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annotate src/share/vm/memory/referenceProcessor.cpp @ 21119:294ed4ce1fa0

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PrintStreamOption: also forward flushes to the VM
author Gilles Duboscq <gilles.m.duboscq@oracle.com>
date Fri, 24 Apr 2015 17:27:32 +0200
parents f01ebceea995
children be896a1983c0
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1 /*
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2 * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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20 * or visit www.oracle.com if you need additional information or have any
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21 * questions.
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22 *
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23 */
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24
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25 #include "precompiled.hpp"
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26 #include "classfile/javaClasses.hpp"
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27 #include "classfile/systemDictionary.hpp"
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28 #include "gc_implementation/shared/gcTimer.hpp"
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29 #include "gc_implementation/shared/gcTraceTime.hpp"
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30 #include "gc_interface/collectedHeap.hpp"
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31 #include "gc_interface/collectedHeap.inline.hpp"
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32 #include "memory/referencePolicy.hpp"
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33 #include "memory/referenceProcessor.hpp"
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34 #include "oops/oop.inline.hpp"
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35 #include "runtime/java.hpp"
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36 #include "runtime/jniHandles.hpp"
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37
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38 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
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39
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40 ReferencePolicy* ReferenceProcessor::_always_clear_soft_ref_policy = NULL;
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41 ReferencePolicy* ReferenceProcessor::_default_soft_ref_policy = NULL;
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42 bool ReferenceProcessor::_pending_list_uses_discovered_field = false;
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43 jlong ReferenceProcessor::_soft_ref_timestamp_clock = 0;
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44
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45 void referenceProcessor_init() {
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46 ReferenceProcessor::init_statics();
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47 }
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48
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49 void ReferenceProcessor::init_statics() {
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50 // We need a monotonically non-deccreasing time in ms but
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51 // os::javaTimeMillis() does not guarantee monotonicity.
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52 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
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53
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54 // Initialize the soft ref timestamp clock.
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55 _soft_ref_timestamp_clock = now;
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56 // Also update the soft ref clock in j.l.r.SoftReference
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57 java_lang_ref_SoftReference::set_clock(_soft_ref_timestamp_clock);
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58
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59 _always_clear_soft_ref_policy = new AlwaysClearPolicy();
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60 #if defined(COMPILER2) || defined(GRAAL)
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61 _default_soft_ref_policy = new LRUMaxHeapPolicy();
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62 #else
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63 _default_soft_ref_policy = new LRUCurrentHeapPolicy();
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64 #endif
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65 if (_always_clear_soft_ref_policy == NULL || _default_soft_ref_policy == NULL) {
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66 vm_exit_during_initialization("Could not allocate reference policy object");
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67 }
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68 guarantee(RefDiscoveryPolicy == ReferenceBasedDiscovery ||
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69 RefDiscoveryPolicy == ReferentBasedDiscovery,
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70 "Unrecongnized RefDiscoveryPolicy");
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71 _pending_list_uses_discovered_field = JDK_Version::current().pending_list_uses_discovered_field();
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72 }
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73
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74 void ReferenceProcessor::enable_discovery(bool verify_disabled, bool check_no_refs) {
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75 #ifdef ASSERT
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76 // Verify that we're not currently discovering refs
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77 assert(!verify_disabled || !_discovering_refs, "nested call?");
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78
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79 if (check_no_refs) {
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80 // Verify that the discovered lists are empty
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81 verify_no_references_recorded();
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82 }
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83 #endif // ASSERT
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84
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85 // Someone could have modified the value of the static
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86 // field in the j.l.r.SoftReference class that holds the
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87 // soft reference timestamp clock using reflection or
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88 // Unsafe between GCs. Unconditionally update the static
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89 // field in ReferenceProcessor here so that we use the new
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90 // value during reference discovery.
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91
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92 _soft_ref_timestamp_clock = java_lang_ref_SoftReference::clock();
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93 _discovering_refs = true;
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94 }
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95
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96 ReferenceProcessor::ReferenceProcessor(MemRegion span,
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97 bool mt_processing,
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98 uint mt_processing_degree,
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99 bool mt_discovery,
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100 uint mt_discovery_degree,
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101 bool atomic_discovery,
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102 BoolObjectClosure* is_alive_non_header) :
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103 _discovering_refs(false),
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104 _enqueuing_is_done(false),
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105 _is_alive_non_header(is_alive_non_header),
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106 _processing_is_mt(mt_processing),
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107 _next_id(0)
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108 {
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109 _span = span;
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110 _discovery_is_atomic = atomic_discovery;
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111 _discovery_is_mt = mt_discovery;
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112 _num_q = MAX2(1U, mt_processing_degree);
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113 _max_num_q = MAX2(_num_q, mt_discovery_degree);
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114 _discovered_refs = NEW_C_HEAP_ARRAY(DiscoveredList,
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115 _max_num_q * number_of_subclasses_of_ref(), mtGC);
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116
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117 if (_discovered_refs == NULL) {
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118 vm_exit_during_initialization("Could not allocated RefProc Array");
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119 }
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120 _discoveredSoftRefs = &_discovered_refs[0];
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121 _discoveredWeakRefs = &_discoveredSoftRefs[_max_num_q];
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122 _discoveredFinalRefs = &_discoveredWeakRefs[_max_num_q];
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123 _discoveredPhantomRefs = &_discoveredFinalRefs[_max_num_q];
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124 _discoveredCleanerRefs = &_discoveredPhantomRefs[_max_num_q];
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125
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126 // Initialize all entries to NULL
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127 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
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128 _discovered_refs[i].set_head(NULL);
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129 _discovered_refs[i].set_length(0);
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130 }
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131
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132 setup_policy(false /* default soft ref policy */);
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133 }
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134
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135 #ifndef PRODUCT
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136 void ReferenceProcessor::verify_no_references_recorded() {
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137 guarantee(!_discovering_refs, "Discovering refs?");
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138 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
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139 guarantee(_discovered_refs[i].is_empty(),
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140 "Found non-empty discovered list");
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141 }
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142 }
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143 #endif
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144
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145 void ReferenceProcessor::weak_oops_do(OopClosure* f) {
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146 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
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147 if (UseCompressedOops) {
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148 f->do_oop((narrowOop*)_discovered_refs[i].adr_head());
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149 } else {
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150 f->do_oop((oop*)_discovered_refs[i].adr_head());
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151 }
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152 }
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153 }
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154
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155 void ReferenceProcessor::update_soft_ref_master_clock() {
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156 // Update (advance) the soft ref master clock field. This must be done
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157 // after processing the soft ref list.
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158
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159 // We need a monotonically non-deccreasing time in ms but
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160 // os::javaTimeMillis() does not guarantee monotonicity.
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161 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
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162 jlong soft_ref_clock = java_lang_ref_SoftReference::clock();
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163 assert(soft_ref_clock == _soft_ref_timestamp_clock, "soft ref clocks out of sync");
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164
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165 NOT_PRODUCT(
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166 if (now < _soft_ref_timestamp_clock) {
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167 warning("time warp: "INT64_FORMAT" to "INT64_FORMAT,
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168 _soft_ref_timestamp_clock, now);
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169 }
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170 )
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171 // The values of now and _soft_ref_timestamp_clock are set using
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172 // javaTimeNanos(), which is guaranteed to be monotonically
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173 // non-decreasing provided the underlying platform provides such
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174 // a time source (and it is bug free).
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175 // In product mode, however, protect ourselves from non-monotonicty.
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176 if (now > _soft_ref_timestamp_clock) {
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177 _soft_ref_timestamp_clock = now;
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178 java_lang_ref_SoftReference::set_clock(now);
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179 }
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180 // Else leave clock stalled at its old value until time progresses
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181 // past clock value.
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182 }
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183
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184 size_t ReferenceProcessor::total_count(DiscoveredList lists[]) {
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185 size_t total = 0;
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186 for (uint i = 0; i < _max_num_q; ++i) {
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187 total += lists[i].length();
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188 }
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189 return total;
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190 }
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191
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192 ReferenceProcessorStats ReferenceProcessor::process_discovered_references(
0
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193 BoolObjectClosure* is_alive,
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194 OopClosure* keep_alive,
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195 VoidClosure* complete_gc,
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196 AbstractRefProcTaskExecutor* task_executor,
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197 GCTimer* gc_timer,
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198 GCId gc_id) {
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199 NOT_PRODUCT(verify_ok_to_handle_reflists());
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200
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201 assert(!enqueuing_is_done(), "If here enqueuing should not be complete");
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202 // Stop treating discovered references specially.
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203 disable_discovery();
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204
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205 // If discovery was concurrent, someone could have modified
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206 // the value of the static field in the j.l.r.SoftReference
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207 // class that holds the soft reference timestamp clock using
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208 // reflection or Unsafe between when discovery was enabled and
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209 // now. Unconditionally update the static field in ReferenceProcessor
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210 // here so that we use the new value during processing of the
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211 // discovered soft refs.
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212
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213 _soft_ref_timestamp_clock = java_lang_ref_SoftReference::clock();
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214
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215 bool trace_time = PrintGCDetails && PrintReferenceGC;
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216
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217 // Soft references
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218 size_t soft_count = 0;
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219 {
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220 GCTraceTime tt("SoftReference", trace_time, false, gc_timer, gc_id);
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221 soft_count =
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222 process_discovered_reflist(_discoveredSoftRefs, _current_soft_ref_policy, true,
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223 is_alive, keep_alive, complete_gc, task_executor);
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224 }
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225
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226 update_soft_ref_master_clock();
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227
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228 // Weak references
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229 size_t weak_count = 0;
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230 {
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231 GCTraceTime tt("WeakReference", trace_time, false, gc_timer, gc_id);
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232 weak_count =
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233 process_discovered_reflist(_discoveredWeakRefs, NULL, true,
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234 is_alive, keep_alive, complete_gc, task_executor);
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235 }
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236
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237 // Final references
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238 size_t final_count = 0;
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239 {
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240 GCTraceTime tt("FinalReference", trace_time, false, gc_timer, gc_id);
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241 final_count =
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242 process_discovered_reflist(_discoveredFinalRefs, NULL, false,
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243 is_alive, keep_alive, complete_gc, task_executor);
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244 }
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245
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246 // Phantom references
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247 size_t phantom_count = 0;
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248 {
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249 GCTraceTime tt("PhantomReference", trace_time, false, gc_timer, gc_id);
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250 phantom_count =
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251 process_discovered_reflist(_discoveredPhantomRefs, NULL, false,
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252 is_alive, keep_alive, complete_gc, task_executor);
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253
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254 // Process cleaners, but include them in phantom statistics. We expect
01dcaba9b3f3 8047125: (ref) More phantom object references
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255 // Cleaner references to be temporary, and don't want to deal with
01dcaba9b3f3 8047125: (ref) More phantom object references
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256 // possible incompatibilities arising from making it more visible.
