke parents: diff changeset	686 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	687 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	688 gclog_or_tty->print_cr(" Dropped %d active Refs out of %d "
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	689 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	690 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	691 }
a61af66fc99e Initial load duke parents: diff changeset	692 )
a61af66fc99e Initial load duke parents: diff changeset	693 }
a61af66fc99e Initial load duke parents: diff changeset	694
a61af66fc99e Initial load duke parents: diff changeset	695 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	696 ReferenceProcessor::pp2_work_concurrent_discovery(DiscoveredList& refs_list,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	697 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	698 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	699 VoidClosure* complete_gc) {
0 a61af66fc99e Initial load duke parents: diff changeset	700 assert(!discovery_is_atomic(), "Error");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	701 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	702 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	703 iter.load_ptrs(DEBUG_ONLY(true /* allow_null_referent */));
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	704 HeapWord* next_addr = java_lang_ref_Reference::next_addr(iter.obj());
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	705 oop next = java_lang_ref_Reference::next(iter.obj());
0 a61af66fc99e Initial load duke parents: diff changeset	706 if ((iter.referent() == NULL \|\| iter.is_referent_alive() \|\|
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	707 next != NULL)) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	708 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	709 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	710 iter.remove();
a61af66fc99e Initial load duke parents: diff changeset	711 // Trace the cohorts
a61af66fc99e Initial load duke parents: diff changeset	712 iter.make_referent_alive();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	713 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	714 keep_alive->do_oop((narrowOop*)next_addr);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	715 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	716 keep_alive->do_oop((oop*)next_addr);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	717 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	718 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	719 } else {
a61af66fc99e Initial load duke parents: diff changeset	720 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	721 }
a61af66fc99e Initial load duke parents: diff changeset	722 }
a61af66fc99e Initial load duke parents: diff changeset	723 // Now close the newly reachable set
a61af66fc99e Initial load duke parents: diff changeset	724 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	725 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	726 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	727 gclog_or_tty->print_cr(" Dropped %d active Refs out of %d "
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	728 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	729 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	730 }
a61af66fc99e Initial load duke parents: diff changeset	731 )
a61af66fc99e Initial load duke parents: diff changeset	732 }
a61af66fc99e Initial load duke parents: diff changeset	733
a61af66fc99e Initial load duke parents: diff changeset	734 // Traverse the list and process the referents, by either
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	735 // clearing them or keeping them (and their reachable
0 a61af66fc99e Initial load duke parents: diff changeset	736 // closure) alive.
a61af66fc99e Initial load duke parents: diff changeset	737 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	738 ReferenceProcessor::process_phase3(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	739 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	740 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	741 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	742 VoidClosure* complete_gc) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	743 ResourceMark rm;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	744 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	745 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	746 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	747 iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	748 if (clear_referent) {
a61af66fc99e Initial load duke parents: diff changeset	749 // NULL out referent pointer
a61af66fc99e Initial load duke parents: diff changeset	750 iter.clear_referent();
a61af66fc99e Initial load duke parents: diff changeset	751 } else {
a61af66fc99e Initial load duke parents: diff changeset	752 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	753 iter.make_referent_alive();
a61af66fc99e Initial load duke parents: diff changeset	754 }
a61af66fc99e Initial load duke parents: diff changeset	755 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	756 gclog_or_tty->print_cr("Adding %sreference (" INTPTR_FORMAT ": %s) as pending",
a61af66fc99e Initial load duke parents: diff changeset	757 clear_referent ? "cleared " : "",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	758 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	759 }
a61af66fc99e Initial load duke parents: diff changeset	760 assert(iter.obj()->is_oop(UseConcMarkSweepGC), "Adding a bad reference");
a61af66fc99e Initial load duke parents: diff changeset	761 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	762 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	763 // Remember to update the next pointer of the last ref.
0 a61af66fc99e Initial load duke parents: diff changeset	764 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	765 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	766 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	767 }
a61af66fc99e Initial load duke parents: diff changeset	768
a61af66fc99e Initial load duke parents: diff changeset	769 void
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	770 ReferenceProcessor::clear_discovered_references(DiscoveredList& refs_list) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	771 oop obj = NULL;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	772 oop next = refs_list.head();
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	773 while (next != obj) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	774 obj = next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	775 next = java_lang_ref_Reference::discovered(obj);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	776 java_lang_ref_Reference::set_discovered_raw(obj, NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	777 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	778 refs_list.set_head(NULL);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	779 refs_list.set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	780 }
a61af66fc99e Initial load duke parents: diff changeset	781
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	782 void
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	783 ReferenceProcessor::abandon_partial_discovered_list(DiscoveredList& refs_list) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	784 clear_discovered_references(refs_list);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	785 }
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	786
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	787 void ReferenceProcessor::abandon_partial_discovery() {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	788 // loop over the lists
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	789 for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	790 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	791 gclog_or_tty->print_cr("\nAbandoning %s discovered list",
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	792 list_name(i));
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	793 }
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	794 abandon_partial_discovered_list(_discoveredSoftRefs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	795 }
a61af66fc99e Initial load duke parents: diff changeset	796 }
a61af66fc99e Initial load duke parents: diff changeset	797
a61af66fc99e Initial load duke parents: diff changeset	798 class RefProcPhase1Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	799 public:
