src/share/vm/gc_implementation/shared/vmGCOperations.cpp

Thu, 13 Feb 2014 10:05:03 +0100

author
sjohanss
date
Thu, 13 Feb 2014 10:05:03 +0100
changeset 6619
9c3dc501b5eb
parent 5946
bf9e50c573ad
child 6876
710a3c8b516e
child 6992
2c6ef90f030a
permissions
-rw-r--r--

8028498: runtime/SharedArchiveFile/CdsDifferentObjectAlignment.java asserts in RT_Baseline
Summary: Preventing GCs to occur before VM is completely initialized. This was previously partly done by one part of the GC locker which not was removed.
Reviewed-by: coleenp, pliden

duke@435 1 /*
acorn@4497 2 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "classfile/classLoader.hpp"
stefank@2314 27 #include "classfile/javaClasses.hpp"
stefank@2314 28 #include "gc_implementation/shared/vmGCOperations.hpp"
stefank@2314 29 #include "memory/gcLocker.inline.hpp"
stefank@2314 30 #include "memory/genCollectedHeap.hpp"
stefank@2314 31 #include "memory/oopFactory.hpp"
stefank@2314 32 #include "oops/instanceKlass.hpp"
stefank@2314 33 #include "oops/instanceRefKlass.hpp"
stefank@2314 34 #include "runtime/handles.inline.hpp"
stefank@2314 35 #include "runtime/init.hpp"
stefank@2314 36 #include "runtime/interfaceSupport.hpp"
stefank@2314 37 #include "utilities/dtrace.hpp"
stefank@2314 38 #include "utilities/preserveException.hpp"
jprovino@4542 39 #include "utilities/macros.hpp"
jprovino@4542 40 #if INCLUDE_ALL_GCS
stefank@2314 41 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
jprovino@4542 42 #endif // INCLUDE_ALL_GCS
kamg@2445 43
dcubed@3202 44 #ifndef USDT2
duke@435 45 HS_DTRACE_PROBE_DECL1(hotspot, gc__begin, bool);
duke@435 46 HS_DTRACE_PROBE_DECL(hotspot, gc__end);
dcubed@3202 47 #endif /* !USDT2 */
duke@435 48
duke@435 49 // The same dtrace probe can't be inserted in two different files, so we
duke@435 50 // have to call it here, so it's only in one file. Can't create new probes
duke@435 51 // for the other file anymore. The dtrace probes have to remain stable.
duke@435 52 void VM_GC_Operation::notify_gc_begin(bool full) {
dcubed@3202 53 #ifndef USDT2
duke@435 54 HS_DTRACE_PROBE1(hotspot, gc__begin, full);
jcoomes@1902 55 HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
dcubed@3202 56 #else /* USDT2 */
dcubed@3202 57 HOTSPOT_GC_BEGIN(
dcubed@3202 58 full);
dcubed@3202 59 #endif /* USDT2 */
duke@435 60 }
duke@435 61
duke@435 62 void VM_GC_Operation::notify_gc_end() {
dcubed@3202 63 #ifndef USDT2
duke@435 64 HS_DTRACE_PROBE(hotspot, gc__end);
jcoomes@1902 65 HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
dcubed@3202 66 #else /* USDT2 */
dcubed@3202 67 HOTSPOT_GC_END(
dcubed@3202 68 );
dcubed@3202 69 #endif /* USDT2 */
duke@435 70 }
duke@435 71
duke@435 72 void VM_GC_Operation::acquire_pending_list_lock() {
duke@435 73 // we may enter this with pending exception set
coleenp@4047 74 InstanceRefKlass::acquire_pending_list_lock(&_pending_list_basic_lock);
duke@435 75 }
duke@435 76
duke@435 77
duke@435 78 void VM_GC_Operation::release_and_notify_pending_list_lock() {
duke@435 79
coleenp@4047 80 InstanceRefKlass::release_and_notify_pending_list_lock(&_pending_list_basic_lock);
duke@435 81 }
duke@435 82
duke@435 83 // Allocations may fail in several threads at about the same time,
duke@435 84 // resulting in multiple gc requests. We only want to do one of them.
duke@435 85 // In case a GC locker is active and the need for a GC is already signalled,
duke@435 86 // we want to skip this GC attempt altogether, without doing a futile
duke@435 87 // safepoint operation.
duke@435 88 bool VM_GC_Operation::skip_operation() const {
duke@435 89 bool skip = (_gc_count_before != Universe::heap()->total_collections());
duke@435 90 if (_full && skip) {
duke@435 91 skip = (_full_gc_count_before != Universe::heap()->total_full_collections());
duke@435 92 }
duke@435 93 if (!skip && GC_locker::is_active_and_needs_gc()) {
duke@435 94 skip = Universe::heap()->is_maximal_no_gc();
duke@435 95 assert(!(skip && (_gc_cause == GCCause::_gc_locker)),
duke@435 96 "GC_locker cannot be active when initiating GC");
duke@435 97 }