01dcaba9b3f3 8047125: (ref) More phantom object references
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257 phantom_count +=
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258 process_discovered_reflist(_discoveredCleanerRefs, NULL, false,
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259 is_alive, keep_alive, complete_gc, task_executor);
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260 }
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261
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262 // Weak global JNI references. It would make more sense (semantically) to
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263 // traverse these simultaneously with the regular weak references above, but
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264 // that is not how the JDK1.2 specification is. See #4126360. Native code can
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265 // thus use JNI weak references to circumvent the phantom references and
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266 // resurrect a "post-mortem" object.
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267 {
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268 GCTraceTime tt("JNI Weak Reference", trace_time, false, gc_timer, gc_id);
0
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269 if (task_executor != NULL) {
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270 task_executor->set_single_threaded_mode();
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271 }
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272 process_phaseJNI(is_alive, keep_alive, complete_gc);
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273 }
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274
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275 return ReferenceProcessorStats(soft_count, weak_count, final_count, phantom_count);
0
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276 }
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277
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278 #ifndef PRODUCT
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279 // Calculate the number of jni handles.
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280 uint ReferenceProcessor::count_jni_refs() {
0
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281 class AlwaysAliveClosure: public BoolObjectClosure {
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282 public:
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283 virtual bool do_object_b(oop obj) { return true; }
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284 };
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285
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286 class CountHandleClosure: public OopClosure {
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287 private:
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288 int _count;
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289 public:
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290 CountHandleClosure(): _count(0) {}
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291 void do_oop(oop* unused) { _count++; }
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292 void do_oop(narrowOop* unused) { ShouldNotReachHere(); }
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293 int count() { return _count; }
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294 };
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295 CountHandleClosure global_handle_count;
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296 AlwaysAliveClosure always_alive;
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297 JNIHandles::weak_oops_do(&always_alive, &global_handle_count);
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298 return global_handle_count.count();
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299 }
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300 #endif
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301
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302 void ReferenceProcessor::process_phaseJNI(BoolObjectClosure* is_alive,
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303 OopClosure* keep_alive,
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304 VoidClosure* complete_gc) {
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305 #ifndef PRODUCT
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306 if (PrintGCDetails && PrintReferenceGC) {
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307 unsigned int count = count_jni_refs();
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308 gclog_or_tty->print(", %u refs", count);
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309 }
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310 #endif
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311 JNIHandles::weak_oops_do(is_alive, keep_alive);
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312 complete_gc->do_void();
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313 }
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314
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315
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diff changeset
316 template <class T>
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317 bool enqueue_discovered_ref_helper(ReferenceProcessor* ref,
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318 AbstractRefProcTaskExecutor* task_executor) {
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319
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320 // Remember old value of pending references list
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321 T* pending_list_addr = (T*)java_lang_ref_Reference::pending_list_addr();
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322 T old_pending_list_value = *pending_list_addr;
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323
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324 // Enqueue references that are not made active again, and
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325 // clear the decks for the next collection (cycle).
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326 ref->enqueue_discovered_reflists((HeapWord*)pending_list_addr, task_executor);
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327 // Do the post-barrier on pending_list_addr missed in
fbc1677398c0 8029255: G1: Reference processing should not enqueue references on the shared SATB queue
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328 // enqueue_discovered_reflist.
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329 oopDesc::bs()->write_ref_field(pending_list_addr, oopDesc::load_decode_heap_oop(pending_list_addr));
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330
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331 // Stop treating discovered references specially.
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332 ref->disable_discovery();
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333
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334 // Return true if new pending references were added
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335 return old_pending_list_value != *pending_list_addr;
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336 }
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337
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338 bool ReferenceProcessor::enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor) {
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339 NOT_PRODUCT(verify_ok_to_handle_reflists());
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340 if (UseCompressedOops) {
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341 return enqueue_discovered_ref_helper<narrowOop>(this, task_executor);
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342 } else {
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343 return enqueue_discovered_ref_helper<oop>(this, task_executor);
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344 }
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345 }
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346
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347 void ReferenceProcessor::enqueue_discovered_reflist(DiscoveredList& refs_list,
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348 HeapWord* pending_list_addr) {
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349 // Given a list of refs linked through the "discovered" field
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350 // (java.lang.ref.Reference.discovered), self-loop their "next" field
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351 // thus distinguishing them from active References, then
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352 // prepend them to the pending list.
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353 //
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354 // The Java threads will see the Reference objects linked together through
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355 // the discovered field. Instead of trying to do the write barrier updates
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356 // in all places in the reference processor where we manipulate the discovered
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357 // field we make sure to do the barrier here where we anyway iterate through
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358 // all linked Reference objects. Note that it is important to not dirty any
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359 // cards during reference processing since this will cause card table
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360 // verification to fail for G1.
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361 //
3917
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362 // BKWRD COMPATIBILITY NOTE: For older JDKs (prior to the fix for 4956777),
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363 // the "next" field is used to chain the pending list, not the discovered
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364 // field.
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365 if (TraceReferenceGC && PrintGCDetails) {
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366 gclog_or_tty->print_cr("ReferenceProcessor::enqueue_discovered_reflist list "
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367 INTPTR_FORMAT, (address)refs_list.head());
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368 }
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369
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370 oop obj = NULL;
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371 oop next_d = refs_list.head();
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372 if (pending_list_uses_discovered_field()) { // New behavior
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373 // Walk down the list, self-looping the next field
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374 // so that the References are not considered active.
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375 while (obj != next_d) {
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376 obj = next_d;
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377 assert(obj->is_instanceRef(), "should be reference object");
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378 next_d = java_lang_ref_Reference::discovered(obj);
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379 if (TraceReferenceGC && PrintGCDetails) {
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380 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
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381 (void *)obj, (void *)next_d);
3917
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382 }
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383 assert(java_lang_ref_Reference::next(obj) == NULL,
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384 "Reference not active; should not be discovered");
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385 // Self-loop next, so as to make Ref not active.
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386 java_lang_ref_Reference::set_next_raw(obj, obj);
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387 if (next_d != obj) {
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388 oopDesc::bs()->write_ref_field(java_lang_ref_Reference::discovered_addr(obj), next_d);
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diff changeset
389 } else {
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390 // This is the last object.
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391 // Swap refs_list into pending_list_addr and
3917
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392 // set obj's discovered to what we read from pending_list_addr.
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393 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
17976
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diff changeset
394 // Need post-barrier on pending_list_addr. See enqueue_discovered_ref_helper() above.
14252
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parents: 12316
diff changeset
395 java_lang_ref_Reference::set_discovered_raw(obj, old); // old may be NULL
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diff changeset
396 oopDesc::bs()->write_ref_field(java_lang_ref_Reference::discovered_addr(obj), old);
3917
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397 }
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398 }
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399 } else { // Old behaviour
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400 // Walk down the list, copying the discovered field into
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401 // the next field and clearing the discovered field.
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402 while (obj != next_d) {
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403 obj = next_d;
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404 assert(obj->is_instanceRef(), "should be reference object");
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405 next_d = java_lang_ref_Reference::discovered(obj);
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406 if (TraceReferenceGC && PrintGCDetails) {
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407 gclog_or_tty->print_cr(" obj " INTPTR_FORMAT "/next_d " INTPTR_FORMAT,
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408 (void *)obj, (void *)next_d);
3917
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409 }
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410 assert(java_lang_ref_Reference::next(obj) == NULL,
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411 "The reference should not be enqueued");
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412 if (next_d == obj) { // obj is last
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413 // Swap refs_list into pendling_list_addr and
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414 // set obj's next to what we read from pending_list_addr.
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415 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
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416 // Need oop_check on pending_list_addr above;
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417 // see special oop-check code at the end of
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
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418 // enqueue_discovered_reflists() further below.
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
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diff changeset
419 if (old == NULL) {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
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diff changeset
420 // obj should be made to point to itself, since
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
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421 // pending list was empty.
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diff changeset
422 java_lang_ref_Reference::set_next(obj, obj);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
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diff changeset
423 } else {
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
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diff changeset
424 java_lang_ref_Reference::set_next(obj, old);
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
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diff changeset
425 }
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426 } else {
3917
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427 java_lang_ref_Reference::set_next(obj, next_d);
0
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428 }
3917
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diff changeset
429 java_lang_ref_Reference::set_discovered(obj, (oop) NULL);
0
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430 }
a61af66fc99e Initial load
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431 }
a61af66fc99e Initial load
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432 }
a61af66fc99e Initial load
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433
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434 // Parallel enqueue task
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435 class RefProcEnqueueTask: public AbstractRefProcTaskExecutor::EnqueueTask {
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436 public:
a61af66fc99e Initial load
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437 RefProcEnqueueTask(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load
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438 DiscoveredList discovered_refs[],
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
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diff changeset
439 HeapWord* pending_list_addr,
0
a61af66fc99e Initial load
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diff changeset
440 int n_queues)
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441 : EnqueueTask(ref_processor, discovered_refs,
3915
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diff changeset
442 pending_list_addr, n_queues)
0
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443 { }
a61af66fc99e Initial load
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444
113
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diff changeset
445 virtual void work(unsigned int work_id) {
2369
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
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parents: 1995
diff changeset
446 assert(work_id < (unsigned int)_ref_processor.max_num_q(), "Index out-of-bounds");
0
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447 // Simplest first cut: static partitioning.
