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

annotate src/share/vm/memory/referenceProcessor.cpp @ 4712:e7dead7e90af

7117303: VM uses non-monotonic time source and complains that it is non-monotonic Summary: Replaces calls to os::javaTimeMillis(), which does not (and cannot) guarantee monotonicity, in GC code to an equivalent expression that uses os::javaTimeNanos(). os::javaTimeNanos is guaranteed monotonically non-decreasing if the underlying platform provides a monotonic time source. Changes in OS files are to make use of the newly defined constants in globalDefinitions.hpp. Reviewed-by: dholmes, ysr

author	johnc
date	Mon, 19 Dec 2011 10:02:05 -0800
parents	bf2d2b8b1726
children	441e946dc1af

rev	line source
0 a61af66fc99e Initial load duke parents: diff changeset	1 /*
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
0 a61af66fc99e Initial load duke parents: diff changeset	3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
a61af66fc99e Initial load duke parents: diff changeset	4 *
a61af66fc99e Initial load duke parents: diff changeset	5 * This code is free software; you can redistribute it and/or modify it
a61af66fc99e Initial load duke parents: diff changeset	6 * under the terms of the GNU General Public License version 2 only, as
a61af66fc99e Initial load duke parents: diff changeset	7 * published by the Free Software Foundation.
a61af66fc99e Initial load duke parents: diff changeset	8 *
a61af66fc99e Initial load duke parents: diff changeset	9 * This code is distributed in the hope that it will be useful, but WITHOUT
a61af66fc99e Initial load duke parents: diff changeset	10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
a61af66fc99e Initial load duke parents: diff changeset	11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
a61af66fc99e Initial load duke parents: diff changeset	12 * version 2 for more details (a copy is included in the LICENSE file that
a61af66fc99e Initial load duke parents: diff changeset	13 * accompanied this code).
a61af66fc99e Initial load duke parents: diff changeset	14 *
a61af66fc99e Initial load duke parents: diff changeset	15 * You should have received a copy of the GNU General Public License version
a61af66fc99e Initial load duke parents: diff changeset	16 * 2 along with this work; if not, write to the Free Software Foundation,
a61af66fc99e Initial load duke parents: diff changeset	17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
a61af66fc99e Initial load duke parents: diff changeset	18 *
1552 c18cbe5936b8 6941466: Oracle rebranding changes for Hotspot repositories trims parents: 1190 diff changeset	19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
c18cbe5936b8 6941466: Oracle rebranding changes for Hotspot repositories trims parents: 1190 diff changeset	20 * or visit www.oracle.com if you need additional information or have any
c18cbe5936b8 6941466: Oracle rebranding changes for Hotspot repositories trims parents: 1190 diff changeset	21 * questions.
0 a61af66fc99e Initial load duke parents: diff changeset	22 *
a61af66fc99e Initial load duke parents: diff changeset	23 */
a61af66fc99e Initial load duke parents: diff changeset	24
1972 f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	25 #include "precompiled.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	26 #include "classfile/javaClasses.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	27 #include "classfile/systemDictionary.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	28 #include "gc_interface/collectedHeap.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	29 #include "gc_interface/collectedHeap.inline.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	30 #include "memory/referencePolicy.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	31 #include "memory/referenceProcessor.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	32 #include "oops/oop.inline.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	33 #include "runtime/java.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	34 #include "runtime/jniHandles.hpp"
0 a61af66fc99e Initial load duke parents: diff changeset	35
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	36 ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	37 ReferencePolicy* ReferenceProcessor::_default_soft_ref_policy = NULL;
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	38 bool ReferenceProcessor::_pending_list_uses_discovered_field = false;
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	39 jlong ReferenceProcessor::_soft_ref_timestamp_clock = 0;
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	40
0 a61af66fc99e Initial load duke parents: diff changeset	41 void referenceProcessor_init() {
a61af66fc99e Initial load duke parents: diff changeset	42 ReferenceProcessor::init_statics();
a61af66fc99e Initial load duke parents: diff changeset	43 }
a61af66fc99e Initial load duke parents: diff changeset	44
a61af66fc99e Initial load duke parents: diff changeset	45 void ReferenceProcessor::init_statics() {
4712 e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	46 // We need a monotonically non-deccreasing time in ms but
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	47 // os::javaTimeMillis() does not guarantee monotonicity.
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	48 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	49
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	50 // Initialize the soft ref timestamp clock.
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	51 _soft_ref_timestamp_clock = now;
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	52 // Also update the soft ref clock in j.l.r.SoftReference
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	53 java_lang_ref_SoftReference::set_clock(_soft_ref_timestamp_clock);
0 a61af66fc99e Initial load duke parents: diff changeset	54
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	55 _always_clear_soft_ref_policy = new AlwaysClearPolicy();
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	56 _default_soft_ref_policy = new COMPILER2_PRESENT(LRUMaxHeapPolicy())
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	57 NOT_COMPILER2(LRUCurrentHeapPolicy());
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	58 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	59 vm_exit_during_initialization("Could not allocate reference policy object");
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	60 }
0 a61af66fc99e Initial load duke parents: diff changeset	61 guarantee(RefDiscoveryPolicy == ReferenceBasedDiscovery \|\|
a61af66fc99e Initial load duke parents: diff changeset	62 RefDiscoveryPolicy == ReferentBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	63 "Unrecongnized RefDiscoveryPolicy");
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	64 _pending_list_uses_discovered_field = JDK_Version::current().pending_list_uses_discovered_field();
0 a61af66fc99e Initial load duke parents: diff changeset	65 }
a61af66fc99e Initial load duke parents: diff changeset	66
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	67 void ReferenceProcessor::enable_discovery(bool verify_disabled, bool check_no_refs) {
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	68 #ifdef ASSERT
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	69 // Verify that we're not currently discovering refs
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	70 assert(!verify_disabled \|\| !_discovering_refs, "nested call?");
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	71
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	72 if (check_no_refs) {
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	73 // Verify that the discovered lists are empty
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	74 verify_no_references_recorded();
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	75 }
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	76 #endif // ASSERT
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	77
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	78 // Someone could have modified the value of the static
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	79 // field in the j.l.r.SoftReference class that holds the
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	80 // soft reference timestamp clock using reflection or
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	81 // Unsafe between GCs. Unconditionally update the static
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	82 // field in ReferenceProcessor here so that we use the new
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	83 // value during reference discovery.
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	84
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	85 _soft_ref_timestamp_clock = java_lang_ref_SoftReference::clock();
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	86 _discovering_refs = true;
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	87 }
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	88
0 a61af66fc99e Initial load duke parents: diff changeset	89 ReferenceProcessor::ReferenceProcessor(MemRegion span,
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	90 bool mt_processing,
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	91 int mt_processing_degree,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	92 bool mt_discovery,
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	93 int mt_discovery_degree,
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	94 bool atomic_discovery,
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	95 BoolObjectClosure* is_alive_non_header,
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	96 bool discovered_list_needs_barrier) :
0 a61af66fc99e Initial load duke parents: diff changeset	97 _discovering_refs(false),
a61af66fc99e Initial load duke parents: diff changeset	98 _enqueuing_is_done(false),
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	99 _is_alive_non_header(is_alive_non_header),
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	100 _discovered_list_needs_barrier(discovered_list_needs_barrier),
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	101 _bs(NULL),
0 a61af66fc99e Initial load duke parents: diff changeset	102 _processing_is_mt(mt_processing),
a61af66fc99e Initial load duke parents: diff changeset	103 _next_id(0)
a61af66fc99e Initial load duke parents: diff changeset	104 {
a61af66fc99e Initial load duke parents: diff changeset	105 _span = span;
a61af66fc99e Initial load duke parents: diff changeset	106 _discovery_is_atomic = atomic_discovery;
a61af66fc99e Initial load duke parents: diff changeset	107 _discovery_is_mt = mt_discovery;
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	108 _num_q = MAX2(1, mt_processing_degree);
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	109 _max_num_q = MAX2(_num_q, mt_discovery_degree);
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	110 _discovered_refs = NEW_C_HEAP_ARRAY(DiscoveredList,
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	111 _max_num_q * number_of_subclasses_of_ref());
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	112 if (_discovered_refs == NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	113 vm_exit_during_initialization("Could not allocated RefProc Array");
a61af66fc99e Initial load duke parents: diff changeset	114 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	115 _discoveredSoftRefs = &_discovered_refs[0];
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	116 _discoveredWeakRefs = &_discoveredSoftRefs[_max_num_q];
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	117 _discoveredFinalRefs = &_discoveredWeakRefs[_max_num_q];
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	118 _discoveredPhantomRefs = &_discoveredFinalRefs[_max_num_q];
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	119
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	120 // Initialize all entries to NULL
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	121 for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	122 _discovered_refs[i].set_head(NULL);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	123 _discovered_refs[i].set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	124 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	125
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	126 // If we do barriers, cache a copy of the barrier set.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	127 if (discovered_list_needs_barrier) {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	128 _bs = Universe::heap()->barrier_set();
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	129 }
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	130 setup_policy(false /* default soft ref policy */);
0 a61af66fc99e Initial load duke parents: diff changeset	131 }
a61af66fc99e Initial load duke parents: diff changeset	132
a61af66fc99e Initial load duke parents: diff changeset	133 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	134 void ReferenceProcessor::verify_no_references_recorded() {
a61af66fc99e Initial load duke parents: diff changeset	135 guarantee(!_discovering_refs, "Discovering refs?");
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	136 for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	137 guarantee(_discovered_refs[i].is_empty(),
0 a61af66fc99e Initial load duke parents: diff changeset	138 "Found non-empty discovered list");
a61af66fc99e Initial load duke parents: diff changeset	139 }
a61af66fc99e Initial load duke parents: diff changeset	140 }
a61af66fc99e Initial load duke parents: diff changeset	141 #endif
a61af66fc99e Initial load duke parents: diff changeset	142
a61af66fc99e Initial load duke parents: diff changeset	143 void ReferenceProcessor::weak_oops_do(OopClosure* f) {
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	144 for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	145 if (UseCompressedOops) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	146 f->do_oop((narrowOop*)_discovered_refs[i].adr_head());
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	147 } else {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	148 f->do_oop((oop*)_discovered_refs[i].adr_head());
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	149 }
0 a61af66fc99e Initial load duke parents: diff changeset	150 }
a61af66fc99e Initial load duke parents: diff changeset	151 }
a61af66fc99e Initial load duke parents: diff changeset	152
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	153 void ReferenceProcessor::update_soft_ref_master_clock() {
0 a61af66fc99e Initial load duke parents: diff changeset	154 // Update (advance) the soft ref master clock field. This must be done
a61af66fc99e Initial load duke parents: diff changeset	155 // after processing the soft ref list.