a61af66fc99e Initial load duke parents: diff changeset	800 RefProcPhase1Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	801 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	802 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	803 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	804 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	805 _policy(policy)
a61af66fc99e Initial load duke parents: diff changeset	806 { }
a61af66fc99e Initial load duke parents: diff changeset	807 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	808 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	809 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	810 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	811 Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	812 int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	813 _ref_processor.process_phase1(_refs_lists[refs_list_index], _policy,
0 a61af66fc99e Initial load duke parents: diff changeset	814 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	815 }
a61af66fc99e Initial load duke parents: diff changeset	816 private:
a61af66fc99e Initial load duke parents: diff changeset	817 ReferencePolicy* _policy;
a61af66fc99e Initial load duke parents: diff changeset	818 };
a61af66fc99e Initial load duke parents: diff changeset	819
a61af66fc99e Initial load duke parents: diff changeset	820 class RefProcPhase2Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	821 public:
a61af66fc99e Initial load duke parents: diff changeset	822 RefProcPhase2Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	823 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	824 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	825 : ProcessTask(ref_processor, refs_lists, marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	826 { }
a61af66fc99e Initial load duke parents: diff changeset	827 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	828 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	829 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	830 {
a61af66fc99e Initial load duke parents: diff changeset	831 _ref_processor.process_phase2(_refs_lists[i],
a61af66fc99e Initial load duke parents: diff changeset	832 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	833 }
a61af66fc99e Initial load duke parents: diff changeset	834 };
a61af66fc99e Initial load duke parents: diff changeset	835
a61af66fc99e Initial load duke parents: diff changeset	836 class RefProcPhase3Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	837 public:
a61af66fc99e Initial load duke parents: diff changeset	838 RefProcPhase3Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	839 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	840 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	841 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	842 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	843 _clear_referent(clear_referent)
a61af66fc99e Initial load duke parents: diff changeset	844 { }
a61af66fc99e Initial load duke parents: diff changeset	845 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	846 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	847 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	848 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	849 // Don't use "refs_list_index" calculated in this way because
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	850 // balance_queues() has moved the Ref's into the first n queues.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	851 // Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	852 // int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	853 // _ref_processor.process_phase3(_refs_lists[refs_list_index], _clear_referent,
0 a61af66fc99e Initial load duke parents: diff changeset	854 _ref_processor.process_phase3(_refs_lists[i], _clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	855 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	856 }
a61af66fc99e Initial load duke parents: diff changeset	857 private:
a61af66fc99e Initial load duke parents: diff changeset	858 bool _clear_referent;
a61af66fc99e Initial load duke parents: diff changeset	859 };
a61af66fc99e Initial load duke parents: diff changeset	860
a61af66fc99e Initial load duke parents: diff changeset	861 // Balances reference queues.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	862 // Move entries from all queues[0, 1, ..., _max_num_q-1] to
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	863 // queues[0, 1, ..., _num_q-1] because only the first _num_q
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	864 // corresponding to the active workers will be processed.
0 a61af66fc99e Initial load duke parents: diff changeset	865 void ReferenceProcessor::balance_queues(DiscoveredList ref_lists[])
a61af66fc99e Initial load duke parents: diff changeset	866 {
a61af66fc99e Initial load duke parents: diff changeset	867 // calculate total length
a61af66fc99e Initial load duke parents: diff changeset	868 size_t total_refs = 0;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	869 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	870 gclog_or_tty->print_cr("\nBalance ref_lists ");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	871 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	872
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	873 for (int i = 0; i < _max_num_q; ++i) {
0 a61af66fc99e Initial load duke parents: diff changeset	874 total_refs += ref_lists[i].length();
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	875 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	876 gclog_or_tty->print("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	877 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	878 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	879 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	880 gclog_or_tty->print_cr(" = %d", total_refs);
0 a61af66fc99e Initial load duke parents: diff changeset	881 }
a61af66fc99e Initial load duke parents: diff changeset	882 size_t avg_refs = total_refs / _num_q + 1;
a61af66fc99e Initial load duke parents: diff changeset	883 int to_idx = 0;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	884 for (int from_idx = 0; from_idx < _max_num_q; from_idx++) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	885 bool move_all = false;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	886 if (from_idx >= _num_q) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	887 move_all = ref_lists[from_idx].length() > 0;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	888 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	889 while ((ref_lists[from_idx].length() > avg_refs) \|\|
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	890 move_all) {
0 a61af66fc99e Initial load duke parents: diff changeset	891 assert(to_idx < _num_q, "Sanity Check!");
a61af66fc99e Initial load duke parents: diff changeset	892 if (ref_lists[to_idx].length() < avg_refs) {
a61af66fc99e Initial load duke parents: diff changeset	893 // move superfluous refs
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	894 size_t refs_to_move;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	895 // Move all the Ref's if the from queue will not be processed.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	896 if (move_all) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	897 refs_to_move = MIN2(ref_lists[from_idx].length(),
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	898 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	899 } else {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	900 refs_to_move = MIN2(ref_lists[from_idx].length() - avg_refs,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	901 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	902 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	903
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	904 assert(refs_to_move > 0, "otherwise the code below will fail");
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	905
0 a61af66fc99e Initial load duke parents: diff changeset	906 oop move_head = ref_lists[from_idx].head();
a61af66fc99e Initial load duke parents: diff changeset	907 oop move_tail = move_head;
a61af66fc99e Initial load duke parents: diff changeset	908 oop new_head = move_head;
a61af66fc99e Initial load duke parents: diff changeset	909 // find an element to split the list on
a61af66fc99e Initial load duke parents: diff changeset	910 for (size_t j = 0; j < refs_to_move; ++j) {
a61af66fc99e Initial load duke parents: diff changeset	911 move_tail = new_head;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	912 new_head = java_lang_ref_Reference::discovered(new_head);
0 a61af66fc99e Initial load duke parents: diff changeset	913 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	914
