graal-compiler: src/share/vm/memory/referenceProcessor.cpp annotate

annotate src/share/vm/memory/referenceProcessor.cpp @ 1190:4788266644c1

6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") Summary: Adjust assertion checking for ExplicitGCInvokesConcurrentAndUnloadsClasses as a reason for class unloading Reviewed-by: ysr

author	jmasa
date	Thu, 21 Jan 2010 11:33:32 -0800
parents	9b9c1ee9b3f6
children	c18cbe5936b8

rev	line source
0 a61af66fc99e Initial load duke parents: diff changeset	1 /*
579 0fbdb4381b99 6814575: Update copyright year xdono parents: 534 diff changeset	2 * Copyright 2001-2009 Sun Microsystems, Inc. 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 *
a61af66fc99e Initial load duke parents: diff changeset	19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
a61af66fc99e Initial load duke parents: diff changeset	20 * CA 95054 USA or visit www.sun.com if you need additional information or
a61af66fc99e Initial load duke parents: diff changeset	21 * have any questions.
a61af66fc99e Initial load duke parents: diff changeset	22 *
a61af66fc99e Initial load duke parents: diff changeset	23 */
a61af66fc99e Initial load duke parents: diff changeset	24
a61af66fc99e Initial load duke parents: diff changeset	25 # include "incls/_precompiled.incl"
a61af66fc99e Initial load duke parents: diff changeset	26 # include "incls/_referenceProcessor.cpp.incl"
a61af66fc99e Initial load duke parents: diff changeset	27
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	28 ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	29 ReferencePolicy* ReferenceProcessor::_default_soft_ref_policy = NULL;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	30 oop ReferenceProcessor::_sentinelRef = NULL;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	31 const int subclasses_of_ref = REF_PHANTOM - REF_OTHER;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	32
0 a61af66fc99e Initial load duke parents: diff changeset	33 // List of discovered references.
a61af66fc99e Initial load duke parents: diff changeset	34 class DiscoveredList {
a61af66fc99e Initial load duke parents: diff changeset	35 public:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	36 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	37 oop head() const {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	38 return UseCompressedOops ? oopDesc::decode_heap_oop_not_null(_compressed_head) :
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	39 _oop_head;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	40 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	41 HeapWord* adr_head() {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	42 return UseCompressedOops ? (HeapWord*)&_compressed_head :
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	43 (HeapWord*)&_oop_head;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	44 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	45 void set_head(oop o) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	46 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	47 // Must compress the head ptr.
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	48 _compressed_head = oopDesc::encode_heap_oop_not_null(o);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	49 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	50 _oop_head = o;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	51 }
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 bool empty() const { return head() == ReferenceProcessor::sentinel_ref(); }
0 a61af66fc99e Initial load duke parents: diff changeset	54 size_t length() { return _len; }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	55 void set_length(size_t len) { _len = len; }
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	56 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	57 void dec_length(size_t dec) { _len -= dec; }
0 a61af66fc99e Initial load duke parents: diff changeset	58 private:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	59 // 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	60 // 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	61 oop _oop_head;
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	62 narrowOop _compressed_head;
0 a61af66fc99e Initial load duke parents: diff changeset	63 size_t _len;
a61af66fc99e Initial load duke parents: diff changeset	64 };
a61af66fc99e Initial load duke parents: diff changeset	65
a61af66fc99e Initial load duke parents: diff changeset	66 void referenceProcessor_init() {
a61af66fc99e Initial load duke parents: diff changeset	67 ReferenceProcessor::init_statics();
a61af66fc99e Initial load duke parents: diff changeset	68 }
a61af66fc99e Initial load duke parents: diff changeset	69
a61af66fc99e Initial load duke parents: diff changeset	70 void ReferenceProcessor::init_statics() {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	71 assert(_sentinelRef == NULL, "should be initialized precisely once");
0 a61af66fc99e Initial load duke parents: diff changeset	72 EXCEPTION_MARK;
a61af66fc99e Initial load duke parents: diff changeset	73 _sentinelRef = instanceKlass::cast(
1142 4ce7240d622c 6914300: ciEnv should export all well known classes never parents: 935 diff changeset	74 SystemDictionary::Reference_klass())->
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	75 allocate_permanent_instance(THREAD);
0 a61af66fc99e Initial load duke parents: diff changeset	76
a61af66fc99e Initial load duke parents: diff changeset	77 // Initialize the master soft ref clock.
a61af66fc99e Initial load duke parents: diff changeset	78 java_lang_ref_SoftReference::set_clock(os::javaTimeMillis());
a61af66fc99e Initial load duke parents: diff changeset	79
a61af66fc99e Initial load duke parents: diff changeset	80 if (HAS_PENDING_EXCEPTION) {
a61af66fc99e Initial load duke parents: diff changeset	81 Handle ex(THREAD, PENDING_EXCEPTION);
a61af66fc99e Initial load duke parents: diff changeset	82 vm_exit_during_initialization(ex);
a61af66fc99e Initial load duke parents: diff changeset	83 }
a61af66fc99e Initial load duke parents: diff changeset	84 assert(_sentinelRef != NULL && _sentinelRef->is_oop(),
a61af66fc99e Initial load duke parents: diff changeset	85 "Just constructed it!");
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	86 _always_clear_soft_ref_policy = new AlwaysClearPolicy();
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	87 _default_soft_ref_policy = new COMPILER2_PRESENT(LRUMaxHeapPolicy())
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	88 NOT_COMPILER2(LRUCurrentHeapPolicy());
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	89 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	90 vm_exit_during_initialization("Could not allocate reference policy object");
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	91 }
0 a61af66fc99e Initial load duke parents: diff changeset	92 guarantee(RefDiscoveryPolicy == ReferenceBasedDiscovery \|\|
a61af66fc99e Initial load duke parents: diff changeset	93 RefDiscoveryPolicy == ReferentBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	94 "Unrecongnized RefDiscoveryPolicy");
a61af66fc99e Initial load duke parents: diff changeset	95 }
a61af66fc99e Initial load duke parents: diff changeset	96
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	97 ReferenceProcessor*
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	98 ReferenceProcessor::create_ref_processor(MemRegion span,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	99 bool atomic_discovery,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	100 bool mt_discovery,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	101 BoolObjectClosure* is_alive_non_header,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	102 int parallel_gc_threads,
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	103 bool mt_processing,
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	104 bool dl_needs_barrier) {
0 a61af66fc99e Initial load duke parents: diff changeset	105 int mt_degree = 1;
a61af66fc99e Initial load duke parents: diff changeset	106 if (parallel_gc_threads > 1) {
a61af66fc99e Initial load duke parents: diff changeset	107 mt_degree = parallel_gc_threads;
a61af66fc99e Initial load duke parents: diff changeset	108 }
a61af66fc99e Initial load duke parents: diff changeset	109 ReferenceProcessor* rp =
a61af66fc99e Initial load duke parents: diff changeset	110 new ReferenceProcessor(span, atomic_discovery,
a61af66fc99e Initial load duke parents: diff changeset	111 mt_discovery, mt_degree,
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	112 mt_processing && (parallel_gc_threads > 0),
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	113 dl_needs_barrier);
0 a61af66fc99e Initial load duke parents: diff changeset	114 if (rp == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	115 vm_exit_during_initialization("Could not allocate ReferenceProcessor object");
a61af66fc99e Initial load duke parents: diff changeset	116 }
a61af66fc99e Initial load duke parents: diff changeset	117 rp->set_is_alive_non_header(is_alive_non_header);
457 27a80744a83b 6778647: snap(), snap_policy() should be renamed setup(), setup_policy() ysr parents: 453 diff changeset	118 rp->setup_policy(false /* default soft ref policy */);
0 a61af66fc99e Initial load duke parents: diff changeset	119 return rp;
a61af66fc99e Initial load duke parents: diff changeset	120 }
a61af66fc99e Initial load duke parents: diff changeset	121
a61af66fc99e Initial load duke parents: diff changeset	122 ReferenceProcessor::ReferenceProcessor(MemRegion span,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	123 bool atomic_discovery,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	124 bool mt_discovery,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	125 int mt_degree,
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	126 bool mt_processing,
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	127 bool discovered_list_needs_barrier) :
0 a61af66fc99e Initial load duke parents: diff changeset	128 _discovering_refs(false),
a61af66fc99e Initial load duke parents: diff changeset	129 _enqueuing_is_done(false),
a61af66fc99e Initial load duke parents: diff changeset	130 _is_alive_non_header(NULL),
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	131 _discovered_list_needs_barrier(discovered_list_needs_barrier),
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	132 _bs(NULL),
0 a61af66fc99e Initial load duke parents: diff changeset	133 _processing_is_mt(mt_processing),
a61af66fc99e Initial load duke parents: diff changeset	134 _next_id(0)
a61af66fc99e Initial load duke parents: diff changeset	135 {
a61af66fc99e Initial load duke parents: diff changeset	136 _span = span;
a61af66fc99e Initial load duke parents: diff changeset	137 _discovery_is_atomic = atomic_discovery;
a61af66fc99e Initial load duke parents: diff changeset	138 _discovery_is_mt = mt_discovery;
a61af66fc99e Initial load duke parents: diff changeset	139 _num_q = mt_degree;
a61af66fc99e Initial load duke parents: diff changeset	140 _discoveredSoftRefs = NEW_C_HEAP_ARRAY(DiscoveredList, _num_q * subclasses_of_ref);
a61af66fc99e Initial load duke parents: diff changeset	141 if (_discoveredSoftRefs == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	142 vm_exit_during_initialization("Could not allocated RefProc Array");
a61af66fc99e Initial load duke parents: diff changeset	143 }
a61af66fc99e Initial load duke parents: diff changeset	144 _discoveredWeakRefs = &_discoveredSoftRefs[_num_q];
a61af66fc99e Initial load duke parents: diff changeset	145 _discoveredFinalRefs = &_discoveredWeakRefs[_num_q];
a61af66fc99e Initial load duke parents: diff changeset	146 _discoveredPhantomRefs = &_discoveredFinalRefs[_num_q];
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	147 assert(sentinel_ref() != NULL, "_sentinelRef is NULL");
0 a61af66fc99e Initial load duke parents: diff changeset	148 // Initialized all entries to _sentinelRef
a61af66fc99e Initial load duke parents: diff changeset	149 for (int i = 0; i < _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 _discoveredSoftRefs[i].set_head(sentinel_ref());
0 a61af66fc99e Initial load duke parents: diff changeset	151 _discoveredSoftRefs[i].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	152 }
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	153 // If we do barreirs, cache a copy of the barrier set.