4712 e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	156
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	157 // We need a monotonically non-deccreasing time in ms but
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	158 // os::javaTimeMillis() does not guarantee monotonicity.
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	159 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	160 jlong soft_ref_clock = java_lang_ref_SoftReference::clock();
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	161 assert(soft_ref_clock == _soft_ref_timestamp_clock, "soft ref clocks out of sync");
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	162
0 a61af66fc99e Initial load duke parents: diff changeset	163 NOT_PRODUCT(
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	164 if (now < _soft_ref_timestamp_clock) {
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	165 warning("time warp: "INT64_FORMAT" to "INT64_FORMAT,
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	166 _soft_ref_timestamp_clock, now);
0 a61af66fc99e Initial load duke parents: diff changeset	167 }
a61af66fc99e Initial load duke parents: diff changeset	168 )
4712 e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	169 // The values of now and _soft_ref_timestamp_clock are set using
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	170 // javaTimeNanos(), which is guaranteed to be monotonically
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	171 // non-decreasing provided the underlying platform provides such
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	172 // a time source (and it is bug free).
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	173 // In product mode, however, protect ourselves from non-monotonicty.
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	174 if (now > _soft_ref_timestamp_clock) {
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	175 _soft_ref_timestamp_clock = now;
0 a61af66fc99e Initial load duke parents: diff changeset	176 java_lang_ref_SoftReference::set_clock(now);
a61af66fc99e Initial load duke parents: diff changeset	177 }
a61af66fc99e Initial load duke parents: diff changeset	178 // Else leave clock stalled at its old value until time progresses
a61af66fc99e Initial load duke parents: diff changeset	179 // past clock value.
a61af66fc99e Initial load duke parents: diff changeset	180 }
a61af66fc99e Initial load duke parents: diff changeset	181
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	182 void ReferenceProcessor::process_discovered_references(
0 a61af66fc99e Initial load duke parents: diff changeset	183 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	184 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	185 VoidClosure* complete_gc,
a61af66fc99e Initial load duke parents: diff changeset	186 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load duke parents: diff changeset	187 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	188
a61af66fc99e Initial load duke parents: diff changeset	189 assert(!enqueuing_is_done(), "If here enqueuing should not be complete");
a61af66fc99e Initial load duke parents: diff changeset	190 // Stop treating discovered references specially.
a61af66fc99e Initial load duke parents: diff changeset	191 disable_discovery();
a61af66fc99e Initial load duke parents: diff changeset	192
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	193 // If discovery was concurrent, someone could have modified
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	194 // the value of the static field in the j.l.r.SoftReference
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	195 // class that holds the soft reference timestamp clock using
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	196 // reflection or Unsafe between when discovery was enabled and
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	197 // now. Unconditionally update the static field in ReferenceProcessor
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	198 // here so that we use the new value during processing of the
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	199 // discovered soft refs.
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	200
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	201 _soft_ref_timestamp_clock = java_lang_ref_SoftReference::clock();
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	202
0 a61af66fc99e Initial load duke parents: diff changeset	203 bool trace_time = PrintGCDetails && PrintReferenceGC;
a61af66fc99e Initial load duke parents: diff changeset	204 // Soft references
a61af66fc99e Initial load duke parents: diff changeset	205 {
a61af66fc99e Initial load duke parents: diff changeset	206 TraceTime tt("SoftReference", trace_time, false, gclog_or_tty);
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	207 process_discovered_reflist(_discoveredSoftRefs, _current_soft_ref_policy, true,
0 a61af66fc99e Initial load duke parents: diff changeset	208 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	209 }
a61af66fc99e Initial load duke parents: diff changeset	210
a61af66fc99e Initial load duke parents: diff changeset	211 update_soft_ref_master_clock();
a61af66fc99e Initial load duke parents: diff changeset	212
a61af66fc99e Initial load duke parents: diff changeset	213 // Weak references
a61af66fc99e Initial load duke parents: diff changeset	214 {
a61af66fc99e Initial load duke parents: diff changeset	215 TraceTime tt("WeakReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	216 process_discovered_reflist(_discoveredWeakRefs, NULL, true,
a61af66fc99e Initial load duke parents: diff changeset	217 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	218 }
a61af66fc99e Initial load duke parents: diff changeset	219
a61af66fc99e Initial load duke parents: diff changeset	220 // Final references
a61af66fc99e Initial load duke parents: diff changeset	221 {
a61af66fc99e Initial load duke parents: diff changeset	222 TraceTime tt("FinalReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	223 process_discovered_reflist(_discoveredFinalRefs, NULL, false,
a61af66fc99e Initial load duke parents: diff changeset	224 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	225 }
a61af66fc99e Initial load duke parents: diff changeset	226
a61af66fc99e Initial load duke parents: diff changeset	227 // Phantom references
a61af66fc99e Initial load duke parents: diff changeset	228 {
a61af66fc99e Initial load duke parents: diff changeset	229 TraceTime tt("PhantomReference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	230 process_discovered_reflist(_discoveredPhantomRefs, NULL, false,
a61af66fc99e Initial load duke parents: diff changeset	231 is_alive, keep_alive, complete_gc, task_executor);
a61af66fc99e Initial load duke parents: diff changeset	232 }
a61af66fc99e Initial load duke parents: diff changeset	233
a61af66fc99e Initial load duke parents: diff changeset	234 // Weak global JNI references. It would make more sense (semantically) to
a61af66fc99e Initial load duke parents: diff changeset	235 // traverse these simultaneously with the regular weak references above, but
a61af66fc99e Initial load duke parents: diff changeset	236 // that is not how the JDK1.2 specification is. See #4126360. Native code can
a61af66fc99e Initial load duke parents: diff changeset	237 // thus use JNI weak references to circumvent the phantom references and
a61af66fc99e Initial load duke parents: diff changeset	238 // resurrect a "post-mortem" object.
a61af66fc99e Initial load duke parents: diff changeset	239 {
a61af66fc99e Initial load duke parents: diff changeset	240 TraceTime tt("JNI Weak Reference", trace_time, false, gclog_or_tty);
a61af66fc99e Initial load duke parents: diff changeset	241 if (task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	242 task_executor->set_single_threaded_mode();
a61af66fc99e Initial load duke parents: diff changeset	243 }
a61af66fc99e Initial load duke parents: diff changeset	244 process_phaseJNI(is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	245 }
a61af66fc99e Initial load duke parents: diff changeset	246 }
a61af66fc99e Initial load duke parents: diff changeset	247
a61af66fc99e Initial load duke parents: diff changeset	248 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	249 // 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	250 uint ReferenceProcessor::count_jni_refs() {
0 a61af66fc99e Initial load duke parents: diff changeset	251 class AlwaysAliveClosure: public BoolObjectClosure {
a61af66fc99e Initial load duke parents: diff changeset	252 public:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	253 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	254 virtual void do_object(oop obj) { assert(false, "Don't call"); }
0 a61af66fc99e Initial load duke parents: diff changeset	255 };
a61af66fc99e Initial load duke parents: diff changeset	256
a61af66fc99e Initial load duke parents: diff changeset	257 class CountHandleClosure: public OopClosure {
a61af66fc99e Initial load duke parents: diff changeset	258 private:
a61af66fc99e Initial load duke parents: diff changeset	259 int _count;
a61af66fc99e Initial load duke parents: diff changeset	260 public:
a61af66fc99e Initial load duke parents: diff changeset	261 CountHandleClosure(): _count(0) {}
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	262 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	263 void do_oop(narrowOop* unused) { ShouldNotReachHere(); }
0 a61af66fc99e Initial load duke parents: diff changeset	264 int count() { return _count; }
a61af66fc99e Initial load duke parents: diff changeset	265 };
a61af66fc99e Initial load duke parents: diff changeset	266 CountHandleClosure global_handle_count;
a61af66fc99e Initial load duke parents: diff changeset	267 AlwaysAliveClosure always_alive;
a61af66fc99e Initial load duke parents: diff changeset	268 JNIHandles::weak_oops_do(&always_alive, &global_handle_count);
a61af66fc99e Initial load duke parents: diff changeset	269 return global_handle_count.count();
a61af66fc99e Initial load duke parents: diff changeset	270 }
a61af66fc99e Initial load duke parents: diff changeset	271 #endif
a61af66fc99e Initial load duke parents: diff changeset	272
a61af66fc99e Initial load duke parents: diff changeset	273 void ReferenceProcessor::process_phaseJNI(BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	274 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	275 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	276 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	277 if (PrintGCDetails && PrintReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	278 unsigned int count = count_jni_refs();
a61af66fc99e Initial load duke parents: diff changeset	279 gclog_or_tty->print(", %u refs", count);
a61af66fc99e Initial load duke parents: diff changeset	280 }
a61af66fc99e Initial load duke parents: diff changeset	281 #endif
a61af66fc99e Initial load duke parents: diff changeset	282 JNIHandles::weak_oops_do(is_alive, keep_alive);
a61af66fc99e Initial load duke parents: diff changeset	283 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	284 }
a61af66fc99e Initial load duke parents: diff changeset	285
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	286
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	287 template <class T>
1123 167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	288 bool enqueue_discovered_ref_helper(ReferenceProcessor* ref,
167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	289 AbstractRefProcTaskExecutor* task_executor) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	290
0 a61af66fc99e Initial load duke parents: diff changeset	291 // 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	292 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	293 T old_pending_list_value = *pending_list_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	294
a61af66fc99e Initial load duke parents: diff changeset	295 // Enqueue references that are not made active again, and
a61af66fc99e Initial load duke parents: diff changeset	296 // 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	297 ref->enqueue_discovered_reflists((HeapWord*)pending_list_addr, task_executor);
0 a61af66fc99e Initial load duke parents: diff changeset	298 // Do the oop-check on pending_list_addr missed in
a61af66fc99e Initial load duke parents: diff changeset	299 // enqueue_discovered_reflist. We should probably
a61af66fc99e Initial load duke parents: diff changeset	300 // do a raw oop_check so that future such idempotent
a61af66fc99e Initial load duke parents: diff changeset	301 // oop_stores relying on the oop-check side-effect
a61af66fc99e Initial load duke parents: diff changeset	302 // may be elided automatically and safely without
a61af66fc99e Initial load duke parents: diff changeset	303 // affecting correctness.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	304 oop_store(pending_list_addr, oopDesc::load_decode_heap_oop(pending_list_addr));
0 a61af66fc99e Initial load duke parents: diff changeset	305
a61af66fc99e Initial load duke parents: diff changeset	306 // 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	307 ref->disable_discovery();
0 a61af66fc99e Initial load duke parents: diff changeset	308
a61af66fc99e Initial load duke parents: diff changeset	309 // Return true if new pending references were added
a61af66fc99e Initial load duke parents: diff changeset	310 return old_pending_list_value != *pending_list_addr;
a61af66fc99e Initial load duke parents: diff changeset	311 }
a61af66fc99e Initial load duke parents: diff changeset	312
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	313 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	314 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	315 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	316 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	317 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	318 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	319 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	320 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	321