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	915 // Add the chain to the to list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	916 if (ref_lists[to_idx].head() == NULL) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	917 // to list is empty. Make a loop at the end.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	918 java_lang_ref_Reference::set_discovered(move_tail, move_tail);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	919 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	920 java_lang_ref_Reference::set_discovered(move_tail, ref_lists[to_idx].head());
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	921 }
0 a61af66fc99e Initial load duke parents: diff changeset	922 ref_lists[to_idx].set_head(move_head);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	923 ref_lists[to_idx].inc_length(refs_to_move);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	924
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	925 // Remove the chain from the from list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	926 if (move_tail == new_head) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	927 // We found the end of the from list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	928 ref_lists[from_idx].set_head(NULL);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	929 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	930 ref_lists[from_idx].set_head(new_head);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	931 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	932 ref_lists[from_idx].dec_length(refs_to_move);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	933 if (ref_lists[from_idx].length() == 0) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	934 break;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	935 }
0 a61af66fc99e Initial load duke parents: diff changeset	936 } else {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	937 to_idx = (to_idx + 1) % _num_q;
0 a61af66fc99e Initial load duke parents: diff changeset	938 }
a61af66fc99e Initial load duke parents: diff changeset	939 }
a61af66fc99e Initial load duke parents: diff changeset	940 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	941 #ifdef ASSERT
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	942 size_t balanced_total_refs = 0;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	943 for (int i = 0; i < _max_num_q; ++i) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	944 balanced_total_refs += ref_lists[i].length();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	945 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	946 gclog_or_tty->print("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	947 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	948 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	949 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	950 gclog_or_tty->print_cr(" = %d", balanced_total_refs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	951 gclog_or_tty->flush();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	952 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	953 assert(total_refs == balanced_total_refs, "Balancing was incomplete");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	954 #endif
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	955 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	956
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	957 void ReferenceProcessor::balance_all_queues() {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	958 balance_queues(_discoveredSoftRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	959 balance_queues(_discoveredWeakRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	960 balance_queues(_discoveredFinalRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	961 balance_queues(_discoveredPhantomRefs);
0 a61af66fc99e Initial load duke parents: diff changeset	962 }
a61af66fc99e Initial load duke parents: diff changeset	963
a61af66fc99e Initial load duke parents: diff changeset	964 void
a61af66fc99e Initial load duke parents: diff changeset	965 ReferenceProcessor::process_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	966 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	967 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	968 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	969 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	970 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	971 VoidClosure* complete_gc,
a61af66fc99e Initial load duke parents: diff changeset	972 AbstractRefProcTaskExecutor* task_executor)
a61af66fc99e Initial load duke parents: diff changeset	973 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	974 bool mt_processing = task_executor != NULL && _processing_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	975 // If discovery used MT and a dynamic number of GC threads, then
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	976 // the queues must be balanced for correctness if fewer than the
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	977 // maximum number of queues were used. The number of queue used
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	978 // during discovery may be different than the number to be used
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	979 // for processing so don't depend of _num_q < _max_num_q as part
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	980 // of the test.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	981 bool must_balance = _discovery_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	982
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	983 if ((mt_processing && ParallelRefProcBalancingEnabled) \|\|
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	984 must_balance) {
0 a61af66fc99e Initial load duke parents: diff changeset	985 balance_queues(refs_lists);
a61af66fc99e Initial load duke parents: diff changeset	986 }
a61af66fc99e Initial load duke parents: diff changeset	987 if (PrintReferenceGC && PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	988 size_t total = 0;
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	989 for (int i = 0; i < _max_num_q; ++i) {
0 a61af66fc99e Initial load duke parents: diff changeset	990 total += refs_lists[i].length();
a61af66fc99e Initial load duke parents: diff changeset	991 }
a61af66fc99e Initial load duke parents: diff changeset	992 gclog_or_tty->print(", %u refs", total);
a61af66fc99e Initial load duke parents: diff changeset	993 }
a61af66fc99e Initial load duke parents: diff changeset	994
a61af66fc99e Initial load duke parents: diff changeset	995 // Phase 1 (soft refs only):
a61af66fc99e Initial load duke parents: diff changeset	996 // . Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	997 // referents are not alive, but that should be kept alive for
a61af66fc99e Initial load duke parents: diff changeset	998 // policy reasons. Keep alive the transitive closure of all
a61af66fc99e Initial load duke parents: diff changeset	999 // such referents.
a61af66fc99e Initial load duke parents: diff changeset	1000 if (policy != NULL) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1001 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	1002 RefProcPhase1Task phase1(this, refs_lists, policy, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	1003 task_executor->execute(phase1);
a61af66fc99e Initial load duke parents: diff changeset	1004 } else {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1005 for (int i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	1006 process_phase1(refs_lists[i], policy,
a61af66fc99e Initial load duke parents: diff changeset	1007 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	1008 }
a61af66fc99e Initial load duke parents: diff changeset	1009 }
a61af66fc99e Initial load duke parents: diff changeset	1010 } else { // policy == NULL
a61af66fc99e Initial load duke parents: diff changeset	1011 assert(refs_lists != _discoveredSoftRefs,
a61af66fc99e Initial load duke parents: diff changeset	1012 "Policy must be specified for soft references.");
a61af66fc99e Initial load duke parents: diff changeset	1013 }
a61af66fc99e Initial load duke parents: diff changeset	1014
a61af66fc99e Initial load duke parents: diff changeset	1015 // Phase 2:
a61af66fc99e Initial load duke parents: diff changeset	1016 // . Traverse the list and remove any refs whose referents are alive.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1017 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	1018 RefProcPhase2Task phase2(this, refs_lists, !discovery_is_atomic() /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	1019 task_executor->execute(phase2);