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	154 if (discovered_list_needs_barrier) {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	155 _bs = Universe::heap()->barrier_set();
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	156 }
0 a61af66fc99e Initial load duke parents: diff changeset	157 }
a61af66fc99e Initial load duke parents: diff changeset	158
a61af66fc99e Initial load duke parents: diff changeset	159 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	160 void ReferenceProcessor::verify_no_references_recorded() {
a61af66fc99e Initial load duke parents: diff changeset	161 guarantee(!_discovering_refs, "Discovering refs?");
a61af66fc99e Initial load duke parents: diff changeset	162 for (int i = 0; i < _num_q * subclasses_of_ref; i++) {
a61af66fc99e Initial load duke parents: diff changeset	163 guarantee(_discoveredSoftRefs[i].empty(),
a61af66fc99e Initial load duke parents: diff changeset	164 "Found non-empty discovered list");
a61af66fc99e Initial load duke parents: diff changeset	165 }
a61af66fc99e Initial load duke parents: diff changeset	166 }
a61af66fc99e Initial load duke parents: diff changeset	167 #endif
a61af66fc99e Initial load duke parents: diff changeset	168
a61af66fc99e Initial load duke parents: diff changeset	169 void ReferenceProcessor::weak_oops_do(OopClosure* f) {
a61af66fc99e Initial load duke parents: diff changeset	170 for (int i = 0; i < _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	171 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	172 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	173 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	174 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	175 }
0 a61af66fc99e Initial load duke parents: diff changeset	176 }
a61af66fc99e Initial load duke parents: diff changeset	177 }
a61af66fc99e Initial load duke parents: diff changeset	178
a61af66fc99e Initial load duke parents: diff changeset	179 void ReferenceProcessor::oops_do(OopClosure* f) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	180 f->do_oop(adr_sentinel_ref());
0 a61af66fc99e Initial load duke parents: diff changeset	181 }
a61af66fc99e Initial load duke parents: diff changeset	182
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	183 void ReferenceProcessor::update_soft_ref_master_clock() {
0 a61af66fc99e Initial load duke parents: diff changeset	184 // Update (advance) the soft ref master clock field. This must be done
a61af66fc99e Initial load duke parents: diff changeset	185 // after processing the soft ref list.
a61af66fc99e Initial load duke parents: diff changeset	186 jlong now = os::javaTimeMillis();
a61af66fc99e Initial load duke parents: diff changeset	187 jlong clock = java_lang_ref_SoftReference::clock();
a61af66fc99e Initial load duke parents: diff changeset	188 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	189 if (now < clock) {
a61af66fc99e Initial load duke parents: diff changeset	190 warning("time warp: %d to %d", clock, now);
a61af66fc99e Initial load duke parents: diff changeset	191 }
a61af66fc99e Initial load duke parents: diff changeset	192 )
a61af66fc99e Initial load duke parents: diff changeset	193 // In product mode, protect ourselves from system time being adjusted
a61af66fc99e Initial load duke parents: diff changeset	194 // externally and going backward; see note in the implementation of
a61af66fc99e Initial load duke parents: diff changeset	195 // GenCollectedHeap::time_since_last_gc() for the right way to fix
a61af66fc99e Initial load duke parents: diff changeset	196 // this uniformly throughout the VM; see bug-id 4741166. XXX
a61af66fc99e Initial load duke parents: diff changeset	197 if (now > clock) {
a61af66fc99e Initial load duke parents: diff changeset	198 java_lang_ref_SoftReference::set_clock(now);
a61af66fc99e Initial load duke parents: diff changeset	199 }
a61af66fc99e Initial load duke parents: diff changeset	200 // Else leave clock stalled at its old value until time progresses
a61af66fc99e Initial load duke parents: diff changeset	201 // past clock value.
a61af66fc99e Initial load duke parents: diff changeset	202 }
a61af66fc99e Initial load duke parents: diff changeset	203
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	204 void ReferenceProcessor::process_discovered_references(
0 a61af66fc99e Initial load duke parents: diff changeset	205 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	206 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	207 VoidClosure* complete_gc,
a61af66fc99e Initial load duke parents: diff changeset	208 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load duke parents: diff changeset	209 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	210
a61af66fc99e Initial load duke parents: diff changeset	211 assert(!enqueuing_is_done(), "If here enqueuing should not be complete");
a61af66fc99e Initial load duke parents: diff changeset	212 // Stop treating discovered references specially.
a61af66fc99e Initial load duke parents: diff changeset	213 disable_discovery();
a61af66fc99e Initial load duke parents: diff changeset	214
a61af66fc99e Initial load duke parents: diff changeset	215 bool trace_time = PrintGCDetails && PrintReferenceGC;
a61af66fc99e Initial load duke parents: diff changeset	216 // Soft references
a61af66fc99e Initial load duke parents: diff changeset	217 {
a61af66fc99e Initial load duke parents: diff changeset	218 TraceTime tt("SoftReference", trace_time, false, gclog_or_tty);
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	219 process_discovered_reflist(_discoveredSoftRefs, _current_soft_ref_policy, true,
0 a61af66fc99e Initial load duke parents: diff changeset	220 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	221 }
a61af66fc99e Initial load duke parents: diff changeset	222
a61af66fc99e Initial load duke parents: diff changeset	223 update_soft_ref_master_clock();
a61af66fc99e Initial load duke parents: diff changeset	224
a61af66fc99e Initial load duke parents: diff changeset	225 // Weak references
a61af66fc99e Initial load duke parents: diff changeset	226 {
a61af66fc99e Initial load duke parents: diff changeset	227 TraceTime tt("WeakReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	228 process_discovered_reflist(_discoveredWeakRefs, NULL, true,
a61af66fc99e Initial load duke parents: diff changeset	229 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	230 }
a61af66fc99e Initial load duke parents: diff changeset	231
a61af66fc99e Initial load duke parents: diff changeset	232 // Final references
a61af66fc99e Initial load duke parents: diff changeset	233 {
a61af66fc99e Initial load duke parents: diff changeset	234 TraceTime tt("FinalReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	235 process_discovered_reflist(_discoveredFinalRefs, NULL, false,
a61af66fc99e Initial load duke parents: diff changeset	236 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	237 }
a61af66fc99e Initial load duke parents: diff changeset	238
a61af66fc99e Initial load duke parents: diff changeset	239 // Phantom references
a61af66fc99e Initial load duke parents: diff changeset	240 {
a61af66fc99e Initial load duke parents: diff changeset	241 TraceTime tt("PhantomReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	242 process_discovered_reflist(_discoveredPhantomRefs, NULL, false,
a61af66fc99e Initial load duke parents: diff changeset	243 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	244 }
a61af66fc99e Initial load duke parents: diff changeset	245
a61af66fc99e Initial load duke parents: diff changeset	246 // Weak global JNI references. It would make more sense (semantically) to
a61af66fc99e Initial load duke parents: diff changeset	247 // traverse these simultaneously with the regular weak references above, but
a61af66fc99e Initial load duke parents: diff changeset	248 // that is not how the JDK1.2 specification is. See #4126360. Native code can
a61af66fc99e Initial load duke parents: diff changeset	249 // thus use JNI weak references to circumvent the phantom references and
a61af66fc99e Initial load duke parents: diff changeset	250 // resurrect a "post-mortem" object.
a61af66fc99e Initial load duke parents: diff changeset	251 {
a61af66fc99e Initial load duke parents: diff changeset	252 TraceTime tt("JNI Weak Reference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	253 if (task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	254 task_executor->set_single_threaded_mode();
a61af66fc99e Initial load duke parents: diff changeset	255 }
a61af66fc99e Initial load duke parents: diff changeset	256 process_phaseJNI(is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	257 }
a61af66fc99e Initial load duke parents: diff changeset	258 }
a61af66fc99e Initial load duke parents: diff changeset	259
a61af66fc99e Initial load duke parents: diff changeset	260 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	261 // 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	262 uint ReferenceProcessor::count_jni_refs() {
0 a61af66fc99e Initial load duke parents: diff changeset	263 class AlwaysAliveClosure: public BoolObjectClosure {
a61af66fc99e Initial load duke parents: diff changeset	264 public:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	265 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	266 virtual void do_object(oop obj) { assert(false, "Don't call"); }
0 a61af66fc99e Initial load duke parents: diff changeset	267 };
a61af66fc99e Initial load duke parents: diff changeset	268
a61af66fc99e Initial load duke parents: diff changeset	269 class CountHandleClosure: public OopClosure {
a61af66fc99e Initial load duke parents: diff changeset	270 private:
a61af66fc99e Initial load duke parents: diff changeset	271 int _count;
a61af66fc99e Initial load duke parents: diff changeset	272 public:
a61af66fc99e Initial load duke parents: diff changeset	273 CountHandleClosure(): _count(0) {}
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	274 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	275 void do_oop(narrowOop* unused) { ShouldNotReachHere(); }
0 a61af66fc99e Initial load duke parents: diff changeset	276 int count() { return _count; }
a61af66fc99e Initial load duke parents: diff changeset	277 };
a61af66fc99e Initial load duke parents: diff changeset	278 CountHandleClosure global_handle_count;
a61af66fc99e Initial load duke parents: diff changeset	279 AlwaysAliveClosure always_alive;
a61af66fc99e Initial load duke parents: diff changeset	280 JNIHandles::weak_oops_do(&always_alive, &global_handle_count);
a61af66fc99e Initial load duke parents: diff changeset	281 return global_handle_count.count();
a61af66fc99e Initial load duke parents: diff changeset	282 }
a61af66fc99e Initial load duke parents: diff changeset	283 #endif
a61af66fc99e Initial load duke parents: diff changeset	284
a61af66fc99e Initial load duke parents: diff changeset	285 void ReferenceProcessor::process_phaseJNI(BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	286 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	287 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	288 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	289 if (PrintGCDetails && PrintReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	290 unsigned int count = count_jni_refs();
a61af66fc99e Initial load duke parents: diff changeset	291 gclog_or_tty->print(", %u refs", count);
a61af66fc99e Initial load duke parents: diff changeset	292 }
a61af66fc99e Initial load duke parents: diff changeset	293 #endif
a61af66fc99e Initial load duke parents: diff changeset	294 JNIHandles::weak_oops_do(is_alive, keep_alive);
a61af66fc99e Initial load duke parents: diff changeset	295 // Finally remember to keep sentinel around
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	296 keep_alive->do_oop(adr_sentinel_ref());
0 a61af66fc99e Initial load duke parents: diff changeset	297 complete_gc->do_void();
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
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	301 template <class T>
1123 167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	302 bool enqueue_discovered_ref_helper(ReferenceProcessor* ref,
167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	303 AbstractRefProcTaskExecutor* task_executor) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	304
0 a61af66fc99e Initial load duke parents: diff changeset	305 // 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	306 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	307 T old_pending_list_value = *pending_list_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	308
a61af66fc99e Initial load duke parents: diff changeset	309 // Enqueue references that are not made active again, and
a61af66fc99e Initial load duke parents: diff changeset	310 // 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	311 ref->enqueue_discovered_reflists((HeapWord*)pending_list_addr, task_executor);
0 a61af66fc99e Initial load duke parents: diff changeset	312 // Do the oop-check on pending_list_addr missed in
a61af66fc99e Initial load duke parents: diff changeset	313 // enqueue_discovered_reflist. We should probably
a61af66fc99e Initial load duke parents: diff changeset	314 // do a raw oop_check so that future such idempotent
a61af66fc99e Initial load duke parents: diff changeset	315 // oop_stores relying on the oop-check side-effect
a61af66fc99e Initial load duke parents: diff changeset	316 // may be elided automatically and safely without
a61af66fc99e Initial load duke parents: diff changeset	317 // affecting correctness.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	318 oop_store(pending_list_addr, oopDesc::load_decode_heap_oop(pending_list_addr));
0 a61af66fc99e Initial load duke parents: diff changeset	319
a61af66fc99e Initial load duke parents: diff changeset	320 // 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	321 ref->disable_discovery();
0 a61af66fc99e Initial load duke parents: diff changeset	322
a61af66fc99e Initial load duke parents: diff changeset	323 // Return true if new pending references were added
a61af66fc99e Initial load duke parents: diff changeset	324 return old_pending_list_value != *pending_list_addr;
a61af66fc99e Initial load duke parents: diff changeset	325 }
a61af66fc99e Initial load duke parents: diff changeset	326
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	327 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	328 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	329 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	330 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	331 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	332 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	333 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	334 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	335
0 a61af66fc99e Initial load duke parents: diff changeset	336 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	337 HeapWord* pending_list_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	338 // Given a list of refs linked through the "discovered" field
a61af66fc99e Initial load duke parents: diff changeset	339 // (java.lang.ref.Reference.discovered) chain them through the
a61af66fc99e Initial load duke parents: diff changeset	340 // "next" field (java.lang.ref.Reference.next) and prepend
a61af66fc99e Initial load duke parents: diff changeset	341 // to the pending list.
a61af66fc99e Initial load duke parents: diff changeset	342 if (TraceReferenceGC && PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	343 gclog_or_tty->print_cr("ReferenceProcessor::enqueue_discovered_reflist list "
a61af66fc99e Initial load duke parents: diff changeset	344 INTPTR_FORMAT, (address)refs_list.head());
a61af66fc99e Initial load duke parents: diff changeset	345 }
a61af66fc99e Initial load duke parents: diff changeset	346 oop obj = refs_list.head();
a61af66fc99e Initial load duke parents: diff changeset	347 // Walk down the list, copying the discovered field into
a61af66fc99e Initial load duke parents: diff changeset	348 // the next field and clearing it (except for the last
a61af66fc99e Initial load duke parents: diff changeset	349 // non-sentinel object which is treated specially to avoid
a61af66fc99e Initial load duke parents: diff changeset	350 // confusion with an active reference).
