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

annotate src/share/vm/memory/referenceProcessor.cpp @ 20755:01dcaba9b3f3

8047125: (ref) More phantom object references Reviewed-by: mchung, dfuchs, ahgross, jmasa, brutisso, mgerdin Contributed-by: kim.barrett@oracle.com

author	jmasa
date	Fri, 26 Sep 2014 17:48:10 -0400
parents	8e20ef014b08
children	c2844108a708

rev	line source
0 a61af66fc99e Initial load duke parents: diff changeset	1 /*
17937 78bbf4d43a14 8037816: Fix for 8036122 breaks build with Xcode5/clang drchase parents: 17748 diff changeset	2 * Copyright (c) 2001, 2014, 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"
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	28 #include "gc_implementation/shared/gcTimer.hpp"
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	29 #include "gc_implementation/shared/gcTraceTime.hpp"
1972 f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	30 #include "gc_interface/collectedHeap.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	31 #include "gc_interface/collectedHeap.inline.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	32 #include "memory/referencePolicy.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	33 #include "memory/referenceProcessor.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	34 #include "oops/oop.inline.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	35 #include "runtime/java.hpp"
f95d63e2154a 6989984: Use standard include model for Hospot stefank parents: 1833 diff changeset	36 #include "runtime/jniHandles.hpp"
0 a61af66fc99e Initial load duke parents: diff changeset	37
17937 78bbf4d43a14 8037816: Fix for 8036122 breaks build with Xcode5/clang drchase parents: 17748 diff changeset	38 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
78bbf4d43a14 8037816: Fix for 8036122 breaks build with Xcode5/clang drchase parents: 17748 diff changeset	39
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	40 ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	41 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	42 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	43 jlong ReferenceProcessor::_soft_ref_timestamp_clock = 0;
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	44
0 a61af66fc99e Initial load duke parents: diff changeset	45 void referenceProcessor_init() {
a61af66fc99e Initial load duke parents: diff changeset	46 ReferenceProcessor::init_statics();
a61af66fc99e Initial load duke parents: diff changeset	47 }
a61af66fc99e Initial load duke parents: diff changeset	48
a61af66fc99e Initial load duke parents: diff changeset	49 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	50 // 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	51 // 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	52 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	53
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	54 // Initialize the soft ref timestamp clock.
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	55 _soft_ref_timestamp_clock = now;
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	56 // 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	57 java_lang_ref_SoftReference::set_clock(_soft_ref_timestamp_clock);
0 a61af66fc99e Initial load duke parents: diff changeset	58
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	59 _always_clear_soft_ref_policy = new AlwaysClearPolicy();
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	60 _default_soft_ref_policy = new COMPILER2_PRESENT(LRUMaxHeapPolicy())
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	61 NOT_COMPILER2(LRUCurrentHeapPolicy());
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	62 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	63 vm_exit_during_initialization("Could not allocate reference policy object");
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	64 }
0 a61af66fc99e Initial load duke parents: diff changeset	65 guarantee(RefDiscoveryPolicy == ReferenceBasedDiscovery \|\|
a61af66fc99e Initial load duke parents: diff changeset	66 RefDiscoveryPolicy == ReferentBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	67 "Unrecongnized RefDiscoveryPolicy");
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	68 _pending_list_uses_discovered_field = JDK_Version::current().pending_list_uses_discovered_field();
0 a61af66fc99e Initial load duke parents: diff changeset	69 }
a61af66fc99e Initial load duke parents: diff changeset	70
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	71 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	72 #ifdef ASSERT
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	73 // 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	74 assert(!verify_disabled \|\| !_discovering_refs, "nested call?");
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 if (check_no_refs) {
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	77 // Verify that the discovered lists are empty
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	78 verify_no_references_recorded();
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	79 }
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	80 #endif // ASSERT
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	81
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	82 // 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	83 // 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	84 // soft reference timestamp clock using reflection or
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	85 // Unsafe between GCs. Unconditionally update the static
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	86 // 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	87 // value during reference discovery.
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	88
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	89 _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	90 _discovering_refs = true;
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	91 }
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	92
0 a61af66fc99e Initial load duke parents: diff changeset	93 ReferenceProcessor::ReferenceProcessor(MemRegion span,
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	94 bool mt_processing,
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	95 uint mt_processing_degree,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	96 bool mt_discovery,
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	97 uint mt_discovery_degree,
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	98 bool atomic_discovery,
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	99 BoolObjectClosure* is_alive_non_header) :
0 a61af66fc99e Initial load duke parents: diff changeset	100 _discovering_refs(false),
a61af66fc99e Initial load duke parents: diff changeset	101 _enqueuing_is_done(false),
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	102 _is_alive_non_header(is_alive_non_header),
0 a61af66fc99e Initial load duke parents: diff changeset	103 _processing_is_mt(mt_processing),
a61af66fc99e Initial load duke parents: diff changeset	104 _next_id(0)
a61af66fc99e Initial load duke parents: diff changeset	105 {
a61af66fc99e Initial load duke parents: diff changeset	106 _span = span;
a61af66fc99e Initial load duke parents: diff changeset	107 _discovery_is_atomic = atomic_discovery;
a61af66fc99e Initial load duke parents: diff changeset	108 _discovery_is_mt = mt_discovery;
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	109 _num_q = MAX2(1U, mt_processing_degree);
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	110 _max_num_q = MAX2(_num_q, mt_discovery_degree);
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	111 _discovered_refs = NEW_C_HEAP_ARRAY(DiscoveredList,
6197 d2a62e0f25eb 6995781: Native Memory Tracking (Phase 1) zgu parents: 4728 diff changeset	112 _max_num_q * number_of_subclasses_of_ref(), mtGC);
d2a62e0f25eb 6995781: Native Memory Tracking (Phase 1) zgu parents: 4728 diff changeset	113
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	114 if (_discovered_refs == NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	115 vm_exit_during_initialization("Could not allocated RefProc Array");
a61af66fc99e Initial load duke parents: diff changeset	116 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	117 _discoveredSoftRefs = &_discovered_refs[0];
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	118 _discoveredWeakRefs = &_discoveredSoftRefs[_max_num_q];
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	119 _discoveredFinalRefs = &_discoveredWeakRefs[_max_num_q];
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	120 _discoveredPhantomRefs = &_discoveredFinalRefs[_max_num_q];
20755 01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	121 _discoveredCleanerRefs = &_discoveredPhantomRefs[_max_num_q];
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	122
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	123 // Initialize all entries to NULL
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	124 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	125 _discovered_refs[i].set_head(NULL);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	126 _discovered_refs[i].set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	127 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	128
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	129 setup_policy(false /* default soft ref policy */);
0 a61af66fc99e Initial load duke parents: diff changeset	130 }
a61af66fc99e Initial load duke parents: diff changeset	131
a61af66fc99e Initial load duke parents: diff changeset	132 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	133 void ReferenceProcessor::verify_no_references_recorded() {
a61af66fc99e Initial load duke parents: diff changeset	134 guarantee(!_discovering_refs, "Discovering refs?");
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	135 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	136 guarantee(_discovered_refs[i].is_empty(),
0 a61af66fc99e Initial load duke parents: diff changeset	137 "Found non-empty discovered list");
a61af66fc99e Initial load duke parents: diff changeset	138 }
a61af66fc99e Initial load duke parents: diff changeset	139 }
a61af66fc99e Initial load duke parents: diff changeset	140 #endif
a61af66fc99e Initial load duke parents: diff changeset	141
a61af66fc99e Initial load duke parents: diff changeset	142 void ReferenceProcessor::weak_oops_do(OopClosure* f) {
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	143 for (uint 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	144 if (UseCompressedOops) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	145 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	146 } else {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	147 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	148 }
0 a61af66fc99e Initial load duke parents: diff changeset	149 }
a61af66fc99e Initial load duke parents: diff changeset	150 }
a61af66fc99e Initial load duke parents: diff changeset	151
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	152 void ReferenceProcessor::update_soft_ref_master_clock() {
0 a61af66fc99e Initial load duke parents: diff changeset	153 // Update (advance) the soft ref master clock field. This must be done
a61af66fc99e Initial load duke parents: diff changeset	154 // 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	155
e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	156 // 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	157 // 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	158 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	159 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	160 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	161
0 a61af66fc99e Initial load duke parents: diff changeset	162 NOT_PRODUCT(
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	163 if (now < _soft_ref_timestamp_clock) {
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	164 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	165 _soft_ref_timestamp_clock, now);
0 a61af66fc99e Initial load duke parents: diff changeset	166 }
a61af66fc99e Initial load duke parents: diff changeset	167 )
4712 e7dead7e90af 7117303: VM uses non-monotonic time source and complains that it is non-monotonic johnc parents: 4014 diff changeset	168 // 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	169 // 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	170 // 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	171 // 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	172 // 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	173 if (now > _soft_ref_timestamp_clock) {
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	174 _soft_ref_timestamp_clock = now;
0 a61af66fc99e Initial load duke parents: diff changeset	175 java_lang_ref_SoftReference::set_clock(now);
a61af66fc99e Initial load duke parents: diff changeset	176 }
a61af66fc99e Initial load duke parents: diff changeset	177 // Else leave clock stalled at its old value until time progresses
a61af66fc99e Initial load duke parents: diff changeset	178 // past clock value.
a61af66fc99e Initial load duke parents: diff changeset	179 }
a61af66fc99e Initial load duke parents: diff changeset	180
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	181 size_t ReferenceProcessor::total_count(DiscoveredList lists[]) {
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	182 size_t total = 0;
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	183 for (uint i = 0; i < _max_num_q; ++i) {
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	184 total += lists[i].length();
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	185 }
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	186 return total;
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	187 }
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	188
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	189 ReferenceProcessorStats ReferenceProcessor::process_discovered_references(
0 a61af66fc99e Initial load duke parents: diff changeset	190 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	191 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	192 VoidClosure* complete_gc,
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	193 AbstractRefProcTaskExecutor* task_executor,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	194 GCTimer* gc_timer) {
0 a61af66fc99e Initial load duke parents: diff changeset	195 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	196
a61af66fc99e Initial load duke parents: diff changeset	197 assert(!enqueuing_is_done(), "If here enqueuing should not be complete");
a61af66fc99e Initial load duke parents: diff changeset	198 // Stop treating discovered references specially.
a61af66fc99e Initial load duke parents: diff changeset	199 disable_discovery();
a61af66fc99e Initial load duke parents: diff changeset	200
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	201 // 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	202 // 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	203 // 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	204 // 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	205 // 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	206 // 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	207 // discovered soft refs.