a61af66fc99e Initial load duke parents: diff changeset	1020 } else {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1021 for (int i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	1022 process_phase2(refs_lists[i], is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	1023 }
a61af66fc99e Initial load duke parents: diff changeset	1024 }
a61af66fc99e Initial load duke parents: diff changeset	1025
a61af66fc99e Initial load duke parents: diff changeset	1026 // Phase 3:
a61af66fc99e Initial load duke parents: diff changeset	1027 // . Traverse the list and process referents as appropriate.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1028 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	1029 RefProcPhase3Task phase3(this, refs_lists, clear_referent, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	1030 task_executor->execute(phase3);
a61af66fc99e Initial load duke parents: diff changeset	1031 } else {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1032 for (int i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	1033 process_phase3(refs_lists[i], clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	1034 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	1035 }
a61af66fc99e Initial load duke parents: diff changeset	1036 }
a61af66fc99e Initial load duke parents: diff changeset	1037 }
a61af66fc99e Initial load duke parents: diff changeset	1038
a61af66fc99e Initial load duke parents: diff changeset	1039 void ReferenceProcessor::clean_up_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	1040 // loop over the lists
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1041 // Should this instead be
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1042 // for (int i = 0; i < subclasses_of_ref; i++_ {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1043 // for (int j = 0; j < _num_q; j++) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1044 // int index = i * _max_num_q + j;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1045 for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1046 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
0 a61af66fc99e Initial load duke parents: diff changeset	1047 gclog_or_tty->print_cr(
a61af66fc99e Initial load duke parents: diff changeset	1048 "\nScrubbing %s discovered list of Null referents",
a61af66fc99e Initial load duke parents: diff changeset	1049 list_name(i));
a61af66fc99e Initial load duke parents: diff changeset	1050 }
a61af66fc99e Initial load duke parents: diff changeset	1051 clean_up_discovered_reflist(_discoveredSoftRefs[i]);
a61af66fc99e Initial load duke parents: diff changeset	1052 }
a61af66fc99e Initial load duke parents: diff changeset	1053 }
a61af66fc99e Initial load duke parents: diff changeset	1054
a61af66fc99e Initial load duke parents: diff changeset	1055 void ReferenceProcessor::clean_up_discovered_reflist(DiscoveredList& refs_list) {
a61af66fc99e Initial load duke parents: diff changeset	1056 assert(!discovery_is_atomic(), "Else why call this method?");
a61af66fc99e Initial load duke parents: diff changeset	1057 DiscoveredListIterator iter(refs_list, NULL, NULL);
a61af66fc99e Initial load duke parents: diff changeset	1058 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	1059 iter.load_ptrs(DEBUG_ONLY(true /* allow_null_referent */));
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1060 oop next = java_lang_ref_Reference::next(iter.obj());
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1061 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	1062 // If referent has been cleared or Reference is not active,
a61af66fc99e Initial load duke parents: diff changeset	1063 // drop it.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1064 if (iter.referent() == NULL \|\| next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1065 debug_only(
a61af66fc99e Initial load duke parents: diff changeset	1066 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1067 gclog_or_tty->print_cr("clean_up_discovered_list: Dropping Reference: "
a61af66fc99e Initial load duke parents: diff changeset	1068 INTPTR_FORMAT " with next field: " INTPTR_FORMAT
a61af66fc99e Initial load duke parents: diff changeset	1069 " and referent: " INTPTR_FORMAT,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1070 iter.obj(), next, iter.referent());
0 a61af66fc99e Initial load duke parents: diff changeset	1071 }
a61af66fc99e Initial load duke parents: diff changeset	1072 )
a61af66fc99e Initial load duke parents: diff changeset	1073 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	1074 iter.remove();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1075 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	1076 } else {
a61af66fc99e Initial load duke parents: diff changeset	1077 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	1078 }
a61af66fc99e Initial load duke parents: diff changeset	1079 }
a61af66fc99e Initial load duke parents: diff changeset	1080 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	1081 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1082 gclog_or_tty->print(
a61af66fc99e Initial load duke parents: diff changeset	1083 " Removed %d Refs with NULL referents out of %d discovered Refs",
a61af66fc99e Initial load duke parents: diff changeset	1084 iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	1085 }
a61af66fc99e Initial load duke parents: diff changeset	1086 )
a61af66fc99e Initial load duke parents: diff changeset	1087 }
a61af66fc99e Initial load duke parents: diff changeset	1088
a61af66fc99e Initial load duke parents: diff changeset	1089 inline DiscoveredList* ReferenceProcessor::get_discovered_list(ReferenceType rt) {
a61af66fc99e Initial load duke parents: diff changeset	1090 int id = 0;
a61af66fc99e Initial load duke parents: diff changeset	1091 // Determine the queue index to use for this object.
a61af66fc99e Initial load duke parents: diff changeset	1092 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1093 // During a multi-threaded discovery phase,
a61af66fc99e Initial load duke parents: diff changeset	1094 // each thread saves to its "own" list.
a61af66fc99e Initial load duke parents: diff changeset	1095 Thread* thr = Thread::current();
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1096 id = thr->as_Worker_thread()->id();
0 a61af66fc99e Initial load duke parents: diff changeset	1097 } else {
a61af66fc99e Initial load duke parents: diff changeset	1098 // single-threaded discovery, we save in round-robin
a61af66fc99e Initial load duke parents: diff changeset	1099 // fashion to each of the lists.
a61af66fc99e Initial load duke parents: diff changeset	1100 if (_processing_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1101 id = next_id();
a61af66fc99e Initial load duke parents: diff changeset	1102 }
a61af66fc99e Initial load duke parents: diff changeset	1103 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1104 assert(0 <= id && id < _max_num_q, "Id is out-of-bounds (call Freud?)");
0 a61af66fc99e Initial load duke parents: diff changeset	1105
a61af66fc99e Initial load duke parents: diff changeset	1106 // Get the discovered queue to which we will add
a61af66fc99e Initial load duke parents: diff changeset	1107 DiscoveredList* list = NULL;
a61af66fc99e Initial load duke parents: diff changeset	1108 switch (rt) {
a61af66fc99e Initial load duke parents: diff changeset	1109 case REF_OTHER:
a61af66fc99e Initial load duke parents: diff changeset	1110 // Unknown reference type, no special treatment
a61af66fc99e Initial load duke parents: diff changeset	1111 break;
a61af66fc99e Initial load duke parents: diff changeset	1112 case REF_SOFT:
a61af66fc99e Initial load duke parents: diff changeset	1113 list = &_discoveredSoftRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1114 break;
a61af66fc99e Initial load duke parents: diff changeset	1115 case REF_WEAK:
a61af66fc99e Initial load duke parents: diff changeset	1116 list = &_discoveredWeakRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1117 break;
a61af66fc99e Initial load duke parents: diff changeset	1118 case REF_FINAL:
a61af66fc99e Initial load duke parents: diff changeset	1119 list = &_discoveredFinalRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1120 break;
a61af66fc99e Initial load duke parents: diff changeset	1121 case REF_PHANTOM:
a61af66fc99e Initial load duke parents: diff changeset	1122 list = &_discoveredPhantomRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1123 break;
a61af66fc99e Initial load duke parents: diff changeset	1124 case REF_NONE:
a61af66fc99e Initial load duke parents: diff changeset	1125 // we should not reach here if we are an instanceRefKlass