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	351 while (obj != sentinel_ref()) {
0 a61af66fc99e Initial load duke parents: diff changeset	352 assert(obj->is_instanceRef(), "should be reference object");
a61af66fc99e Initial load duke parents: diff changeset	353 oop next = java_lang_ref_Reference::discovered(obj);
a61af66fc99e Initial load duke parents: diff changeset	354 if (TraceReferenceGC && PrintGCDetails) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	355 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next " INTPTR_FORMAT,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	356 obj, next);
0 a61af66fc99e Initial load duke parents: diff changeset	357 }
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	358 assert(java_lang_ref_Reference::next(obj) == NULL,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	359 "The reference should not be enqueued");
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	360 if (next == sentinel_ref()) { // obj is last
0 a61af66fc99e Initial load duke parents: diff changeset	361 // Swap refs_list into pendling_list_addr and
a61af66fc99e Initial load duke parents: diff changeset	362 // set obj's next to what we read from pending_list_addr.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	363 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
0 a61af66fc99e Initial load duke parents: diff changeset	364 // Need oop_check on pending_list_addr above;
a61af66fc99e Initial load duke parents: diff changeset	365 // see special oop-check code at the end of
a61af66fc99e Initial load duke parents: diff changeset	366 // enqueue_discovered_reflists() further below.
a61af66fc99e Initial load duke parents: diff changeset	367 if (old == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	368 // obj should be made to point to itself, since
a61af66fc99e Initial load duke parents: diff changeset	369 // pending list was empty.
a61af66fc99e Initial load duke parents: diff changeset	370 java_lang_ref_Reference::set_next(obj, obj);
a61af66fc99e Initial load duke parents: diff changeset	371 } else {
a61af66fc99e Initial load duke parents: diff changeset	372 java_lang_ref_Reference::set_next(obj, old);
a61af66fc99e Initial load duke parents: diff changeset	373 }
a61af66fc99e Initial load duke parents: diff changeset	374 } else {
a61af66fc99e Initial load duke parents: diff changeset	375 java_lang_ref_Reference::set_next(obj, next);
a61af66fc99e Initial load duke parents: diff changeset	376 }
a61af66fc99e Initial load duke parents: diff changeset	377 java_lang_ref_Reference::set_discovered(obj, (oop) NULL);
a61af66fc99e Initial load duke parents: diff changeset	378 obj = next;
a61af66fc99e Initial load duke parents: diff changeset	379 }
a61af66fc99e Initial load duke parents: diff changeset	380 }
a61af66fc99e Initial load duke parents: diff changeset	381
a61af66fc99e Initial load duke parents: diff changeset	382 // Parallel enqueue task
a61af66fc99e Initial load duke parents: diff changeset	383 class RefProcEnqueueTask: public AbstractRefProcTaskExecutor::EnqueueTask {
a61af66fc99e Initial load duke parents: diff changeset	384 public:
a61af66fc99e Initial load duke parents: diff changeset	385 RefProcEnqueueTask(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	386 DiscoveredList discovered_refs[],
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	387 HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	388 oop sentinel_ref,
a61af66fc99e Initial load duke parents: diff changeset	389 int n_queues)
a61af66fc99e Initial load duke parents: diff changeset	390 : EnqueueTask(ref_processor, discovered_refs,
a61af66fc99e Initial load duke parents: diff changeset	391 pending_list_addr, sentinel_ref, n_queues)
a61af66fc99e Initial load duke parents: diff changeset	392 { }
a61af66fc99e Initial load duke parents: diff changeset	393
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	394 virtual void work(unsigned int work_id) {
0 a61af66fc99e Initial load duke parents: diff changeset	395 assert(work_id < (unsigned int)_ref_processor.num_q(), "Index out-of-bounds");
a61af66fc99e Initial load duke parents: diff changeset	396 // Simplest first cut: static partitioning.
a61af66fc99e Initial load duke parents: diff changeset	397 int index = work_id;
a61af66fc99e Initial load duke parents: diff changeset	398 for (int j = 0; j < subclasses_of_ref; j++, index += _n_queues) {
a61af66fc99e Initial load duke parents: diff changeset	399 _ref_processor.enqueue_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	400 _refs_lists[index], _pending_list_addr);
a61af66fc99e Initial load duke parents: diff changeset	401 _refs_lists[index].set_head(_sentinel_ref);
a61af66fc99e Initial load duke parents: diff changeset	402 _refs_lists[index].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	403 }
a61af66fc99e Initial load duke parents: diff changeset	404 }
a61af66fc99e Initial load duke parents: diff changeset	405 };
a61af66fc99e Initial load duke parents: diff changeset	406
a61af66fc99e Initial load duke parents: diff changeset	407 // 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	408 void ReferenceProcessor::enqueue_discovered_reflists(HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	409 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load duke parents: diff changeset	410 if (_processing_is_mt && task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	411 // Parallel code
a61af66fc99e Initial load duke parents: diff changeset	412 RefProcEnqueueTask tsk(*this, _discoveredSoftRefs,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	413 pending_list_addr, sentinel_ref(), _num_q);
0 a61af66fc99e Initial load duke parents: diff changeset	414 task_executor->execute(tsk);
a61af66fc99e Initial load duke parents: diff changeset	415 } else {
a61af66fc99e Initial load duke parents: diff changeset	416 // Serial code: call the parent class's implementation
a61af66fc99e Initial load duke parents: diff changeset	417 for (int i = 0; i < _num_q * subclasses_of_ref; i++) {
a61af66fc99e Initial load duke parents: diff changeset	418 enqueue_discovered_reflist(_discoveredSoftRefs[i], pending_list_addr);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	419 _discoveredSoftRefs[i].set_head(sentinel_ref());
0 a61af66fc99e Initial load duke parents: diff changeset	420 _discoveredSoftRefs[i].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	421 }
a61af66fc99e Initial load duke parents: diff changeset	422 }
a61af66fc99e Initial load duke parents: diff changeset	423 }
a61af66fc99e Initial load duke parents: diff changeset	424
a61af66fc99e Initial load duke parents: diff changeset	425 // Iterator for the list of discovered references.
a61af66fc99e Initial load duke parents: diff changeset	426 class DiscoveredListIterator {
a61af66fc99e Initial load duke parents: diff changeset	427 public:
a61af66fc99e Initial load duke parents: diff changeset	428 inline DiscoveredListIterator(DiscoveredList& refs_list,
a61af66fc99e Initial load duke parents: diff changeset	429 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	430 BoolObjectClosure* is_alive);
a61af66fc99e Initial load duke parents: diff changeset	431
a61af66fc99e Initial load duke parents: diff changeset	432 // End Of List.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	433 inline bool has_next() const { return _next != ReferenceProcessor::sentinel_ref(); }
0 a61af66fc99e Initial load duke parents: diff changeset	434
a61af66fc99e Initial load duke parents: diff changeset	435 // 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	436 inline oop obj() const { return _ref; }
0 a61af66fc99e Initial load duke parents: diff changeset	437
a61af66fc99e Initial load duke parents: diff changeset	438 // 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	439 inline oop referent() const { return _referent; }
0 a61af66fc99e Initial load duke parents: diff changeset	440
a61af66fc99e Initial load duke parents: diff changeset	441 // Returns true if referent is alive.
a61af66fc99e Initial load duke parents: diff changeset	442 inline bool is_referent_alive() const;
a61af66fc99e Initial load duke parents: diff changeset	443
a61af66fc99e Initial load duke parents: diff changeset	444 // Loads data for the current reference.
a61af66fc99e Initial load duke parents: diff changeset	445 // The "allow_null_referent" argument tells us to allow for the possibility
a61af66fc99e Initial load duke parents: diff changeset	446 // of a NULL referent in the discovered Reference object. This typically
a61af66fc99e Initial load duke parents: diff changeset	447 // 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	448 // discovery concurrently, or interleaved, with mutator execution.
0 a61af66fc99e Initial load duke parents: diff changeset	449 inline void load_ptrs(DEBUG_ONLY(bool allow_null_referent));
a61af66fc99e Initial load duke parents: diff changeset	450
a61af66fc99e Initial load duke parents: diff changeset	451 // Move to the next discovered reference.
a61af66fc99e Initial load duke parents: diff changeset	452 inline void next();
a61af66fc99e Initial load duke parents: diff changeset	453
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	454 // Remove the current reference from the list
0 a61af66fc99e Initial load duke parents: diff changeset	455 inline void remove();
a61af66fc99e Initial load duke parents: diff changeset	456
a61af66fc99e Initial load duke parents: diff changeset	457 // Make the Reference object active again.