0 a61af66fc99e Initial load duke parents: diff changeset	322 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	323 HeapWord* pending_list_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	324 // Given a list of refs linked through the "discovered" field
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	325 // (java.lang.ref.Reference.discovered), self-loop their "next" field
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	326 // thus distinguishing them from active References, then
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	327 // prepend them to the pending list.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	328 // BKWRD COMPATIBILITY NOTE: For older JDKs (prior to the fix for 4956777),
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	329 // the "next" field is used to chain the pending list, not the discovered
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	330 // field.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	331
0 a61af66fc99e Initial load duke parents: diff changeset	332 if (TraceReferenceGC && PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	333 gclog_or_tty->print_cr("ReferenceProcessor::enqueue_discovered_reflist list "
a61af66fc99e Initial load duke parents: diff changeset	334 INTPTR_FORMAT, (address)refs_list.head());
a61af66fc99e Initial load duke parents: diff changeset	335 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	336
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	337 oop obj = NULL;
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	338 oop next_d = refs_list.head();
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	339 if (pending_list_uses_discovered_field()) { // New behaviour
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	340 // Walk down the list, self-looping the next field
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	341 // so that the References are not considered active.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	342 while (obj != next_d) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	343 obj = next_d;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	344 assert(obj->is_instanceRef(), "should be reference object");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	345 next_d = java_lang_ref_Reference::discovered(obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	346 if (TraceReferenceGC && PrintGCDetails) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	347 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	348 obj, next_d);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	349 }
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	350 assert(java_lang_ref_Reference::next(obj) == NULL,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	351 "Reference not active; should not be discovered");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	352 // Self-loop next, so as to make Ref not active.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	353 java_lang_ref_Reference::set_next(obj, obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	354 if (next_d == obj) { // obj is last
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	355 // Swap refs_list into pendling_list_addr and
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	356 // set obj's discovered to what we read from pending_list_addr.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	357 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	358 // Need oop_check on pending_list_addr above;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	359 // see special oop-check code at the end of
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	360 // enqueue_discovered_reflists() further below.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	361 java_lang_ref_Reference::set_discovered(obj, old); // old may be NULL
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	362 }
0 a61af66fc99e Initial load duke parents: diff changeset	363 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	364 } else { // Old behaviour
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	365 // Walk down the list, copying the discovered field into
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	366 // the next field and clearing the discovered field.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	367 while (obj != next_d) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	368 obj = next_d;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	369 assert(obj->is_instanceRef(), "should be reference object");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	370 next_d = java_lang_ref_Reference::discovered(obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	371 if (TraceReferenceGC && PrintGCDetails) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	372 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	373 obj, next_d);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	374 }
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	375 assert(java_lang_ref_Reference::next(obj) == NULL,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	376 "The reference should not be enqueued");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	377 if (next_d == obj) { // obj is last
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	378 // Swap refs_list into pendling_list_addr and
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	379 // set obj's next to what we read from pending_list_addr.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	380 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	381 // Need oop_check on pending_list_addr above;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	382 // see special oop-check code at the end of
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	383 // enqueue_discovered_reflists() further below.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	384 if (old == NULL) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	385 // obj should be made to point to itself, since
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	386 // pending list was empty.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	387 java_lang_ref_Reference::set_next(obj, obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	388 } else {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	389 java_lang_ref_Reference::set_next(obj, old);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	390 }
0 a61af66fc99e Initial load duke parents: diff changeset	391 } else {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	392 java_lang_ref_Reference::set_next(obj, next_d);
0 a61af66fc99e Initial load duke parents: diff changeset	393 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	394 java_lang_ref_Reference::set_discovered(obj, (oop) NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	395 }
a61af66fc99e Initial load duke parents: diff changeset	396 }
a61af66fc99e Initial load duke parents: diff changeset	397 }
a61af66fc99e Initial load duke parents: diff changeset	398
a61af66fc99e Initial load duke parents: diff changeset	399 // Parallel enqueue task
a61af66fc99e Initial load duke parents: diff changeset	400 class RefProcEnqueueTask: public AbstractRefProcTaskExecutor::EnqueueTask {
a61af66fc99e Initial load duke parents: diff changeset	401 public:
a61af66fc99e Initial load duke parents: diff changeset	402 RefProcEnqueueTask(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	403 DiscoveredList discovered_refs[],
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	404 HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	405 int n_queues)
a61af66fc99e Initial load duke parents: diff changeset	406 : EnqueueTask(ref_processor, discovered_refs,
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	407 pending_list_addr, n_queues)
0 a61af66fc99e Initial load duke parents: diff changeset	408 { }
a61af66fc99e Initial load duke parents: diff changeset	409
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	410 virtual void work(unsigned int work_id) {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	411 assert(work_id < (unsigned int)_ref_processor.max_num_q(), "Index out-of-bounds");
0 a61af66fc99e Initial load duke parents: diff changeset	412 // Simplest first cut: static partitioning.
a61af66fc99e Initial load duke parents: diff changeset	413 int index = work_id;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	414 // The increment on "index" must correspond to the maximum number of queues
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	415 // (n_queues) with which that ReferenceProcessor was created. That
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	416 // is because of the "clever" way the discovered references lists were
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	417 // allocated and are indexed into.
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	418 assert(_n_queues == (int) _ref_processor.max_num_q(), "Different number not expected");
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	419 for (int j = 0;
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	420 j < ReferenceProcessor::number_of_subclasses_of_ref();
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	421 j++, index += _n_queues) {
0 a61af66fc99e Initial load duke parents: diff changeset	422 _ref_processor.enqueue_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	423 _refs_lists[index], _pending_list_addr);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	424 _refs_lists[index].set_head(NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	425 _refs_lists[index].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	426 }
a61af66fc99e Initial load duke parents: diff changeset	427 }
a61af66fc99e Initial load duke parents: diff changeset	428 };
a61af66fc99e Initial load duke parents: diff changeset	429
a61af66fc99e Initial load duke parents: diff changeset	430 // 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	431 void ReferenceProcessor::enqueue_discovered_reflists(HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	432 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load duke parents: diff changeset	433 if (_processing_is_mt && task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	434 // Parallel code
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	435 RefProcEnqueueTask tsk(*this, _discovered_refs,
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	436 pending_list_addr, _max_num_q);
0 a61af66fc99e Initial load duke parents: diff changeset	437 task_executor->execute(tsk);
a61af66fc99e Initial load duke parents: diff changeset	438 } else {
a61af66fc99e Initial load duke parents: diff changeset	439 // Serial code: call the parent class's implementation
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	440 for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	441 enqueue_discovered_reflist(_discovered_refs[i], pending_list_addr);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	442 _discovered_refs[i].set_head(NULL);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	443 _discovered_refs[i].set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	444 }
a61af66fc99e Initial load duke parents: diff changeset	445 }
a61af66fc99e Initial load duke parents: diff changeset	446 }
a61af66fc99e Initial load duke parents: diff changeset	447
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	448 void DiscoveredListIterator::load_ptrs(DEBUG_ONLY(bool allow_null_referent)) {
0 a61af66fc99e Initial load duke parents: diff changeset	449 _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	450 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	451 assert(_discovered_addr && discovered->is_oop_or_null(),
0 a61af66fc99e Initial load duke parents: diff changeset	452 "discovered field is bad");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	453 _next = discovered;
0 a61af66fc99e Initial load duke parents: diff changeset	454 _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	455 _referent = java_lang_ref_Reference::referent(_ref);
0 a61af66fc99e Initial load duke parents: diff changeset	456 assert(Universe::heap()->is_in_reserved_or_null(_referent),
a61af66fc99e Initial load duke parents: diff changeset	457 "Wrong oop found in java.lang.Reference object");
a61af66fc99e Initial load duke parents: diff changeset	458 assert(allow_null_referent ?
a61af66fc99e Initial load duke parents: diff changeset	459 _referent->is_oop_or_null()
a61af66fc99e Initial load duke parents: diff changeset	460 : _referent->is_oop(),
a61af66fc99e Initial load duke parents: diff changeset	461 "bad referent");
a61af66fc99e Initial load duke parents: diff changeset	462 }
a61af66fc99e Initial load duke parents: diff changeset	463
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	464 void DiscoveredListIterator::remove() {
0 a61af66fc99e Initial load duke parents: diff changeset	465 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	466 oop_store_raw(_discovered_addr, NULL);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	467
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	468 // First _prev_next ref actually points into DiscoveredList (gross).
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	469 oop new_next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	470 if (_next == _ref) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	471 // At the end of the list, we should make _prev point to itself.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	472 // If _ref is the first ref, then _prev_next will be in the DiscoveredList,
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	473 // and _prev will be NULL.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	474 new_next = _prev;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	475 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	476 new_next = _next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	477 }
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	478
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	479 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	480 // Remove Reference object from list.