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448 int index = work_id;
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
449 // 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
450 // (n_queues) with which that ReferenceProcessor was created. That
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
451 // 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
452 // allocated and are indexed into.
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents: 1995
diff changeset
453 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
454 for (int j = 0;
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
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diff changeset
455 j < ReferenceProcessor::number_of_subclasses_of_ref();
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
456 j++, index += _n_queues) {
0
a61af66fc99e Initial load
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diff changeset
457 _ref_processor.enqueue_discovered_reflist(
a61af66fc99e Initial load
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diff changeset
458 _refs_lists[index], _pending_list_addr);
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
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diff changeset
459 _refs_lists[index].set_head(NULL);
0
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diff changeset
460 _refs_lists[index].set_length(0);
a61af66fc99e Initial load
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diff changeset
461 }
a61af66fc99e Initial load
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parents:
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462 }
a61af66fc99e Initial load
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diff changeset
463 };
a61af66fc99e Initial load
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464
a61af66fc99e Initial load
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parents:
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465 // Enqueue references that are not made active again
113
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parents: 5
diff changeset
466 void ReferenceProcessor::enqueue_discovered_reflists(HeapWord* pending_list_addr,
0
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parents:
diff changeset
467 AbstractRefProcTaskExecutor* task_executor) {
a61af66fc99e Initial load
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parents:
diff changeset
468 if (_processing_is_mt && task_executor != NULL) {
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parents:
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469 // Parallel code
4014
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs
johnc
parents: 3992
diff changeset
470 RefProcEnqueueTask tsk(*this, _discovered_refs,
3915
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stefank
parents: 2369
diff changeset
471 pending_list_addr, _max_num_q);
0
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472 task_executor->execute(tsk);
a61af66fc99e Initial load
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parents:
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473 } else {
a61af66fc99e Initial load
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parents:
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474 // 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
475 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
476 enqueue_discovered_reflist(_discovered_refs[i], pending_list_addr);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs
johnc
parents: 3992
diff changeset
477 _discovered_refs[i].set_head(NULL);
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs
johnc
parents: 3992
diff changeset
478 _discovered_refs[i].set_length(0);
0
a61af66fc99e Initial load
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parents:
diff changeset
479 }
a61af66fc99e Initial load
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parents:
diff changeset
480 }
a61af66fc99e Initial load
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parents:
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481 }
a61af66fc99e Initial load
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parents:
diff changeset
482
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
483 void DiscoveredListIterator::load_ptrs(DEBUG_ONLY(bool allow_null_referent)) {
0
a61af66fc99e Initial load
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diff changeset
484 _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
485 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
486 assert(_discovered_addr && discovered->is_oop_or_null(),
0
a61af66fc99e Initial load
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parents:
diff changeset
487 "discovered field is bad");
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
488 _next = discovered;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
489 _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
490 _referent = java_lang_ref_Reference::referent(_ref);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
491 assert(Universe::heap()->is_in_reserved_or_null(_referent),
a61af66fc99e Initial load
duke
parents:
diff changeset
492 "Wrong oop found in java.lang.Reference object");
a61af66fc99e Initial load
duke
parents:
diff changeset
493 assert(allow_null_referent ?
a61af66fc99e Initial load
duke
parents:
diff changeset
494 _referent->is_oop_or_null()
a61af66fc99e Initial load
duke
parents:
diff changeset
495 : _referent->is_oop(),
a61af66fc99e Initial load
duke
parents:
diff changeset
496 "bad referent");
a61af66fc99e Initial load
duke
parents:
diff changeset
497 }
a61af66fc99e Initial load
duke
parents:
diff changeset
498
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
499 void DiscoveredListIterator::remove() {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
500 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
501 oop_store_raw(_discovered_addr, NULL);
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
502
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
503 // 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
504 oop new_next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
505 if (_next == _ref) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
506 // 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
507 // 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
508 // and _prev will be NULL.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
509 new_next = _prev;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
510 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
511 new_next = _next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
512 }
17748
d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor
pliden
parents: 14252
diff changeset
513 // Remove Reference object from discovered list. Note that G1 does not need a
d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor
pliden
parents: 14252
diff changeset
514 // pre-barrier here because we know the Reference has already been found/marked,
d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor
pliden
parents: 14252
diff changeset
515 // that's how it ended up in the discovered list in the first place.
d60ecdb2773e 8031703: Missing post-barrier in ReferenceProcessor
pliden
parents: 14252
diff changeset
516 oop_store_raw(_prev_next, new_next);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
517 NOT_PRODUCT(_removed++);
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
518 _refs_list.dec_length(1);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
519 }
a61af66fc99e Initial load
duke
parents:
diff changeset
520
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
521 // Make the Reference object active again.
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
522 void DiscoveredListIterator::make_active() {
17976
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects
brutisso
parents: 17937
diff changeset
523 // 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
524 // 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
525 // ReferenceProcessor::pending_list_uses_discovered_field() ?
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
526 if (UseG1GC) {
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
527 HeapWord* next_addr = java_lang_ref_Reference::next_addr(_ref);
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
528 if (UseCompressedOops) {
14252
fbc1677398c0 8029255: G1: Reference processing should not enqueue references on the shared SATB queue
pliden
parents: 12316
diff changeset
529 oopDesc::bs()->write_ref_field_pre((narrowOop*)next_addr, NULL);
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
530 } else {
14252
fbc1677398c0 8029255: G1: Reference processing should not enqueue references on the shared SATB queue
pliden
parents: 12316
diff changeset
531 oopDesc::bs()->write_ref_field_pre((oop*)next_addr, NULL);
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
532 }
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
533 }
17976
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects
brutisso
parents: 17937
diff changeset
534 java_lang_ref_Reference::set_next_raw(_ref, NULL);
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
535 }
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
536
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
537 void DiscoveredListIterator::clear_referent() {
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
538 oop_store_raw(_referent_addr, NULL);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
539 }
a61af66fc99e Initial load
duke
parents:
diff changeset
540
a61af66fc99e Initial load
duke
parents:
diff changeset
541 // NOTE: process_phase*() are largely similar, and at a high level
a61af66fc99e Initial load
duke
parents:
diff changeset
542 // merely iterate over the extant list applying a predicate to
a61af66fc99e Initial load
duke
parents:
diff changeset
543 // each of its elements and possibly removing that element from the
a61af66fc99e Initial load
duke
parents:
diff changeset
544 // list and applying some further closures to that element.
a61af66fc99e Initial load
duke
parents:
diff changeset
545 // We should consider the possibility of replacing these
a61af66fc99e Initial load
duke
parents:
diff changeset
546 // process_phase*() methods by abstracting them into
a61af66fc99e Initial load
duke
parents:
diff changeset
547 // a single general iterator invocation that receives appropriate
a61af66fc99e Initial load
duke
parents:
diff changeset
548 // closures that accomplish this work.
a61af66fc99e Initial load
duke
parents:
diff changeset
549
a61af66fc99e Initial load
duke
parents:
diff changeset
550 // (SoftReferences only) Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load
duke
parents:
diff changeset
551 // referents are not alive, but that should be kept alive for policy reasons.
a61af66fc99e Initial load
duke
parents:
diff changeset
552 // Keep alive the transitive closure of all such referents.
a61af66fc99e Initial load
duke
parents:
diff changeset
553 void
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
554 ReferenceProcessor::process_phase1(DiscoveredList& refs_list,
0
a61af66fc99e Initial load
duke
parents:
diff changeset
555 ReferencePolicy* policy,
a61af66fc99e Initial load
duke
parents:
diff changeset
556 BoolObjectClosure* is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
557 OopClosure* keep_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
558 VoidClosure* complete_gc) {
a61af66fc99e Initial load
duke
parents:
diff changeset
559 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
560 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
561 // Decide which softly reachable refs should be kept alive.
a61af66fc99e Initial load
duke
parents:
diff changeset
562 while (iter.has_next()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
563 iter.load_ptrs(DEBUG_ONLY(!discovery_is_atomic() /* allow_null_referent */));
a61af66fc99e Initial load
duke
parents:
diff changeset
564 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
565 if (referent_is_dead &&
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
johnc
parents: 3979
diff changeset
566 !policy->should_clear_reference(iter.obj(), _soft_ref_timestamp_clock)) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
567 if (TraceReferenceGC) {
a61af66fc99e Initial load
duke
parents:
diff changeset
568 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
569 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
570 }
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
571 // Remove Reference object from list
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
572 iter.remove();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
573 // Make the Reference object active again
a61af66fc99e Initial load
duke
parents:
diff changeset
574 iter.make_active();
a61af66fc99e Initial load
duke
parents:
diff changeset
575 // keep the referent around
a61af66fc99e Initial load
duke
parents:
diff changeset
576 iter.make_referent_alive();
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
577 iter.move_to_next();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
578 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
579 iter.next();
a61af66fc99e Initial load
duke
parents:
diff changeset
580 }
a61af66fc99e Initial load
duke
parents:
diff changeset
581 }
a61af66fc99e Initial load
duke
parents:
diff changeset
582 // Close the reachable set
a61af66fc99e Initial load
duke
parents:
diff changeset
583 complete_gc->do_void();
a61af66fc99e Initial load
duke
parents:
diff changeset
584 NOT_PRODUCT(
a61af66fc99e Initial load
duke
parents:
diff changeset
585 if (PrintGCDetails && TraceReferenceGC) {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
586 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
587 "discovered Refs by policy, from list " INTPTR_FORMAT,
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
588 iter.removed(), iter.processed(), (address)refs_list.head());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
589 }
a61af66fc99e Initial load
duke
parents:
diff changeset
590 )
a61af66fc99e Initial load
duke
parents:
diff changeset
591 }
a61af66fc99e Initial load
duke
parents:
diff changeset
592
a61af66fc99e Initial load
duke
parents:
diff changeset
593 // Traverse the list and remove any Refs that are not active, or
a61af66fc99e Initial load
duke
parents:
diff changeset
594 // whose referents are either alive or NULL.
a61af66fc99e Initial load
duke
parents:
diff changeset
595 void
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
596 ReferenceProcessor::pp2_work(DiscoveredList& refs_list,
0
a61af66fc99e Initial load
duke
parents:
diff changeset
597 BoolObjectClosure* is_alive,
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
598 OopClosure* keep_alive) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
599 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
600 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
601 while (iter.has_next()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
602 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
603 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
604 assert(next == NULL, "Should not discover inactive Reference");
0
a61af66fc99e Initial load
duke
parents:
diff changeset
605 if (iter.is_referent_alive()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
606 if (TraceReferenceGC) {
a61af66fc99e Initial load
duke
parents:
diff changeset
607 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
608 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
609 }
a61af66fc99e Initial load
duke
parents:
diff changeset
610 // The referent is reachable after all.