a61af66fc99e Initial load duke parents: diff changeset	1126 default:
a61af66fc99e Initial load duke parents: diff changeset	1127 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1128 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1129 if (TraceReferenceGC && PrintGCDetails) {
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1130 gclog_or_tty->print_cr("Thread %d gets list " INTPTR_FORMAT, id, list);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1131 }
0 a61af66fc99e Initial load duke parents: diff changeset	1132 return list;
a61af66fc99e Initial load duke parents: diff changeset	1133 }
a61af66fc99e Initial load duke parents: diff changeset	1134
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1135 inline void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1136 ReferenceProcessor::add_to_discovered_list_mt(DiscoveredList& refs_list,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1137 oop obj,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1138 HeapWord* discovered_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	1139 assert(_discovery_is_mt, "!_discovery_is_mt should have been handled by caller");
a61af66fc99e Initial load duke parents: diff changeset	1140 // First we must make sure this object is only enqueued once. CAS in a non null
a61af66fc99e Initial load duke parents: diff changeset	1141 // discovered_addr.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1142 oop current_head = refs_list.head();
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1143 // The last ref must have its discovered field pointing to itself.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1144 oop next_discovered = (current_head != NULL) ? current_head : obj;
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1145
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1146 // Note: In the case of G1, this specific pre-barrier is strictly
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1147 // not necessary because the only case we are interested in
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1148 // here is when *discovered_addr is NULL (see the CAS further below),
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1149 // so this will expand to nothing. As a result, we have manually
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1150 // elided this out for G1, but left in the test for some future
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1151 // collector that might have need for a pre-barrier here, e.g.:-
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1152 // _bs->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1153 assert(!_discovered_list_needs_barrier \|\| UseG1GC,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1154 "Need to check non-G1 collector: "
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1155 "may need a pre-write-barrier for CAS from NULL below");
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1156 oop retest = oopDesc::atomic_compare_exchange_oop(next_discovered, discovered_addr,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1157 NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	1158 if (retest == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1159 // This thread just won the right to enqueue the object.
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1160 // We have separate lists for enqueueing, so no synchronization
0 a61af66fc99e Initial load duke parents: diff changeset	1161 // is necessary.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1162 refs_list.set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1163 refs_list.inc_length(1);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1164 if (_discovered_list_needs_barrier) {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1165 _bs->write_ref_field((void*)discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1166 }
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1167
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1168 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1169 gclog_or_tty->print_cr("Discovered reference (mt) (" INTPTR_FORMAT ": %s)",
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1170 obj, obj->blueprint()->internal_name());
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1171 }
0 a61af66fc99e Initial load duke parents: diff changeset	1172 } else {
a61af66fc99e Initial load duke parents: diff changeset	1173 // If retest was non NULL, another thread beat us to it:
a61af66fc99e Initial load duke parents: diff changeset	1174 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1175 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1176 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
0 a61af66fc99e Initial load duke parents: diff changeset	1177 obj, obj->blueprint()->internal_name());
a61af66fc99e Initial load duke parents: diff changeset	1178 }
a61af66fc99e Initial load duke parents: diff changeset	1179 }
a61af66fc99e Initial load duke parents: diff changeset	1180 }
a61af66fc99e Initial load duke parents: diff changeset	1181
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1182 #ifndef PRODUCT
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1183 // Non-atomic (i.e. concurrent) discovery might allow us
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1184 // to observe j.l.References with NULL referents, being those
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1185 // cleared concurrently by mutators during (or after) discovery.
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1186 void ReferenceProcessor::verify_referent(oop obj) {
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1187 bool da = discovery_is_atomic();
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1188 oop referent = java_lang_ref_Reference::referent(obj);
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1189 assert(da ? referent->is_oop() : referent->is_oop_or_null(),
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1190 err_msg("Bad referent " INTPTR_FORMAT " found in Reference "
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1191 INTPTR_FORMAT " during %satomic discovery ",
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1192 (intptr_t)referent, (intptr_t)obj, da ? "" : "non-"));
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1193 }
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1194 #endif
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1195
0 a61af66fc99e Initial load duke parents: diff changeset	1196 // We mention two of several possible choices here:
a61af66fc99e Initial load duke parents: diff changeset	1197 // #0: if the reference object is not in the "originating generation"
a61af66fc99e Initial load duke parents: diff changeset	1198 // (or part of the heap being collected, indicated by our "span"
a61af66fc99e Initial load duke parents: diff changeset	1199 // we don't treat it specially (i.e. we scan it as we would
a61af66fc99e Initial load duke parents: diff changeset	1200 // a normal oop, treating its references as strong references).
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1201 // This means that references can't be discovered unless their
0 a61af66fc99e Initial load duke parents: diff changeset	1202 // referent is also in the same span. This is the simplest,
a61af66fc99e Initial load duke parents: diff changeset	1203 // most "local" and most conservative approach, albeit one
a61af66fc99e Initial load duke parents: diff changeset	1204 // that may cause weak references to be enqueued least promptly.
a61af66fc99e Initial load duke parents: diff changeset	1205 // We call this choice the "ReferenceBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1206 // #1: the reference object may be in any generation (span), but if
a61af66fc99e Initial load duke parents: diff changeset	1207 // the referent is in the generation (span) being currently collected
a61af66fc99e Initial load duke parents: diff changeset	1208 // then we can discover the reference object, provided
a61af66fc99e Initial load duke parents: diff changeset	1209 // the object has not already been discovered by
a61af66fc99e Initial load duke parents: diff changeset	1210 // a different concurrently running collector (as may be the
a61af66fc99e Initial load duke parents: diff changeset	1211 // case, for instance, if the reference object is in CMS and
a61af66fc99e Initial load duke parents: diff changeset	1212 // the referent in DefNewGeneration), and provided the processing
a61af66fc99e Initial load duke parents: diff changeset	1213 // of this reference object by the current collector will
a61af66fc99e Initial load duke parents: diff changeset	1214 // appear atomic to every other collector in the system.