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	481 oopDesc::encode_store_heap_oop((narrowOop*)_prev_next, new_next);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	482 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	483 // Remove Reference object from list.
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	484 oopDesc::store_heap_oop((oop*)_prev_next, new_next);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	485 }
0 a61af66fc99e Initial load duke parents: diff changeset	486 NOT_PRODUCT(_removed++);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	487 _refs_list.dec_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	488 }
a61af66fc99e Initial load duke parents: diff changeset	489
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	490 // Make the Reference object active again.
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	491 void DiscoveredListIterator::make_active() {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	492 // For G1 we don't want to use set_next - it
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	493 // will dirty the card for the next field of
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	494 // the reference object and will fail
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	495 // CT verification.
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	496 if (UseG1GC) {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	497 BarrierSet* bs = oopDesc::bs();
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	498 HeapWord* next_addr = java_lang_ref_Reference::next_addr(_ref);
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	499
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	500 if (UseCompressedOops) {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	501 bs->write_ref_field_pre((narrowOop*)next_addr, NULL);
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	502 } else {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	503 bs->write_ref_field_pre((oop*)next_addr, NULL);
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	504 }
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	505 java_lang_ref_Reference::set_next_raw(_ref, NULL);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	506 } else {
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	507 java_lang_ref_Reference::set_next(_ref, NULL);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	508 }
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	509 }
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	510
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	511 void DiscoveredListIterator::clear_referent() {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	512 oop_store_raw(_referent_addr, NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	513 }
a61af66fc99e Initial load duke parents: diff changeset	514
a61af66fc99e Initial load duke parents: diff changeset	515 // NOTE: process_phase*() are largely similar, and at a high level
a61af66fc99e Initial load duke parents: diff changeset	516 // merely iterate over the extant list applying a predicate to
a61af66fc99e Initial load duke parents: diff changeset	517 // each of its elements and possibly removing that element from the
a61af66fc99e Initial load duke parents: diff changeset	518 // list and applying some further closures to that element.
a61af66fc99e Initial load duke parents: diff changeset	519 // We should consider the possibility of replacing these
a61af66fc99e Initial load duke parents: diff changeset	520 // process_phase*() methods by abstracting them into
a61af66fc99e Initial load duke parents: diff changeset	521 // a single general iterator invocation that receives appropriate
a61af66fc99e Initial load duke parents: diff changeset	522 // closures that accomplish this work.
a61af66fc99e Initial load duke parents: diff changeset	523
a61af66fc99e Initial load duke parents: diff changeset	524 // (SoftReferences only) Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	525 // referents are not alive, but that should be kept alive for policy reasons.
a61af66fc99e Initial load duke parents: diff changeset	526 // Keep alive the transitive closure of all such referents.
a61af66fc99e Initial load duke parents: diff changeset	527 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	528 ReferenceProcessor::process_phase1(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	529 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	530 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	531 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	532 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	533 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	534 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	535 // Decide which softly reachable refs should be kept alive.
a61af66fc99e Initial load duke parents: diff changeset	536 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	537 iter.load_ptrs(DEBUG_ONLY(!discovery_is_atomic() /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	538 bool referent_is_dead = (iter.referent() != NULL) && !iter.is_referent_alive();
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	539 if (referent_is_dead &&
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	540 !policy->should_clear_reference(iter.obj(), _soft_ref_timestamp_clock)) {
0 a61af66fc99e Initial load duke parents: diff changeset	541 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	542 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	543 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	544 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	545 // Remove Reference object from list
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	546 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	547 // Make the Reference object active again
a61af66fc99e Initial load duke parents: diff changeset	548 iter.make_active();
a61af66fc99e Initial load duke parents: diff changeset	549 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	550 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	551 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	552 } else {
a61af66fc99e Initial load duke parents: diff changeset	553 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	554 }
a61af66fc99e Initial load duke parents: diff changeset	555 }
a61af66fc99e Initial load duke parents: diff changeset	556 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	557 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	558 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	559 if (PrintGCDetails && TraceReferenceGC) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	560 gclog_or_tty->print_cr(" Dropped %d dead Refs out of %d "
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	561 "discovered Refs by policy, from list " INTPTR_FORMAT,
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	562 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	563 }
a61af66fc99e Initial load duke parents: diff changeset	564 )
a61af66fc99e Initial load duke parents: diff changeset	565 }
a61af66fc99e Initial load duke parents: diff changeset	566
a61af66fc99e Initial load duke parents: diff changeset	567 // Traverse the list and remove any Refs that are not active, or
a61af66fc99e Initial load duke parents: diff changeset	568 // whose referents are either alive or NULL.
a61af66fc99e Initial load duke parents: diff changeset	569 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	570 ReferenceProcessor::pp2_work(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	571 BoolObjectClosure* is_alive,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	572 OopClosure* keep_alive) {
0 a61af66fc99e Initial load duke parents: diff changeset	573 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	574 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	575 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	576 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	577 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	578 assert(next == NULL, "Should not discover inactive Reference");
0 a61af66fc99e Initial load duke parents: diff changeset	579 if (iter.is_referent_alive()) {
a61af66fc99e Initial load duke parents: diff changeset	580 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	581 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	582 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	583 }
a61af66fc99e Initial load duke parents: diff changeset	584 // The referent is reachable after all.
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	585 // Remove Reference object from list.
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	586 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	587 // Update the referent pointer as necessary: Note that this
a61af66fc99e Initial load duke parents: diff changeset	588 // should not entail any recursive marking because the
a61af66fc99e Initial load duke parents: diff changeset	589 // referent must already have been traversed.
a61af66fc99e Initial load duke parents: diff changeset	590 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	591 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	592 } else {
a61af66fc99e Initial load duke parents: diff changeset	593 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	594 }
a61af66fc99e Initial load duke parents: diff changeset	595 }
a61af66fc99e Initial load duke parents: diff changeset	596 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	597 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	598 gclog_or_tty->print_cr(" Dropped %d active Refs out of %d "
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	599 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	600 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	601 }
a61af66fc99e Initial load duke parents: diff changeset	602 )
a61af66fc99e Initial load duke parents: diff changeset	603 }
a61af66fc99e Initial load duke parents: diff changeset	604
a61af66fc99e Initial load duke parents: diff changeset	605 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	606 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	607 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	608 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	609 VoidClosure* complete_gc) {
0 a61af66fc99e Initial load duke parents: diff changeset	610 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	611 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	612 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	613 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	614 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	615 oop next = java_lang_ref_Reference::next(iter.obj());
0 a61af66fc99e Initial load duke parents: diff changeset	616 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	617 next != NULL)) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	618 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	619 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	620 iter.remove();
a61af66fc99e Initial load duke parents: diff changeset	621 // Trace the cohorts
a61af66fc99e Initial load duke parents: diff changeset	622 iter.make_referent_alive();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	623 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	624 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	625 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	626 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	627 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	628 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	629 } else {
a61af66fc99e Initial load duke parents: diff changeset	630 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	631 }
a61af66fc99e Initial load duke parents: diff changeset	632 }
a61af66fc99e Initial load duke parents: diff changeset	633 // Now close the newly reachable set
a61af66fc99e Initial load duke parents: diff changeset	634 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	635 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	636 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	637 gclog_or_tty->print_cr(" Dropped %d active Refs out of %d "
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	638 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	639 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	640 }
a61af66fc99e Initial load duke parents: diff changeset	641 )
a61af66fc99e Initial load duke parents: diff changeset	642 }
a61af66fc99e Initial load duke parents: diff changeset	643
a61af66fc99e Initial load duke parents: diff changeset	644 // 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	645 // clearing them or keeping them (and their reachable
0 a61af66fc99e Initial load duke parents: diff changeset	646 // closure) alive.
a61af66fc99e Initial load duke parents: diff changeset	647 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	648 ReferenceProcessor::process_phase3(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	649 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	650 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	651 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	652 VoidClosure* complete_gc) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	653 ResourceMark rm;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	654 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	655 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	656 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	657 iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	658 if (clear_referent) {
a61af66fc99e Initial load duke parents: diff changeset	659 // NULL out referent pointer
a61af66fc99e Initial load duke parents: diff changeset	660 iter.clear_referent();
a61af66fc99e Initial load duke parents: diff changeset	661 } else {
a61af66fc99e Initial load duke parents: diff changeset	662 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	663 iter.make_referent_alive();
a61af66fc99e Initial load duke parents: diff changeset	664 }
a61af66fc99e Initial load duke parents: diff changeset	665 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	666 gclog_or_tty->print_cr("Adding %sreference (" INTPTR_FORMAT ": %s) as pending",
a61af66fc99e Initial load duke parents: diff changeset	667 clear_referent ? "cleared " : "",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	668 iter.obj(), iter.obj()->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	669 }
a61af66fc99e Initial load duke parents: diff changeset	670 assert(iter.obj()->is_oop(UseConcMarkSweepGC), "Adding a bad reference");
a61af66fc99e Initial load duke parents: diff changeset	671 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	672 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	673 // Remember to update the next pointer of the last ref.