duke@435 98 return skip;
duke@435 99 }
duke@435 100
duke@435 101 bool VM_GC_Operation::doit_prologue() {
duke@435 102 assert(Thread::current()->is_Java_thread(), "just checking");
brutisso@2532 103 assert(((_gc_cause != GCCause::_no_gc) &&
brutisso@2532 104 (_gc_cause != GCCause::_no_cause_specified)), "Illegal GCCause");
duke@435 105
sjohanss@6619 106 // To be able to handle a GC the VM initialization needs to be completed.
sjohanss@6619 107 if (!is_init_completed()) {
sjohanss@6619 108 vm_exit_during_initialization(
sjohanss@6619 109 err_msg("GC triggered before VM initialization completed. Try increasing "
sjohanss@6619 110 "NewSize, current value " UINTX_FORMAT "%s.",
sjohanss@6619 111 byte_size_in_proper_unit(NewSize),
sjohanss@6619 112 proper_unit_for_byte_size(NewSize)));
sjohanss@6619 113 }
sjohanss@6619 114
duke@435 115 acquire_pending_list_lock();
duke@435 116 // If the GC count has changed someone beat us to the collection
duke@435 117 // Get the Heap_lock after the pending_list_lock.
duke@435 118 Heap_lock->lock();
ysr@777 119
duke@435 120 // Check invocations
duke@435 121 if (skip_operation()) {
duke@435 122 // skip collection
duke@435 123 Heap_lock->unlock();
duke@435 124 release_and_notify_pending_list_lock();
duke@435 125 _prologue_succeeded = false;
duke@435 126 } else {
duke@435 127 _prologue_succeeded = true;
ysr@777 128 SharedHeap* sh = SharedHeap::heap();
ysr@777 129 if (sh != NULL) sh->_thread_holds_heap_lock_for_gc = true;
duke@435 130 }
duke@435 131 return _prologue_succeeded;
duke@435 132 }
duke@435 133
duke@435 134
duke@435 135 void VM_GC_Operation::doit_epilogue() {
duke@435 136 assert(Thread::current()->is_Java_thread(), "just checking");
duke@435 137 // Release the Heap_lock first.
ysr@777 138 SharedHeap* sh = SharedHeap::heap();
ysr@777 139 if (sh != NULL) sh->_thread_holds_heap_lock_for_gc = false;
duke@435 140 Heap_lock->unlock();
duke@435 141 release_and_notify_pending_list_lock();
duke@435 142 }
duke@435 143
duke@435 144 bool VM_GC_HeapInspection::doit_prologue() {
duke@435 145 if (Universe::heap()->supports_heap_inspection()) {
duke@435 146 return VM_GC_Operation::doit_prologue();
duke@435 147 } else {
duke@435 148 return false;
duke@435 149 }
duke@435 150 }
duke@435 151
duke@435 152 bool VM_GC_HeapInspection::skip_operation() const {
duke@435 153 assert(Universe::heap()->supports_heap_inspection(), "huh?");
duke@435 154 return false;
duke@435 155 }
duke@435 156
sla@5237 157 bool VM_GC_HeapInspection::collect() {
sla@5237 158 if (GC_locker::is_active()) {
sla@5237 159 return false;
sla@5237 160 }
sla@5237 161 Universe::heap()->collect_as_vm_thread(GCCause::_heap_inspection);
sla@5237 162 return true;
sla@5237 163 }
sla@5237 164
duke@435 165 void VM_GC_HeapInspection::doit() {
duke@435 166 HandleMark hm;
sla@5237 167 Universe::heap()->ensure_parsability(false); // must happen, even if collection does
sla@5237 168 // not happen (e.g. due to GC_locker)
sla@5237 169 // or _full_gc being false
duke@435 170 if (_full_gc) {
sla@5237 171 if (!collect()) {
sla@5237 172 // The collection attempt was skipped because the gc locker is held.
sla@5237 173 // The following dump may then be a tad misleading to someone expecting
sla@5237 174 // only live objects to show up in the dump (see CR 6944195). Just issue
sla@5237 175 // a suitable warning in that case and do not attempt to do a collection.
sla@5237 176 // The latter is a subtle point, because even a failed attempt
sla@5237 177 // to GC will, in fact, induce one in the future, which we
sla@5237 178 // probably want to avoid in this case because the GC that we may
sla@5237 179 // be about to attempt holds value for us only
sla@5237 180 // if it happens now and not if it happens in the eventual
sla@5237 181 // future.
kevinw@1827 182 warning("GC locker is held; pre-dump GC was skipped");
kevinw@1827 183 }
duke@435 184 }
acorn@4497 185 HeapInspection inspect(_csv_format, _print_help, _print_class_stats,
acorn@4497 186 _columns);
sla@5237 187 inspect.heap_inspection(_out);