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
611 // Remove Reference object from list.
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
612 iter.remove();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
613 // Update the referent pointer as necessary: Note that this
a61af66fc99e Initial load
duke
parents:
diff changeset
614 // should not entail any recursive marking because the
a61af66fc99e Initial load
duke
parents:
diff changeset
615 // referent must already have been traversed.
a61af66fc99e Initial load
duke
parents:
diff changeset
616 iter.make_referent_alive();
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
617 iter.move_to_next();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
618 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
619 iter.next();
a61af66fc99e Initial load
duke
parents:
diff changeset
620 }
a61af66fc99e Initial load
duke
parents:
diff changeset
621 }
a61af66fc99e Initial load
duke
parents:
diff changeset
622 NOT_PRODUCT(
2369
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents: 1995
diff changeset
623 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
624 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
625 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
626 iter.removed(), iter.processed(), (address)refs_list.head());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
627 }
a61af66fc99e Initial load
duke
parents:
diff changeset
628 )
a61af66fc99e Initial load
duke
parents:
diff changeset
629 }
a61af66fc99e Initial load
duke
parents:
diff changeset
630
a61af66fc99e Initial load
duke
parents:
diff changeset
631 void
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
632 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
633 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
634 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
635 VoidClosure* complete_gc) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
636 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
637 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
638 while (iter.has_next()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
639 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
640 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
641 oop next = java_lang_ref_Reference::next(iter.obj());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
642 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
643 next != NULL)) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
644 assert(next->is_oop_or_null(), "bad next field");
0
a61af66fc99e Initial load
duke
parents:
diff changeset
645 // Remove Reference object from list
a61af66fc99e Initial load
duke
parents:
diff changeset
646 iter.remove();
a61af66fc99e Initial load
duke
parents:
diff changeset
647 // Trace the cohorts
a61af66fc99e Initial load
duke
parents:
diff changeset
648 iter.make_referent_alive();
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
649 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
650 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
651 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
652 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
653 }
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
654 iter.move_to_next();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
655 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
656 iter.next();
a61af66fc99e Initial load
duke
parents:
diff changeset
657 }
a61af66fc99e Initial load
duke
parents:
diff changeset
658 }
a61af66fc99e Initial load
duke
parents:
diff changeset
659 // Now close the newly reachable set
a61af66fc99e Initial load
duke
parents:
diff changeset
660 complete_gc->do_void();
a61af66fc99e Initial load
duke
parents:
diff changeset
661 NOT_PRODUCT(
2369
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents: 1995
diff changeset
662 if (PrintGCDetails && TraceReferenceGC && (iter.processed() > 0)) {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
663 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
664 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
665 iter.removed(), iter.processed(), (address)refs_list.head());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
666 }
a61af66fc99e Initial load
duke
parents:
diff changeset
667 )
a61af66fc99e Initial load
duke
parents:
diff changeset
668 }
a61af66fc99e Initial load
duke
parents:
diff changeset
669
a61af66fc99e Initial load
duke
parents:
diff changeset
670 // 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
671 // clearing them or keeping them (and their reachable
0
a61af66fc99e Initial load
duke
parents:
diff changeset
672 // closure) alive.
a61af66fc99e Initial load
duke
parents:
diff changeset
673 void
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
674 ReferenceProcessor::process_phase3(DiscoveredList& refs_list,
0
a61af66fc99e Initial load
duke
parents:
diff changeset
675 bool clear_referent,
a61af66fc99e Initial load
duke
parents:
diff changeset
676 BoolObjectClosure* is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
677 OopClosure* keep_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
678 VoidClosure* complete_gc) {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
679 ResourceMark rm;
17976
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects
brutisso
parents: 17937
diff changeset
680 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
681 while (iter.has_next()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
682 iter.update_discovered();
a61af66fc99e Initial load
duke
parents:
diff changeset
683 iter.load_ptrs(DEBUG_ONLY(false /* allow_null_referent */));
a61af66fc99e Initial load
duke
parents:
diff changeset
684 if (clear_referent) {
a61af66fc99e Initial load
duke
parents:
diff changeset
685 // NULL out referent pointer
a61af66fc99e Initial load
duke
parents:
diff changeset
686 iter.clear_referent();
a61af66fc99e Initial load
duke
parents:
diff changeset
687 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
688 // keep the referent around
a61af66fc99e Initial load
duke
parents:
diff changeset
689 iter.make_referent_alive();
a61af66fc99e Initial load
duke
parents:
diff changeset
690 }
a61af66fc99e Initial load
duke
parents:
diff changeset
691 if (TraceReferenceGC) {
a61af66fc99e Initial load
duke
parents:
diff changeset
692 gclog_or_tty->print_cr("Adding %sreference (" INTPTR_FORMAT ": %s) as pending",
a61af66fc99e Initial load
duke
parents:
diff changeset
693 clear_referent ? "cleared " : "",
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
694 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
695 }
a61af66fc99e Initial load
duke
parents:
diff changeset
696 assert(iter.obj()->is_oop(UseConcMarkSweepGC), "Adding a bad reference");
a61af66fc99e Initial load
duke
parents:
diff changeset
697 iter.next();
a61af66fc99e Initial load
duke
parents:
diff changeset
698 }
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
699 // Remember to update the next pointer of the last ref.
0
a61af66fc99e Initial load
duke
parents:
diff changeset
700 iter.update_discovered();
a61af66fc99e Initial load
duke
parents:
diff changeset
701 // Close the reachable set
a61af66fc99e Initial load
duke
parents:
diff changeset
702 complete_gc->do_void();
a61af66fc99e Initial load
duke
parents:
diff changeset
703 }
a61af66fc99e Initial load
duke
parents:
diff changeset
704
a61af66fc99e Initial load
duke
parents:
diff changeset
705 void
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
706 ReferenceProcessor::clear_discovered_references(DiscoveredList& refs_list) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
707 oop obj = NULL;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
708 oop next = refs_list.head();
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
709 while (next != obj) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
710 obj = next;
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
711 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
712 java_lang_ref_Reference::set_discovered_raw(obj, NULL);
0
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 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
715 refs_list.set_length(0);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
716 }
a61af66fc99e Initial load
duke
parents:
diff changeset
717
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
718 void
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
719 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
720 clear_discovered_references(refs_list);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
721 }
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
722
342
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
ysr
parents: 113
diff changeset
723 void ReferenceProcessor::abandon_partial_discovery() {
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
ysr
parents: 113
diff changeset
724 // loop over the lists
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
725 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
726 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
727 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
728 }
4014
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs
johnc
parents: 3992
diff changeset
729 abandon_partial_discovered_list(_discovered_refs[i]);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
730 }
a61af66fc99e Initial load
duke
parents:
diff changeset
731 }
a61af66fc99e Initial load
duke
parents:
diff changeset
732
a61af66fc99e Initial load
duke
parents:
diff changeset
733 class RefProcPhase1Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load
duke
parents:
diff changeset
734 public:
a61af66fc99e Initial load
duke
parents:
diff changeset
735 RefProcPhase1Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load
duke
parents:
diff changeset
736 DiscoveredList refs_lists[],
a61af66fc99e Initial load
duke
parents:
diff changeset
737 ReferencePolicy* policy,
a61af66fc99e Initial load
duke
parents:
diff changeset
738 bool marks_oops_alive)
a61af66fc99e Initial load
duke
parents:
diff changeset
739 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load
duke
parents:
diff changeset
740 _policy(policy)
a61af66fc99e Initial load
duke
parents:
diff changeset
741 { }
a61af66fc99e Initial load
duke
parents:
diff changeset
742 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
743 OopClosure& keep_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
744 VoidClosure& complete_gc)
a61af66fc99e Initial load
duke
parents:
diff changeset
745 {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
746 Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
747 int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
748 _ref_processor.process_phase1(_refs_lists[refs_list_index], _policy,
0
a61af66fc99e Initial load
duke
parents:
diff changeset
749 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load
duke
parents:
diff changeset
750 }
a61af66fc99e Initial load
duke
parents:
diff changeset
751 private:
a61af66fc99e Initial load
duke
parents:
diff changeset
752 ReferencePolicy* _policy;
a61af66fc99e Initial load
duke
parents:
diff changeset
753 };
a61af66fc99e Initial load
duke
parents:
diff changeset
754
a61af66fc99e Initial load
duke
parents:
diff changeset
755 class RefProcPhase2Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load
duke
parents:
diff changeset
756 public:
a61af66fc99e Initial load
duke
parents:
diff changeset
757 RefProcPhase2Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load
duke
parents:
diff changeset
758 DiscoveredList refs_lists[],
a61af66fc99e Initial load
duke
parents:
diff changeset
759 bool marks_oops_alive)
a61af66fc99e Initial load
duke
parents:
diff changeset
760 : ProcessTask(ref_processor, refs_lists, marks_oops_alive)
a61af66fc99e Initial load
duke
parents:
diff changeset
761 { }
a61af66fc99e Initial load
duke
parents:
diff changeset
762 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
763 OopClosure& keep_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
764 VoidClosure& complete_gc)
a61af66fc99e Initial load
duke
parents:
diff changeset
765 {
a61af66fc99e Initial load
duke
parents:
diff changeset
766 _ref_processor.process_phase2(_refs_lists[i],
a61af66fc99e Initial load
duke
parents:
diff changeset
767 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load
duke
parents:
diff changeset
768 }
a61af66fc99e Initial load
duke
parents:
diff changeset
769 };
a61af66fc99e Initial load
duke
parents:
diff changeset
770
a61af66fc99e Initial load
duke
parents:
diff changeset
771 class RefProcPhase3Task: public AbstractRefProcTaskExecutor::ProcessTask {
a61af66fc99e Initial load
duke
parents:
diff changeset
772 public:
a61af66fc99e Initial load
duke
parents:
diff changeset
773 RefProcPhase3Task(ReferenceProcessor& ref_processor,
a61af66fc99e Initial load
duke
parents:
diff changeset
774 DiscoveredList refs_lists[],
a61af66fc99e Initial load
duke
parents:
diff changeset
775 bool clear_referent,
a61af66fc99e Initial load
duke
parents:
diff changeset
776 bool marks_oops_alive)
a61af66fc99e Initial load
duke
parents:
diff changeset
777 : ProcessTask(ref_processor, refs_lists, marks_oops_alive),
a61af66fc99e Initial load
duke
parents:
diff changeset
778 _clear_referent(clear_referent)
a61af66fc99e Initial load
duke
parents:
diff changeset
779 { }
a61af66fc99e Initial load
duke
parents:
diff changeset
780 virtual void work(unsigned int i, BoolObjectClosure& is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
781 OopClosure& keep_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
782 VoidClosure& complete_gc)
a61af66fc99e Initial load
duke
parents:
diff changeset
783 {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
784 // 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
785 // 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
786 // Thread* thr = Thread::current();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
787 // int refs_list_index = ((WorkerThread*)thr)->id();
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
788 // _ref_processor.process_phase3(_refs_lists[refs_list_index], _clear_referent,
0
a61af66fc99e Initial load
duke
parents:
diff changeset
789 _ref_processor.process_phase3(_refs_lists[i], _clear_referent,
a61af66fc99e Initial load
duke
parents:
diff changeset
790 &is_alive, &keep_alive, &complete_gc);
a61af66fc99e Initial load
duke
parents:
diff changeset
791 }
a61af66fc99e Initial load
duke
parents:
diff changeset
792 private:
a61af66fc99e Initial load
duke
parents:
diff changeset
793 bool _clear_referent;
a61af66fc99e Initial load
duke
parents:
diff changeset
794 };
a61af66fc99e Initial load
duke
parents:
diff changeset
795
a61af66fc99e Initial load
duke
parents:
diff changeset
796 // Balances reference queues.