a61af66fc99e Initial load duke parents: diff changeset	458 inline void make_active() { java_lang_ref_Reference::set_next(_ref, NULL); }
a61af66fc99e Initial load duke parents: diff changeset	459
a61af66fc99e Initial load duke parents: diff changeset	460 // Make the referent alive.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	461 inline void make_referent_alive() {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	462 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	463 _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	464 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	465 _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	466 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	467 }
0 a61af66fc99e Initial load duke parents: diff changeset	468
a61af66fc99e Initial load duke parents: diff changeset	469 // Update the discovered field.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	470 inline void update_discovered() {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	471 // 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	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*)_prev_next);
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*)_prev_next);
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 // NULL out referent pointer.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	480 inline void clear_referent() { oop_store_raw(_referent_addr, NULL); }
0 a61af66fc99e Initial load duke parents: diff changeset	481
a61af66fc99e Initial load duke parents: diff changeset	482 // Statistics
a61af66fc99e Initial load duke parents: diff changeset	483 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	484 inline size_t processed() const { return _processed; }
a61af66fc99e Initial load duke parents: diff changeset	485 inline size_t removed() const { return _removed; }
a61af66fc99e Initial load duke parents: diff changeset	486 )
a61af66fc99e Initial load duke parents: diff changeset	487
a61af66fc99e Initial load duke parents: diff changeset	488 inline void move_to_next();
a61af66fc99e Initial load duke parents: diff changeset	489
a61af66fc99e Initial load duke parents: diff changeset	490 private:
a61af66fc99e Initial load duke parents: diff changeset	491 DiscoveredList& _refs_list;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	492 HeapWord* _prev_next;
0 a61af66fc99e Initial load duke parents: diff changeset	493 oop _ref;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	494 HeapWord* _discovered_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	495 oop _next;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	496 HeapWord* _referent_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	497 oop _referent;
a61af66fc99e Initial load duke parents: diff changeset	498 OopClosure* _keep_alive;
a61af66fc99e Initial load duke parents: diff changeset	499 BoolObjectClosure* _is_alive;
a61af66fc99e Initial load duke parents: diff changeset	500 DEBUG_ONLY(
a61af66fc99e Initial load duke parents: diff changeset	501 oop _first_seen; // cyclic linked list check
a61af66fc99e Initial load duke parents: diff changeset	502 )
a61af66fc99e Initial load duke parents: diff changeset	503 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	504 size_t _processed;
a61af66fc99e Initial load duke parents: diff changeset	505 size_t _removed;
a61af66fc99e Initial load duke parents: diff changeset	506 )
a61af66fc99e Initial load duke parents: diff changeset	507 };
a61af66fc99e Initial load duke parents: diff changeset	508
a61af66fc99e Initial load duke parents: diff changeset	509 inline DiscoveredListIterator::DiscoveredListIterator(DiscoveredList& refs_list,
a61af66fc99e Initial load duke parents: diff changeset	510 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	511 BoolObjectClosure* is_alive)
a61af66fc99e Initial load duke parents: diff changeset	512 : _refs_list(refs_list),
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	513 _prev_next(refs_list.adr_head()),
0 a61af66fc99e Initial load duke parents: diff changeset	514 _ref(refs_list.head()),
a61af66fc99e Initial load duke parents: diff changeset	515 #ifdef ASSERT
a61af66fc99e Initial load duke parents: diff changeset	516 _first_seen(refs_list.head()),
a61af66fc99e Initial load duke parents: diff changeset	517 #endif
a61af66fc99e Initial load duke parents: diff changeset	518 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	519 _processed(0),
a61af66fc99e Initial load duke parents: diff changeset	520 _removed(0),
a61af66fc99e Initial load duke parents: diff changeset	521 #endif
a61af66fc99e Initial load duke parents: diff changeset	522 _next(refs_list.head()),
a61af66fc99e Initial load duke parents: diff changeset	523 _keep_alive(keep_alive),
a61af66fc99e Initial load duke parents: diff changeset	524 _is_alive(is_alive)
a61af66fc99e Initial load duke parents: diff changeset	525 { }
a61af66fc99e Initial load duke parents: diff changeset	526
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	527 inline bool DiscoveredListIterator::is_referent_alive() const {
0 a61af66fc99e Initial load duke parents: diff changeset	528 return _is_alive->do_object_b(_referent);
a61af66fc99e Initial load duke parents: diff changeset	529 }
a61af66fc99e Initial load duke parents: diff changeset	530
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	531 inline void DiscoveredListIterator::load_ptrs(DEBUG_ONLY(bool allow_null_referent)) {
0 a61af66fc99e Initial load duke parents: diff changeset	532 _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	533 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	534 assert(_discovered_addr && discovered->is_oop_or_null(),
0 a61af66fc99e Initial load duke parents: diff changeset	535 "discovered field is bad");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	536 _next = discovered;
0 a61af66fc99e Initial load duke parents: diff changeset	537 _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	538 _referent = java_lang_ref_Reference::referent(_ref);
0 a61af66fc99e Initial load duke parents: diff changeset	539 assert(Universe::heap()->is_in_reserved_or_null(_referent),
a61af66fc99e Initial load duke parents: diff changeset	540 "Wrong oop found in java.lang.Reference object");
a61af66fc99e Initial load duke parents: diff changeset	541 assert(allow_null_referent ?
a61af66fc99e Initial load duke parents: diff changeset	542 _referent->is_oop_or_null()
a61af66fc99e Initial load duke parents: diff changeset	543 : _referent->is_oop(),
a61af66fc99e Initial load duke parents: diff changeset	544 "bad 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::next() {
0 a61af66fc99e Initial load duke parents: diff changeset	548 _prev_next = _discovered_addr;
a61af66fc99e Initial load duke parents: diff changeset	549 move_to_next();
a61af66fc99e Initial load duke parents: diff changeset	550 }
a61af66fc99e Initial load duke parents: diff changeset	551
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	552 inline void DiscoveredListIterator::remove() {
0 a61af66fc99e Initial load duke parents: diff changeset	553 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	554 oop_store_raw(_discovered_addr, NULL);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	555 // 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	556 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	557 // Remove Reference object from list.
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	558 oopDesc::encode_store_heap_oop_not_null((narrowOop*)_prev_next, _next);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	559 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	560 // Remove Reference object from list.
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	561 oopDesc::store_heap_oop((oop*)_prev_next, _next);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	562 }
0 a61af66fc99e Initial load duke parents: diff changeset	563 NOT_PRODUCT(_removed++);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	564 _refs_list.dec_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	565 }
a61af66fc99e Initial load duke parents: diff changeset	566
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	567 inline void DiscoveredListIterator::move_to_next() {
0 a61af66fc99e Initial load duke parents: diff changeset	568 _ref = _next;
a61af66fc99e Initial load duke parents: diff changeset	569 assert(_ref != _first_seen, "cyclic ref_list found");
a61af66fc99e Initial load duke parents: diff changeset	570 NOT_PRODUCT(_processed++);
a61af66fc99e Initial load duke parents: diff changeset	571 }
a61af66fc99e Initial load duke parents: diff changeset	572
a61af66fc99e Initial load duke parents: diff changeset	573 // NOTE: process_phase*() are largely similar, and at a high level
a61af66fc99e Initial load duke parents: diff changeset	574 // merely iterate over the extant list applying a predicate to
a61af66fc99e Initial load duke parents: diff changeset	575 // each of its elements and possibly removing that element from the
a61af66fc99e Initial load duke parents: diff changeset	576 // list and applying some further closures to that element.
a61af66fc99e Initial load duke parents: diff changeset	577 // We should consider the possibility of replacing these
a61af66fc99e Initial load duke parents: diff changeset	578 // process_phase*() methods by abstracting them into
a61af66fc99e Initial load duke parents: diff changeset	579 // a single general iterator invocation that receives appropriate
a61af66fc99e Initial load duke parents: diff changeset	580 // closures that accomplish this work.
a61af66fc99e Initial load duke parents: diff changeset	581
a61af66fc99e Initial load duke parents: diff changeset	582 // (SoftReferences only) Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	583 // referents are not alive, but that should be kept alive for policy reasons.
a61af66fc99e Initial load duke parents: diff changeset	584 // Keep alive the transitive closure of all such referents.
a61af66fc99e Initial load duke parents: diff changeset	585 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	586 ReferenceProcessor::process_phase1(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	587 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	588 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	589 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	590 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	591 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	592 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	593 // Decide which softly reachable refs should be kept alive.
a61af66fc99e Initial load duke parents: diff changeset	594 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	595 iter.load_ptrs(DEBUG_ONLY(!discovery_is_atomic() /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	596 bool referent_is_dead = (iter.referent() != NULL) && !iter.is_referent_alive();
a61af66fc99e Initial load duke parents: diff changeset	597 if (referent_is_dead && !policy->should_clear_reference(iter.obj())) {
a61af66fc99e Initial load duke parents: diff changeset	598 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	599 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	600 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	601 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	602 // Remove Reference object from list
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	603 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	604 // Make the Reference object active again
a61af66fc99e Initial load duke parents: diff changeset	605 iter.make_active();
a61af66fc99e Initial load duke parents: diff changeset	606 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	607 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	608 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	609 } else {
a61af66fc99e Initial load duke parents: diff changeset	610 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	611 }
a61af66fc99e Initial load duke parents: diff changeset	612 }
a61af66fc99e Initial load duke parents: diff changeset	613 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	614 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	615 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	616 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	617 gclog_or_tty->print(" Dropped %d dead Refs out of %d "
a61af66fc99e Initial load duke parents: diff changeset	618 "discovered Refs by policy ", iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	619 }
a61af66fc99e Initial load duke parents: diff changeset	620 )
a61af66fc99e Initial load duke parents: diff changeset	621 }
a61af66fc99e Initial load duke parents: diff changeset	622
a61af66fc99e Initial load duke parents: diff changeset	623 // Traverse the list and remove any Refs that are not active, or
a61af66fc99e Initial load duke parents: diff changeset	624 // whose referents are either alive or NULL.
a61af66fc99e Initial load duke parents: diff changeset	625 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	626 ReferenceProcessor::pp2_work(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	627 BoolObjectClosure* is_alive,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	628 OopClosure* keep_alive) {
0 a61af66fc99e Initial load duke parents: diff changeset	629 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	630 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	631 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	632 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	633 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	634 assert(next == NULL, "Should not discover inactive Reference");
0 a61af66fc99e Initial load duke parents: diff changeset	635 if (iter.is_referent_alive()) {
a61af66fc99e Initial load duke parents: diff changeset	636 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	637 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	638 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	639 }
a61af66fc99e Initial load duke parents: diff changeset	640 // The referent is reachable after all.
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	641 // Remove Reference object from list.
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	642 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	643 // Update the referent pointer as necessary: Note that this
a61af66fc99e Initial load duke parents: diff changeset	644 // should not entail any recursive marking because the
a61af66fc99e Initial load duke parents: diff changeset	645 // referent must already have been traversed.
a61af66fc99e Initial load duke parents: diff changeset	646 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	647 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	648 } else {
a61af66fc99e Initial load duke parents: diff changeset	649 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	650 }
a61af66fc99e Initial load duke parents: diff changeset	651 }
a61af66fc99e Initial load duke parents: diff changeset	652 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	653 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	654 gclog_or_tty->print(" Dropped %d active Refs out of %d "
a61af66fc99e Initial load duke parents: diff changeset	655 "Refs in discovered list ", iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	656 }
a61af66fc99e Initial load duke parents: diff changeset	657 )
a61af66fc99e Initial load duke parents: diff changeset	658 }
a61af66fc99e Initial load duke parents: diff changeset	659
a61af66fc99e Initial load duke parents: diff changeset	660 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	661 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	662 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	663 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	664 VoidClosure* complete_gc) {
0 a61af66fc99e Initial load duke parents: diff changeset	665 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	666 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	667 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	668 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	669 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	670 oop next = java_lang_ref_Reference::next(iter.obj());
0 a61af66fc99e Initial load duke parents: diff changeset	671 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	672 next != NULL)) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	673 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	674 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	675 iter.remove();
a61af66fc99e Initial load duke parents: diff changeset	676 // Trace the cohorts
a61af66fc99e Initial load duke parents: diff changeset	677 iter.make_referent_alive();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	678 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	679 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	680 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	681 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	682 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	683 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	684 } else {
a61af66fc99e Initial load duke parents: diff changeset	685 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	686 }
a61af66fc99e Initial load duke parents: diff changeset	687 }
a61af66fc99e Initial load duke parents: diff changeset	688 // Now close the newly reachable set
a61af66fc99e Initial load duke parents: diff changeset	689 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	690 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	691 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	692 gclog_or_tty->print(" Dropped %d active Refs out of %d "
a61af66fc99e Initial load duke parents: diff changeset	693 "Refs in discovered list ", iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	694 }
a61af66fc99e Initial load duke parents: diff changeset	695 )
a61af66fc99e Initial load duke parents: diff changeset	696 }
a61af66fc99e Initial load duke parents: diff changeset	697
a61af66fc99e Initial load duke parents: diff changeset	698 // 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	699 // clearing them or keeping them (and their reachable
0 a61af66fc99e Initial load duke parents: diff changeset	700 // closure) alive.