duke@435 188 }
duke@435 189
duke@435 190
duke@435 191 void VM_GenCollectForAllocation::doit() {
kamg@2445 192 SvcGCMarker sgcm(SvcGCMarker::MINOR);
duke@435 193
duke@435 194 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 195 GCCauseSetter gccs(gch, _gc_cause);
duke@435 196 _res = gch->satisfy_failed_allocation(_size, _tlab);
duke@435 197 assert(gch->is_in_reserved_or_null(_res), "result not in heap");
duke@435 198
duke@435 199 if (_res == NULL && GC_locker::is_active_and_needs_gc()) {
duke@435 200 set_gc_locked();
duke@435 201 }
duke@435 202 }
duke@435 203
duke@435 204 void VM_GenCollectFull::doit() {
kamg@2445 205 SvcGCMarker sgcm(SvcGCMarker::FULL);
duke@435 206
duke@435 207 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 208 GCCauseSetter gccs(gch, _gc_cause);
duke@435 209 gch->do_full_collection(gch->must_clear_all_soft_refs(), _max_level);
duke@435 210 }
apetrusenko@574 211
coleenp@4037 212 void VM_CollectForMetadataAllocation::doit() {
kamg@2445 213 SvcGCMarker sgcm(SvcGCMarker::FULL);
kamg@2445 214
coleenp@4037 215 CollectedHeap* heap = Universe::heap();
ysr@777 216 GCCauseSetter gccs(heap, _gc_cause);
coleenp@4037 217
coleenp@4037 218 // Check again if the space is available. Another thread
coleenp@4037 219 // may have similarly failed a metadata allocation and induced
coleenp@4037 220 // a GC that freed space for the allocation.
coleenp@4037 221 if (!MetadataAllocationFailALot) {
coleenp@4037 222 _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
jmasa@5946 223 }
coleenp@4037 224
coleenp@4037 225 if (_result == NULL) {
jmasa@4131 226 if (UseConcMarkSweepGC) {
jmasa@4131 227 if (CMSClassUnloadingEnabled) {
jmasa@4131 228 MetaspaceGC::set_should_concurrent_collect(true);
jmasa@4131 229 }
jmasa@4131 230 // For CMS expand since the collection is going to be concurrent.
jmasa@4131 231 _result =
jmasa@4131 232 _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
jmasa@4131 233 }
jmasa@4131 234 if (_result == NULL) {
jmasa@5946 235 // Don't clear the soft refs yet.
jmasa@4131 236 if (Verbose && PrintGCDetails && UseConcMarkSweepGC) {
jmasa@4131 237 gclog_or_tty->print_cr("\nCMS full GC for Metaspace");
jmasa@4131 238 }
coleenp@4037 239 heap->collect_as_vm_thread(GCCause::_metadata_GC_threshold);
jmasa@5015 240 // After a GC try to allocate without expanding. Could fail
jmasa@5015 241 // and expansion will be tried below.
jmasa@5015 242 _result =
jmasa@5015 243 _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
ysr@777 244 }
jmasa@5946 245 if (_result == NULL) {
coleenp@4037 246 // If still failing, allow the Metaspace to expand.
coleenp@4037 247 // See delta_capacity_until_GC() for explanation of the
coleenp@4037 248 // amount of the expansion.
coleenp@4037 249 // This should work unless there really is no more space
coleenp@4037 250 // or a MaxMetaspaceSize has been specified on the command line.
jmasa@4064 251 _result =
jmasa@4064 252 _loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
jmasa@5946 253 if (_result == NULL) {
jmasa@5946 254 // If expansion failed, do a last-ditch collection and try allocating
jmasa@5946 255 // again. A last-ditch collection will clear softrefs. This
jmasa@5946 256 // behavior is similar to the last-ditch collection done for perm
jmasa@5946 257 // gen when it was full and a collection for failed allocation
jmasa@5946 258 // did not free perm gen space.
jmasa@5946 259 heap->collect_as_vm_thread(GCCause::_last_ditch_collection);
jmasa@5946 260 _result =
jmasa@5946 261 _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
jmasa@5946 262 }
jmasa@4131 263 }
jmasa@4131 264 if (Verbose && PrintGCDetails && _result == NULL) {
jmasa@4131 265 gclog_or_tty->print_cr("\nAfter Metaspace GC failed to allocate size "
jmasa@4131 266 SIZE_FORMAT, _size);
coleenp@4037 267 }
coleenp@4037 268 }
coleenp@4037 269
coleenp@4037 270 if (_result == NULL && GC_locker::is_active_and_needs_gc()) {
apetrusenko@574 271 set_gc_locked();
apetrusenko@574 272 }
apetrusenko@574 273 }

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