0 a61af66fc99e Initial load duke parents: diff changeset	674 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	675 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	676 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	677 }
a61af66fc99e Initial load duke parents: diff changeset	678
a61af66fc99e Initial load duke parents: diff changeset	679 void
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	680 ReferenceProcessor::clear_discovered_references(DiscoveredList& refs_list) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	681 oop obj = NULL;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	682 oop next = refs_list.head();
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	683 while (next != obj) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	684 obj = next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	685 next = java_lang_ref_Reference::discovered(obj);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	686 java_lang_ref_Reference::set_discovered_raw(obj, NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	687 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	688 refs_list.set_head(NULL);
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	689 refs_list.set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	690 }
a61af66fc99e Initial load duke parents: diff changeset	691
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	692 void
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	693 ReferenceProcessor::abandon_partial_discovered_list(DiscoveredList& refs_list) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	694 clear_discovered_references(refs_list);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	695 }
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	696
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	697 void ReferenceProcessor::abandon_partial_discovery() {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	698 // loop over the lists
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	699 for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	700 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	701 gclog_or_tty->print_cr("\nAbandoning %s discovered list", list_name(i));
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	702 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	703 abandon_partial_discovered_list(_discovered_refs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	704 }
a61af66fc99e Initial load duke parents: diff changeset	705 }
a61af66fc99e Initial load duke parents: diff changeset	706
a61af66fc99e Initial load duke parents: diff changeset	707 class RefProcPhase1Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	708 public:
a61af66fc99e Initial load duke parents: diff changeset	709 RefProcPhase1Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	710 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	711 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	712 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	713 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	714 _policy(policy)
a61af66fc99e Initial load duke parents: diff changeset	715 { }
a61af66fc99e Initial load duke parents: diff changeset	716 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	717 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	718 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	719 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	720 Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	721 int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	722 _ref_processor.process_phase1(_refs_lists[refs_list_index], _policy,
0 a61af66fc99e Initial load duke parents: diff changeset	723 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	724 }
a61af66fc99e Initial load duke parents: diff changeset	725 private:
a61af66fc99e Initial load duke parents: diff changeset	726 ReferencePolicy* _policy;
a61af66fc99e Initial load duke parents: diff changeset	727 };
a61af66fc99e Initial load duke parents: diff changeset	728
a61af66fc99e Initial load duke parents: diff changeset	729 class RefProcPhase2Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	730 public:
a61af66fc99e Initial load duke parents: diff changeset	731 RefProcPhase2Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	732 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	733 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	734 : ProcessTask(ref_processor, refs_lists, marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	735 { }
a61af66fc99e Initial load duke parents: diff changeset	736 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	737 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	738 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	739 {
a61af66fc99e Initial load duke parents: diff changeset	740 _ref_processor.process_phase2(_refs_lists[i],
a61af66fc99e Initial load duke parents: diff changeset	741 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	742 }
a61af66fc99e Initial load duke parents: diff changeset	743 };
a61af66fc99e Initial load duke parents: diff changeset	744
a61af66fc99e Initial load duke parents: diff changeset	745 class RefProcPhase3Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	746 public:
a61af66fc99e Initial load duke parents: diff changeset	747 RefProcPhase3Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	748 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	749 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	750 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	751 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	752 _clear_referent(clear_referent)
a61af66fc99e Initial load duke parents: diff changeset	753 { }
a61af66fc99e Initial load duke parents: diff changeset	754 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	755 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	756 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	757 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	758 // Don't use "refs_list_index" calculated in this way because
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	759 // balance_queues() has moved the Ref's into the first n queues.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	760 // Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	761 // int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	762 // _ref_processor.process_phase3(_refs_lists[refs_list_index], _clear_referent,
0 a61af66fc99e Initial load duke parents: diff changeset	763 _ref_processor.process_phase3(_refs_lists[i], _clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	764 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	765 }
a61af66fc99e Initial load duke parents: diff changeset	766 private:
a61af66fc99e Initial load duke parents: diff changeset	767 bool _clear_referent;
a61af66fc99e Initial load duke parents: diff changeset	768 };
a61af66fc99e Initial load duke parents: diff changeset	769
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	770 void ReferenceProcessor::set_discovered(oop ref, oop value) {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	771 if (_discovered_list_needs_barrier) {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	772 java_lang_ref_Reference::set_discovered(ref, value);
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	773 } else {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	774 java_lang_ref_Reference::set_discovered_raw(ref, value);
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	775 }
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	776 }
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	777
0 a61af66fc99e Initial load duke parents: diff changeset	778 // Balances reference queues.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	779 // Move entries from all queues[0, 1, ..., _max_num_q-1] to
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	780 // queues[0, 1, ..., _num_q-1] because only the first _num_q
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	781 // corresponding to the active workers will be processed.
0 a61af66fc99e Initial load duke parents: diff changeset	782 void ReferenceProcessor::balance_queues(DiscoveredList ref_lists[])
a61af66fc99e Initial load duke parents: diff changeset	783 {
a61af66fc99e Initial load duke parents: diff changeset	784 // calculate total length
a61af66fc99e Initial load duke parents: diff changeset	785 size_t total_refs = 0;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	786 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	787 gclog_or_tty->print_cr("\nBalance ref_lists ");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	788 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	789
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	790 for (int i = 0; i < _max_num_q; ++i) {
0 a61af66fc99e Initial load duke parents: diff changeset	791 total_refs += ref_lists[i].length();
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	792 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	793 gclog_or_tty->print("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	794 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	795 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	796 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	797 gclog_or_tty->print_cr(" = %d", total_refs);
0 a61af66fc99e Initial load duke parents: diff changeset	798 }
a61af66fc99e Initial load duke parents: diff changeset	799 size_t avg_refs = total_refs / _num_q + 1;
a61af66fc99e Initial load duke parents: diff changeset	800 int to_idx = 0;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	801 for (int from_idx = 0; from_idx < _max_num_q; from_idx++) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	802 bool move_all = false;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	803 if (from_idx >= _num_q) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	804 move_all = ref_lists[from_idx].length() > 0;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	805 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	806 while ((ref_lists[from_idx].length() > avg_refs) \|\|
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	807 move_all) {
0 a61af66fc99e Initial load duke parents: diff changeset	808 assert(to_idx < _num_q, "Sanity Check!");
a61af66fc99e Initial load duke parents: diff changeset	809 if (ref_lists[to_idx].length() < avg_refs) {
a61af66fc99e Initial load duke parents: diff changeset	810 // move superfluous refs
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	811 size_t refs_to_move;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	812 // Move all the Ref's if the from queue will not be processed.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	813 if (move_all) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	814 refs_to_move = MIN2(ref_lists[from_idx].length(),
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	815 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	816 } else {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	817 refs_to_move = MIN2(ref_lists[from_idx].length() - avg_refs,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	818 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	819 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	820
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	821 assert(refs_to_move > 0, "otherwise the code below will fail");
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	822
0 a61af66fc99e Initial load duke parents: diff changeset	823 oop move_head = ref_lists[from_idx].head();
a61af66fc99e Initial load duke parents: diff changeset	824 oop move_tail = move_head;
a61af66fc99e Initial load duke parents: diff changeset	825 oop new_head = move_head;
a61af66fc99e Initial load duke parents: diff changeset	826 // find an element to split the list on
a61af66fc99e Initial load duke parents: diff changeset	827 for (size_t j = 0; j < refs_to_move; ++j) {
a61af66fc99e Initial load duke parents: diff changeset	828 move_tail = new_head;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	829 new_head = java_lang_ref_Reference::discovered(new_head);
0 a61af66fc99e Initial load duke parents: diff changeset	830 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	831
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	832 // Add the chain to the to list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	833 if (ref_lists[to_idx].head() == NULL) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	834 // to list is empty. Make a loop at the end.
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	835 set_discovered(move_tail, move_tail);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	836 } else {
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	837 set_discovered(move_tail, ref_lists[to_idx].head());
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	838 }
0 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);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	841
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	842 // Remove the chain from the from list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	843 if (move_tail == new_head) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	844 // We found the end of the from list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	845 ref_lists[from_idx].set_head(NULL);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	846 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	847 ref_lists[from_idx].set_head(new_head);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	848 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	849 ref_lists[from_idx].dec_length(refs_to_move);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	850 if (ref_lists[from_idx].length() == 0) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	851 break;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	852 }
0 a61af66fc99e Initial load duke parents: diff changeset	853 } else {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	854 to_idx = (to_idx + 1) % _num_q;
0 a61af66fc99e Initial load duke parents: diff changeset	855 }
a61af66fc99e Initial load duke parents: diff changeset	856 }
a61af66fc99e Initial load duke parents: diff changeset	857 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	858 #ifdef ASSERT
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	859 size_t balanced_total_refs = 0;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	860 for (int i = 0; i < _max_num_q; ++i) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	861 balanced_total_refs += ref_lists[i].length();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	862 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	863 gclog_or_tty->print("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	864 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	865 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	866 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	867 gclog_or_tty->print_cr(" = %d", balanced_total_refs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	868 gclog_or_tty->flush();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	869 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	870 assert(total_refs == balanced_total_refs, "Balancing was incomplete");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	871 #endif
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	872 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	873
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	874 void ReferenceProcessor::balance_all_queues() {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	875 balance_queues(_discoveredSoftRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	876 balance_queues(_discoveredWeakRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	877 balance_queues(_discoveredFinalRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	878 balance_queues(_discoveredPhantomRefs);
0 a61af66fc99e Initial load duke parents: diff changeset	879 }
a61af66fc99e Initial load duke parents: diff changeset	880
a61af66fc99e Initial load duke parents: diff changeset	881 void
a61af66fc99e Initial load duke parents: diff changeset	882 ReferenceProcessor::process_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	883 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	884 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	885 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	886 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	887 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	888 VoidClosure* complete_gc,
a61af66fc99e Initial load duke parents: diff changeset	889 AbstractRefProcTaskExecutor* task_executor)
a61af66fc99e Initial load duke parents: diff changeset	890 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	891 bool mt_processing = task_executor != NULL && _processing_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	892 // If discovery used MT and a dynamic number of GC threads, then
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	893 // the queues must be balanced for correctness if fewer than the
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	894 // maximum number of queues were used. The number of queue used
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	895 // during discovery may be different than the number to be used
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	896 // for processing so don't depend of _num_q < _max_num_q as part
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	897 // of the test.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	898 bool must_balance = _discovery_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	899
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	900 if ((mt_processing && ParallelRefProcBalancingEnabled) \|\|
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	901 must_balance) {
0 a61af66fc99e Initial load duke parents: diff changeset	902 balance_queues(refs_lists);
a61af66fc99e Initial load duke parents: diff changeset	903 }
a61af66fc99e Initial load duke parents: diff changeset	904 if (PrintReferenceGC && PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	905 size_t total = 0;
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	906 for (int i = 0; i < _max_num_q; ++i) {
0 a61af66fc99e Initial load duke parents: diff changeset	907 total += refs_lists[i].length();
a61af66fc99e Initial load duke parents: diff changeset	908 }
a61af66fc99e Initial load duke parents: diff changeset	909 gclog_or_tty->print(", %u refs", total);
a61af66fc99e Initial load duke parents: diff changeset	910 }
a61af66fc99e Initial load duke parents: diff changeset	911
a61af66fc99e Initial load duke parents: diff changeset	912 // Phase 1 (soft refs only):
a61af66fc99e Initial load duke parents: diff changeset	913 // . Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	914 // referents are not alive, but that should be kept alive for
a61af66fc99e Initial load duke parents: diff changeset	915 // policy reasons. Keep alive the transitive closure of all
a61af66fc99e Initial load duke parents: diff changeset	916 // such referents.