a61af66fc99e Initial load duke parents: diff changeset	701 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	702 ReferenceProcessor::process_phase3(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	703 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	704 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	705 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	706 VoidClosure* complete_gc) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	707 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	708 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	709 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	710 iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	711 if (clear_referent) {
a61af66fc99e Initial load duke parents: diff changeset	712 // NULL out referent pointer
a61af66fc99e Initial load duke parents: diff changeset	713 iter.clear_referent();
a61af66fc99e Initial load duke parents: diff changeset	714 } else {
a61af66fc99e Initial load duke parents: diff changeset	715 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	716 iter.make_referent_alive();
a61af66fc99e Initial load duke parents: diff changeset	717 }
a61af66fc99e Initial load duke parents: diff changeset	718 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	719 gclog_or_tty->print_cr("Adding %sreference (" INTPTR_FORMAT ": %s) as pending",
a61af66fc99e Initial load duke parents: diff changeset	720 clear_referent ? "cleared " : "",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	721 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	722 }
a61af66fc99e Initial load duke parents: diff changeset	723 assert(iter.obj()->is_oop(UseConcMarkSweepGC), "Adding a bad reference");
a61af66fc99e Initial load duke parents: diff changeset	724 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	725 }
a61af66fc99e Initial load duke parents: diff changeset	726 // Remember to keep sentinel pointer around
a61af66fc99e Initial load duke parents: diff changeset	727 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	728 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	729 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	730 }
a61af66fc99e Initial load duke parents: diff changeset	731
a61af66fc99e Initial load duke parents: diff changeset	732 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	733 ReferenceProcessor::abandon_partial_discovered_list(DiscoveredList& refs_list) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	734 oop obj = refs_list.head();
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	735 while (obj != sentinel_ref()) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	736 oop discovered = java_lang_ref_Reference::discovered(obj);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	737 java_lang_ref_Reference::set_discovered_raw(obj, NULL);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	738 obj = discovered;
0 a61af66fc99e Initial load duke parents: diff changeset	739 }
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	740 refs_list.set_head(sentinel_ref());
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	741 refs_list.set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	742 }
a61af66fc99e Initial load duke parents: diff changeset	743
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	744 void ReferenceProcessor::abandon_partial_discovery() {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	745 // loop over the lists
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	746 for (int i = 0; i < _num_q * subclasses_of_ref; i++) {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	747 if (TraceReferenceGC && PrintGCDetails && ((i % _num_q) == 0)) {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	748 gclog_or_tty->print_cr(
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	749 "\nAbandoning %s discovered list",
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	750 list_name(i));
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	751 }
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	752 abandon_partial_discovered_list(_discoveredSoftRefs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	753 }
a61af66fc99e Initial load duke parents: diff changeset	754 }
a61af66fc99e Initial load duke parents: diff changeset	755
a61af66fc99e Initial load duke parents: diff changeset	756 class RefProcPhase1Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	757 public:
a61af66fc99e Initial load duke parents: diff changeset	758 RefProcPhase1Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	759 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	760 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	761 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	762 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	763 _policy(policy)
a61af66fc99e Initial load duke parents: diff changeset	764 { }
a61af66fc99e Initial load duke parents: diff changeset	765 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	766 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	767 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	768 {
a61af66fc99e Initial load duke parents: diff changeset	769 _ref_processor.process_phase1(_refs_lists[i], _policy,
a61af66fc99e Initial load duke parents: diff changeset	770 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	771 }
a61af66fc99e Initial load duke parents: diff changeset	772 private:
a61af66fc99e Initial load duke parents: diff changeset	773 ReferencePolicy* _policy;
a61af66fc99e Initial load duke parents: diff changeset	774 };
a61af66fc99e Initial load duke parents: diff changeset	775
a61af66fc99e Initial load duke parents: diff changeset	776 class RefProcPhase2Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	777 public:
a61af66fc99e Initial load duke parents: diff changeset	778 RefProcPhase2Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	779 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	780 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	781 : ProcessTask(ref_processor, refs_lists, marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	782 { }
a61af66fc99e Initial load duke parents: diff changeset	783 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	784 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	785 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	786 {
a61af66fc99e Initial load duke parents: diff changeset	787 _ref_processor.process_phase2(_refs_lists[i],
a61af66fc99e Initial load duke parents: diff changeset	788 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	789 }
a61af66fc99e Initial load duke parents: diff changeset	790 };
a61af66fc99e Initial load duke parents: diff changeset	791
a61af66fc99e Initial load duke parents: diff changeset	792 class RefProcPhase3Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	793 public:
a61af66fc99e Initial load duke parents: diff changeset	794 RefProcPhase3Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	795 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	796 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	797 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	798 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	799 _clear_referent(clear_referent)
a61af66fc99e Initial load duke parents: diff changeset	800 { }
a61af66fc99e Initial load duke parents: diff changeset	801 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	802 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	803 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	804 {
a61af66fc99e Initial load duke parents: diff changeset	805 _ref_processor.process_phase3(_refs_lists[i], _clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	806 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	807 }
a61af66fc99e Initial load duke parents: diff changeset	808 private:
a61af66fc99e Initial load duke parents: diff changeset	809 bool _clear_referent;
a61af66fc99e Initial load duke parents: diff changeset	810 };
a61af66fc99e Initial load duke parents: diff changeset	811
a61af66fc99e Initial load duke parents: diff changeset	812 // Balances reference queues.
a61af66fc99e Initial load duke parents: diff changeset	813 void ReferenceProcessor::balance_queues(DiscoveredList ref_lists[])
a61af66fc99e Initial load duke parents: diff changeset	814 {
a61af66fc99e Initial load duke parents: diff changeset	815 // calculate total length
a61af66fc99e Initial load duke parents: diff changeset	816 size_t total_refs = 0;
a61af66fc99e Initial load duke parents: diff changeset	817 for (int i = 0; i < _num_q; ++i) {
a61af66fc99e Initial load duke parents: diff changeset	818 total_refs += ref_lists[i].length();
a61af66fc99e Initial load duke parents: diff changeset	819 }
a61af66fc99e Initial load duke parents: diff changeset	820 size_t avg_refs = total_refs / _num_q + 1;
a61af66fc99e Initial load duke parents: diff changeset	821 int to_idx = 0;
a61af66fc99e Initial load duke parents: diff changeset	822 for (int from_idx = 0; from_idx < _num_q; from_idx++) {
a61af66fc99e Initial load duke parents: diff changeset	823 while (ref_lists[from_idx].length() > avg_refs) {
a61af66fc99e Initial load duke parents: diff changeset	824 assert(to_idx < _num_q, "Sanity Check!");
a61af66fc99e Initial load duke parents: diff changeset	825 if (ref_lists[to_idx].length() < avg_refs) {
a61af66fc99e Initial load duke parents: diff changeset	826 // move superfluous refs
a61af66fc99e Initial load duke parents: diff changeset	827 size_t refs_to_move =
a61af66fc99e Initial load duke parents: diff changeset	828 MIN2(ref_lists[from_idx].length() - avg_refs,
a61af66fc99e Initial load duke parents: diff changeset	829 avg_refs - ref_lists[to_idx].length());
a61af66fc99e Initial load duke parents: diff changeset	830 oop move_head = ref_lists[from_idx].head();
a61af66fc99e Initial load duke parents: diff changeset	831 oop move_tail = move_head;
a61af66fc99e Initial load duke parents: diff changeset	832 oop new_head = move_head;
a61af66fc99e Initial load duke parents: diff changeset	833 // find an element to split the list on
a61af66fc99e Initial load duke parents: diff changeset	834 for (size_t j = 0; j < refs_to_move; ++j) {
a61af66fc99e Initial load duke parents: diff changeset	835 move_tail = new_head;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	836 new_head = java_lang_ref_Reference::discovered(new_head);
0 a61af66fc99e Initial load duke parents: diff changeset	837 }
a61af66fc99e Initial load duke parents: diff changeset	838 java_lang_ref_Reference::set_discovered(move_tail, ref_lists[to_idx].head());
a61af66fc99e Initial load duke parents: diff changeset	839 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	840 ref_lists[to_idx].inc_length(refs_to_move);
0 a61af66fc99e Initial load duke parents: diff changeset	841 ref_lists[from_idx].set_head(new_head);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	842 ref_lists[from_idx].dec_length(refs_to_move);
0 a61af66fc99e Initial load duke parents: diff changeset	843 } else {
a61af66fc99e Initial load duke parents: diff changeset	844 ++to_idx;
a61af66fc99e Initial load duke parents: diff changeset	845 }
a61af66fc99e Initial load duke parents: diff changeset	846 }
a61af66fc99e Initial load duke parents: diff changeset	847 }
a61af66fc99e Initial load duke parents: diff changeset	848 }
a61af66fc99e Initial load duke parents: diff changeset	849
a61af66fc99e Initial load duke parents: diff changeset	850 void
a61af66fc99e Initial load duke parents: diff changeset	851 ReferenceProcessor::process_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	852 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	853 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	854 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	855 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	856 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	857 VoidClosure* complete_gc,
a61af66fc99e Initial load duke parents: diff changeset	858 AbstractRefProcTaskExecutor* task_executor)
a61af66fc99e Initial load duke parents: diff changeset	859 {
a61af66fc99e Initial load duke parents: diff changeset	860 bool mt = task_executor != NULL && _processing_is_mt;
a61af66fc99e Initial load duke parents: diff changeset	861 if (mt && ParallelRefProcBalancingEnabled) {
a61af66fc99e Initial load duke parents: diff changeset	862 balance_queues(refs_lists);
a61af66fc99e Initial load duke parents: diff changeset	863 }
a61af66fc99e Initial load duke parents: diff changeset	864 if (PrintReferenceGC && PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	865 size_t total = 0;
a61af66fc99e Initial load duke parents: diff changeset	866 for (int i = 0; i < _num_q; ++i) {
a61af66fc99e Initial load duke parents: diff changeset	867 total += refs_lists[i].length();
a61af66fc99e Initial load duke parents: diff changeset	868 }
a61af66fc99e Initial load duke parents: diff changeset	869 gclog_or_tty->print(", %u refs", total);
a61af66fc99e Initial load duke parents: diff changeset	870 }
a61af66fc99e Initial load duke parents: diff changeset	871
a61af66fc99e Initial load duke parents: diff changeset	872 // Phase 1 (soft refs only):
a61af66fc99e Initial load duke parents: diff changeset	873 // . Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	874 // referents are not alive, but that should be kept alive for
a61af66fc99e Initial load duke parents: diff changeset	875 // policy reasons. Keep alive the transitive closure of all
a61af66fc99e Initial load duke parents: diff changeset	876 // such referents.