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
797 // 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
798 // 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
799 // corresponding to the active workers will be processed.
0
a61af66fc99e Initial load
duke
parents:
diff changeset
800 void ReferenceProcessor::balance_queues(DiscoveredList ref_lists[])
a61af66fc99e Initial load
duke
parents:
diff changeset
801 {
a61af66fc99e Initial load
duke
parents:
diff changeset
802 // calculate total length
a61af66fc99e Initial load
duke
parents:
diff changeset
803 size_t total_refs = 0;
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
804 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
805 gclog_or_tty->print_cr("\nBalance ref_lists ");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
806 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
807
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
808 for (uint i = 0; i < _max_num_q; ++i) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
809 total_refs += ref_lists[i].length();
1833
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("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
812 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
813 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
814 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
815 gclog_or_tty->print_cr(" = %d", total_refs);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
816 }
a61af66fc99e Initial load
duke
parents:
diff changeset
817 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
818 uint to_idx = 0;
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
819 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
820 bool move_all = false;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
821 if (from_idx >= _num_q) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
822 move_all = ref_lists[from_idx].length() > 0;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
823 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
824 while ((ref_lists[from_idx].length() > avg_refs) ||
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
825 move_all) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
826 assert(to_idx < _num_q, "Sanity Check!");
a61af66fc99e Initial load
duke
parents:
diff changeset
827 if (ref_lists[to_idx].length() < avg_refs) {
a61af66fc99e Initial load
duke
parents:
diff changeset
828 // move superfluous refs
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
829 size_t refs_to_move;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
830 // 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
831 if (move_all) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
832 refs_to_move = MIN2(ref_lists[from_idx].length(),
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
833 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
834 } else {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
835 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
836 avg_refs - ref_lists[to_idx].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
837 }
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
838
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
839 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
840
0
a61af66fc99e Initial load
duke
parents:
diff changeset
841 oop move_head = ref_lists[from_idx].head();
a61af66fc99e Initial load
duke
parents:
diff changeset
842 oop move_tail = move_head;
a61af66fc99e Initial load
duke
parents:
diff changeset
843 oop new_head = move_head;
a61af66fc99e Initial load
duke
parents:
diff changeset
844 // find an element to split the list on
a61af66fc99e Initial load
duke
parents:
diff changeset
845 for (size_t j = 0; j < refs_to_move; ++j) {
a61af66fc99e Initial load
duke
parents:
diff changeset
846 move_tail = new_head;
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
847 new_head = java_lang_ref_Reference::discovered(new_head);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
848 }
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
849
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
850 // Add the chain to the to list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
851 if (ref_lists[to_idx].head() == NULL) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
852 // 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
853 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
854 } else {
17976
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects
brutisso
parents: 17937
diff changeset
855 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
856 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
857 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
858 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
859
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
860 // Remove the chain from the from list.
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
861 if (move_tail == new_head) {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
862 // 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
863 ref_lists[from_idx].set_head(NULL);
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
864 } else {
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
865 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
866 }
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
867 ref_lists[from_idx].dec_length(refs_to_move);
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
868 if (ref_lists[from_idx].length() == 0) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
869 break;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
870 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
871 } else {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
872 to_idx = (to_idx + 1) % _num_q;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
873 }
a61af66fc99e Initial load
duke
parents:
diff changeset
874 }
a61af66fc99e Initial load
duke
parents:
diff changeset
875 }
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
876 #ifdef ASSERT
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
877 size_t balanced_total_refs = 0;
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
878 for (uint i = 0; i < _max_num_q; ++i) {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
879 balanced_total_refs += ref_lists[i].length();
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("%d ", ref_lists[i].length());
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
882 }
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 if (TraceReferenceGC && PrintGCDetails) {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
885 gclog_or_tty->print_cr(" = %d", balanced_total_refs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
886 gclog_or_tty->flush();
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 assert(total_refs == balanced_total_refs, "Balancing was incomplete");
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
889 #endif
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
890 }
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
891
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
892 void ReferenceProcessor::balance_all_queues() {
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
893 balance_queues(_discoveredSoftRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
894 balance_queues(_discoveredWeakRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
895 balance_queues(_discoveredFinalRefs);
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
896 balance_queues(_discoveredPhantomRefs);
20755
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
897 balance_queues(_discoveredCleanerRefs);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
898 }
a61af66fc99e Initial load
duke
parents:
diff changeset
899
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
900 size_t
0
a61af66fc99e Initial load
duke
parents:
diff changeset
901 ReferenceProcessor::process_discovered_reflist(
a61af66fc99e Initial load
duke
parents:
diff changeset
902 DiscoveredList refs_lists[],
a61af66fc99e Initial load
duke
parents:
diff changeset
903 ReferencePolicy* policy,
a61af66fc99e Initial load
duke
parents:
diff changeset
904 bool clear_referent,
a61af66fc99e Initial load
duke
parents:
diff changeset
905 BoolObjectClosure* is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
906 OopClosure* keep_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
907 VoidClosure* complete_gc,
a61af66fc99e Initial load
duke
parents:
diff changeset
908 AbstractRefProcTaskExecutor* task_executor)
a61af66fc99e Initial load
duke
parents:
diff changeset
909 {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
910 bool mt_processing = task_executor != NULL && _processing_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
911 // 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
912 // 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
913 // 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
914 // 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
915 // 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
916 // of the test.
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
917 bool must_balance = _discovery_is_mt;
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
918
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
919 if ((mt_processing && ParallelRefProcBalancingEnabled) ||
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
920 must_balance) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
921 balance_queues(refs_lists);
a61af66fc99e Initial load
duke
parents:
diff changeset
922 }
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
923
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
924 size_t total_list_count = total_count(refs_lists);
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
925
0
a61af66fc99e Initial load
duke
parents:
diff changeset
926 if (PrintReferenceGC && PrintGCDetails) {
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
927 gclog_or_tty->print(", %u refs", total_list_count);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
928 }
a61af66fc99e Initial load
duke
parents:
diff changeset
929
a61af66fc99e Initial load
duke
parents:
diff changeset
930 // Phase 1 (soft refs only):
a61af66fc99e Initial load
duke
parents:
diff changeset
931 // . Traverse the list and remove any SoftReferences whose
a61af66fc99e Initial load
duke
parents:
diff changeset
932 // referents are not alive, but that should be kept alive for
a61af66fc99e Initial load
duke
parents:
diff changeset
933 // policy reasons. Keep alive the transitive closure of all
a61af66fc99e Initial load
duke
parents:
diff changeset
934 // such referents.
a61af66fc99e Initial load
duke
parents:
diff changeset
935 if (policy != NULL) {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
936 if (mt_processing) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
937 RefProcPhase1Task phase1(*this, refs_lists, policy, true /*marks_oops_alive*/);
a61af66fc99e Initial load
duke
parents:
diff changeset
938 task_executor->execute(phase1);
a61af66fc99e Initial load
duke
parents:
diff changeset
939 } else {
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
940 for (uint i = 0; i < _max_num_q; i++) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
941 process_phase1(refs_lists[i], policy,
a61af66fc99e Initial load
duke
parents:
diff changeset
942 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load
duke
parents:
diff changeset
943 }
a61af66fc99e Initial load
duke
parents:
diff changeset
944 }
a61af66fc99e Initial load
duke
parents:
diff changeset
945 } else { // policy == NULL
a61af66fc99e Initial load
duke
parents:
diff changeset
946 assert(refs_lists != _discoveredSoftRefs,
a61af66fc99e Initial load
duke
parents:
diff changeset
947 "Policy must be specified for soft references.");
a61af66fc99e Initial load
duke
parents:
diff changeset
948 }
a61af66fc99e Initial load
duke
parents:
diff changeset
949
a61af66fc99e Initial load
duke
parents:
diff changeset
950 // Phase 2:
a61af66fc99e Initial load
duke
parents:
diff changeset
951 // . 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
952 if (mt_processing) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
953 RefProcPhase2Task phase2(*this, refs_lists, !discovery_is_atomic() /*marks_oops_alive*/);
a61af66fc99e Initial load
duke
parents:
diff changeset
954 task_executor->execute(phase2);
a61af66fc99e Initial load
duke
parents:
diff changeset
955 } else {
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
956 for (uint i = 0; i < _max_num_q; i++) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
957 process_phase2(refs_lists[i], is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load
duke
parents:
diff changeset
958 }
a61af66fc99e Initial load
duke
parents:
diff changeset
959 }
a61af66fc99e Initial load
duke
parents:
diff changeset
960
a61af66fc99e Initial load
duke
parents:
diff changeset
961 // Phase 3:
a61af66fc99e Initial load
duke
parents:
diff changeset
962 // . Traverse the list and process referents as appropriate.