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	208
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	209 _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	210
0 a61af66fc99e Initial load duke parents: diff changeset	211 bool trace_time = PrintGCDetails && PrintReferenceGC;
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	212
0 a61af66fc99e Initial load duke parents: diff changeset	213 // Soft references
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	214 size_t soft_count = 0;
0 a61af66fc99e Initial load duke parents: diff changeset	215 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	216 GCTraceTime tt("SoftReference", trace_time, false, gc_timer);
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	217 soft_count =
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	218 process_discovered_reflist(_discoveredSoftRefs, _current_soft_ref_policy, true,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	219 is_alive, keep_alive, complete_gc, task_executor);
0 a61af66fc99e Initial load duke parents: diff changeset	220 }
a61af66fc99e Initial load duke parents: diff changeset	221
a61af66fc99e Initial load duke parents: diff changeset	222 update_soft_ref_master_clock();
a61af66fc99e Initial load duke parents: diff changeset	223
a61af66fc99e Initial load duke parents: diff changeset	224 // Weak references
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	225 size_t weak_count = 0;
0 a61af66fc99e Initial load duke parents: diff changeset	226 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	227 GCTraceTime tt("WeakReference", trace_time, false, gc_timer);
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	228 weak_count =
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	229 process_discovered_reflist(_discoveredWeakRefs, NULL, true,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	230 is_alive, keep_alive, complete_gc, task_executor);
0 a61af66fc99e Initial load duke parents: diff changeset	231 }
a61af66fc99e Initial load duke parents: diff changeset	232
a61af66fc99e Initial load duke parents: diff changeset	233 // Final references
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	234 size_t final_count = 0;
0 a61af66fc99e Initial load duke parents: diff changeset	235 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	236 GCTraceTime tt("FinalReference", trace_time, false, gc_timer);
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	237 final_count =
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	238 process_discovered_reflist(_discoveredFinalRefs, NULL, false,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	239 is_alive, keep_alive, complete_gc, task_executor);
0 a61af66fc99e Initial load duke parents: diff changeset	240 }
a61af66fc99e Initial load duke parents: diff changeset	241
a61af66fc99e Initial load duke parents: diff changeset	242 // Phantom references
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	243 size_t phantom_count = 0;
0 a61af66fc99e Initial load duke parents: diff changeset	244 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	245 GCTraceTime tt("PhantomReference", trace_time, false, gc_timer);
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	246 phantom_count =
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	247 process_discovered_reflist(_discoveredPhantomRefs, NULL, false,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	248 is_alive, keep_alive, complete_gc, task_executor);
20755 01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	249
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	250 // Process cleaners, but include them in phantom statistics. We expect
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	251 // Cleaner references to be temporary, and don't want to deal with
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	252 // possible incompatibilities arising from making it more visible.
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	253 phantom_count +=
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	254 process_discovered_reflist(_discoveredCleanerRefs, NULL, false,
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	255 is_alive, keep_alive, complete_gc, task_executor);
0 a61af66fc99e Initial load duke parents: diff changeset	256 }
a61af66fc99e Initial load duke parents: diff changeset	257
a61af66fc99e Initial load duke parents: diff changeset	258 // Weak global JNI references. It would make more sense (semantically) to
a61af66fc99e Initial load duke parents: diff changeset	259 // traverse these simultaneously with the regular weak references above, but
a61af66fc99e Initial load duke parents: diff changeset	260 // that is not how the JDK1.2 specification is. See #4126360. Native code can
a61af66fc99e Initial load duke parents: diff changeset	261 // thus use JNI weak references to circumvent the phantom references and
a61af66fc99e Initial load duke parents: diff changeset	262 // resurrect a "post-mortem" object.
a61af66fc99e Initial load duke parents: diff changeset	263 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	264 GCTraceTime tt("JNI Weak Reference", trace_time, false, gc_timer);
0 a61af66fc99e Initial load duke parents: diff changeset	265 if (task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	266 task_executor->set_single_threaded_mode();
a61af66fc99e Initial load duke parents: diff changeset	267 }
a61af66fc99e Initial load duke parents: diff changeset	268 process_phaseJNI(is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	269 }
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	270
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	271 return ReferenceProcessorStats(soft_count, weak_count, final_count, phantom_count);
0 a61af66fc99e Initial load duke parents: diff changeset	272 }
a61af66fc99e Initial load duke parents: diff changeset	273
a61af66fc99e Initial load duke parents: diff changeset	274 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	275 // 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	276 uint ReferenceProcessor::count_jni_refs() {
0 a61af66fc99e Initial load duke parents: diff changeset	277 class AlwaysAliveClosure: public BoolObjectClosure {
a61af66fc99e Initial load duke parents: diff changeset	278 public:
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	279 virtual bool do_object_b(oop obj) { return true; }
0 a61af66fc99e Initial load duke parents: diff changeset	280 };
a61af66fc99e Initial load duke parents: diff changeset	281
a61af66fc99e Initial load duke parents: diff changeset	282 class CountHandleClosure: public OopClosure {
a61af66fc99e Initial load duke parents: diff changeset	283 private:
a61af66fc99e Initial load duke parents: diff changeset	284 int _count;
a61af66fc99e Initial load duke parents: diff changeset	285 public:
a61af66fc99e Initial load duke parents: diff changeset	286 CountHandleClosure(): _count(0) {}
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	287 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	288 void do_oop(narrowOop* unused) { ShouldNotReachHere(); }
0 a61af66fc99e Initial load duke parents: diff changeset	289 int count() { return _count; }
a61af66fc99e Initial load duke parents: diff changeset	290 };
a61af66fc99e Initial load duke parents: diff changeset	291 CountHandleClosure global_handle_count;
a61af66fc99e Initial load duke parents: diff changeset	292 AlwaysAliveClosure always_alive;
a61af66fc99e Initial load duke parents: diff changeset	293 JNIHandles::weak_oops_do(&always_alive, &global_handle_count);
a61af66fc99e Initial load duke parents: diff changeset	294 return global_handle_count.count();
a61af66fc99e Initial load duke parents: diff changeset	295 }
a61af66fc99e Initial load duke parents: diff changeset	296 #endif
a61af66fc99e Initial load duke parents: diff changeset	297
a61af66fc99e Initial load duke parents: diff changeset	298 void ReferenceProcessor::process_phaseJNI(BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	299 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	300 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	301 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	302 if (PrintGCDetails && PrintReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	303 unsigned int count = count_jni_refs();
a61af66fc99e Initial load duke parents: diff changeset	304 gclog_or_tty->print(", %u refs", count);
a61af66fc99e Initial load duke parents: diff changeset	305 }
a61af66fc99e Initial load duke parents: diff changeset	306 #endif
a61af66fc99e Initial load duke parents: diff changeset	307 JNIHandles::weak_oops_do(is_alive, keep_alive);
a61af66fc99e Initial load duke parents: diff changeset	308 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	309 }
a61af66fc99e Initial load duke parents: diff changeset	310
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	311
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	312 template <class T>
1123 167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	313 bool enqueue_discovered_ref_helper(ReferenceProcessor* ref,
167c2986d91b 6843629: Make current hotspot build part of jdk5 control build phh parents: 935 diff changeset	314 AbstractRefProcTaskExecutor* task_executor) {
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	315
0 a61af66fc99e Initial load duke parents: diff changeset	316 // 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	317 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	318 T old_pending_list_value = *pending_list_addr;
0 a61af66fc99e Initial load duke parents: diff changeset	319
a61af66fc99e Initial load duke parents: diff changeset	320 // Enqueue references that are not made active again, and
a61af66fc99e Initial load duke parents: diff changeset	321 // 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	322 ref->enqueue_discovered_reflists((HeapWord*)pending_list_addr, task_executor);
17746 a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	323 // Do the post-barrier on pending_list_addr missed in
a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	324 // enqueue_discovered_reflist.
a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	325 oopDesc::bs()->write_ref_field(pending_list_addr, oopDesc::load_decode_heap_oop(pending_list_addr));
0 a61af66fc99e Initial load duke parents: diff changeset	326
a61af66fc99e Initial load duke parents: diff changeset	327 // 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	328 ref->disable_discovery();
0 a61af66fc99e Initial load duke parents: diff changeset	329
a61af66fc99e Initial load duke parents: diff changeset	330 // Return true if new pending references were added
a61af66fc99e Initial load duke parents: diff changeset	331 return old_pending_list_value != *pending_list_addr;
a61af66fc99e Initial load duke parents: diff changeset	332 }
a61af66fc99e Initial load duke parents: diff changeset	333
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	334 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	335 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	336 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	337 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	338 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	339 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	340 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	341 }
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	342
0 a61af66fc99e Initial load duke parents: diff changeset	343 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	344 HeapWord* pending_list_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	345 // 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	346 // (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	347 // 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	348 // prepend them to the pending list.