a61af66fc99e Initial load duke parents: diff changeset	917 if (policy != NULL) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	918 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	919 RefProcPhase1Task phase1(this, refs_lists, policy, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	920 task_executor->execute(phase1);
a61af66fc99e Initial load duke parents: diff changeset	921 } else {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	922 for (int i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	923 process_phase1(refs_lists[i], policy,
a61af66fc99e Initial load duke parents: diff changeset	924 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	925 }
a61af66fc99e Initial load duke parents: diff changeset	926 }
a61af66fc99e Initial load duke parents: diff changeset	927 } else { // policy == NULL
a61af66fc99e Initial load duke parents: diff changeset	928 assert(refs_lists != _discoveredSoftRefs,
a61af66fc99e Initial load duke parents: diff changeset	929 "Policy must be specified for soft references.");
a61af66fc99e Initial load duke parents: diff changeset	930 }
a61af66fc99e Initial load duke parents: diff changeset	931
a61af66fc99e Initial load duke parents: diff changeset	932 // Phase 2:
a61af66fc99e Initial load duke parents: diff changeset	933 // . Traverse the list and remove any refs whose referents are alive.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	934 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	935 RefProcPhase2Task phase2(this, refs_lists, !discovery_is_atomic() /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	936 task_executor->execute(phase2);
a61af66fc99e Initial load duke parents: diff changeset	937 } else {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	938 for (int i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	939 process_phase2(refs_lists[i], is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	940 }
a61af66fc99e Initial load duke parents: diff changeset	941 }
a61af66fc99e Initial load duke parents: diff changeset	942
a61af66fc99e Initial load duke parents: diff changeset	943 // Phase 3:
a61af66fc99e Initial load duke parents: diff changeset	944 // . Traverse the list and process referents as appropriate.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	945 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	946 RefProcPhase3Task phase3(this, refs_lists, clear_referent, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	947 task_executor->execute(phase3);
a61af66fc99e Initial load duke parents: diff changeset	948 } else {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	949 for (int i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	950 process_phase3(refs_lists[i], clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	951 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	952 }
a61af66fc99e Initial load duke parents: diff changeset	953 }
a61af66fc99e Initial load duke parents: diff changeset	954 }
a61af66fc99e Initial load duke parents: diff changeset	955
a61af66fc99e Initial load duke parents: diff changeset	956 void ReferenceProcessor::clean_up_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	957 // loop over the lists
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	958 for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	959 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
0 a61af66fc99e Initial load duke parents: diff changeset	960 gclog_or_tty->print_cr(
a61af66fc99e Initial load duke parents: diff changeset	961 "\nScrubbing %s discovered list of Null referents",
a61af66fc99e Initial load duke parents: diff changeset	962 list_name(i));
a61af66fc99e Initial load duke parents: diff changeset	963 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	964 clean_up_discovered_reflist(_discovered_refs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	965 }
a61af66fc99e Initial load duke parents: diff changeset	966 }
a61af66fc99e Initial load duke parents: diff changeset	967
a61af66fc99e Initial load duke parents: diff changeset	968 void ReferenceProcessor::clean_up_discovered_reflist(DiscoveredList& refs_list) {
a61af66fc99e Initial load duke parents: diff changeset	969 assert(!discovery_is_atomic(), "Else why call this method?");
a61af66fc99e Initial load duke parents: diff changeset	970 DiscoveredListIterator iter(refs_list, NULL, NULL);
a61af66fc99e Initial load duke parents: diff changeset	971 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	972 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	973 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	974 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	975 // If referent has been cleared or Reference is not active,
a61af66fc99e Initial load duke parents: diff changeset	976 // drop it.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	977 if (iter.referent() == NULL \|\| next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	978 debug_only(
a61af66fc99e Initial load duke parents: diff changeset	979 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	980 gclog_or_tty->print_cr("clean_up_discovered_list: Dropping Reference: "
a61af66fc99e Initial load duke parents: diff changeset	981 INTPTR_FORMAT " with next field: " INTPTR_FORMAT
a61af66fc99e Initial load duke parents: diff changeset	982 " and referent: " INTPTR_FORMAT,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	983 iter.obj(), next, iter.referent());
0 a61af66fc99e Initial load duke parents: diff changeset	984 }
a61af66fc99e Initial load duke parents: diff changeset	985 )
a61af66fc99e Initial load duke parents: diff changeset	986 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	987 iter.remove();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	988 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	989 } else {
a61af66fc99e Initial load duke parents: diff changeset	990 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	991 }
a61af66fc99e Initial load duke parents: diff changeset	992 }
a61af66fc99e Initial load duke parents: diff changeset	993 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	994 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	995 gclog_or_tty->print(
a61af66fc99e Initial load duke parents: diff changeset	996 " Removed %d Refs with NULL referents out of %d discovered Refs",
a61af66fc99e Initial load duke parents: diff changeset	997 iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	998 }
a61af66fc99e Initial load duke parents: diff changeset	999 )
a61af66fc99e Initial load duke parents: diff changeset	1000 }
a61af66fc99e Initial load duke parents: diff changeset	1001
a61af66fc99e Initial load duke parents: diff changeset	1002 inline DiscoveredList* ReferenceProcessor::get_discovered_list(ReferenceType rt) {
a61af66fc99e Initial load duke parents: diff changeset	1003 int id = 0;
a61af66fc99e Initial load duke parents: diff changeset	1004 // Determine the queue index to use for this object.
a61af66fc99e Initial load duke parents: diff changeset	1005 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1006 // During a multi-threaded discovery phase,
a61af66fc99e Initial load duke parents: diff changeset	1007 // each thread saves to its "own" list.
a61af66fc99e Initial load duke parents: diff changeset	1008 Thread* thr = Thread::current();
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1009 id = thr->as_Worker_thread()->id();
0 a61af66fc99e Initial load duke parents: diff changeset	1010 } else {
a61af66fc99e Initial load duke parents: diff changeset	1011 // single-threaded discovery, we save in round-robin
a61af66fc99e Initial load duke parents: diff changeset	1012 // fashion to each of the lists.
a61af66fc99e Initial load duke parents: diff changeset	1013 if (_processing_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1014 id = next_id();
a61af66fc99e Initial load duke parents: diff changeset	1015 }
a61af66fc99e Initial load duke parents: diff changeset	1016 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1017 assert(0 <= id && id < _max_num_q, "Id is out-of-bounds (call Freud?)");
0 a61af66fc99e Initial load duke parents: diff changeset	1018
a61af66fc99e Initial load duke parents: diff changeset	1019 // Get the discovered queue to which we will add
a61af66fc99e Initial load duke parents: diff changeset	1020 DiscoveredList* list = NULL;
a61af66fc99e Initial load duke parents: diff changeset	1021 switch (rt) {
a61af66fc99e Initial load duke parents: diff changeset	1022 case REF_OTHER:
a61af66fc99e Initial load duke parents: diff changeset	1023 // Unknown reference type, no special treatment
a61af66fc99e Initial load duke parents: diff changeset	1024 break;
a61af66fc99e Initial load duke parents: diff changeset	1025 case REF_SOFT:
a61af66fc99e Initial load duke parents: diff changeset	1026 list = &_discoveredSoftRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1027 break;
a61af66fc99e Initial load duke parents: diff changeset	1028 case REF_WEAK:
a61af66fc99e Initial load duke parents: diff changeset	1029 list = &_discoveredWeakRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1030 break;
a61af66fc99e Initial load duke parents: diff changeset	1031 case REF_FINAL:
a61af66fc99e Initial load duke parents: diff changeset	1032 list = &_discoveredFinalRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1033 break;
a61af66fc99e Initial load duke parents: diff changeset	1034 case REF_PHANTOM:
a61af66fc99e Initial load duke parents: diff changeset	1035 list = &_discoveredPhantomRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1036 break;
a61af66fc99e Initial load duke parents: diff changeset	1037 case REF_NONE:
a61af66fc99e Initial load duke parents: diff changeset	1038 // we should not reach here if we are an instanceRefKlass
a61af66fc99e Initial load duke parents: diff changeset	1039 default:
a61af66fc99e Initial load duke parents: diff changeset	1040 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1041 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1042 if (TraceReferenceGC && PrintGCDetails) {
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1043 gclog_or_tty->print_cr("Thread %d gets list " INTPTR_FORMAT, id, list);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1044 }
0 a61af66fc99e Initial load duke parents: diff changeset	1045 return list;
a61af66fc99e Initial load duke parents: diff changeset	1046 }
a61af66fc99e Initial load duke parents: diff changeset	1047
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1048 inline void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1049 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	1050 oop obj,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1051 HeapWord* discovered_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	1052 assert(_discovery_is_mt, "!_discovery_is_mt should have been handled by caller");
a61af66fc99e Initial load duke parents: diff changeset	1053 // First we must make sure this object is only enqueued once. CAS in a non null
a61af66fc99e Initial load duke parents: diff changeset	1054 // discovered_addr.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1055 oop current_head = refs_list.head();
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1056 // The last ref must have its discovered field pointing to itself.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1057 oop next_discovered = (current_head != NULL) ? current_head : obj;
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1058
845 df6caf649ff7 6700789: G1: Enable use of compressed oops with G1 heaps ysr parents: 579 diff changeset	1059 // 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	1060 // 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	1061 // 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	1062 // 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	1063 // elided this out for G1, but left in the test for some future
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1064 // collector that might have need for a pre-barrier here, e.g.:-
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1065 // _bs->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1066 assert(!_discovered_list_needs_barrier \|\| UseG1GC,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1067 "Need to check non-G1 collector: "
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1068 "may need a pre-write-barrier for CAS from NULL below");
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1069 oop retest = oopDesc::atomic_compare_exchange_oop(next_discovered, discovered_addr,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1070 NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	1071 if (retest == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1072 // This thread just won the right to enqueue the object.