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
963 if (mt_processing) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
964 RefProcPhase3Task phase3(*this, refs_lists, clear_referent, true /*marks_oops_alive*/);
a61af66fc99e Initial load
duke
parents:
diff changeset
965 task_executor->execute(phase3);
a61af66fc99e Initial load
duke
parents:
diff changeset
966 } else {
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
967 for (uint i = 0; i < _max_num_q; i++) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
968 process_phase3(refs_lists[i], clear_referent,
a61af66fc99e Initial load
duke
parents:
diff changeset
969 is_alive, keep_alive, complete_gc);
a61af66fc99e Initial load
duke
parents:
diff changeset
970 }
a61af66fc99e Initial load
duke
parents:
diff changeset
971 }
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
972
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
973 return total_list_count;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
974 }
a61af66fc99e Initial load
duke
parents:
diff changeset
975
a61af66fc99e Initial load
duke
parents:
diff changeset
976 void ReferenceProcessor::clean_up_discovered_references() {
a61af66fc99e Initial load
duke
parents:
diff changeset
977 // loop over the lists
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
978 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
979 if (TraceReferenceGC && PrintGCDetails && ((i % _max_num_q) == 0)) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
980 gclog_or_tty->print_cr(
a61af66fc99e Initial load
duke
parents:
diff changeset
981 "\nScrubbing %s discovered list of Null referents",
a61af66fc99e Initial load
duke
parents:
diff changeset
982 list_name(i));
a61af66fc99e Initial load
duke
parents:
diff changeset
983 }
4014
bf2d2b8b1726 7095243: Disambiguate ReferenceProcessor::_discoveredSoftRefs
johnc
parents: 3992
diff changeset
984 clean_up_discovered_reflist(_discovered_refs[i]);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
985 }
a61af66fc99e Initial load
duke
parents:
diff changeset
986 }
a61af66fc99e Initial load
duke
parents:
diff changeset
987
a61af66fc99e Initial load
duke
parents:
diff changeset
988 void ReferenceProcessor::clean_up_discovered_reflist(DiscoveredList& refs_list) {
a61af66fc99e Initial load
duke
parents:
diff changeset
989 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
990 DiscoveredListIterator iter(refs_list, NULL, NULL);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
991 while (iter.has_next()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
992 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
993 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
994 assert(next->is_oop_or_null(), "bad next field");
0
a61af66fc99e Initial load
duke
parents:
diff changeset
995 // If referent has been cleared or Reference is not active,
a61af66fc99e Initial load
duke
parents:
diff changeset
996 // drop it.
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
997 if (iter.referent() == NULL || next != NULL) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
998 debug_only(
a61af66fc99e Initial load
duke
parents:
diff changeset
999 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1000 gclog_or_tty->print_cr("clean_up_discovered_list: Dropping Reference: "
a61af66fc99e Initial load
duke
parents:
diff changeset
1001 INTPTR_FORMAT " with next field: " INTPTR_FORMAT
a61af66fc99e Initial load
duke
parents:
diff changeset
1002 " and referent: " INTPTR_FORMAT,
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
1003 (void *)iter.obj(), (void *)next, (void *)iter.referent());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1004 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1005 )
a61af66fc99e Initial load
duke
parents:
diff changeset
1006 // Remove Reference object from list
a61af66fc99e Initial load
duke
parents:
diff changeset
1007 iter.remove();
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1008 iter.move_to_next();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1009 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
1010 iter.next();
a61af66fc99e Initial load
duke
parents:
diff changeset
1011 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1012 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1013 NOT_PRODUCT(
a61af66fc99e Initial load
duke
parents:
diff changeset
1014 if (PrintGCDetails && TraceReferenceGC) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1015 gclog_or_tty->print(
a61af66fc99e Initial load
duke
parents:
diff changeset
1016 " Removed %d Refs with NULL referents out of %d discovered Refs",
a61af66fc99e Initial load
duke
parents:
diff changeset
1017 iter.removed(), iter.processed());
a61af66fc99e Initial load
duke
parents:
diff changeset
1018 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1019 )
a61af66fc99e Initial load
duke
parents:
diff changeset
1020 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1021
a61af66fc99e Initial load
duke
parents:
diff changeset
1022 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
1023 uint id = 0;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1024 // Determine the queue index to use for this object.
a61af66fc99e Initial load
duke
parents:
diff changeset
1025 if (_discovery_is_mt) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1026 // During a multi-threaded discovery phase,
a61af66fc99e Initial load
duke
parents:
diff changeset
1027 // each thread saves to its "own" list.
a61af66fc99e Initial load
duke
parents:
diff changeset
1028 Thread* thr = Thread::current();
1974
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1029 id = thr->as_Worker_thread()->id();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1030 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
1031 // single-threaded discovery, we save in round-robin
a61af66fc99e Initial load
duke
parents:
diff changeset
1032 // fashion to each of the lists.
a61af66fc99e Initial load
duke
parents:
diff changeset
1033 if (_processing_is_mt) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1034 id = next_id();
a61af66fc99e Initial load
duke
parents:
diff changeset
1035 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1036 }
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
1037 assert(0 <= id && id < _max_num_q, "Id is out-of-bounds (call Freud?)");
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1038
a61af66fc99e Initial load
duke
parents:
diff changeset
1039 // Get the discovered queue to which we will add
a61af66fc99e Initial load
duke
parents:
diff changeset
1040 DiscoveredList* list = NULL;
a61af66fc99e Initial load
duke
parents:
diff changeset
1041 switch (rt) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1042 case REF_OTHER:
a61af66fc99e Initial load
duke
parents:
diff changeset
1043 // Unknown reference type, no special treatment
a61af66fc99e Initial load
duke
parents:
diff changeset
1044 break;
a61af66fc99e Initial load
duke
parents:
diff changeset
1045 case REF_SOFT:
a61af66fc99e Initial load
duke
parents:
diff changeset
1046 list = &_discoveredSoftRefs[id];
a61af66fc99e Initial load
duke
parents:
diff changeset
1047 break;
a61af66fc99e Initial load
duke
parents:
diff changeset
1048 case REF_WEAK:
a61af66fc99e Initial load
duke
parents:
diff changeset
1049 list = &_discoveredWeakRefs[id];
a61af66fc99e Initial load
duke
parents:
diff changeset
1050 break;
a61af66fc99e Initial load
duke
parents:
diff changeset
1051 case REF_FINAL:
a61af66fc99e Initial load
duke
parents:
diff changeset
1052 list = &_discoveredFinalRefs[id];
a61af66fc99e Initial load
duke
parents:
diff changeset
1053 break;
a61af66fc99e Initial load
duke
parents:
diff changeset
1054 case REF_PHANTOM:
a61af66fc99e Initial load
duke
parents:
diff changeset
1055 list = &_discoveredPhantomRefs[id];
a61af66fc99e Initial load
duke
parents:
diff changeset
1056 break;
20755
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1057 case REF_CLEANER:
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1058 list = &_discoveredCleanerRefs[id];
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1059 break;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1060 case REF_NONE:
6735
aed758eda82a 7195833: NPG: Rename instanceClassLoaderKlass, instanceRefKlass and instanceMirrorKlass
coleenp
parents: 6725
diff changeset
1061 // we should not reach here if we are an InstanceRefKlass
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1062 default:
a61af66fc99e Initial load
duke
parents:
diff changeset
1063 ShouldNotReachHere();
a61af66fc99e Initial load
duke
parents:
diff changeset
1064 }
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
1065 if (TraceReferenceGC && PrintGCDetails) {
1974
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1066 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
1067 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1068 return list;
a61af66fc99e Initial load
duke
parents:
diff changeset
1069 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1070
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1071 inline void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1072 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
1073 oop obj,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1074 HeapWord* discovered_addr) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1075 assert(_discovery_is_mt, "!_discovery_is_mt should have been handled by caller");
a61af66fc99e Initial load
duke
parents:
diff changeset
1076 // First we must make sure this object is only enqueued once. CAS in a non null
a61af66fc99e Initial load
duke
parents:
diff changeset
1077 // discovered_addr.
342
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
ysr
parents: 113
diff changeset
1078 oop current_head = refs_list.head();
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
1079 // 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
1080 oop next_discovered = (current_head != NULL) ? current_head : obj;
342
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
ysr
parents: 113
diff changeset
1081
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
1082 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
1083 NULL);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1084 if (retest == NULL) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1085 // 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
1086 // We have separate lists for enqueueing, so no synchronization
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1087 // is necessary.