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	349 //
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	350 // The Java threads will see the Reference objects linked together through
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	351 // the discovered field. Instead of trying to do the write barrier updates
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	352 // in all places in the reference processor where we manipulate the discovered
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	353 // field we make sure to do the barrier here where we anyway iterate through
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	354 // all linked Reference objects. Note that it is important to not dirty any
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	355 // cards during reference processing since this will cause card table
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	356 // verification to fail for G1.
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	357 //
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	358 // 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	359 // 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	360 // field.
0 a61af66fc99e Initial load duke parents: diff changeset	361 if (TraceReferenceGC && PrintGCDetails) {
a61af66fc99e Initial load duke parents: diff changeset	362 gclog_or_tty->print_cr("ReferenceProcessor::enqueue_discovered_reflist list "
a61af66fc99e Initial load duke parents: diff changeset	363 INTPTR_FORMAT, (address)refs_list.head());
a61af66fc99e Initial load duke parents: diff changeset	364 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	365
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	366 oop obj = NULL;
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	367 oop next_d = refs_list.head();
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	368 if (pending_list_uses_discovered_field()) { // New behavior
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	369 // 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	370 // 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	371 while (obj != next_d) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	372 obj = next_d;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	373 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	374 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	375 if (TraceReferenceGC && PrintGCDetails) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	376 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	377 (void )obj, (void )next_d);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	378 }
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	379 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	380 "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	381 // Self-loop next, so as to make Ref not active.
17746 a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	382 java_lang_ref_Reference::set_next_raw(obj, obj);
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	383 if (next_d != obj) {
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	384 oopDesc::bs()->write_ref_field(java_lang_ref_Reference::discovered_addr(obj), next_d);
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	385 } else {
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	386 // This is the last object.
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	387 // Swap refs_list into pending_list_addr and
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	388 // 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	389 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	390 // Need post-barrier on pending_list_addr. See enqueue_discovered_ref_helper() above.
17746 a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	391 java_lang_ref_Reference::set_discovered_raw(obj, old); // old may be NULL
a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	392 oopDesc::bs()->write_ref_field(java_lang_ref_Reference::discovered_addr(obj), old);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	393 }
0 a61af66fc99e Initial load duke parents: diff changeset	394 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	395 } else { // Old behaviour
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	396 // 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	397 // 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	398 while (obj != next_d) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	399 obj = next_d;
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	400 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	401 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	402 if (TraceReferenceGC && PrintGCDetails) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	403 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	404 (void )obj, (void )next_d);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	405 }
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	406 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	407 "The reference should not be enqueued");
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	408 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	409 // 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	410 // 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	411 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	412 // 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	413 // 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	414 // enqueue_discovered_reflists() further below.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	415 if (old == NULL) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	416 // 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	417 // pending list was empty.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	418 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	419 } else {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	420 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	421 }
0 a61af66fc99e Initial load duke parents: diff changeset	422 } else {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	423 java_lang_ref_Reference::set_next(obj, next_d);
0 a61af66fc99e Initial load duke parents: diff changeset	424 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	425 java_lang_ref_Reference::set_discovered(obj, (oop) NULL);
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 // Parallel enqueue task
a61af66fc99e Initial load duke parents: diff changeset	431 class RefProcEnqueueTask: public AbstractRefProcTaskExecutor::EnqueueTask {
a61af66fc99e Initial load duke parents: diff changeset	432 public:
a61af66fc99e Initial load duke parents: diff changeset	433 RefProcEnqueueTask(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	434 DiscoveredList discovered_refs[],
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	435 HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	436 int n_queues)
a61af66fc99e Initial load duke parents: diff changeset	437 : EnqueueTask(ref_processor, discovered_refs,
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	438 pending_list_addr, n_queues)
0 a61af66fc99e Initial load duke parents: diff changeset	439 { }
a61af66fc99e Initial load duke parents: diff changeset	440
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	441 virtual void work(unsigned int work_id) {
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	442 assert(work_id < (unsigned int)_ref_processor.max_num_q(), "Index out-of-bounds");
0 a61af66fc99e Initial load duke parents: diff changeset	443 // Simplest first cut: static partitioning.
a61af66fc99e Initial load duke parents: diff changeset	444 int index = work_id;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	445 // 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	446 // (n_queues) with which that ReferenceProcessor was created. That
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	447 // 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	448 // allocated and are indexed into.
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	449 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	450 for (int j = 0;
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	451 j < ReferenceProcessor::number_of_subclasses_of_ref();
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	452 j++, index += _n_queues) {
0 a61af66fc99e Initial load duke parents: diff changeset	453 _ref_processor.enqueue_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	454 _refs_lists[index], _pending_list_addr);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	455 _refs_lists[index].set_head(NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	456 _refs_lists[index].set_length(0);
a61af66fc99e Initial load duke parents: diff changeset	457 }
a61af66fc99e Initial load duke parents: diff changeset	458 }
a61af66fc99e Initial load duke parents: diff changeset	459 };
a61af66fc99e Initial load duke parents: diff changeset	460
a61af66fc99e Initial load duke parents: diff changeset	461 // 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	462 void ReferenceProcessor::enqueue_discovered_reflists(HeapWord* pending_list_addr,
0 a61af66fc99e Initial load duke parents: diff changeset	463 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load duke parents: diff changeset	464 if (_processing_is_mt && task_executor != NULL) {
a61af66fc99e Initial load duke parents: diff changeset	465 // Parallel code
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	466 RefProcEnqueueTask tsk(*this, _discovered_refs,
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	467 pending_list_addr, _max_num_q);
0 a61af66fc99e Initial load duke parents: diff changeset	468 task_executor->execute(tsk);
a61af66fc99e Initial load duke parents: diff changeset	469 } else {
a61af66fc99e Initial load duke parents: diff changeset	470 // Serial code: call the parent class's implementation
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	471 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	472 enqueue_discovered_reflist(_discovered_refs[i], pending_list_addr);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	473 _discovered_refs[i].set_head(NULL);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	474 _discovered_refs[i].set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	475 }
a61af66fc99e Initial load duke parents: diff changeset	476 }
a61af66fc99e Initial load duke parents: diff changeset	477 }
a61af66fc99e Initial load duke parents: diff changeset	478
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	479 void DiscoveredListIterator::load_ptrs(DEBUG_ONLY(bool allow_null_referent)) {
0 a61af66fc99e Initial load duke parents: diff changeset	480 _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	481 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	482 assert(_discovered_addr && discovered->is_oop_or_null(),
0 a61af66fc99e Initial load duke parents: diff changeset	483 "discovered field is bad");
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	484 _next = discovered;
0 a61af66fc99e Initial load duke parents: diff changeset	485 _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	486 _referent = java_lang_ref_Reference::referent(_ref);
0 a61af66fc99e Initial load duke parents: diff changeset	487 assert(Universe::heap()->is_in_reserved_or_null(_referent),
a61af66fc99e Initial load duke parents: diff changeset	488 "Wrong oop found in java.lang.Reference object");
a61af66fc99e Initial load duke parents: diff changeset	489 assert(allow_null_referent ?
a61af66fc99e Initial load duke parents: diff changeset	490 _referent->is_oop_or_null()
a61af66fc99e Initial load duke parents: diff changeset	491 : _referent->is_oop(),
a61af66fc99e Initial load duke parents: diff changeset	492 "bad referent");
a61af66fc99e Initial load duke parents: diff changeset	493 }
a61af66fc99e Initial load duke parents: diff changeset	494
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	495 void DiscoveredListIterator::remove() {
0 a61af66fc99e Initial load duke parents: diff changeset	496 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	497 oop_store_raw(_discovered_addr, NULL);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	498
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	499 // 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	500 oop new_next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	501 if (_next == _ref) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	502 // 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	503 // 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	504 // and _prev will be NULL.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	505 new_next = _prev;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	506 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	507 new_next = _next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	508 }
17748 d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor pliden parents: 17746 diff changeset	509 // Remove Reference object from discovered list. Note that G1 does not need a
d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor pliden parents: 17746 diff changeset	510 // pre-barrier here because we know the Reference has already been found/marked,
d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor pliden parents: 17746 diff changeset	511 // that's how it ended up in the discovered list in the first place.
d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor pliden parents: 17746 diff changeset	512 oop_store_raw(_prev_next, new_next);
0 a61af66fc99e Initial load duke parents: diff changeset	513 NOT_PRODUCT(_removed++);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	514 _refs_list.dec_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	515 }
a61af66fc99e Initial load duke parents: diff changeset	516
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	517 // Make the Reference object active again.
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	518 void DiscoveredListIterator::make_active() {
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	519 // The pre barrier for G1 is probably just needed for the old
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	520 // reference processing behavior. Should we guard this with
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	521 // ReferenceProcessor::pending_list_uses_discovered_field() ?