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1073 // We have separate lists for enqueueing, so no synchronization
0 a61af66fc99e Initial load duke parents: diff changeset	1074 // is necessary.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1075 refs_list.set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1076 refs_list.inc_length(1);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1077 if (_discovered_list_needs_barrier) {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1078 _bs->write_ref_field((void*)discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1079 }
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1080
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1081 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1082 gclog_or_tty->print_cr("Discovered reference (mt) (" INTPTR_FORMAT ": %s)",
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1083 obj, obj->blueprint()->internal_name());
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1084 }
0 a61af66fc99e Initial load duke parents: diff changeset	1085 } else {
a61af66fc99e Initial load duke parents: diff changeset	1086 // If retest was non NULL, another thread beat us to it:
a61af66fc99e Initial load duke parents: diff changeset	1087 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1088 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1089 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
0 a61af66fc99e Initial load duke parents: diff changeset	1090 obj, obj->blueprint()->internal_name());
a61af66fc99e Initial load duke parents: diff changeset	1091 }
a61af66fc99e Initial load duke parents: diff changeset	1092 }
a61af66fc99e Initial load duke parents: diff changeset	1093 }
a61af66fc99e Initial load duke parents: diff changeset	1094
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1095 #ifndef PRODUCT
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1096 // Non-atomic (i.e. concurrent) discovery might allow us
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1097 // to observe j.l.References with NULL referents, being those
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1098 // cleared concurrently by mutators during (or after) discovery.
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1099 void ReferenceProcessor::verify_referent(oop obj) {
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1100 bool da = discovery_is_atomic();
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1101 oop referent = java_lang_ref_Reference::referent(obj);
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1102 assert(da ? referent->is_oop() : referent->is_oop_or_null(),
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1103 err_msg("Bad referent " INTPTR_FORMAT " found in Reference "
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1104 INTPTR_FORMAT " during %satomic discovery ",
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1105 (intptr_t)referent, (intptr_t)obj, da ? "" : "non-"));
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1106 }
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1107 #endif
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1108
0 a61af66fc99e Initial load duke parents: diff changeset	1109 // We mention two of several possible choices here:
a61af66fc99e Initial load duke parents: diff changeset	1110 // #0: if the reference object is not in the "originating generation"
a61af66fc99e Initial load duke parents: diff changeset	1111 // (or part of the heap being collected, indicated by our "span"
a61af66fc99e Initial load duke parents: diff changeset	1112 // we don't treat it specially (i.e. we scan it as we would
a61af66fc99e Initial load duke parents: diff changeset	1113 // a normal oop, treating its references as strong references).
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1114 // This means that references can't be discovered unless their
0 a61af66fc99e Initial load duke parents: diff changeset	1115 // referent is also in the same span. This is the simplest,
a61af66fc99e Initial load duke parents: diff changeset	1116 // most "local" and most conservative approach, albeit one
a61af66fc99e Initial load duke parents: diff changeset	1117 // that may cause weak references to be enqueued least promptly.
a61af66fc99e Initial load duke parents: diff changeset	1118 // We call this choice the "ReferenceBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1119 // #1: the reference object may be in any generation (span), but if
a61af66fc99e Initial load duke parents: diff changeset	1120 // the referent is in the generation (span) being currently collected
a61af66fc99e Initial load duke parents: diff changeset	1121 // then we can discover the reference object, provided
a61af66fc99e Initial load duke parents: diff changeset	1122 // the object has not already been discovered by
a61af66fc99e Initial load duke parents: diff changeset	1123 // a different concurrently running collector (as may be the
a61af66fc99e Initial load duke parents: diff changeset	1124 // case, for instance, if the reference object is in CMS and
a61af66fc99e Initial load duke parents: diff changeset	1125 // the referent in DefNewGeneration), and provided the processing
a61af66fc99e Initial load duke parents: diff changeset	1126 // of this reference object by the current collector will
a61af66fc99e Initial load duke parents: diff changeset	1127 // appear atomic to every other collector in the system.
a61af66fc99e Initial load duke parents: diff changeset	1128 // (Thus, for instance, a concurrent collector may not
a61af66fc99e Initial load duke parents: diff changeset	1129 // discover references in other generations even if the
a61af66fc99e Initial load duke parents: diff changeset	1130 // referent is in its own generation). This policy may,
a61af66fc99e Initial load duke parents: diff changeset	1131 // in certain cases, enqueue references somewhat sooner than
a61af66fc99e Initial load duke parents: diff changeset	1132 // might Policy #0 above, but at marginally increased cost
a61af66fc99e Initial load duke parents: diff changeset	1133 // and complexity in processing these references.
a61af66fc99e Initial load duke parents: diff changeset	1134 // We call this choice the "RefeferentBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1135 bool ReferenceProcessor::discover_reference(oop obj, ReferenceType rt) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1136 // Make sure we are discovering refs (rather than processing discovered refs).
0 a61af66fc99e Initial load duke parents: diff changeset	1137 if (!_discovering_refs \|\| !RegisterReferences) {
a61af66fc99e Initial load duke parents: diff changeset	1138 return false;
a61af66fc99e Initial load duke parents: diff changeset	1139 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1140 // We only discover active references.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1141 oop next = java_lang_ref_Reference::next(obj);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1142 if (next != NULL) { // Ref is no longer active
0 a61af66fc99e Initial load duke parents: diff changeset	1143 return false;
a61af66fc99e Initial load duke parents: diff changeset	1144 }
a61af66fc99e Initial load duke parents: diff changeset	1145
a61af66fc99e Initial load duke parents: diff changeset	1146 HeapWord* obj_addr = (HeapWord*)obj;
a61af66fc99e Initial load duke parents: diff changeset	1147 if (RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1148 !_span.contains(obj_addr)) {
a61af66fc99e Initial load duke parents: diff changeset	1149 // Reference is not in the originating generation;
a61af66fc99e Initial load duke parents: diff changeset	1150 // don't treat it specially (i.e. we want to scan it as a normal
a61af66fc99e Initial load duke parents: diff changeset	1151 // object with strong references).
a61af66fc99e Initial load duke parents: diff changeset	1152 return false;
a61af66fc99e Initial load duke parents: diff changeset	1153 }
a61af66fc99e Initial load duke parents: diff changeset	1154
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1155 // We only discover references whose referents are not (yet)
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1156 // known to be strongly reachable.
0 a61af66fc99e Initial load duke parents: diff changeset	1157 if (is_alive_non_header() != NULL) {
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1158 verify_referent(obj);
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1159 if (is_alive_non_header()->do_object_b(java_lang_ref_Reference::referent(obj))) {
0 a61af66fc99e Initial load duke parents: diff changeset	1160 return false; // referent is reachable
a61af66fc99e Initial load duke parents: diff changeset	1161 }
a61af66fc99e Initial load duke parents: diff changeset	1162 }
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1163 if (rt == REF_SOFT) {
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1164 // 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	1165 // current candidates for clearing, in which case we
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1166 // can mark through them now, rather than delaying that
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1167 // to the reference-processing phase. Since all current
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1168 // time-stamp policies advance the soft-ref clock only
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1169 // at a major collection cycle, this is always currently
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1170 // accurate.
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	1171 if (!_current_soft_ref_policy->should_clear_reference(obj, _soft_ref_timestamp_clock)) {
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1172 return false;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1173 }
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1174 }
0 a61af66fc99e Initial load duke parents: diff changeset	1175
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1176 ResourceMark rm; // Needed for tracing.
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1177
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1178 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	1179 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	1180 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	1181 if (discovered != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1182 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1183 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1184 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1185 obj, obj->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1186 }
a61af66fc99e Initial load duke parents: diff changeset	1187 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
a61af66fc99e Initial load duke parents: diff changeset	1188 // assumes that an object is not processed twice;
a61af66fc99e Initial load duke parents: diff changeset	1189 // if it's been already discovered it must be on another
a61af66fc99e Initial load duke parents: diff changeset	1190 // generation's discovered list; so we won't discover it.
a61af66fc99e Initial load duke parents: diff changeset	1191 return false;
a61af66fc99e Initial load duke parents: diff changeset	1192 } else {
a61af66fc99e Initial load duke parents: diff changeset	1193 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	1194 "Unrecognized policy");
a61af66fc99e Initial load duke parents: diff changeset	1195 // Check assumption that an object is not potentially
a61af66fc99e Initial load duke parents: diff changeset	1196 // discovered twice except by concurrent collectors that potentially
a61af66fc99e Initial load duke parents: diff changeset	1197 // trace the same Reference object twice.
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1198 assert(UseConcMarkSweepGC \|\| UseG1GC,
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1199 "Only possible with a concurrent marking collector");
0 a61af66fc99e Initial load duke parents: diff changeset	1200 return true;
a61af66fc99e Initial load duke parents: diff changeset	1201 }
a61af66fc99e Initial load duke parents: diff changeset	1202 }
a61af66fc99e Initial load duke parents: diff changeset	1203
a61af66fc99e Initial load duke parents: diff changeset	1204 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1205 verify_referent(obj);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1206 // Discover if and only if EITHER:
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1207 // .. reference is in our span, OR
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1208 // .. we are an atomic collector and referent is in our span
0 a61af66fc99e Initial load duke parents: diff changeset	1209 if (_span.contains(obj_addr) \|\|
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1210 (discovery_is_atomic() &&
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1211 _span.contains(java_lang_ref_Reference::referent(obj)))) {
0 a61af66fc99e Initial load duke parents: diff changeset	1212 // should_enqueue = true;
a61af66fc99e Initial load duke parents: diff changeset	1213 } else {
a61af66fc99e Initial load duke parents: diff changeset	1214 return false;
a61af66fc99e Initial load duke parents: diff changeset	1215 }
a61af66fc99e Initial load duke parents: diff changeset	1216 } else {
a61af66fc99e Initial load duke parents: diff changeset	1217 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1218 _span.contains(obj_addr), "code inconsistency");
a61af66fc99e Initial load duke parents: diff changeset	1219 }
a61af66fc99e Initial load duke parents: diff changeset	1220
a61af66fc99e Initial load duke parents: diff changeset	1221 // Get the right type of discovered queue head.
a61af66fc99e Initial load duke parents: diff changeset	1222 DiscoveredList* list = get_discovered_list(rt);
a61af66fc99e Initial load duke parents: diff changeset	1223 if (list == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1224 return false; // nothing special needs to be done
a61af66fc99e Initial load duke parents: diff changeset	1225 }
a61af66fc99e Initial load duke parents: diff changeset	1226
a61af66fc99e Initial load duke parents: diff changeset	1227 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1228 add_to_discovered_list_mt(*list, obj, discovered_addr);
a61af66fc99e Initial load duke parents: diff changeset	1229 } else {
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1230 // If "_discovered_list_needs_barrier", we do write barriers when
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1231 // 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	1232 // 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	1233 // references.