a61af66fc99e Initial load duke parents: diff changeset	877 if (policy != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	878 if (mt) {
a61af66fc99e Initial load duke parents: diff changeset	879 RefProcPhase1Task phase1(this, refs_lists, policy, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	880 task_executor->execute(phase1);
a61af66fc99e Initial load duke parents: diff changeset	881 } else {
a61af66fc99e Initial load duke parents: diff changeset	882 for (int i = 0; i < _num_q; i++) {
a61af66fc99e Initial load duke parents: diff changeset	883 process_phase1(refs_lists[i], policy,
a61af66fc99e Initial load duke parents: diff changeset	884 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	885 }
a61af66fc99e Initial load duke parents: diff changeset	886 }
a61af66fc99e Initial load duke parents: diff changeset	887 } else { // policy == NULL
a61af66fc99e Initial load duke parents: diff changeset	888 assert(refs_lists != _discoveredSoftRefs,
a61af66fc99e Initial load duke parents: diff changeset	889 "Policy must be specified for soft references.");
a61af66fc99e Initial load duke parents: diff changeset	890 }
a61af66fc99e Initial load duke parents: diff changeset	891
a61af66fc99e Initial load duke parents: diff changeset	892 // Phase 2:
a61af66fc99e Initial load duke parents: diff changeset	893 // . Traverse the list and remove any refs whose referents are alive.
a61af66fc99e Initial load duke parents: diff changeset	894 if (mt) {
a61af66fc99e Initial load duke parents: diff changeset	895 RefProcPhase2Task phase2(this, refs_lists, !discovery_is_atomic() /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	896 task_executor->execute(phase2);
a61af66fc99e Initial load duke parents: diff changeset	897 } else {
a61af66fc99e Initial load duke parents: diff changeset	898 for (int i = 0; i < _num_q; i++) {
a61af66fc99e Initial load duke parents: diff changeset	899 process_phase2(refs_lists[i], is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	900 }
a61af66fc99e Initial load duke parents: diff changeset	901 }
a61af66fc99e Initial load duke parents: diff changeset	902
a61af66fc99e Initial load duke parents: diff changeset	903 // Phase 3:
a61af66fc99e Initial load duke parents: diff changeset	904 // . Traverse the list and process referents as appropriate.
a61af66fc99e Initial load duke parents: diff changeset	905 if (mt) {
a61af66fc99e Initial load duke parents: diff changeset	906 RefProcPhase3Task phase3(this, refs_lists, clear_referent, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	907 task_executor->execute(phase3);
a61af66fc99e Initial load duke parents: diff changeset	908 } else {
a61af66fc99e Initial load duke parents: diff changeset	909 for (int i = 0; i < _num_q; i++) {
a61af66fc99e Initial load duke parents: diff changeset	910 process_phase3(refs_lists[i], clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	911 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	912 }
a61af66fc99e Initial load duke parents: diff changeset	913 }
a61af66fc99e Initial load duke parents: diff changeset	914 }
a61af66fc99e Initial load duke parents: diff changeset	915
a61af66fc99e Initial load duke parents: diff changeset	916 void ReferenceProcessor::clean_up_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	917 // loop over the lists
a61af66fc99e Initial load duke parents: diff changeset	918 for (int i = 0; i < _num_q * subclasses_of_ref; i++) {
a61af66fc99e Initial load duke parents: diff changeset	919 if (TraceReferenceGC && PrintGCDetails && ((i % _num_q) == 0)) {
a61af66fc99e Initial load duke parents: diff changeset	920 gclog_or_tty->print_cr(
a61af66fc99e Initial load duke parents: diff changeset	921 "\nScrubbing %s discovered list of Null referents",
a61af66fc99e Initial load duke parents: diff changeset	922 list_name(i));
a61af66fc99e Initial load duke parents: diff changeset	923 }
a61af66fc99e Initial load duke parents: diff changeset	924 clean_up_discovered_reflist(_discoveredSoftRefs[i]);
a61af66fc99e Initial load duke parents: diff changeset	925 }
a61af66fc99e Initial load duke parents: diff changeset	926 }
a61af66fc99e Initial load duke parents: diff changeset	927
a61af66fc99e Initial load duke parents: diff changeset	928 void ReferenceProcessor::clean_up_discovered_reflist(DiscoveredList& refs_list) {
a61af66fc99e Initial load duke parents: diff changeset	929 assert(!discovery_is_atomic(), "Else why call this method?");
a61af66fc99e Initial load duke parents: diff changeset	930 DiscoveredListIterator iter(refs_list, NULL, NULL);
a61af66fc99e Initial load duke parents: diff changeset	931 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	932 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	933 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	934 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	935 // If referent has been cleared or Reference is not active,
a61af66fc99e Initial load duke parents: diff changeset	936 // drop it.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	937 if (iter.referent() == NULL \|\| next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	938 debug_only(
a61af66fc99e Initial load duke parents: diff changeset	939 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	940 gclog_or_tty->print_cr("clean_up_discovered_list: Dropping Reference: "
a61af66fc99e Initial load duke parents: diff changeset	941 INTPTR_FORMAT " with next field: " INTPTR_FORMAT
a61af66fc99e Initial load duke parents: diff changeset	942 " and referent: " INTPTR_FORMAT,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	943 iter.obj(), next, iter.referent());
0 a61af66fc99e Initial load duke parents: diff changeset	944 }
a61af66fc99e Initial load duke parents: diff changeset	945 )
a61af66fc99e Initial load duke parents: diff changeset	946 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	947 iter.remove();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	948 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	949 } else {
a61af66fc99e Initial load duke parents: diff changeset	950 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	951 }
a61af66fc99e Initial load duke parents: diff changeset	952 }
a61af66fc99e Initial load duke parents: diff changeset	953 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	954 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	955 gclog_or_tty->print(
a61af66fc99e Initial load duke parents: diff changeset	956 " Removed %d Refs with NULL referents out of %d discovered Refs",
a61af66fc99e Initial load duke parents: diff changeset	957 iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	958 }
a61af66fc99e Initial load duke parents: diff changeset	959 )
a61af66fc99e Initial load duke parents: diff changeset	960 }
a61af66fc99e Initial load duke parents: diff changeset	961
a61af66fc99e Initial load duke parents: diff changeset	962 inline DiscoveredList* ReferenceProcessor::get_discovered_list(ReferenceType rt) {
a61af66fc99e Initial load duke parents: diff changeset	963 int id = 0;
a61af66fc99e Initial load duke parents: diff changeset	964 // Determine the queue index to use for this object.
a61af66fc99e Initial load duke parents: diff changeset	965 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	966 // During a multi-threaded discovery phase,
a61af66fc99e Initial load duke parents: diff changeset	967 // each thread saves to its "own" list.
a61af66fc99e Initial load duke parents: diff changeset	968 Thread* thr = Thread::current();
a61af66fc99e Initial load duke parents: diff changeset	969 assert(thr->is_GC_task_thread(),
a61af66fc99e Initial load duke parents: diff changeset	970 "Dubious cast from Thread* to WorkerThread*?");
a61af66fc99e Initial load duke parents: diff changeset	971 id = ((WorkerThread*)thr)->id();
a61af66fc99e Initial load duke parents: diff changeset	972 } else {
a61af66fc99e Initial load duke parents: diff changeset	973 // single-threaded discovery, we save in round-robin
a61af66fc99e Initial load duke parents: diff changeset	974 // fashion to each of the lists.
a61af66fc99e Initial load duke parents: diff changeset	975 if (_processing_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	976 id = next_id();
a61af66fc99e Initial load duke parents: diff changeset	977 }
a61af66fc99e Initial load duke parents: diff changeset	978 }
a61af66fc99e Initial load duke parents: diff changeset	979 assert(0 <= id && id < _num_q, "Id is out-of-bounds (call Freud?)");
a61af66fc99e Initial load duke parents: diff changeset	980
a61af66fc99e Initial load duke parents: diff changeset	981 // Get the discovered queue to which we will add
a61af66fc99e Initial load duke parents: diff changeset	982 DiscoveredList* list = NULL;
a61af66fc99e Initial load duke parents: diff changeset	983 switch (rt) {
a61af66fc99e Initial load duke parents: diff changeset	984 case REF_OTHER:
a61af66fc99e Initial load duke parents: diff changeset	985 // Unknown reference type, no special treatment
a61af66fc99e Initial load duke parents: diff changeset	986 break;
a61af66fc99e Initial load duke parents: diff changeset	987 case REF_SOFT:
a61af66fc99e Initial load duke parents: diff changeset	988 list = &_discoveredSoftRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	989 break;
a61af66fc99e Initial load duke parents: diff changeset	990 case REF_WEAK:
a61af66fc99e Initial load duke parents: diff changeset	991 list = &_discoveredWeakRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	992 break;
a61af66fc99e Initial load duke parents: diff changeset	993 case REF_FINAL:
a61af66fc99e Initial load duke parents: diff changeset	994 list = &_discoveredFinalRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	995 break;
a61af66fc99e Initial load duke parents: diff changeset	996 case REF_PHANTOM:
a61af66fc99e Initial load duke parents: diff changeset	997 list = &_discoveredPhantomRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	998 break;
a61af66fc99e Initial load duke parents: diff changeset	999 case REF_NONE:
a61af66fc99e Initial load duke parents: diff changeset	1000 // we should not reach here if we are an instanceRefKlass
a61af66fc99e Initial load duke parents: diff changeset	1001 default:
a61af66fc99e Initial load duke parents: diff changeset	1002 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1003 }
a61af66fc99e Initial load duke parents: diff changeset	1004 return list;
a61af66fc99e Initial load duke parents: diff changeset	1005 }
a61af66fc99e Initial load duke parents: diff changeset	1006
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1007 inline void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1008 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	1009 oop obj,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1010 HeapWord* discovered_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	1011 assert(_discovery_is_mt, "!_discovery_is_mt should have been handled by caller");
a61af66fc99e Initial load duke parents: diff changeset	1012 // First we must make sure this object is only enqueued once. CAS in a non null
a61af66fc99e Initial load duke parents: diff changeset	1013 // discovered_addr.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1014 oop current_head = refs_list.head();
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1015
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1016 // 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	1017 // 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	1018 // 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	1019 // 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	1020 // elided this out for G1, but left in the test for some future
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1021 // collector that might have need for a pre-barrier here.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1022 if (_discovered_list_needs_barrier && !UseG1GC) {
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1023 if (UseCompressedOops) {
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1024 _bs->write_ref_field_pre((narrowOop*)discovered_addr, current_head);
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1025 } else {
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1026 _bs->write_ref_field_pre((oop*)discovered_addr, current_head);
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1027 }
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1028 guarantee(false, "Need to check non-G1 collector");
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1029 }
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1030 oop retest = oopDesc::atomic_compare_exchange_oop(current_head, discovered_addr,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1031 NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	1032 if (retest == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1033 // This thread just won the right to enqueue the object.