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	522 if (UseG1GC) {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	523 HeapWord* next_addr = java_lang_ref_Reference::next_addr(_ref);
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	524 if (UseCompressedOops) {
17746 a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	525 oopDesc::bs()->write_ref_field_pre((narrowOop*)next_addr, NULL);
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	526 } else {
17746 a258f8cb530f 8029255: G1: Reference processing should not enqueue references on the shared SATB queue pliden parents: 12316 diff changeset	527 oopDesc::bs()->write_ref_field_pre((oop*)next_addr, NULL);
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	528 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	529 }
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	530 java_lang_ref_Reference::set_next_raw(_ref, NULL);
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	531 }
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	532
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	533 void DiscoveredListIterator::clear_referent() {
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	534 oop_store_raw(_referent_addr, NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	535 }
a61af66fc99e Initial load duke parents: diff changeset	536
a61af66fc99e Initial load duke parents: diff changeset	537 // NOTE: process_phase*() are largely similar, and at a high level
a61af66fc99e Initial load duke parents: diff changeset	538 // merely iterate over the extant list applying a predicate to
a61af66fc99e Initial load duke parents: diff changeset	539 // each of its elements and possibly removing that element from the
a61af66fc99e Initial load duke parents: diff changeset	540 // list and applying some further closures to that element.
a61af66fc99e Initial load duke parents: diff changeset	541 // We should consider the possibility of replacing these
a61af66fc99e Initial load duke parents: diff changeset	542 // process_phase*() methods by abstracting them into
a61af66fc99e Initial load duke parents: diff changeset	543 // a single general iterator invocation that receives appropriate
a61af66fc99e Initial load duke parents: diff changeset	544 // closures that accomplish this work.
a61af66fc99e Initial load duke parents: diff changeset	545
a61af66fc99e Initial load duke parents: diff changeset	546 // (SoftReferences only) Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	547 // referents are not alive, but that should be kept alive for policy reasons.
a61af66fc99e Initial load duke parents: diff changeset	548 // Keep alive the transitive closure of all such referents.
a61af66fc99e Initial load duke parents: diff changeset	549 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	550 ReferenceProcessor::process_phase1(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	551 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	552 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	553 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	554 VoidClosure* complete_gc) {
a61af66fc99e Initial load duke parents: diff changeset	555 assert(policy != NULL, "Must have a non-NULL policy");
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	556 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	557 // Decide which softly reachable refs should be kept alive.
a61af66fc99e Initial load duke parents: diff changeset	558 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	559 iter.load_ptrs(DEBUG_ONLY(!discovery_is_atomic() /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	560 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	561 if (referent_is_dead &&
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	562 !policy->should_clear_reference(iter.obj(), _soft_ref_timestamp_clock)) {
0 a61af66fc99e Initial load duke parents: diff changeset	563 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	564 gclog_or_tty->print_cr("Dropping reference (" INTPTR_FORMAT ": %s" ") by policy",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	565 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	566 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	567 // Remove Reference object from list
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	568 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	569 // Make the Reference object active again
a61af66fc99e Initial load duke parents: diff changeset	570 iter.make_active();
a61af66fc99e Initial load duke parents: diff changeset	571 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	572 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	573 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	574 } else {
a61af66fc99e Initial load duke parents: diff changeset	575 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	576 }
a61af66fc99e Initial load duke parents: diff changeset	577 }
a61af66fc99e Initial load duke parents: diff changeset	578 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	579 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	580 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	581 if (PrintGCDetails && TraceReferenceGC) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	582 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	583 "discovered Refs by policy, from list " INTPTR_FORMAT,
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	584 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	585 }
a61af66fc99e Initial load duke parents: diff changeset	586 )
a61af66fc99e Initial load duke parents: diff changeset	587 }
a61af66fc99e Initial load duke parents: diff changeset	588
a61af66fc99e Initial load duke parents: diff changeset	589 // Traverse the list and remove any Refs that are not active, or
a61af66fc99e Initial load duke parents: diff changeset	590 // whose referents are either alive or NULL.
a61af66fc99e Initial load duke parents: diff changeset	591 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	592 ReferenceProcessor::pp2_work(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	593 BoolObjectClosure* is_alive,
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	594 OopClosure* keep_alive) {
0 a61af66fc99e Initial load duke parents: diff changeset	595 assert(discovery_is_atomic(), "Error");
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	596 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	597 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	598 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	599 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	600 assert(next == NULL, "Should not discover inactive Reference");
0 a61af66fc99e Initial load duke parents: diff changeset	601 if (iter.is_referent_alive()) {
a61af66fc99e Initial load duke parents: diff changeset	602 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	603 gclog_or_tty->print_cr("Dropping strongly reachable reference (" INTPTR_FORMAT ": %s)",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	604 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	605 }
a61af66fc99e Initial load duke parents: diff changeset	606 // The referent is reachable after all.
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	607 // Remove Reference object from list.
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	608 iter.remove();
0 a61af66fc99e Initial load duke parents: diff changeset	609 // Update the referent pointer as necessary: Note that this
a61af66fc99e Initial load duke parents: diff changeset	610 // should not entail any recursive marking because the
a61af66fc99e Initial load duke parents: diff changeset	611 // referent must already have been traversed.
a61af66fc99e Initial load duke parents: diff changeset	612 iter.make_referent_alive();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	613 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	614 } else {
a61af66fc99e Initial load duke parents: diff changeset	615 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	616 }
a61af66fc99e Initial load duke parents: diff changeset	617 }
a61af66fc99e Initial load duke parents: diff changeset	618 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	619 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	620 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	621 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	622 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	623 }
a61af66fc99e Initial load duke parents: diff changeset	624 )
a61af66fc99e Initial load duke parents: diff changeset	625 }
a61af66fc99e Initial load duke parents: diff changeset	626
a61af66fc99e Initial load duke parents: diff changeset	627 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	628 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	629 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	630 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	631 VoidClosure* complete_gc) {
0 a61af66fc99e Initial load duke parents: diff changeset	632 assert(!discovery_is_atomic(), "Error");
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	633 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	634 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	635 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	636 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	637 oop next = java_lang_ref_Reference::next(iter.obj());
0 a61af66fc99e Initial load duke parents: diff changeset	638 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	639 next != NULL)) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	640 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	641 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	642 iter.remove();
a61af66fc99e Initial load duke parents: diff changeset	643 // Trace the cohorts
a61af66fc99e Initial load duke parents: diff changeset	644 iter.make_referent_alive();
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	645 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	646 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	647 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	648 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	649 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	650 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	651 } else {
a61af66fc99e Initial load duke parents: diff changeset	652 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	653 }
a61af66fc99e Initial load duke parents: diff changeset	654 }
a61af66fc99e Initial load duke parents: diff changeset	655 // Now close the newly reachable set
a61af66fc99e Initial load duke parents: diff changeset	656 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	657 NOT_PRODUCT(
2369 92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads ysr parents: 1995 diff changeset	658 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	659 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	660 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	661 iter.removed(), iter.processed(), (address)refs_list.head());
0 a61af66fc99e Initial load duke parents: diff changeset	662 }
a61af66fc99e Initial load duke parents: diff changeset	663 )
a61af66fc99e Initial load duke parents: diff changeset	664 }
a61af66fc99e Initial load duke parents: diff changeset	665
a61af66fc99e Initial load duke parents: diff changeset	666 // 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	667 // clearing them or keeping them (and their reachable
0 a61af66fc99e Initial load duke parents: diff changeset	668 // closure) alive.
a61af66fc99e Initial load duke parents: diff changeset	669 void
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	670 ReferenceProcessor::process_phase3(DiscoveredList& refs_list,
0 a61af66fc99e Initial load duke parents: diff changeset	671 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	672 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	673 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	674 VoidClosure* complete_gc) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	675 ResourceMark rm;
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	676 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 a61af66fc99e Initial load duke parents: diff changeset	677 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	678 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	679 iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
a61af66fc99e Initial load duke parents: diff changeset	680 if (clear_referent) {
a61af66fc99e Initial load duke parents: diff changeset	681 // NULL out referent pointer
a61af66fc99e Initial load duke parents: diff changeset	682 iter.clear_referent();
a61af66fc99e Initial load duke parents: diff changeset	683 } else {
a61af66fc99e Initial load duke parents: diff changeset	684 // keep the referent around
a61af66fc99e Initial load duke parents: diff changeset	685 iter.make_referent_alive();
a61af66fc99e Initial load duke parents: diff changeset	686 }
a61af66fc99e Initial load duke parents: diff changeset	687 if (TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	688 gclog_or_tty->print_cr("Adding %sreference (" INTPTR_FORMAT ": %s) as pending",
a61af66fc99e Initial load duke parents: diff changeset	689 clear_referent ? "cleared " : "",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	690 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	691 }
a61af66fc99e Initial load duke parents: diff changeset	692 assert(iter.obj()->is_oop(UseConcMarkSweepGC), "Adding a bad reference");
a61af66fc99e Initial load duke parents: diff changeset	693 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	694 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	695 // Remember to update the next pointer of the last ref.