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1234 oop current_head = list->head();
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1235 // The last ref must have its discovered field pointing to itself.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1236 oop next_discovered = (current_head != NULL) ? current_head : obj;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1237
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1238 // 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	1239 // pre-value, we can safely elide the pre-barrier here for the case of G1.
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1240 // e.g.:- _bs->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1241 assert(discovered == NULL, "control point invariant");
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1242 assert(!_discovered_list_needs_barrier \|\| UseG1GC,
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1243 "For non-G1 collector, may need a pre-write-barrier for CAS from NULL below");
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1244 oop_store_raw(discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1245 if (_discovered_list_needs_barrier) {
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1246 _bs->write_ref_field((void*)discovered_addr, next_discovered);
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1247 }
0 a61af66fc99e Initial load duke parents: diff changeset	1248 list->set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1249 list->inc_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	1250
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1251 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1252 gclog_or_tty->print_cr("Discovered reference (" INTPTR_FORMAT ": %s)",
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1253 obj, obj->blueprint()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1254 }
a61af66fc99e Initial load duke parents: diff changeset	1255 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1256 assert(obj->is_oop(), "Discovered a bad reference");
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1257 verify_referent(obj);
0 a61af66fc99e Initial load duke parents: diff changeset	1258 return true;
a61af66fc99e Initial load duke parents: diff changeset	1259 }
a61af66fc99e Initial load duke parents: diff changeset	1260
a61af66fc99e Initial load duke parents: diff changeset	1261 // Preclean the discovered references by removing those
a61af66fc99e Initial load duke parents: diff changeset	1262 // whose referents are alive, and by marking from those that
a61af66fc99e Initial load duke parents: diff changeset	1263 // are not active. These lists can be handled here
a61af66fc99e Initial load duke parents: diff changeset	1264 // in any order and, indeed, concurrently.
a61af66fc99e Initial load duke parents: diff changeset	1265 void ReferenceProcessor::preclean_discovered_references(
a61af66fc99e Initial load duke parents: diff changeset	1266 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1267 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	1268 VoidClosure* complete_gc,
1190 4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1269 YieldClosure* yield,
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1270 bool should_unload_classes) {
0 a61af66fc99e Initial load duke parents: diff changeset	1271
a61af66fc99e Initial load duke parents: diff changeset	1272 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	1273
935 05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1274 #ifdef ASSERT
05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1275 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	1276 CMSClassUnloadingEnabled && UseConcMarkSweepGC \|\|
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1277 ExplicitGCInvokesConcurrentAndUnloadsClasses &&
4788266644c1 6895236: CMS: cmsOopClosures.inline.hpp:43 assert(..., "Should remember klasses in this context") jmasa parents: 1144 diff changeset	1278 UseConcMarkSweepGC && should_unload_classes;
935 05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1279 RememberKlassesChecker mx(must_remember_klasses);
05f89f00a864 6798898: CMS: bugs related to class unloading jmasa parents: 845 diff changeset	1280 #endif
0 a61af66fc99e Initial load duke parents: diff changeset	1281 // Soft references
a61af66fc99e Initial load duke parents: diff changeset	1282 {
a61af66fc99e Initial load duke parents: diff changeset	1283 TraceTime tt("Preclean SoftReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1284 false, gclog_or_tty);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1285 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	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(_discoveredSoftRefs[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 // Weak references
a61af66fc99e Initial load duke parents: diff changeset	1295 {
a61af66fc99e Initial load duke parents: diff changeset	1296 TraceTime tt("Preclean WeakReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1297 false, gclog_or_tty);
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1298 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1299 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1300 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1301 }
0 a61af66fc99e Initial load duke parents: diff changeset	1302 preclean_discovered_reflist(_discoveredWeakRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1303 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1304 }
a61af66fc99e Initial load duke parents: diff changeset	1305 }
a61af66fc99e Initial load duke parents: diff changeset	1306
a61af66fc99e Initial load duke parents: diff changeset	1307 // Final references
a61af66fc99e Initial load duke parents: diff changeset	1308 {
a61af66fc99e Initial load duke parents: diff changeset	1309 TraceTime tt("Preclean FinalReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1310 false, gclog_or_tty);
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1311 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1312 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1313 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1314 }
0 a61af66fc99e Initial load duke parents: diff changeset	1315 preclean_discovered_reflist(_discoveredFinalRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1316 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1317 }
a61af66fc99e Initial load duke parents: diff changeset	1318 }
a61af66fc99e Initial load duke parents: diff changeset	1319
a61af66fc99e Initial load duke parents: diff changeset	1320 // Phantom references
a61af66fc99e Initial load duke parents: diff changeset	1321 {
a61af66fc99e Initial load duke parents: diff changeset	1322 TraceTime tt("Preclean PhantomReferences", PrintGCDetails && PrintReferenceGC,
a61af66fc99e Initial load duke parents: diff changeset	1323 false, gclog_or_tty);
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1324 for (int i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1325 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1326 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1327 }
0 a61af66fc99e Initial load duke parents: diff changeset	1328 preclean_discovered_reflist(_discoveredPhantomRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1329 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1330 }
a61af66fc99e Initial load duke parents: diff changeset	1331 }
a61af66fc99e Initial load duke parents: diff changeset	1332 }
a61af66fc99e Initial load duke parents: diff changeset	1333
a61af66fc99e Initial load duke parents: diff changeset	1334 // Walk the given discovered ref list, and remove all reference objects
a61af66fc99e Initial load duke parents: diff changeset	1335 // 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	1336 // 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	1337 // 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	1338 // 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	1339 // 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	1340 // 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	1341 // (in this thread).
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1342 void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1343 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	1344 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1345 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1346 VoidClosure* complete_gc,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1347 YieldClosure* yield) {
0 a61af66fc99e Initial load duke parents: diff changeset	1348 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
a61af66fc99e Initial load duke parents: diff changeset	1349 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	1350 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	1351 oop obj = iter.obj();
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1352 oop next = java_lang_ref_Reference::next(obj);
0 a61af66fc99e Initial load duke parents: diff changeset	1353 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	1354 next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1355 // The referent has been cleared, or is alive, or the Reference is not
a61af66fc99e Initial load duke parents: diff changeset	1356 // active; we need to trace and mark its cohort.
a61af66fc99e Initial load duke parents: diff changeset	1357 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1358 gclog_or_tty->print_cr("Precleaning Reference (" INTPTR_FORMAT ": %s)",
a61af66fc99e Initial load duke parents: diff changeset	1359 iter.obj(), iter.obj()->blueprint()->internal_name());
a61af66fc99e Initial load duke parents: diff changeset	1360 }
a61af66fc99e Initial load duke parents: diff changeset	1361 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	1362 iter.remove();
a61af66fc99e Initial load duke parents: diff changeset	1363 // Keep alive its cohort.
a61af66fc99e Initial load duke parents: diff changeset	1364 iter.make_referent_alive();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1365 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1366 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	1367 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	1368 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1369 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	1370 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	1371 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1372 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	1373 } else {
a61af66fc99e Initial load duke parents: diff changeset	1374 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	1375 }
a61af66fc99e Initial load duke parents: diff changeset	1376 }
a61af66fc99e Initial load duke parents: diff changeset	1377 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	1378 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	1379
a61af66fc99e Initial load duke parents: diff changeset	1380 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	1381 if (PrintGCDetails && PrintReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1382 gclog_or_tty->print_cr(" Dropped %d Refs out of %d "
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1383 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1384 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	1385 }
a61af66fc99e Initial load duke parents: diff changeset	1386 )
a61af66fc99e Initial load duke parents: diff changeset	1387 }
a61af66fc99e Initial load duke parents: diff changeset	1388
a61af66fc99e Initial load duke parents: diff changeset	1389 const char* ReferenceProcessor::list_name(int i) {
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1390 assert(i >= 0 && i <= _max_num_q * number_of_subclasses_of_ref(),
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1391 "Out of bounds index");
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1392
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1393 int j = i / _max_num_q;
0 a61af66fc99e Initial load duke parents: diff changeset	1394 switch (j) {
a61af66fc99e Initial load duke parents: diff changeset	1395 case 0: return "SoftRef";
a61af66fc99e Initial load duke parents: diff changeset	1396 case 1: return "WeakRef";
a61af66fc99e Initial load duke parents: diff changeset	1397 case 2: return "FinalRef";
a61af66fc99e Initial load duke parents: diff changeset	1398 case 3: return "PhantomRef";
a61af66fc99e Initial load duke parents: diff changeset	1399 }
a61af66fc99e Initial load duke parents: diff changeset	1400 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1401 return NULL;
a61af66fc99e Initial load duke parents: diff changeset	1402 }
a61af66fc99e Initial load duke parents: diff changeset	1403
a61af66fc99e Initial load duke parents: diff changeset	1404 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1405 void ReferenceProcessor::verify_ok_to_handle_reflists() {
a61af66fc99e Initial load duke parents: diff changeset	1406 // empty for now
a61af66fc99e Initial load duke parents: diff changeset	1407 }
a61af66fc99e Initial load duke parents: diff changeset	1408 #endif
a61af66fc99e Initial load duke parents: diff changeset	1409
a61af66fc99e Initial load duke parents: diff changeset	1410 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1411 void ReferenceProcessor::clear_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	1412 guarantee(!_discovering_refs, "Discovering refs?");
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1413 for (int i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	1414 clear_discovered_references(_discovered_refs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	1415 }
a61af66fc99e Initial load duke parents: diff changeset	1416 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1417
0 a61af66fc99e Initial load duke parents: diff changeset	1418 #endif // PRODUCT

Mercurial > hg > truffle

annotate src/share/vm/memory/referenceProcessor.cpp @ 4712:e7dead7e90af