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1088 refs_list.set_head(obj);
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1089 refs_list.inc_length(1);
1974
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1090
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1091 if (TraceReferenceGC) {
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1092 gclog_or_tty->print_cr("Discovered reference (mt) (" INTPTR_FORMAT ": %s)",
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
1093 (void *)obj, obj->klass()->internal_name());
1974
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1094 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1095 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
1096 // If retest was non NULL, another thread beat us to it:
a61af66fc99e Initial load
duke
parents:
diff changeset
1097 // The reference has already been discovered...
a61af66fc99e Initial load
duke
parents:
diff changeset
1098 if (TraceReferenceGC) {
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1099 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
1100 (void *)obj, obj->klass()->internal_name());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1101 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1102 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1103 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1104
1995
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1105 #ifndef PRODUCT
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1106 // 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
1107 // 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
1108 // 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
1109 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
1110 bool da = discovery_is_atomic();
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1111 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
1112 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
1113 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
1114 INTPTR_FORMAT " during %satomic discovery ",
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
1115 (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
1116 }
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1117 #endif
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1118
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1119 // We mention two of several possible choices here:
a61af66fc99e Initial load
duke
parents:
diff changeset
1120 // #0: if the reference object is not in the "originating generation"
a61af66fc99e Initial load
duke
parents:
diff changeset
1121 // (or part of the heap being collected, indicated by our "span"
a61af66fc99e Initial load
duke
parents:
diff changeset
1122 // we don't treat it specially (i.e. we scan it as we would
a61af66fc99e Initial load
duke
parents:
diff changeset
1123 // 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
1124 // This means that references can't be discovered unless their
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1125 // referent is also in the same span. This is the simplest,
a61af66fc99e Initial load
duke
parents:
diff changeset
1126 // most "local" and most conservative approach, albeit one
a61af66fc99e Initial load
duke
parents:
diff changeset
1127 // that may cause weak references to be enqueued least promptly.
a61af66fc99e Initial load
duke
parents:
diff changeset
1128 // We call this choice the "ReferenceBasedDiscovery" policy.
a61af66fc99e Initial load
duke
parents:
diff changeset
1129 // #1: the reference object may be in any generation (span), but if
a61af66fc99e Initial load
duke
parents:
diff changeset
1130 // the referent is in the generation (span) being currently collected
a61af66fc99e Initial load
duke
parents:
diff changeset
1131 // then we can discover the reference object, provided
a61af66fc99e Initial load
duke
parents:
diff changeset
1132 // the object has not already been discovered by
a61af66fc99e Initial load
duke
parents:
diff changeset
1133 // a different concurrently running collector (as may be the
a61af66fc99e Initial load
duke
parents:
diff changeset
1134 // case, for instance, if the reference object is in CMS and
a61af66fc99e Initial load
duke
parents:
diff changeset
1135 // the referent in DefNewGeneration), and provided the processing
a61af66fc99e Initial load
duke
parents:
diff changeset
1136 // of this reference object by the current collector will
a61af66fc99e Initial load
duke
parents:
diff changeset
1137 // appear atomic to every other collector in the system.
a61af66fc99e Initial load
duke
parents:
diff changeset
1138 // (Thus, for instance, a concurrent collector may not
a61af66fc99e Initial load
duke
parents:
diff changeset
1139 // discover references in other generations even if the
a61af66fc99e Initial load
duke
parents:
diff changeset
1140 // referent is in its own generation). This policy may,
a61af66fc99e Initial load
duke
parents:
diff changeset
1141 // in certain cases, enqueue references somewhat sooner than
a61af66fc99e Initial load
duke
parents:
diff changeset
1142 // might Policy #0 above, but at marginally increased cost
a61af66fc99e Initial load
duke
parents:
diff changeset
1143 // and complexity in processing these references.
a61af66fc99e Initial load
duke
parents:
diff changeset
1144 // We call this choice the "RefeferentBasedDiscovery" policy.
a61af66fc99e Initial load
duke
parents:
diff changeset
1145 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
1146 // Make sure we are discovering refs (rather than processing discovered refs).
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1147 if (!_discovering_refs || !RegisterReferences) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1148 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
1149 }
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1150 // 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
1151 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
1152 if (next != NULL) { // Ref is no longer active
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1153 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
1154 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1155
a61af66fc99e Initial load
duke
parents:
diff changeset
1156 HeapWord* obj_addr = (HeapWord*)obj;
a61af66fc99e Initial load
duke
parents:
diff changeset
1157 if (RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load
duke
parents:
diff changeset
1158 !_span.contains(obj_addr)) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1159 // Reference is not in the originating generation;
a61af66fc99e Initial load
duke
parents:
diff changeset
1160 // don't treat it specially (i.e. we want to scan it as a normal
a61af66fc99e Initial load
duke
parents:
diff changeset
1161 // object with strong references).
a61af66fc99e Initial load
duke
parents:
diff changeset
1162 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
1163 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1164
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1165 // 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
1166 // known to be strongly reachable.
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1167 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
1168 verify_referent(obj);
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1169 if (is_alive_non_header()->do_object_b(java_lang_ref_Reference::referent(obj))) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1170 return false; // referent is reachable
a61af66fc99e Initial load
duke
parents:
diff changeset
1171 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1172 }
453
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1173 if (rt == REF_SOFT) {
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1174 // 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
1175 // current candidates for clearing, in which case we
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1176 // can mark through them now, rather than delaying that
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1177 // to the reference-processing phase. Since all current
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1178 // time-stamp policies advance the soft-ref clock only
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1179 // at a major collection cycle, this is always currently
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1180 // accurate.
3992
d1bdeef3e3e2 7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
johnc
parents: 3979
diff changeset
1181 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
1182 return false;
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1183 }
c96030fff130 6684579: SoftReference processing can be made more efficient
ysr
parents: 452
diff changeset
1184 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1185
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
1186 ResourceMark rm; // Needed for tracing.
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
1187
342
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
ysr
parents: 113
diff changeset
1188 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
1189 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
1190 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
1191 if (discovered != NULL) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1192 // The reference has already been discovered...
a61af66fc99e Initial load
duke
parents:
diff changeset
1193 if (TraceReferenceGC) {
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1194 gclog_or_tty->print_cr("Already discovered reference (" INTPTR_FORMAT ": %s)",
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
1195 (void *)obj, obj->klass()->internal_name());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1196 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1197 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1198 // assumes that an object is not processed twice;
a61af66fc99e Initial load
duke
parents:
diff changeset
1199 // if it's been already discovered it must be on another
a61af66fc99e Initial load
duke
parents:
diff changeset
1200 // generation's discovered list; so we won't discover it.
a61af66fc99e Initial load
duke
parents:
diff changeset
1201 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
1202 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
1203 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery,
a61af66fc99e Initial load
duke
parents:
diff changeset
1204 "Unrecognized policy");
a61af66fc99e Initial load
duke
parents:
diff changeset
1205 // Check assumption that an object is not potentially
a61af66fc99e Initial load
duke
parents:
diff changeset
1206 // discovered twice except by concurrent collectors that potentially
a61af66fc99e Initial load
duke
parents:
diff changeset
1207 // trace the same Reference object twice.
1974
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1208 assert(UseConcMarkSweepGC || UseG1GC,
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1209 "Only possible with a concurrent marking collector");
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1210 return true;
a61af66fc99e Initial load
duke
parents:
diff changeset
1211 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1212 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1213
a61af66fc99e Initial load
duke
parents:
diff changeset
1214 if (RefDiscoveryPolicy == ReferentBasedDiscovery) {
1995
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1215 verify_referent(obj);
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1216 // Discover if and only if EITHER:
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1217 // .. reference is in our span, OR
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1218 // .. we are an atomic collector and referent is in our span
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1219 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
1220 (discovery_is_atomic() &&
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1221 _span.contains(java_lang_ref_Reference::referent(obj)))) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1222 // should_enqueue = true;
a61af66fc99e Initial load
duke
parents:
diff changeset
1223 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
1224 return false;
a61af66fc99e Initial load
duke
parents:
diff changeset
1225 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1226 } else {
a61af66fc99e Initial load
duke
parents:
diff changeset
1227 assert(RefDiscoveryPolicy == ReferenceBasedDiscovery &&
a61af66fc99e Initial load
duke
parents:
diff changeset
1228 _span.contains(obj_addr), "code inconsistency");
a61af66fc99e Initial load
duke
parents:
diff changeset
1229 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1230
a61af66fc99e Initial load
duke
parents:
diff changeset
1231 // Get the right type of discovered queue head.
a61af66fc99e Initial load
duke
parents:
diff changeset
1232 DiscoveredList* list = get_discovered_list(rt);
a61af66fc99e Initial load
duke
parents:
diff changeset
1233 if (list == NULL) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1234 return false; // nothing special needs to be done
a61af66fc99e Initial load
duke
parents:
diff changeset
1235 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1236
a61af66fc99e Initial load
duke
parents:
diff changeset
1237 if (_discovery_is_mt) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1238 add_to_discovered_list_mt(*list, obj, discovered_addr);
a61af66fc99e Initial load
duke
parents:
diff changeset
1239 } else {
17976
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects
brutisso
parents: 17937
diff changeset
1240 // 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
1241 // the discovered references.
342
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
ysr
parents: 113
diff changeset
1242 oop current_head = list->head();
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
1243 // 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
1244 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
1245
342
37f87013dfd8 6711316: Open source the Garbage-First garbage collector
ysr
parents: 113
diff changeset
1246 assert(discovered == NULL, "control point invariant");
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
1247 oop_store_raw(discovered_addr, next_discovered);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1248 list->set_head(obj);
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1249 list->inc_length(1);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1250
1974
fd1d227ef1b9 6983204: G1: Nightly test nsk/regression/b4958615 failing with +ExplicitGCInvokesConcurrent
johnc
parents: 1972
diff changeset
1251 if (TraceReferenceGC) {
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1252 gclog_or_tty->print_cr("Discovered reference (" INTPTR_FORMAT ": %s)",
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
1253 (void *)obj, obj->klass()->internal_name());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1254 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1255 }
3917
eca1193ca245 4965777: GC changes to support use of discovered field for pending references
ysr
parents: 3915
diff changeset
1256 assert(obj->is_oop(), "Discovered a bad reference");
1995
8df09fb45352 7005259: CMS: BubbleUpRef asserts referent(obj)->is_oop() failed: Enqueued a bad referent
ysr
parents: 1974
diff changeset
1257 verify_referent(obj);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1258 return true;
a61af66fc99e Initial load
duke
parents:
diff changeset
1259 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1260
a61af66fc99e Initial load
duke
parents:
diff changeset
1261 // Preclean the discovered references by removing those
a61af66fc99e Initial load
duke
parents:
diff changeset
1262 // whose referents are alive, and by marking from those that
a61af66fc99e Initial load
duke
parents:
diff changeset
1263 // are not active. These lists can be handled here
a61af66fc99e Initial load
duke
parents:
diff changeset
1264 // in any order and, indeed, concurrently.