0 a61af66fc99e Initial load duke parents: diff changeset	696 iter.update_discovered();
a61af66fc99e Initial load duke parents: diff changeset	697 // Close the reachable set
a61af66fc99e Initial load duke parents: diff changeset	698 complete_gc->do_void();
a61af66fc99e Initial load duke parents: diff changeset	699 }
a61af66fc99e Initial load duke parents: diff changeset	700
a61af66fc99e Initial load duke parents: diff changeset	701 void
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	702 ReferenceProcessor::clear_discovered_references(DiscoveredList& refs_list) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	703 oop obj = NULL;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	704 oop next = refs_list.head();
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	705 while (next != obj) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	706 obj = next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	707 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	708 java_lang_ref_Reference::set_discovered_raw(obj, NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	709 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	710 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	711 refs_list.set_length(0);
0 a61af66fc99e Initial load duke parents: diff changeset	712 }
a61af66fc99e Initial load duke parents: diff changeset	713
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	714 void
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	715 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	716 clear_discovered_references(refs_list);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	717 }
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	718
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	719 void ReferenceProcessor::abandon_partial_discovery() {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	720 // loop over the lists
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	721 for (uint 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	722 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	723 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	724 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	725 abandon_partial_discovered_list(_discovered_refs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	726 }
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 RefProcPhase1Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	730 public:
a61af66fc99e Initial load duke parents: diff changeset	731 RefProcPhase1Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	732 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	733 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	734 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	735 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	736 _policy(policy)
a61af66fc99e Initial load duke parents: diff changeset	737 { }
a61af66fc99e Initial load duke parents: diff changeset	738 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	739 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	740 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	741 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	742 Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	743 int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	744 _ref_processor.process_phase1(_refs_lists[refs_list_index], _policy,
0 a61af66fc99e Initial load duke parents: diff changeset	745 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	746 }
a61af66fc99e Initial load duke parents: diff changeset	747 private:
a61af66fc99e Initial load duke parents: diff changeset	748 ReferencePolicy* _policy;
a61af66fc99e Initial load duke parents: diff changeset	749 };
a61af66fc99e Initial load duke parents: diff changeset	750
a61af66fc99e Initial load duke parents: diff changeset	751 class RefProcPhase2Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	752 public:
a61af66fc99e Initial load duke parents: diff changeset	753 RefProcPhase2Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	754 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	755 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	756 : ProcessTask(ref_processor, refs_lists, marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	757 { }
a61af66fc99e Initial load duke parents: diff changeset	758 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	759 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	760 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	761 {
a61af66fc99e Initial load duke parents: diff changeset	762 _ref_processor.process_phase2(_refs_lists[i],
a61af66fc99e Initial load duke parents: diff changeset	763 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	764 }
a61af66fc99e Initial load duke parents: diff changeset	765 };
a61af66fc99e Initial load duke parents: diff changeset	766
a61af66fc99e Initial load duke parents: diff changeset	767 class RefProcPhase3Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load duke parents: diff changeset	768 public:
a61af66fc99e Initial load duke parents: diff changeset	769 RefProcPhase3Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load duke parents: diff changeset	770 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	771 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	772 bool marks_oops_alive)
a61af66fc99e Initial load duke parents: diff changeset	773 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load duke parents: diff changeset	774 _clear_referent(clear_referent)
a61af66fc99e Initial load duke parents: diff changeset	775 { }
a61af66fc99e Initial load duke parents: diff changeset	776 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load duke parents: diff changeset	777 OopClosure& keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	778 VoidClosure& complete_gc)
a61af66fc99e Initial load duke parents: diff changeset	779 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	780 // 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	781 // 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	782 // Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	783 // int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	784 // _ref_processor.process_phase3(_refs_lists[refs_list_index], _clear_referent,
0 a61af66fc99e Initial load duke parents: diff changeset	785 _ref_processor.process_phase3(_refs_lists[i], _clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	786 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	787 }
a61af66fc99e Initial load duke parents: diff changeset	788 private:
a61af66fc99e Initial load duke parents: diff changeset	789 bool _clear_referent;
a61af66fc99e Initial load duke parents: diff changeset	790 };
a61af66fc99e Initial load duke parents: diff changeset	791
a61af66fc99e Initial load duke parents: diff changeset	792 // Balances reference queues.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	793 // 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	794 // 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	795 // corresponding to the active workers will be processed.
0 a61af66fc99e Initial load duke parents: diff changeset	796 void ReferenceProcessor::balance_queues(DiscoveredList ref_lists[])
a61af66fc99e Initial load duke parents: diff changeset	797 {
a61af66fc99e Initial load duke parents: diff changeset	798 // calculate total length
a61af66fc99e Initial load duke parents: diff changeset	799 size_t total_refs = 0;
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	800 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	801 gclog_or_tty->print_cr("\nBalance ref_lists ");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	802 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	803
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	804 for (uint i = 0; i < _max_num_q; ++i) {
0 a61af66fc99e Initial load duke parents: diff changeset	805 total_refs += ref_lists[i].length();
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	806 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	807 gclog_or_tty->print("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	808 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	809 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	810 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	811 gclog_or_tty->print_cr(" = %d", total_refs);
0 a61af66fc99e Initial load duke parents: diff changeset	812 }
a61af66fc99e Initial load duke parents: diff changeset	813 size_t avg_refs = total_refs / _num_q + 1;
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	814 uint to_idx = 0;
441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	815 for (uint from_idx = 0; from_idx < _max_num_q; from_idx++) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	816 bool move_all = false;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	817 if (from_idx >= _num_q) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	818 move_all = ref_lists[from_idx].length() > 0;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	819 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	820 while ((ref_lists[from_idx].length() > avg_refs) \|\|
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	821 move_all) {
0 a61af66fc99e Initial load duke parents: diff changeset	822 assert(to_idx < _num_q, "Sanity Check!");
a61af66fc99e Initial load duke parents: diff changeset	823 if (ref_lists[to_idx].length() < avg_refs) {
a61af66fc99e Initial load duke parents: diff changeset	824 // move superfluous refs
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	825 size_t refs_to_move;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	826 // 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	827 if (move_all) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	828 refs_to_move = MIN2(ref_lists[from_idx].length(),
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	829 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	830 } else {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	831 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	832 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	833 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	834
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	835 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	836
0 a61af66fc99e Initial load duke parents: diff changeset	837 oop move_head = ref_lists[from_idx].head();
a61af66fc99e Initial load duke parents: diff changeset	838 oop move_tail = move_head;
a61af66fc99e Initial load duke parents: diff changeset	839 oop new_head = move_head;
a61af66fc99e Initial load duke parents: diff changeset	840 // find an element to split the list on
a61af66fc99e Initial load duke parents: diff changeset	841 for (size_t j = 0; j < refs_to_move; ++j) {
a61af66fc99e Initial load duke parents: diff changeset	842 move_tail = new_head;
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	843 new_head = java_lang_ref_Reference::discovered(new_head);
0 a61af66fc99e Initial load duke parents: diff changeset	844 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	845
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	846 // Add the chain to the to list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	847 if (ref_lists[to_idx].head() == NULL) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	848 // to list is empty. Make a loop at the end.
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	849 java_lang_ref_Reference::set_discovered_raw(move_tail, move_tail);
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	850 } else {
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	851 java_lang_ref_Reference::set_discovered_raw(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	852 }
0 a61af66fc99e Initial load duke parents: diff changeset	853 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	854 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	855
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	856 // Remove the chain from the from list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	857 if (move_tail == new_head) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	858 // 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	859 ref_lists[from_idx].set_head(NULL);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	860 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	861 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	862 }
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	863 ref_lists[from_idx].dec_length(refs_to_move);
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	864 if (ref_lists[from_idx].length() == 0) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	865 break;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	866 }
0 a61af66fc99e Initial load duke parents: diff changeset	867 } else {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	868 to_idx = (to_idx + 1) % _num_q;
0 a61af66fc99e Initial load duke parents: diff changeset	869 }
a61af66fc99e Initial load duke parents: diff changeset	870 }
a61af66fc99e Initial load duke parents: diff changeset	871 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	872 #ifdef ASSERT
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	873 size_t balanced_total_refs = 0;
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	874 for (uint i = 0; i < _max_num_q; ++i) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	875 balanced_total_refs += ref_lists[i].length();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	876 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	877 gclog_or_tty->print("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	878 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	879 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	880 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	881 gclog_or_tty->print_cr(" = %d", balanced_total_refs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	882 gclog_or_tty->flush();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	883 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	884 assert(total_refs == balanced_total_refs, "Balancing was incomplete");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	885 #endif
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	886 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	887
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	888 void ReferenceProcessor::balance_all_queues() {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	889 balance_queues(_discoveredSoftRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	890 balance_queues(_discoveredWeakRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	891 balance_queues(_discoveredFinalRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	892 balance_queues(_discoveredPhantomRefs);
20755 01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	893 balance_queues(_discoveredCleanerRefs);
0 a61af66fc99e Initial load duke parents: diff changeset	894 }
a61af66fc99e Initial load duke parents: diff changeset	895
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	896 size_t
0 a61af66fc99e Initial load duke parents: diff changeset	897 ReferenceProcessor::process_discovered_reflist(
a61af66fc99e Initial load duke parents: diff changeset	898 DiscoveredList refs_lists[],
a61af66fc99e Initial load duke parents: diff changeset	899 ReferencePolicy* policy,
a61af66fc99e Initial load duke parents: diff changeset	900 bool clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	901 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	902 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	903 VoidClosure* complete_gc,
a61af66fc99e Initial load duke parents: diff changeset	904 AbstractRefProcTaskExecutor* task_executor)
a61af66fc99e Initial load duke parents: diff changeset	905 {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	906 bool mt_processing = task_executor != NULL && _processing_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	907 // 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	908 // 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	909 // 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	910 // 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	911 // 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	912 // of the test.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	913 bool must_balance = _discovery_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	914
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	915 if ((mt_processing && ParallelRefProcBalancingEnabled) \|\|
8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	916 must_balance) {
0 a61af66fc99e Initial load duke parents: diff changeset	917 balance_queues(refs_lists);
a61af66fc99e Initial load duke parents: diff changeset	918 }
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	919
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	920 size_t total_list_count = total_count(refs_lists);
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	921
0 a61af66fc99e Initial load duke parents: diff changeset	922 if (PrintReferenceGC && PrintGCDetails) {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	923 gclog_or_tty->print(", %u refs", total_list_count);
0 a61af66fc99e Initial load duke parents: diff changeset	924 }
a61af66fc99e Initial load duke parents: diff changeset	925
a61af66fc99e Initial load duke parents: diff changeset	926 // Phase 1 (soft refs only):
a61af66fc99e Initial load duke parents: diff changeset	927 // . Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load duke parents: diff changeset	928 // referents are not alive, but that should be kept alive for
a61af66fc99e Initial load duke parents: diff changeset	929 // policy reasons. Keep alive the transitive closure of all
a61af66fc99e Initial load duke parents: diff changeset	930 // such referents.