a61af66fc99e Initial load duke parents: diff changeset	1215 // (Thus, for instance, a concurrent collector may not
a61af66fc99e Initial load duke parents: diff changeset	1216 // discover references in other generations even if the
a61af66fc99e Initial load duke parents: diff changeset	1217 // referent is in its own generation). This policy may,
a61af66fc99e Initial load duke parents: diff changeset	1218 // in certain cases, enqueue references somewhat sooner than
a61af66fc99e Initial load duke parents: diff changeset	1219 // might Policy #0 above, but at marginally increased cost
a61af66fc99e Initial load duke parents: diff changeset	1220 // and complexity in processing these references.
a61af66fc99e Initial load duke parents: diff changeset	1221 // We call this choice the "RefeferentBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1222 bool ReferenceProcessor::discover_reference(oop obj, ReferenceType rt) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1223 // Make sure we are discovering refs (rather than processing discovered refs).
0 a61af66fc99e Initial load duke parents: diff changeset	1224 if (!_discovering_refs \|\| !RegisterReferences) {
a61af66fc99e Initial load duke parents: diff changeset	1225 return false;
a61af66fc99e Initial load duke parents: diff changeset	1226 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1227 // We only discover active references.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1228 oop next = java_lang_ref_Reference::next(obj);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1229 if (next != NULL) { // Ref is no longer active
0 a61af66fc99e Initial load duke parents: diff changeset	1230 return false;
a61af66fc99e Initial load duke parents: diff changeset	1231 }
a61af66fc99e Initial load duke parents: diff changeset	1232
a61af66fc99e Initial load duke parents: diff changeset	1233 HeapWord* obj_addr = (HeapWord*)obj;
a61af66fc99e Initial load duke parents: diff changeset	1234 if (RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1235 !_span.contains(obj_addr)) {
a61af66fc99e Initial load duke parents: diff changeset	1236 // Reference is not in the originating generation;
a61af66fc99e Initial load duke parents: diff changeset	1237 // don't treat it specially (i.e. we want to scan it as a normal
a61af66fc99e Initial load duke parents: diff changeset	1238 // object with strong references).
a61af66fc99e Initial load duke parents: diff changeset	1239 return false;
a61af66fc99e Initial load duke parents: diff changeset	1240 }
a61af66fc99e Initial load duke parents: diff changeset	1241
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1242 // We only discover references whose referents are not (yet)
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1243 // known to be strongly reachable.
0 a61af66fc99e Initial load duke parents: diff changeset	1244 if (is_alive_non_header() != NULL) {
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1245 verify_referent(obj);
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1246 if (is_alive_non_header()->do_object_b(java_lang_ref_Reference::referent(obj))) {
0 a61af66fc99e Initial load duke parents: diff changeset	1247 return false; // referent is reachable
a61af66fc99e Initial load duke parents: diff changeset	1248 }
a61af66fc99e Initial load duke parents: diff changeset	1249 }
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1250 if (rt == REF_SOFT) {
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1251 // For soft refs we can decide now if these are not
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1252 // current candidates for clearing, in which case we
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1253 // can mark through them now, rather than delaying that
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1254 // to the reference-processing phase. Since all current
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1255 // time-stamp policies advance the soft-ref clock only
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1256 // at a major collection cycle, this is always currently
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1257 // accurate.
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1258 if (!_current_soft_ref_policy->should_clear_reference(obj)) {
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1259 return false;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1260 }
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1261 }
0 a61af66fc99e Initial load duke parents: diff changeset	1262
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1263 HeapWord* const discovered_addr = java_lang_ref_Reference::discovered_addr(obj);
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1264 const oop discovered = java_lang_ref_Reference::discovered(obj);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1265 assert(discovered->is_oop_or_null(), "bad discovered field");
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1266 if (discovered != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1267 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1268 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1269 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1270 obj, obj->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1271 }
a61af66fc99e Initial load duke parents: diff changeset	1272 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
a61af66fc99e Initial load duke parents: diff changeset	1273 // assumes that an object is not processed twice;
a61af66fc99e Initial load duke parents: diff changeset	1274 // if it's been already discovered it must be on another
a61af66fc99e Initial load duke parents: diff changeset	1275 // generation's discovered list; so we won't discover it.
a61af66fc99e Initial load duke parents: diff changeset	1276 return false;
a61af66fc99e Initial load duke parents: diff changeset	1277 } else {
a61af66fc99e Initial load duke parents: diff changeset	1278 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	1279 "Unrecognized policy");
a61af66fc99e Initial load duke parents: diff changeset	1280 // Check assumption that an object is not potentially
a61af66fc99e Initial load duke parents: diff changeset	1281 // discovered twice except by concurrent collectors that potentially
a61af66fc99e Initial load duke parents: diff changeset	1282 // trace the same Reference object twice.
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1283 assert(UseConcMarkSweepGC \|\| UseG1GC,
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1284 "Only possible with a concurrent marking collector");
0 a61af66fc99e Initial load duke parents: diff changeset	1285 return true;
a61af66fc99e Initial load duke parents: diff changeset	1286 }
a61af66fc99e Initial load duke parents: diff changeset	1287 }
a61af66fc99e Initial load duke parents: diff changeset	1288
a61af66fc99e Initial load duke parents: diff changeset	1289 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1290 verify_referent(obj);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1291 // Discover if and only if EITHER:
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1292 // .. reference is in our span, OR
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1293 // .. we are an atomic collector and referent is in our span
0 a61af66fc99e Initial load duke parents: diff changeset	1294 if (_span.contains(obj_addr) \|\|
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1295 (discovery_is_atomic() &&
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1296 _span.contains(java_lang_ref_Reference::referent(obj)))) {
0 a61af66fc99e Initial load duke parents: diff changeset	1297 // should_enqueue = true;
a61af66fc99e Initial load duke parents: diff changeset	1298 } else {
a61af66fc99e Initial load duke parents: diff changeset	1299 return false;
a61af66fc99e Initial load duke parents: diff changeset	1300 }
a61af66fc99e Initial load duke parents: diff changeset	1301 } else {
a61af66fc99e Initial load duke parents: diff changeset	1302 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1303 _span.contains(obj_addr), "code inconsistency");
a61af66fc99e Initial load duke parents: diff changeset	1304 }
a61af66fc99e Initial load duke parents: diff changeset	1305
a61af66fc99e Initial load duke parents: diff changeset	1306 // Get the right type of discovered queue head.