a61af66fc99e Initial load
duke
parents:
diff changeset
1265 void ReferenceProcessor::preclean_discovered_references(
a61af66fc99e Initial load
duke
parents:
diff changeset
1266 BoolObjectClosure* is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
1267 OopClosure* keep_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
1268 VoidClosure* complete_gc,
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
1269 YieldClosure* yield,
20190
0982ec23da03 8043607: Add a GC id as a log decoration similar to PrintGCTimeStamps
brutisso
parents: 17976
diff changeset
1270 GCTimer* gc_timer,
0982ec23da03 8043607: Add a GC id as a log decoration similar to PrintGCTimeStamps
brutisso
parents: 17976
diff changeset
1271 GCId gc_id) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1272
a61af66fc99e Initial load
duke
parents:
diff changeset
1273 NOT_PRODUCT(verify_ok_to_handle_reflists());
a61af66fc99e Initial load
duke
parents:
diff changeset
1274
a61af66fc99e Initial load
duke
parents:
diff changeset
1275 // Soft references
a61af66fc99e Initial load
duke
parents:
diff changeset
1276 {
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
1277 GCTraceTime tt("Preclean SoftReferences", PrintGCDetails && PrintReferenceGC,
20190
0982ec23da03 8043607: Add a GC id as a log decoration similar to PrintGCTimeStamps
brutisso
parents: 17976
diff changeset
1278 false, gc_timer, gc_id);
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
1279 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
1280 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1281 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1282 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1283 preclean_discovered_reflist(_discoveredSoftRefs[i], is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
1284 keep_alive, complete_gc, yield);
a61af66fc99e Initial load
duke
parents:
diff changeset
1285 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1286 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1287
a61af66fc99e Initial load
duke
parents:
diff changeset
1288 // Weak references
a61af66fc99e Initial load
duke
parents:
diff changeset
1289 {
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
1290 GCTraceTime tt("Preclean WeakReferences", PrintGCDetails && PrintReferenceGC,
20190
0982ec23da03 8043607: Add a GC id as a log decoration similar to PrintGCTimeStamps
brutisso
parents: 17976
diff changeset
1291 false, gc_timer, gc_id);
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
1292 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
1293 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1294 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1295 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1296 preclean_discovered_reflist(_discoveredWeakRefs[i], is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
1297 keep_alive, complete_gc, yield);
a61af66fc99e Initial load
duke
parents:
diff changeset
1298 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1299 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1300
a61af66fc99e Initial load
duke
parents:
diff changeset
1301 // Final references
a61af66fc99e Initial load
duke
parents:
diff changeset
1302 {
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
1303 GCTraceTime tt("Preclean FinalReferences", PrintGCDetails && PrintReferenceGC,
20190
0982ec23da03 8043607: Add a GC id as a log decoration similar to PrintGCTimeStamps
brutisso
parents: 17976
diff changeset
1304 false, gc_timer, gc_id);
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
1305 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
1306 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1307 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1308 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1309 preclean_discovered_reflist(_discoveredFinalRefs[i], is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
1310 keep_alive, complete_gc, yield);
a61af66fc99e Initial load
duke
parents:
diff changeset
1311 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1312 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1313
a61af66fc99e Initial load
duke
parents:
diff changeset
1314 // Phantom references
a61af66fc99e Initial load
duke
parents:
diff changeset
1315 {
10405
f2110083203d 8005849: JEP 167: Event-Based JVM Tracing
sla
parents: 10327
diff changeset
1316 GCTraceTime tt("Preclean PhantomReferences", PrintGCDetails && PrintReferenceGC,
20190
0982ec23da03 8043607: Add a GC id as a log decoration similar to PrintGCTimeStamps
brutisso
parents: 17976
diff changeset
1317 false, gc_timer, gc_id);
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
1318 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
1319 if (yield->should_return()) {
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1320 return;
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1321 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1322 preclean_discovered_reflist(_discoveredPhantomRefs[i], is_alive,
a61af66fc99e Initial load
duke
parents:
diff changeset
1323 keep_alive, complete_gc, yield);
a61af66fc99e Initial load
duke
parents:
diff changeset
1324 }
20755
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1325
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1326 // Cleaner references. Included in timing for phantom references. We
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1327 // 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
1328 // possible incompatibilities arising from making it more visible.
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1329 for (uint i = 0; i < _max_num_q; i++) {
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1330 if (yield->should_return()) {
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1331 return;
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1332 }
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1333 preclean_discovered_reflist(_discoveredCleanerRefs[i], is_alive,
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1334 keep_alive, complete_gc, yield);
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1335 }
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1336 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1337 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1338
a61af66fc99e Initial load
duke
parents:
diff changeset
1339 // Walk the given discovered ref list, and remove all reference objects
a61af66fc99e Initial load
duke
parents:
diff changeset
1340 // 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
1341 // 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
1342 // 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
1343 // 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
1344 // 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
1345 // 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
1346 // (in this thread).
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1347 void
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1348 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
1349 BoolObjectClosure* is_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1350 OopClosure* keep_alive,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1351 VoidClosure* complete_gc,
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1352 YieldClosure* yield) {
17976
8e20ef014b08 8043239: G1: Missing post barrier in processing of j.l.ref.Reference objects
brutisso
parents: 17937
diff changeset
1353 DiscoveredListIterator iter(refs_list, keep_alive, is_alive);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1354 while (iter.has_next()) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1355 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
1356 oop obj = iter.obj();
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1357 oop next = java_lang_ref_Reference::next(obj);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1358 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
1359 next != NULL) {
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1360 // The referent has been cleared, or is alive, or the Reference is not
a61af66fc99e Initial load
duke
parents:
diff changeset
1361 // active; we need to trace and mark its cohort.
a61af66fc99e Initial load
duke
parents:
diff changeset
1362 if (TraceReferenceGC) {
a61af66fc99e Initial load
duke
parents:
diff changeset
1363 gclog_or_tty->print_cr("Precleaning Reference (" INTPTR_FORMAT ": %s)",
12316
190899198332 7195622: CheckUnhandledOops has limited usefulness now
hseigel
parents: 10405
diff changeset
1364 (void *)iter.obj(), iter.obj()->klass()->internal_name());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1365 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1366 // Remove Reference object from list
a61af66fc99e Initial load
duke
parents:
diff changeset
1367 iter.remove();
a61af66fc99e Initial load
duke
parents:
diff changeset
1368 // Keep alive its cohort.
a61af66fc99e Initial load
duke
parents:
diff changeset
1369 iter.make_referent_alive();
113
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1370 if (UseCompressedOops) {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1371 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
1372 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
1373 } else {
ba764ed4b6f2 6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents: 5
diff changeset
1374 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
1375 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
1376 }
452
00b023ae2d78 6722113: CMS: Incorrect overflow handling during precleaning of Reference lists
ysr
parents: 356
diff changeset
1377 iter.move_to_next();
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1378 } else {
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duke
parents:
diff changeset
1379 iter.next();
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duke
parents:
diff changeset
1380 }
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duke
parents:
diff changeset
1381 }
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duke
parents:
diff changeset
1382 // Close the reachable set
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parents:
diff changeset
1383 complete_gc->do_void();
a61af66fc99e Initial load
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parents:
diff changeset
1384
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parents:
diff changeset
1385 NOT_PRODUCT(
2369
92da084fefc9 6668573: CMS: reference processing crash if ParallelCMSThreads > ParallelGCThreads
ysr
parents: 1995
diff changeset
1386 if (PrintGCDetails && PrintReferenceGC && (iter.processed() > 0)) {
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
1387 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
1388 "Refs in discovered list " INTPTR_FORMAT,
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
1389 iter.removed(), iter.processed(), (address)refs_list.head());
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1390 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1391 )
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duke
parents:
diff changeset
1392 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1393
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
1394 const char* ReferenceProcessor::list_name(uint i) {
3979
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
1395 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
1396 "Out of bounds index");
4dfb2df418f2 6484982: G1: process references during evacuation pauses
johnc
parents: 3917
diff changeset
1397
1833
8b10f48633dc 6984287: Regularize how GC parallel workers are specified.
jmasa
parents: 1552
diff changeset
1398 int j = i / _max_num_q;
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1399 switch (j) {
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duke
parents:
diff changeset
1400 case 0: return "SoftRef";
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duke
parents:
diff changeset
1401 case 1: return "WeakRef";
a61af66fc99e Initial load
duke
parents:
diff changeset
1402 case 2: return "FinalRef";
a61af66fc99e Initial load
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parents:
diff changeset
1403 case 3: return "PhantomRef";
20755
01dcaba9b3f3 8047125: (ref) More phantom object references
jmasa
parents: 17976
diff changeset
1404 case 4: return "CleanerRef";
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1405 }
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duke
parents:
diff changeset
1406 ShouldNotReachHere();
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parents:
diff changeset
1407 return NULL;
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duke
parents:
diff changeset
1408 }
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duke
parents:
diff changeset
1409
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duke
parents:
diff changeset
1410 #ifndef PRODUCT
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duke
parents:
diff changeset
1411 void ReferenceProcessor::verify_ok_to_handle_reflists() {
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duke
parents:
diff changeset
1412 // empty for now
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duke
parents:
diff changeset
1413 }
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duke
parents:
diff changeset
1414 #endif
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parents:
diff changeset
1415
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duke
parents:
diff changeset
1416 #ifndef PRODUCT
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duke
parents:
diff changeset
1417 void ReferenceProcessor::clear_discovered_references() {
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duke
parents:
diff changeset
1418 guarantee(!_discovering_refs, "Discovering refs?");
4728
441e946dc1af 7121618: Change type of number of GC workers to unsigned int.
jmasa
parents: 4712
diff changeset
1419 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
1420 clear_discovered_references(_discovered_refs[i]);
0
a61af66fc99e Initial load
duke
parents:
diff changeset
1421 }
a61af66fc99e Initial load
duke
parents:
diff changeset
1422 }
3915
c2bf0120ee5d 7085906: Replace the permgen allocated sentinelRef with a self-looped end
stefank
parents: 2369
diff changeset
1423
0
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duke
parents:
diff changeset
1424 #endif // PRODUCT