a61af66fc99e Initial load duke parents: diff changeset	931 if (policy != NULL) {
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	932 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	933 RefProcPhase1Task phase1(this, refs_lists, policy, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	934 task_executor->execute(phase1);
a61af66fc99e Initial load duke parents: diff changeset	935 } else {
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	936 for (uint i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	937 process_phase1(refs_lists[i], policy,
a61af66fc99e Initial load duke parents: diff changeset	938 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	939 }
a61af66fc99e Initial load duke parents: diff changeset	940 }
a61af66fc99e Initial load duke parents: diff changeset	941 } else { // policy == NULL
a61af66fc99e Initial load duke parents: diff changeset	942 assert(refs_lists != _discoveredSoftRefs,
a61af66fc99e Initial load duke parents: diff changeset	943 "Policy must be specified for soft references.");
a61af66fc99e Initial load duke parents: diff changeset	944 }
a61af66fc99e Initial load duke parents: diff changeset	945
a61af66fc99e Initial load duke parents: diff changeset	946 // Phase 2:
a61af66fc99e Initial load duke parents: diff changeset	947 // . 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	948 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	949 RefProcPhase2Task phase2(this, refs_lists, !discovery_is_atomic() /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	950 task_executor->execute(phase2);
a61af66fc99e Initial load duke parents: diff changeset	951 } else {
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	952 for (uint i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	953 process_phase2(refs_lists[i], is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	954 }
a61af66fc99e Initial load duke parents: diff changeset	955 }
a61af66fc99e Initial load duke parents: diff changeset	956
a61af66fc99e Initial load duke parents: diff changeset	957 // Phase 3:
a61af66fc99e Initial load duke parents: diff changeset	958 // . Traverse the list and process referents as appropriate.
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	959 if (mt_processing) {
0 a61af66fc99e Initial load duke parents: diff changeset	960 RefProcPhase3Task phase3(this, refs_lists, clear_referent, true /marks_oops_alive*/);
a61af66fc99e Initial load duke parents: diff changeset	961 task_executor->execute(phase3);
a61af66fc99e Initial load duke parents: diff changeset	962 } else {
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	963 for (uint i = 0; i < _max_num_q; i++) {
0 a61af66fc99e Initial load duke parents: diff changeset	964 process_phase3(refs_lists[i], clear_referent,
a61af66fc99e Initial load duke parents: diff changeset	965 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load duke parents: diff changeset	966 }
a61af66fc99e Initial load duke parents: diff changeset	967 }
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	968
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	969 return total_list_count;
0 a61af66fc99e Initial load duke parents: diff changeset	970 }
a61af66fc99e Initial load duke parents: diff changeset	971
a61af66fc99e Initial load duke parents: diff changeset	972 void ReferenceProcessor::clean_up_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	973 // loop over the lists
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	974 for (uint 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	975 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
0 a61af66fc99e Initial load duke parents: diff changeset	976 gclog_or_tty->print_cr(
a61af66fc99e Initial load duke parents: diff changeset	977 "\nScrubbing %s discovered list of Null referents",
a61af66fc99e Initial load duke parents: diff changeset	978 list_name(i));
a61af66fc99e Initial load duke parents: diff changeset	979 }
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	980 clean_up_discovered_reflist(_discovered_refs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	981 }
a61af66fc99e Initial load duke parents: diff changeset	982 }
a61af66fc99e Initial load duke parents: diff changeset	983
a61af66fc99e Initial load duke parents: diff changeset	984 void ReferenceProcessor::clean_up_discovered_reflist(DiscoveredList& refs_list) {
a61af66fc99e Initial load duke parents: diff changeset	985 assert(!discovery_is_atomic(), "Else why call this method?");
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	986 DiscoveredListIterator iter(refs_list, NULL, NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	987 while (iter.has_next()) {
a61af66fc99e Initial load duke parents: diff changeset	988 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	989 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	990 assert(next->is_oop_or_null(), "bad next field");
0 a61af66fc99e Initial load duke parents: diff changeset	991 // If referent has been cleared or Reference is not active,
a61af66fc99e Initial load duke parents: diff changeset	992 // drop it.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	993 if (iter.referent() == NULL \|\| next != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	994 debug_only(
a61af66fc99e Initial load duke parents: diff changeset	995 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	996 gclog_or_tty->print_cr("clean_up_discovered_list: Dropping Reference: "
a61af66fc99e Initial load duke parents: diff changeset	997 INTPTR_FORMAT " with next field: " INTPTR_FORMAT
a61af66fc99e Initial load duke parents: diff changeset	998 " and referent: " INTPTR_FORMAT,
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	999 (void )iter.obj(), (void )next, (void *)iter.referent());
0 a61af66fc99e Initial load duke parents: diff changeset	1000 }
a61af66fc99e Initial load duke parents: diff changeset	1001 )
a61af66fc99e Initial load duke parents: diff changeset	1002 // Remove Reference object from list
a61af66fc99e Initial load duke parents: diff changeset	1003 iter.remove();
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1004 iter.move_to_next();
0 a61af66fc99e Initial load duke parents: diff changeset	1005 } else {
a61af66fc99e Initial load duke parents: diff changeset	1006 iter.next();
a61af66fc99e Initial load duke parents: diff changeset	1007 }
a61af66fc99e Initial load duke parents: diff changeset	1008 }
a61af66fc99e Initial load duke parents: diff changeset	1009 NOT_PRODUCT(
a61af66fc99e Initial load duke parents: diff changeset	1010 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load duke parents: diff changeset	1011 gclog_or_tty->print(
a61af66fc99e Initial load duke parents: diff changeset	1012 " Removed %d Refs with NULL referents out of %d discovered Refs",
a61af66fc99e Initial load duke parents: diff changeset	1013 iter.removed(), iter.processed());
a61af66fc99e Initial load duke parents: diff changeset	1014 }
a61af66fc99e Initial load duke parents: diff changeset	1015 )
a61af66fc99e Initial load duke parents: diff changeset	1016 }
a61af66fc99e Initial load duke parents: diff changeset	1017
a61af66fc99e Initial load duke parents: diff changeset	1018 inline DiscoveredList* ReferenceProcessor::get_discovered_list(ReferenceType rt) {
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	1019 uint id = 0;
0 a61af66fc99e Initial load duke parents: diff changeset	1020 // Determine the queue index to use for this object.
a61af66fc99e Initial load duke parents: diff changeset	1021 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1022 // During a multi-threaded discovery phase,
a61af66fc99e Initial load duke parents: diff changeset	1023 // each thread saves to its "own" list.
a61af66fc99e Initial load duke parents: diff changeset	1024 Thread* thr = Thread::current();
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1025 id = thr->as_Worker_thread()->id();
0 a61af66fc99e Initial load duke parents: diff changeset	1026 } else {
a61af66fc99e Initial load duke parents: diff changeset	1027 // single-threaded discovery, we save in round-robin
a61af66fc99e Initial load duke parents: diff changeset	1028 // fashion to each of the lists.
a61af66fc99e Initial load duke parents: diff changeset	1029 if (_processing_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1030 id = next_id();
a61af66fc99e Initial load duke parents: diff changeset	1031 }
a61af66fc99e Initial load duke parents: diff changeset	1032 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1033 assert(0 <= id && id < _max_num_q, "Id is out-of-bounds (call Freud?)");
0 a61af66fc99e Initial load duke parents: diff changeset	1034
a61af66fc99e Initial load duke parents: diff changeset	1035 // Get the discovered queue to which we will add
a61af66fc99e Initial load duke parents: diff changeset	1036 DiscoveredList* list = NULL;
a61af66fc99e Initial load duke parents: diff changeset	1037 switch (rt) {
a61af66fc99e Initial load duke parents: diff changeset	1038 case REF_OTHER:
a61af66fc99e Initial load duke parents: diff changeset	1039 // Unknown reference type, no special treatment
a61af66fc99e Initial load duke parents: diff changeset	1040 break;
a61af66fc99e Initial load duke parents: diff changeset	1041 case REF_SOFT:
a61af66fc99e Initial load duke parents: diff changeset	1042 list = &_discoveredSoftRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1043 break;
a61af66fc99e Initial load duke parents: diff changeset	1044 case REF_WEAK:
a61af66fc99e Initial load duke parents: diff changeset	1045 list = &_discoveredWeakRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1046 break;
a61af66fc99e Initial load duke parents: diff changeset	1047 case REF_FINAL:
a61af66fc99e Initial load duke parents: diff changeset	1048 list = &_discoveredFinalRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1049 break;
a61af66fc99e Initial load duke parents: diff changeset	1050 case REF_PHANTOM:
a61af66fc99e Initial load duke parents: diff changeset	1051 list = &_discoveredPhantomRefs[id];
a61af66fc99e Initial load duke parents: diff changeset	1052 break;
20755 01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1053 case REF_CLEANER:
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1054 list = &_discoveredCleanerRefs[id];
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1055 break;
0 a61af66fc99e Initial load duke parents: diff changeset	1056 case REF_NONE:
6735 aed758eda82a 7195833: NPG: Rename instanceClassLoaderKlass, instanceRefKlass and instanceMirrorKlass coleenp parents: 6725 diff changeset	1057 // we should not reach here if we are an InstanceRefKlass
0 a61af66fc99e Initial load duke parents: diff changeset	1058 default:
a61af66fc99e Initial load duke parents: diff changeset	1059 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1060 }
1833 8b10f48633dc 6984287: Regularize how GC parallel workers are specified. jmasa parents: 1552 diff changeset	1061 if (TraceReferenceGC && PrintGCDetails) {
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1062 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	1063 }
0 a61af66fc99e Initial load duke parents: diff changeset	1064 return list;
a61af66fc99e Initial load duke parents: diff changeset	1065 }
a61af66fc99e Initial load duke parents: diff changeset	1066
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1067 inline void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1068 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	1069 oop obj,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1070 HeapWord* discovered_addr) {
0 a61af66fc99e Initial load duke parents: diff changeset	1071 assert(_discovery_is_mt, "!_discovery_is_mt should have been handled by caller");
a61af66fc99e Initial load duke parents: diff changeset	1072 // First we must make sure this object is only enqueued once. CAS in a non null
a61af66fc99e Initial load duke parents: diff changeset	1073 // discovered_addr.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1074 oop current_head = refs_list.head();
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1075 // 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	1076 oop next_discovered = (current_head != NULL) ? current_head : obj;
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1077
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1078 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	1079 NULL);
0 a61af66fc99e Initial load duke parents: diff changeset	1080 if (retest == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1081 // 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	1082 // We have separate lists for enqueueing, so no synchronization
0 a61af66fc99e Initial load duke parents: diff changeset	1083 // is necessary.