a61af66fc99e Initial load duke parents: diff changeset	1307 DiscoveredList* list = get_discovered_list(rt);
a61af66fc99e Initial load duke parents: diff changeset	1308 if (list == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1309 return false; // nothing special needs to be done
a61af66fc99e Initial load duke parents: diff changeset	1310 }
a61af66fc99e Initial load duke parents: diff changeset	1311
a61af66fc99e Initial load duke parents: diff changeset	1312 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1313 add_to_discovered_list_mt(*list, obj, discovered_addr);
a61af66fc99e Initial load duke parents: diff changeset	1314 } else {
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1315 // If "_discovered_list_needs_barrier", we do write barriers when
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1316 // updating the discovered reference list. Otherwise, we do a raw store
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1317 // here: the field will be visited later when processing the discovered
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1318 // references.
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1319 oop current_head = list->head();
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1320 // The last ref must have its discovered field pointing to itself.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1321 oop next_discovered = (current_head != NULL) ? current_head : obj;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1322
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1323 // As in the case further above, since we are over-writing a NULL
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1324 // pre-value, we can safely elide the pre-barrier here for the case of G1.
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1325 // e.g.:- _bs->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1326 assert(discovered == NULL, "control point invariant");
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1327 assert(!_discovered_list_needs_barrier \|\| UseG1GC,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1328 "For non-G1 collector, may need a pre-write-barrier for CAS from NULL below");
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1329 oop_store_raw(discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1330 if (_discovered_list_needs_barrier) {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1331 _bs->write_ref_field((void*)discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1332 }
0 a61af66fc99e Initial load duke parents: diff changeset	1333 list->set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1334 list->inc_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	1335
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1336 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1337 gclog_or_tty->print_cr("Discovered reference (" INTPTR_FORMAT ": %s)",
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1338 obj, obj->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1339 }
a61af66fc99e Initial load duke parents: diff changeset	1340 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1341 assert(obj->is_oop(), "Discovered a bad reference");
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1342 verify_referent(obj);
0 a61af66fc99e Initial load duke parents: diff changeset	1343 return true;
a61af66fc99e Initial load duke parents: diff changeset	1344 }
a61af66fc99e Initial load duke parents: diff changeset	1345
a61af66fc99e Initial load duke parents: diff changeset	1346 // Preclean the discovered references by removing those
a61af66fc99e Initial load duke parents: diff changeset	1347 // whose referents are alive, and by marking from those that
a61af66fc99e Initial load duke parents: diff changeset	1348 // are not active. These lists can be handled here
a61af66fc99e Initial load duke parents: diff changeset	1349 // in any order and, indeed, concurrently.
a61af66fc99e Initial load duke parents: diff changeset	1350 void ReferenceProcessor::preclean_discovered_references(
a61af66fc99e Initial load duke parents: diff changeset	1351 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1352 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	1353 VoidClosure* complete_gc,
1190 4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1354 YieldClosure* yield,
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1355 bool should_unload_classes) {
0 a61af66fc99e Initial load duke parents: diff changeset	1356
a61af66fc99e Initial load duke parents: diff changeset	1357 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	1358
935 05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1359 #ifdef ASSERT
05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1360 bool must_remember_klasses = ClassUnloading && !UseConcMarkSweepGC \|\|
1190 4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1361 CMSClassUnloadingEnabled && UseConcMarkSweepGC \|\|
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1362 ExplicitGCInvokesConcurrentAndUnloadsClasses &&
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1363 UseConcMarkSweepGC && should_unload_classes;
935 05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1364 RememberKlassesChecker mx(must_remember_klasses);
05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1365 #endif
0 a61af66fc99e Initial load duke parents: diff changeset	1366 // Soft references
a61af66fc99e Initial load duke parents: diff changeset	1367 {
a61af66fc99e Initial load duke parents: diff changeset	1368 TraceTime tt("Preclean SoftReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1369 false, gclog_or_tty);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1370 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1371 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1372 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1373 }
0 a61af66fc99e Initial load duke parents: diff changeset	1374 preclean_discovered_reflist(_discoveredSoftRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1375 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1376 }
a61af66fc99e Initial load duke parents: diff changeset	1377 }
a61af66fc99e Initial load duke parents: diff changeset	1378
a61af66fc99e Initial load duke parents: diff changeset	1379 // Weak references
a61af66fc99e Initial load duke parents: diff changeset	1380 {
a61af66fc99e Initial load duke parents: diff changeset	1381 TraceTime tt("Preclean WeakReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1382 false, gclog_or_tty);
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1383 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1384 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1385 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1386 }
0 a61af66fc99e Initial load duke parents: diff changeset	1387 preclean_discovered_reflist(_discoveredWeakRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1388 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1389 }
a61af66fc99e Initial load duke parents: diff changeset	1390 }
a61af66fc99e Initial load duke parents: diff changeset	1391
a61af66fc99e Initial load duke parents: diff changeset	1392 // Final references
a61af66fc99e Initial load duke parents: diff changeset	1393 {
a61af66fc99e Initial load duke parents: diff changeset	1394 TraceTime tt("Preclean FinalReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1395 false, gclog_or_tty);
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1396 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1397 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1398 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1399 }
0 a61af66fc99e Initial load duke parents: diff changeset	1400 preclean_discovered_reflist(_discoveredFinalRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1401 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1402 }
a61af66fc99e Initial load duke parents: diff changeset	1403 }
a61af66fc99e Initial load duke parents: diff changeset	1404
a61af66fc99e Initial load duke parents: diff changeset	1405 // Phantom references
a61af66fc99e Initial load duke parents: diff changeset	1406 {
a61af66fc99e Initial load duke parents: diff changeset	1407 TraceTime tt("Preclean PhantomReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1408 false, gclog_or_tty);
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1409 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1410 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1411 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1412 }
0 a61af66fc99e Initial load duke parents: diff changeset	1413 preclean_discovered_reflist(_discoveredPhantomRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1414 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1415 }
a61af66fc99e Initial load duke parents: diff changeset	1416 }
a61af66fc99e Initial load duke parents: diff changeset	1417 }
a61af66fc99e Initial load duke parents: diff changeset	1418
a61af66fc99e Initial load duke parents: diff changeset	1419 // Walk the given discovered ref list, and remove all reference objects
a61af66fc99e Initial load duke parents: diff changeset	1420 // whose referents are still alive, whose referents are NULL or which
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1421 // are not active (have a non-NULL next field). NOTE: When we are
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1422 // thus precleaning the ref lists (which happens single-threaded today),
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1423 // we do not disable refs discovery to honour the correct semantics of
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1424 // java.lang.Reference. As a result, we need to be careful below
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1425 // that ref removal steps interleave safely with ref discovery steps
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1426 // (in this thread).