a61af66fc99e Initial load duke parents: diff changeset	1034 // We have separate lists for enqueueing so no synchronization
a61af66fc99e Initial load duke parents: diff changeset	1035 // is necessary.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1036 refs_list.set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1037 refs_list.inc_length(1);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1038 if (_discovered_list_needs_barrier) {
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1039 _bs->write_ref_field((void*)discovered_addr, current_head);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1040 }
0 a61af66fc99e Initial load duke parents: diff changeset	1041 } else {
a61af66fc99e Initial load duke parents: diff changeset	1042 // If retest was non NULL, another thread beat us to it:
a61af66fc99e Initial load duke parents: diff changeset	1043 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1044 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1045 gclog_or_tty->print_cr("Already enqueued reference (" INTPTR_FORMAT ": %s)",
a61af66fc99e Initial load duke parents: diff changeset	1046 obj, obj->blueprint()->internal_name());
a61af66fc99e Initial load duke parents: diff changeset	1047 }
a61af66fc99e Initial load duke parents: diff changeset	1048 }
a61af66fc99e Initial load duke parents: diff changeset	1049 }
a61af66fc99e Initial load duke parents: diff changeset	1050
a61af66fc99e Initial load duke parents: diff changeset	1051 // We mention two of several possible choices here:
a61af66fc99e Initial load duke parents: diff changeset	1052 // #0: if the reference object is not in the "originating generation"
a61af66fc99e Initial load duke parents: diff changeset	1053 // (or part of the heap being collected, indicated by our "span"
a61af66fc99e Initial load duke parents: diff changeset	1054 // we don't treat it specially (i.e. we scan it as we would
a61af66fc99e Initial load duke parents: diff changeset	1055 // a normal oop, treating its references as strong references).
a61af66fc99e Initial load duke parents: diff changeset	1056 // This means that references can't be enqueued unless their
a61af66fc99e Initial load duke parents: diff changeset	1057 // referent is also in the same span. This is the simplest,
a61af66fc99e Initial load duke parents: diff changeset	1058 // most "local" and most conservative approach, albeit one
a61af66fc99e Initial load duke parents: diff changeset	1059 // that may cause weak references to be enqueued least promptly.
a61af66fc99e Initial load duke parents: diff changeset	1060 // We call this choice the "ReferenceBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1061 // #1: the reference object may be in any generation (span), but if
a61af66fc99e Initial load duke parents: diff changeset	1062 // the referent is in the generation (span) being currently collected
a61af66fc99e Initial load duke parents: diff changeset	1063 // then we can discover the reference object, provided
a61af66fc99e Initial load duke parents: diff changeset	1064 // the object has not already been discovered by
a61af66fc99e Initial load duke parents: diff changeset	1065 // a different concurrently running collector (as may be the
a61af66fc99e Initial load duke parents: diff changeset	1066 // case, for instance, if the reference object is in CMS and
a61af66fc99e Initial load duke parents: diff changeset	1067 // the referent in DefNewGeneration), and provided the processing
a61af66fc99e Initial load duke parents: diff changeset	1068 // of this reference object by the current collector will
a61af66fc99e Initial load duke parents: diff changeset	1069 // appear atomic to every other collector in the system.
a61af66fc99e Initial load duke parents: diff changeset	1070 // (Thus, for instance, a concurrent collector may not
a61af66fc99e Initial load duke parents: diff changeset	1071 // discover references in other generations even if the
a61af66fc99e Initial load duke parents: diff changeset	1072 // referent is in its own generation). This policy may,
a61af66fc99e Initial load duke parents: diff changeset	1073 // in certain cases, enqueue references somewhat sooner than
a61af66fc99e Initial load duke parents: diff changeset	1074 // might Policy #0 above, but at marginally increased cost
a61af66fc99e Initial load duke parents: diff changeset	1075 // and complexity in processing these references.
a61af66fc99e Initial load duke parents: diff changeset	1076 // We call this choice the "RefeferentBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1077 bool ReferenceProcessor::discover_reference(oop obj, ReferenceType rt) {
a61af66fc99e Initial load duke parents: diff changeset	1078 // We enqueue references only if we are discovering refs
a61af66fc99e Initial load duke parents: diff changeset	1079 // (rather than processing discovered refs).
a61af66fc99e Initial load duke parents: diff changeset	1080 if (!_discovering_refs \|\| !RegisterReferences) {
a61af66fc99e Initial load duke parents: diff changeset	1081 return false;
a61af66fc99e Initial load duke parents: diff changeset	1082 }
a61af66fc99e Initial load duke parents: diff changeset	1083 // We only enqueue active references.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1084 oop next = java_lang_ref_Reference::next(obj);
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1085 if (next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1086 return false;
a61af66fc99e Initial load duke parents: diff changeset	1087 }
a61af66fc99e Initial load duke parents: diff changeset	1088
a61af66fc99e Initial load duke parents: diff changeset	1089 HeapWord* obj_addr = (HeapWord*)obj;
a61af66fc99e Initial load duke parents: diff changeset	1090 if (RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1091 !_span.contains(obj_addr)) {
a61af66fc99e Initial load duke parents: diff changeset	1092 // Reference is not in the originating generation;
a61af66fc99e Initial load duke parents: diff changeset	1093 // don't treat it specially (i.e. we want to scan it as a normal
a61af66fc99e Initial load duke parents: diff changeset	1094 // object with strong references).
a61af66fc99e Initial load duke parents: diff changeset	1095 return false;
a61af66fc99e Initial load duke parents: diff changeset	1096 }
a61af66fc99e Initial load duke parents: diff changeset	1097
a61af66fc99e Initial load duke parents: diff changeset	1098 // We only enqueue references whose referents are not (yet) strongly
a61af66fc99e Initial load duke parents: diff changeset	1099 // reachable.
a61af66fc99e Initial load duke parents: diff changeset	1100 if (is_alive_non_header() != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1101 oop referent = java_lang_ref_Reference::referent(obj);
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1102 // In the case of non-concurrent discovery, the last
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1103 // disjunct below should hold. It may not hold in the
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1104 // case of concurrent discovery because mutators may
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1105 // concurrently clear() a Reference.
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1106 assert(UseConcMarkSweepGC \|\| UseG1GC \|\| referent != NULL,
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1107 "Refs with null referents already filtered");
0 a61af66fc99e Initial load duke parents: diff changeset	1108 if (is_alive_non_header()->do_object_b(referent)) {
a61af66fc99e Initial load duke parents: diff changeset	1109 return false; // referent is reachable
a61af66fc99e Initial load duke parents: diff changeset	1110 }
a61af66fc99e Initial load duke parents: diff changeset	1111 }
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1112 if (rt == REF_SOFT) {
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1113 // 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	1114 // current candidates for clearing, in which case we
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1115 // can mark through them now, rather than delaying that
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1116 // to the reference-processing phase. Since all current
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1117 // time-stamp policies advance the soft-ref clock only
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1118 // at a major collection cycle, this is always currently
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1119 // accurate.
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1120 if (!_current_soft_ref_policy->should_clear_reference(obj)) {
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1121 return false;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1122 }
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1123 }
0 a61af66fc99e Initial load duke parents: diff changeset	1124
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1125 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	1126 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	1127 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	1128 if (discovered != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1129 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1130 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1131 gclog_or_tty->print_cr("Already enqueued reference (" INTPTR_FORMAT ": %s)",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1132 obj, obj->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1133 }
a61af66fc99e Initial load duke parents: diff changeset	1134 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
a61af66fc99e Initial load duke parents: diff changeset	1135 // assumes that an object is not processed twice;
a61af66fc99e Initial load duke parents: diff changeset	1136 // if it's been already discovered it must be on another
a61af66fc99e Initial load duke parents: diff changeset	1137 // generation's discovered list; so we won't discover it.
a61af66fc99e Initial load duke parents: diff changeset	1138 return false;
a61af66fc99e Initial load duke parents: diff changeset	1139 } else {
a61af66fc99e Initial load duke parents: diff changeset	1140 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	1141 "Unrecognized policy");
a61af66fc99e Initial load duke parents: diff changeset	1142 // Check assumption that an object is not potentially
a61af66fc99e Initial load duke parents: diff changeset	1143 // discovered twice except by concurrent collectors that potentially
a61af66fc99e Initial load duke parents: diff changeset	1144 // trace the same Reference object twice.
a61af66fc99e Initial load duke parents: diff changeset	1145 assert(UseConcMarkSweepGC,
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1146 "Only possible with an incremental-update concurrent collector");
0 a61af66fc99e Initial load duke parents: diff changeset	1147 return true;
a61af66fc99e Initial load duke parents: diff changeset	1148 }
a61af66fc99e Initial load duke parents: diff changeset	1149 }
a61af66fc99e Initial load duke parents: diff changeset	1150
a61af66fc99e Initial load duke parents: diff changeset	1151 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
a61af66fc99e Initial load duke parents: diff changeset	1152 oop referent = java_lang_ref_Reference::referent(obj);
a61af66fc99e Initial load duke parents: diff changeset	1153 assert(referent->is_oop(), "bad referent");
a61af66fc99e Initial load duke parents: diff changeset	1154 // enqueue if and only if either:
a61af66fc99e Initial load duke parents: diff changeset	1155 // reference is in our span or
a61af66fc99e Initial load duke parents: diff changeset	1156 // we are an atomic collector and referent is in our span
a61af66fc99e Initial load duke parents: diff changeset	1157 if (_span.contains(obj_addr) \|\|
a61af66fc99e Initial load duke parents: diff changeset	1158 (discovery_is_atomic() && _span.contains(referent))) {
a61af66fc99e Initial load duke parents: diff changeset	1159 // should_enqueue = true;
a61af66fc99e Initial load duke parents: diff changeset	1160 } else {
a61af66fc99e Initial load duke parents: diff changeset	1161 return false;
a61af66fc99e Initial load duke parents: diff changeset	1162 }
a61af66fc99e Initial load duke parents: diff changeset	1163 } else {
a61af66fc99e Initial load duke parents: diff changeset	1164 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1165 _span.contains(obj_addr), "code inconsistency");
a61af66fc99e Initial load duke parents: diff changeset	1166 }
a61af66fc99e Initial load duke parents: diff changeset	1167
a61af66fc99e Initial load duke parents: diff changeset	1168 // Get the right type of discovered queue head.
a61af66fc99e Initial load duke parents: diff changeset	1169 DiscoveredList* list = get_discovered_list(rt);
a61af66fc99e Initial load duke parents: diff changeset	1170 if (list == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1171 return false; // nothing special needs to be done
a61af66fc99e Initial load duke parents: diff changeset	1172 }
a61af66fc99e Initial load duke parents: diff changeset	1173
a61af66fc99e Initial load duke parents: diff changeset	1174 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1175 add_to_discovered_list_mt(*list, obj, discovered_addr);
a61af66fc99e Initial load duke parents: diff changeset	1176 } else {
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1177 // If "_discovered_list_needs_barrier", we do write barriers when
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1178 // 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	1179 // 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	1180 // references.
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1181 oop current_head = list->head();
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1182 // 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	1183 // pre-value, we can safely elide the pre-barrier here for the case of G1.