113 ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes coleenp parents: 5 diff changeset	1084 refs_list.set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1085 refs_list.inc_length(1);
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1086
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1087 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1088 gclog_or_tty->print_cr("Discovered reference (mt) (" INTPTR_FORMAT ": %s)",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	1089 (void *)obj, obj->klass()->internal_name());
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1090 }
0 a61af66fc99e Initial load duke parents: diff changeset	1091 } else {
a61af66fc99e Initial load duke parents: diff changeset	1092 // If retest was non NULL, another thread beat us to it:
a61af66fc99e Initial load duke parents: diff changeset	1093 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1094 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1095 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	1096 (void *)obj, obj->klass()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1097 }
a61af66fc99e Initial load duke parents: diff changeset	1098 }
a61af66fc99e Initial load duke parents: diff changeset	1099 }
a61af66fc99e Initial load duke parents: diff changeset	1100
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1101 #ifndef PRODUCT
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1102 // 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	1103 // 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	1104 // 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	1105 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	1106 bool da = discovery_is_atomic();
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1107 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	1108 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	1109 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	1110 INTPTR_FORMAT " during %satomic discovery ",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	1111 (void )referent, (void )obj, da ? "" : "non-"));
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1112 }
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1113 #endif
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1114
0 a61af66fc99e Initial load duke parents: diff changeset	1115 // We mention two of several possible choices here:
a61af66fc99e Initial load duke parents: diff changeset	1116 // #0: if the reference object is not in the "originating generation"
a61af66fc99e Initial load duke parents: diff changeset	1117 // (or part of the heap being collected, indicated by our "span"
a61af66fc99e Initial load duke parents: diff changeset	1118 // we don't treat it specially (i.e. we scan it as we would
a61af66fc99e Initial load duke parents: diff changeset	1119 // 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	1120 // This means that references can't be discovered unless their
0 a61af66fc99e Initial load duke parents: diff changeset	1121 // referent is also in the same span. This is the simplest,
a61af66fc99e Initial load duke parents: diff changeset	1122 // most "local" and most conservative approach, albeit one
a61af66fc99e Initial load duke parents: diff changeset	1123 // that may cause weak references to be enqueued least promptly.
a61af66fc99e Initial load duke parents: diff changeset	1124 // We call this choice the "ReferenceBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1125 // #1: the reference object may be in any generation (span), but if
a61af66fc99e Initial load duke parents: diff changeset	1126 // the referent is in the generation (span) being currently collected
a61af66fc99e Initial load duke parents: diff changeset	1127 // then we can discover the reference object, provided
a61af66fc99e Initial load duke parents: diff changeset	1128 // the object has not already been discovered by
a61af66fc99e Initial load duke parents: diff changeset	1129 // a different concurrently running collector (as may be the
a61af66fc99e Initial load duke parents: diff changeset	1130 // case, for instance, if the reference object is in CMS and
a61af66fc99e Initial load duke parents: diff changeset	1131 // the referent in DefNewGeneration), and provided the processing
a61af66fc99e Initial load duke parents: diff changeset	1132 // of this reference object by the current collector will
a61af66fc99e Initial load duke parents: diff changeset	1133 // appear atomic to every other collector in the system.
a61af66fc99e Initial load duke parents: diff changeset	1134 // (Thus, for instance, a concurrent collector may not
a61af66fc99e Initial load duke parents: diff changeset	1135 // discover references in other generations even if the
a61af66fc99e Initial load duke parents: diff changeset	1136 // referent is in its own generation). This policy may,
a61af66fc99e Initial load duke parents: diff changeset	1137 // in certain cases, enqueue references somewhat sooner than
a61af66fc99e Initial load duke parents: diff changeset	1138 // might Policy #0 above, but at marginally increased cost
a61af66fc99e Initial load duke parents: diff changeset	1139 // and complexity in processing these references.
a61af66fc99e Initial load duke parents: diff changeset	1140 // We call this choice the "RefeferentBasedDiscovery" policy.
a61af66fc99e Initial load duke parents: diff changeset	1141 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	1142 // Make sure we are discovering refs (rather than processing discovered refs).
0 a61af66fc99e Initial load duke parents: diff changeset	1143 if (!_discovering_refs \|\| !RegisterReferences) {
a61af66fc99e Initial load duke parents: diff changeset	1144 return false;
a61af66fc99e Initial load duke parents: diff changeset	1145 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1146 // 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	1147 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	1148 if (next != NULL) { // Ref is no longer active
0 a61af66fc99e Initial load duke parents: diff changeset	1149 return false;
a61af66fc99e Initial load duke parents: diff changeset	1150 }
a61af66fc99e Initial load duke parents: diff changeset	1151
a61af66fc99e Initial load duke parents: diff changeset	1152 HeapWord* obj_addr = (HeapWord*)obj;
a61af66fc99e Initial load duke parents: diff changeset	1153 if (RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1154 !_span.contains(obj_addr)) {
a61af66fc99e Initial load duke parents: diff changeset	1155 // Reference is not in the originating generation;
a61af66fc99e Initial load duke parents: diff changeset	1156 // don't treat it specially (i.e. we want to scan it as a normal
a61af66fc99e Initial load duke parents: diff changeset	1157 // object with strong references).
a61af66fc99e Initial load duke parents: diff changeset	1158 return false;
a61af66fc99e Initial load duke parents: diff changeset	1159 }
a61af66fc99e Initial load duke parents: diff changeset	1160
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1161 // 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	1162 // known to be strongly reachable.
0 a61af66fc99e Initial load duke parents: diff changeset	1163 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	1164 verify_referent(obj);
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1165 if (is_alive_non_header()->do_object_b(java_lang_ref_Reference::referent(obj))) {
0 a61af66fc99e Initial load duke parents: diff changeset	1166 return false; // referent is reachable
a61af66fc99e Initial load duke parents: diff changeset	1167 }
a61af66fc99e Initial load duke parents: diff changeset	1168 }
453 c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1169 if (rt == REF_SOFT) {
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1170 // 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	1171 // current candidates for clearing, in which case we
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1172 // can mark through them now, rather than delaying that
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1173 // to the reference-processing phase. Since all current
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1174 // time-stamp policies advance the soft-ref clock only
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1175 // at a major collection cycle, this is always currently
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1176 // accurate.
3992 d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76 johnc parents: 3979 diff changeset	1177 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	1178 return false;
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1179 }
c96030fff130 6684579: SoftReference processing can be made more efficient ysr parents: 452 diff changeset	1180 }
0 a61af66fc99e Initial load duke parents: diff changeset	1181
3979 4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1182 ResourceMark rm; // Needed for tracing.
4dfb2df418f2 6484982: G1: process references during evacuation pauses johnc parents: 3917 diff changeset	1183
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1184 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	1185 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	1186 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	1187 if (discovered != NULL) {
0 a61af66fc99e Initial load duke parents: diff changeset	1188 // The reference has already been discovered...
a61af66fc99e Initial load duke parents: diff changeset	1189 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1190 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	1191 (void *)obj, obj->klass()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1192 }
a61af66fc99e Initial load duke parents: diff changeset	1193 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
a61af66fc99e Initial load duke parents: diff changeset	1194 // assumes that an object is not processed twice;
a61af66fc99e Initial load duke parents: diff changeset	1195 // if it's been already discovered it must be on another
a61af66fc99e Initial load duke parents: diff changeset	1196 // generation's discovered list; so we won't discover it.
a61af66fc99e Initial load duke parents: diff changeset	1197 return false;
a61af66fc99e Initial load duke parents: diff changeset	1198 } else {
a61af66fc99e Initial load duke parents: diff changeset	1199 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery,
a61af66fc99e Initial load duke parents: diff changeset	1200 "Unrecognized policy");
a61af66fc99e Initial load duke parents: diff changeset	1201 // Check assumption that an object is not potentially
a61af66fc99e Initial load duke parents: diff changeset	1202 // discovered twice except by concurrent collectors that potentially
a61af66fc99e Initial load duke parents: diff changeset	1203 // trace the same Reference object twice.