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1427 void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1428 ReferenceProcessor::preclean_discovered_reflist(DiscoveredList& refs_list,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1429 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1430 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1431 VoidClosure* complete_gc,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1432 YieldClosure* yield) {
0 a61af66fc99e Initial load duke parents: diff changeset	1433 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
a61af66fc99e Initial load duke parents: diff changeset	1434 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	1435 iter.load_ptrs(DEBUG_ONLY(true /* allow_null_referent */));
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1436 oop obj = iter.obj();
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1437 oop next = java_lang_ref_Reference::next(obj);
0 a61af66fc99e Initial load duke parents: diff changeset	1438 if (iter.referent() == NULL \|\| iter.is_referent_alive() \|\|
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1439 next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1440 // The referent has been cleared, or is alive, or the Reference is not
a61af66fc99e Initial load duke parents: diff changeset	1441 // active; we need to trace and mark its cohort.
a61af66fc99e Initial load duke parents: diff changeset	1442 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1443 gclog_or_tty->print_cr("Precleaning Reference (" INTPTR_FORMAT ": %s)",
a61af66fc99e Initial load duke parents: diff changeset	1444 iter.obj(), iter.obj()->blueprint()->internal_name());
a61af66fc99e Initial load duke parents: diff changeset	1445 }
a61af66fc99e Initial load duke parents: diff changeset	1446 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	1447 iter.remove();
a61af66fc99e Initial load duke parents: diff changeset	1448 // Keep alive its cohort.
a61af66fc99e Initial load duke parents: diff changeset	1449 iter.make_referent_alive();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1450 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1451 narrowOop* next_addr = (narrowOop*)java_lang_ref_Reference::next_addr(obj);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1452 keep_alive->do_oop(next_addr);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1453 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1454 oop* next_addr = (oop*)java_lang_ref_Reference::next_addr(obj);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1455 keep_alive->do_oop(next_addr);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1456 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1457 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	1458 } else {
a61af66fc99e Initial load duke parents: diff changeset	1459 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	1460 }
a61af66fc99e Initial load duke parents: diff changeset	1461 }
a61af66fc99e Initial load duke parents: diff changeset	1462 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	1463 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	1464
a61af66fc99e Initial load duke parents: diff changeset	1465 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1466 if (PrintGCDetails && PrintReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1467 gclog_or_tty->print_cr(" Dropped %d Refs out of %d "
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1468 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1469 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	1470 }
a61af66fc99e Initial load duke parents: diff changeset	1471 )
a61af66fc99e Initial load duke parents: diff changeset	1472 }
a61af66fc99e Initial load duke parents: diff changeset	1473
a61af66fc99e Initial load duke parents: diff changeset	1474 const char* ReferenceProcessor::list_name(int i) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1475 assert(i >= 0 && i <= _max_num_q * subclasses_of_ref, "Out of bounds index");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1476 int j = i / _max_num_q;
0 a61af66fc99e Initial load duke parents: diff changeset	1477 switch (j) {
a61af66fc99e Initial load duke parents: diff changeset	1478 case 0: return "SoftRef";
a61af66fc99e Initial load duke parents: diff changeset	1479 case 1: return "WeakRef";
a61af66fc99e Initial load duke parents: diff changeset	1480 case 2: return "FinalRef";
a61af66fc99e Initial load duke parents: diff changeset	1481 case 3: return "PhantomRef";
a61af66fc99e Initial load duke parents: diff changeset	1482 }
a61af66fc99e Initial load duke parents: diff changeset	1483 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1484 return NULL;
a61af66fc99e Initial load duke parents: diff changeset	1485 }
a61af66fc99e Initial load duke parents: diff changeset	1486
a61af66fc99e Initial load duke parents: diff changeset	1487 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1488 void ReferenceProcessor::verify_ok_to_handle_reflists() {
a61af66fc99e Initial load duke parents: diff changeset	1489 // empty for now
a61af66fc99e Initial load duke parents: diff changeset	1490 }
a61af66fc99e Initial load duke parents: diff changeset	1491 #endif
a61af66fc99e Initial load duke parents: diff changeset	1492
a61af66fc99e Initial load duke parents: diff changeset	1493 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1494 void ReferenceProcessor::clear_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	1495 guarantee(!_discovering_refs, "Discovering refs?");
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1496 for (int i = 0; i < _max_num_q * subclasses_of_ref; i++) {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1497 clear_discovered_references(_discoveredSoftRefs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	1498 }
a61af66fc99e Initial load duke parents: diff changeset	1499 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1500
0 a61af66fc99e Initial load duke parents: diff changeset	1501 #endif // PRODUCT

Mercurial > hg > truffle

annotate src/share/vm/memory/referenceProcessor.cpp @ 3938:e6b1331a51d2