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1184 assert(discovered == NULL, "control point invariant");
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1185 if (_discovered_list_needs_barrier && !UseG1GC) { // safe to elide for G1
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1186 if (UseCompressedOops) {
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1187 _bs->write_ref_field_pre((narrowOop*)discovered_addr, current_head);
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1188 } else {
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1189 _bs->write_ref_field_pre((oop*)discovered_addr, current_head);
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1190 }
df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1191 guarantee(false, "Need to check non-G1 collector");
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1192 }
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1193 oop_store_raw(discovered_addr, current_head);
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1194 if (_discovered_list_needs_barrier) {
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1195 _bs->write_ref_field((void*)discovered_addr, current_head);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1196 }
0 a61af66fc99e Initial load duke parents: diff changeset	1197 list->set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1198 list->inc_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	1199 }
a61af66fc99e Initial load duke parents: diff changeset	1200
a61af66fc99e Initial load duke parents: diff changeset	1201 // In the MT discovery case, it is currently possible to see
a61af66fc99e Initial load duke parents: diff changeset	1202 // the following message multiple times if several threads
a61af66fc99e Initial load duke parents: diff changeset	1203 // discover a reference about the same time. Only one will
a61af66fc99e Initial load duke parents: diff changeset	1204 // however have actually added it to the disocvered queue.
a61af66fc99e Initial load duke parents: diff changeset	1205 // One could let add_to_discovered_list_mt() return an
a61af66fc99e Initial load duke parents: diff changeset	1206 // indication for success in queueing (by 1 thread) or
a61af66fc99e Initial load duke parents: diff changeset	1207 // failure (by all other threads), but I decided the extra
a61af66fc99e Initial load duke parents: diff changeset	1208 // code was not worth the effort for something that is
a61af66fc99e Initial load duke parents: diff changeset	1209 // only used for debugging support.
a61af66fc99e Initial load duke parents: diff changeset	1210 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1211 oop referent = java_lang_ref_Reference::referent(obj);
a61af66fc99e Initial load duke parents: diff changeset	1212 if (PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	1213 gclog_or_tty->print_cr("Enqueued reference (" INTPTR_FORMAT ": %s)",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1214 obj, obj->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1215 }
a61af66fc99e Initial load duke parents: diff changeset	1216 assert(referent->is_oop(), "Enqueued a bad referent");
a61af66fc99e Initial load duke parents: diff changeset	1217 }
a61af66fc99e Initial load duke parents: diff changeset	1218 assert(obj->is_oop(), "Enqueued a bad reference");
a61af66fc99e Initial load duke parents: diff changeset	1219 return true;
a61af66fc99e Initial load duke parents: diff changeset	1220 }
a61af66fc99e Initial load duke parents: diff changeset	1221
a61af66fc99e Initial load duke parents: diff changeset	1222 // Preclean the discovered references by removing those
a61af66fc99e Initial load duke parents: diff changeset	1223 // whose referents are alive, and by marking from those that
a61af66fc99e Initial load duke parents: diff changeset	1224 // are not active. These lists can be handled here
a61af66fc99e Initial load duke parents: diff changeset	1225 // in any order and, indeed, concurrently.
a61af66fc99e Initial load duke parents: diff changeset	1226 void ReferenceProcessor::preclean_discovered_references(
a61af66fc99e Initial load duke parents: diff changeset	1227 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1228 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	1229 VoidClosure* complete_gc,
1190 4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1230 YieldClosure* yield,
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1231 bool should_unload_classes) {
0 a61af66fc99e Initial load duke parents: diff changeset	1232
a61af66fc99e Initial load duke parents: diff changeset	1233 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	1234
935 05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1235 #ifdef ASSERT
05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1236 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	1237 CMSClassUnloadingEnabled && UseConcMarkSweepGC \|\|
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1238 ExplicitGCInvokesConcurrentAndUnloadsClasses &&
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1239 UseConcMarkSweepGC && should_unload_classes;
935 05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1240 RememberKlassesChecker mx(must_remember_klasses);
05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1241 #endif
0 a61af66fc99e Initial load duke parents: diff changeset	1242 // Soft references
a61af66fc99e Initial load duke parents: diff changeset	1243 {
a61af66fc99e Initial load duke parents: diff changeset	1244 TraceTime tt("Preclean SoftReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1245 false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	1246 for (int i = 0; i < _num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1247 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1248 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1249 }
0 a61af66fc99e Initial load duke parents: diff changeset	1250 preclean_discovered_reflist(_discoveredSoftRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1251 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1252 }
a61af66fc99e Initial load duke parents: diff changeset	1253 }
a61af66fc99e Initial load duke parents: diff changeset	1254
a61af66fc99e Initial load duke parents: diff changeset	1255 // Weak references
a61af66fc99e Initial load duke parents: diff changeset	1256 {
a61af66fc99e Initial load duke parents: diff changeset	1257 TraceTime tt("Preclean WeakReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1258 false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	1259 for (int i = 0; i < _num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1260 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1261 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1262 }
0 a61af66fc99e Initial load duke parents: diff changeset	1263 preclean_discovered_reflist(_discoveredWeakRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1264 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1265 }
a61af66fc99e Initial load duke parents: diff changeset	1266 }
a61af66fc99e Initial load duke parents: diff changeset	1267
a61af66fc99e Initial load duke parents: diff changeset	1268 // Final references
a61af66fc99e Initial load duke parents: diff changeset	1269 {
a61af66fc99e Initial load duke parents: diff changeset	1270 TraceTime tt("Preclean FinalReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1271 false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	1272 for (int i = 0; i < _num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1273 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1274 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1275 }
0 a61af66fc99e Initial load duke parents: diff changeset	1276 preclean_discovered_reflist(_discoveredFinalRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1277 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1278 }
a61af66fc99e Initial load duke parents: diff changeset	1279 }
a61af66fc99e Initial load duke parents: diff changeset	1280
a61af66fc99e Initial load duke parents: diff changeset	1281 // Phantom references
a61af66fc99e Initial load duke parents: diff changeset	1282 {
a61af66fc99e Initial load duke parents: diff changeset	1283 TraceTime tt("Preclean PhantomReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1284 false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	1285 for (int i = 0; i < _num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1286 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1287 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1288 }
0 a61af66fc99e Initial load duke parents: diff changeset	1289 preclean_discovered_reflist(_discoveredPhantomRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1290 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1291 }
a61af66fc99e Initial load duke parents: diff changeset	1292 }
a61af66fc99e Initial load duke parents: diff changeset	1293 }
a61af66fc99e Initial load duke parents: diff changeset	1294
a61af66fc99e Initial load duke parents: diff changeset	1295 // Walk the given discovered ref list, and remove all reference objects
a61af66fc99e Initial load duke parents: diff changeset	1296 // 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	1297 // 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	1298 // 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	1299 // 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	1300 // 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	1301 // 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	1302 // (in this thread).
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1303 void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1304 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	1305 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1306 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1307 VoidClosure* complete_gc,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1308 YieldClosure* yield) {
0 a61af66fc99e Initial load duke parents: diff changeset	1309 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
a61af66fc99e Initial load duke parents: diff changeset	1310 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	1311 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	1312 oop obj = iter.obj();
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1313 oop next = java_lang_ref_Reference::next(obj);
0 a61af66fc99e Initial load duke parents: diff changeset	1314 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	1315 next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1316 // The referent has been cleared, or is alive, or the Reference is not
a61af66fc99e Initial load duke parents: diff changeset	1317 // active; we need to trace and mark its cohort.
a61af66fc99e Initial load duke parents: diff changeset	1318 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1319 gclog_or_tty->print_cr("Precleaning Reference (" INTPTR_FORMAT ": %s)",
a61af66fc99e Initial load duke parents: diff changeset	1320 iter.obj(), iter.obj()->blueprint()->internal_name());
a61af66fc99e Initial load duke parents: diff changeset	1321 }
a61af66fc99e Initial load duke parents: diff changeset	1322 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	1323 iter.remove();
a61af66fc99e Initial load duke parents: diff changeset	1324 // Keep alive its cohort.
a61af66fc99e Initial load duke parents: diff changeset	1325 iter.make_referent_alive();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1326 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1327 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	1328 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	1329 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1330 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	1331 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	1332 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1333 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	1334 } else {
a61af66fc99e Initial load duke parents: diff changeset	1335 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	1336 }
a61af66fc99e Initial load duke parents: diff changeset	1337 }
a61af66fc99e Initial load duke parents: diff changeset	1338 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	1339 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	1340
a61af66fc99e Initial load duke parents: diff changeset	1341 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	1342 if (PrintGCDetails && PrintReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1343 gclog_or_tty->print(" Dropped %d Refs out of %d "
a61af66fc99e Initial load duke parents: diff changeset	1344 "Refs in discovered list ", iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	1345 }
a61af66fc99e Initial load duke parents: diff changeset	1346 )
a61af66fc99e Initial load duke parents: diff changeset	1347 }
a61af66fc99e Initial load duke parents: diff changeset	1348
a61af66fc99e Initial load duke parents: diff changeset	1349 const char* ReferenceProcessor::list_name(int i) {
a61af66fc99e Initial load duke parents: diff changeset	1350 assert(i >= 0 && i <= _num_q * subclasses_of_ref, "Out of bounds index");
a61af66fc99e Initial load duke parents: diff changeset	1351 int j = i / _num_q;
a61af66fc99e Initial load duke parents: diff changeset	1352 switch (j) {
a61af66fc99e Initial load duke parents: diff changeset	1353 case 0: return "SoftRef";
a61af66fc99e Initial load duke parents: diff changeset	1354 case 1: return "WeakRef";
a61af66fc99e Initial load duke parents: diff changeset	1355 case 2: return "FinalRef";
a61af66fc99e Initial load duke parents: diff changeset	1356 case 3: return "PhantomRef";
a61af66fc99e Initial load duke parents: diff changeset	1357 }
a61af66fc99e Initial load duke parents: diff changeset	1358 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1359 return NULL;
a61af66fc99e Initial load duke parents: diff changeset	1360 }
a61af66fc99e Initial load duke parents: diff changeset	1361
a61af66fc99e Initial load duke parents: diff changeset	1362 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1363 void ReferenceProcessor::verify_ok_to_handle_reflists() {
a61af66fc99e Initial load duke parents: diff changeset	1364 // empty for now
a61af66fc99e Initial load duke parents: diff changeset	1365 }
a61af66fc99e Initial load duke parents: diff changeset	1366 #endif
a61af66fc99e Initial load duke parents: diff changeset	1367
a61af66fc99e Initial load duke parents: diff changeset	1368 void ReferenceProcessor::verify() {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1369 guarantee(sentinel_ref() != NULL && sentinel_ref()->is_oop(), "Lost _sentinelRef");
0 a61af66fc99e Initial load duke parents: diff changeset	1370 }
a61af66fc99e Initial load duke parents: diff changeset	1371
a61af66fc99e Initial load duke parents: diff changeset	1372 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1373 void ReferenceProcessor::clear_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	1374 guarantee(!_discovering_refs, "Discovering refs?");
a61af66fc99e Initial load duke parents: diff changeset	1375 for (int i = 0; i < _num_q * subclasses_of_ref; i++) {
a61af66fc99e Initial load duke parents: diff changeset	1376 oop obj = _discoveredSoftRefs[i].head();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1377 while (obj != sentinel_ref()) {
0 a61af66fc99e Initial load duke parents: diff changeset	1378 oop next = java_lang_ref_Reference::discovered(obj);
a61af66fc99e Initial load duke parents: diff changeset	1379 java_lang_ref_Reference::set_discovered(obj, (oop) NULL);
a61af66fc99e Initial load duke parents: diff changeset	1380 obj = next;
a61af66fc99e Initial load duke parents: diff changeset	1381 }
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1382 _discoveredSoftRefs[i].set_head(sentinel_ref());
0 a61af66fc99e Initial load duke parents: diff changeset	1383 _discoveredSoftRefs[i].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	1384 }
a61af66fc99e Initial load duke parents: diff changeset	1385 }
a61af66fc99e Initial load duke parents: diff changeset	1386 #endif // PRODUCT

Mercurial > hg > graal-compiler

annotate src/share/vm/memory/referenceProcessor.cpp @ 1190:4788266644c1