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1204 assert(UseConcMarkSweepGC \|\| UseG1GC,
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1205 "Only possible with a concurrent marking collector");
0 a61af66fc99e Initial load duke parents: diff changeset	1206 return true;
a61af66fc99e Initial load duke parents: diff changeset	1207 }
a61af66fc99e Initial load duke parents: diff changeset	1208 }
a61af66fc99e Initial load duke parents: diff changeset	1209
a61af66fc99e Initial load duke parents: diff changeset	1210 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
1995 8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1211 verify_referent(obj);
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1212 // Discover if and only if EITHER:
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1213 // .. reference is in our span, OR
eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1214 // .. we are an atomic collector and referent is in our span
0 a61af66fc99e Initial load duke parents: diff changeset	1215 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	1216 (discovery_is_atomic() &&
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent ysr parents: 1974 diff changeset	1217 _span.contains(java_lang_ref_Reference::referent(obj)))) {
0 a61af66fc99e Initial load duke parents: diff changeset	1218 // should_enqueue = true;
a61af66fc99e Initial load duke parents: diff changeset	1219 } else {
a61af66fc99e Initial load duke parents: diff changeset	1220 return false;
a61af66fc99e Initial load duke parents: diff changeset	1221 }
a61af66fc99e Initial load duke parents: diff changeset	1222 } else {
a61af66fc99e Initial load duke parents: diff changeset	1223 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load duke parents: diff changeset	1224 _span.contains(obj_addr), "code inconsistency");
a61af66fc99e Initial load duke parents: diff changeset	1225 }
a61af66fc99e Initial load duke parents: diff changeset	1226
a61af66fc99e Initial load duke parents: diff changeset	1227 // Get the right type of discovered queue head.
a61af66fc99e Initial load duke parents: diff changeset	1228 DiscoveredList* list = get_discovered_list(rt);
a61af66fc99e Initial load duke parents: diff changeset	1229 if (list == NULL) {
a61af66fc99e Initial load duke parents: diff changeset	1230 return false; // nothing special needs to be done
a61af66fc99e Initial load duke parents: diff changeset	1231 }
a61af66fc99e Initial load duke parents: diff changeset	1232
a61af66fc99e Initial load duke parents: diff changeset	1233 if (_discovery_is_mt) {
a61af66fc99e Initial load duke parents: diff changeset	1234 add_to_discovered_list_mt(*list, obj, discovered_addr);
a61af66fc99e Initial load duke parents: diff changeset	1235 } else {
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	1236 // We do a raw store here: the field will be visited later when processing
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	1237 // the discovered references.
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1238 oop current_head = list->head();
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1239 // 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	1240 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	1241
342 37f87013dfd8 6711316: Open source the Garbage-First garbage collector ysr parents: 113 diff changeset	1242 assert(discovered == NULL, "control point invariant");
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1243 oop_store_raw(discovered_addr, next_discovered);
0 a61af66fc99e Initial load duke parents: diff changeset	1244 list->set_head(obj);
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1245 list->inc_length(1);
0 a61af66fc99e Initial load duke parents: diff changeset	1246
1974 fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent johnc parents: 1972 diff changeset	1247 if (TraceReferenceGC) {
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1248 gclog_or_tty->print_cr("Discovered reference (" INTPTR_FORMAT ": %s)",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	1249 (void *)obj, obj->klass()->internal_name());
0 a61af66fc99e Initial load duke parents: diff changeset	1250 }
a61af66fc99e Initial load duke parents: diff changeset	1251 }
3917 eca1193ca245 4965777: GC changes to support use of discovered field for pending references ysr parents: 3915 diff changeset	1252 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	1253 verify_referent(obj);
0 a61af66fc99e Initial load duke parents: diff changeset	1254 return true;
a61af66fc99e Initial load duke parents: diff changeset	1255 }
a61af66fc99e Initial load duke parents: diff changeset	1256
a61af66fc99e Initial load duke parents: diff changeset	1257 // Preclean the discovered references by removing those
a61af66fc99e Initial load duke parents: diff changeset	1258 // whose referents are alive, and by marking from those that
a61af66fc99e Initial load duke parents: diff changeset	1259 // are not active. These lists can be handled here
a61af66fc99e Initial load duke parents: diff changeset	1260 // in any order and, indeed, concurrently.
a61af66fc99e Initial load duke parents: diff changeset	1261 void ReferenceProcessor::preclean_discovered_references(
a61af66fc99e Initial load duke parents: diff changeset	1262 BoolObjectClosure* is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1263 OopClosure* keep_alive,
a61af66fc99e Initial load duke parents: diff changeset	1264 VoidClosure* complete_gc,
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1265 YieldClosure* yield,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1266 GCTimer* gc_timer) {
0 a61af66fc99e Initial load duke parents: diff changeset	1267
a61af66fc99e Initial load duke parents: diff changeset	1268 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load duke parents: diff changeset	1269
a61af66fc99e Initial load duke parents: diff changeset	1270 // Soft references
a61af66fc99e Initial load duke parents: diff changeset	1271 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1272 GCTraceTime tt("Preclean SoftReferences", PrintGCDetails && PrintReferenceGC,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1273 false, gc_timer);
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	1274 for (uint i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1275 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1276 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1277 }
0 a61af66fc99e Initial load duke parents: diff changeset	1278 preclean_discovered_reflist(_discoveredSoftRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1279 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1280 }
a61af66fc99e Initial load duke parents: diff changeset	1281 }
a61af66fc99e Initial load duke parents: diff changeset	1282
a61af66fc99e Initial load duke parents: diff changeset	1283 // Weak references
a61af66fc99e Initial load duke parents: diff changeset	1284 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1285 GCTraceTime tt("Preclean WeakReferences", PrintGCDetails && PrintReferenceGC,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1286 false, gc_timer);
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	1287 for (uint i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1288 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1289 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1290 }
0 a61af66fc99e Initial load duke parents: diff changeset	1291 preclean_discovered_reflist(_discoveredWeakRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1292 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1293 }
a61af66fc99e Initial load duke parents: diff changeset	1294 }
a61af66fc99e Initial load duke parents: diff changeset	1295
a61af66fc99e Initial load duke parents: diff changeset	1296 // Final references
a61af66fc99e Initial load duke parents: diff changeset	1297 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1298 GCTraceTime tt("Preclean FinalReferences", PrintGCDetails && PrintReferenceGC,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1299 false, gc_timer);
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	1300 for (uint i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1301 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1302 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1303 }
0 a61af66fc99e Initial load duke parents: diff changeset	1304 preclean_discovered_reflist(_discoveredFinalRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1305 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1306 }
a61af66fc99e Initial load duke parents: diff changeset	1307 }
a61af66fc99e Initial load duke parents: diff changeset	1308
a61af66fc99e Initial load duke parents: diff changeset	1309 // Phantom references
a61af66fc99e Initial load duke parents: diff changeset	1310 {
10405 f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1311 GCTraceTime tt("Preclean PhantomReferences", PrintGCDetails && PrintReferenceGC,
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing sla parents: 10327 diff changeset	1312 false, gc_timer);
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	1313 for (uint i = 0; i < _max_num_q; i++) {
452 00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1314 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1315 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists ysr parents: 356 diff changeset	1316 }
0 a61af66fc99e Initial load duke parents: diff changeset	1317 preclean_discovered_reflist(_discoveredPhantomRefs[i], is_alive,
a61af66fc99e Initial load duke parents: diff changeset	1318 keep_alive, complete_gc, yield);
a61af66fc99e Initial load duke parents: diff changeset	1319 }
20755 01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1320
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1321 // Cleaner references. Included in timing for phantom references. We
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1322 // expect Cleaner references to be temporary, and don't want to deal with
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1323 // possible incompatibilities arising from making it more visible.
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1324 for (uint i = 0; i < _max_num_q; i++) {
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1325 if (yield->should_return()) {
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1326 return;
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1327 }
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1328 preclean_discovered_reflist(_discoveredCleanerRefs[i], is_alive,
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1329 keep_alive, complete_gc, yield);
01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1330 }
0 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) {
17976 8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects brutisso parents: 17937 diff changeset	1348 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0 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)",
12316 190899198332 7195622: CheckUnhandledOops has limited usefulness now hseigel parents: 10405 diff changeset	1359 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0 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
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	1389 const char* ReferenceProcessor::list_name(uint 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";
20755 01dcaba9b3f3 8047125: (ref) More phantom object references jmasa parents: 17976 diff changeset	1399 case 4: return "CleanerRef";
0 a61af66fc99e Initial load duke parents: diff changeset	1400 }
a61af66fc99e Initial load duke parents: diff changeset	1401 ShouldNotReachHere();
a61af66fc99e Initial load duke parents: diff changeset	1402 return NULL;
a61af66fc99e Initial load duke parents: diff changeset	1403 }
a61af66fc99e Initial load duke parents: diff changeset	1404
a61af66fc99e Initial load duke parents: diff changeset	1405 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1406 void ReferenceProcessor::verify_ok_to_handle_reflists() {
a61af66fc99e Initial load duke parents: diff changeset	1407 // empty for now
a61af66fc99e Initial load duke parents: diff changeset	1408 }
a61af66fc99e Initial load duke parents: diff changeset	1409 #endif
a61af66fc99e Initial load duke parents: diff changeset	1410
a61af66fc99e Initial load duke parents: diff changeset	1411 #ifndef PRODUCT
a61af66fc99e Initial load duke parents: diff changeset	1412 void ReferenceProcessor::clear_discovered_references() {
a61af66fc99e Initial load duke parents: diff changeset	1413 guarantee(!_discovering_refs, "Discovering refs?");
4728 441e946dc1af 7121618: Change type of number of GC workers to unsigned int. jmasa parents: 4712 diff changeset	1414 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
4014 bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs johnc parents: 3992 diff changeset	1415 clear_discovered_references(_discovered_refs[i]);
0 a61af66fc99e Initial load duke parents: diff changeset	1416 }
a61af66fc99e Initial load duke parents: diff changeset	1417 }
3915 c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end stefank parents: 2369 diff changeset	1418
0 a61af66fc99e Initial load duke parents: diff changeset	1419 #endif // PRODUCT

Mercurial > hg > graal-compiler

annotate src/share/vm/memory/referenceProcessor.cpp @ 20755:01dcaba9b3f3