src/share/vm/memory/sharedHeap.cpp

Thu, 13 Jun 2013 22:02:40 -0700

author
ccheung
date
Thu, 13 Jun 2013 22:02:40 -0700
changeset 5259
ef57c43512d6
parent 5194
eda078b01c65
child 5277
01522ca68fc7
permissions
-rw-r--r--

8014431: cleanup warnings indicated by the -Wunused-value compiler option on linux
Reviewed-by: dholmes, coleenp
Contributed-by: jeremymanson@google.com, calvin.cheung@oracle.com

duke@435 1 /*
coleenp@4037 2 * Copyright (c) 2000, 2012, 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/symbolTable.hpp"
stefank@2314 27 #include "classfile/systemDictionary.hpp"
stefank@2314 28 #include "code/codeCache.hpp"
stefank@2314 29 #include "gc_interface/collectedHeap.inline.hpp"
stefank@2314 30 #include "memory/sharedHeap.hpp"
stefank@2314 31 #include "oops/oop.inline.hpp"
stefank@2314 32 #include "runtime/fprofiler.hpp"
stefank@2314 33 #include "runtime/java.hpp"
stefank@2314 34 #include "services/management.hpp"
stefank@2314 35 #include "utilities/copy.hpp"
stefank@2314 36 #include "utilities/workgroup.hpp"
duke@435 37
duke@435 38 SharedHeap* SharedHeap::_sh;
duke@435 39
duke@435 40 // The set of potentially parallel tasks in strong root scanning.
duke@435 41 enum SH_process_strong_roots_tasks {
duke@435 42 SH_PS_Universe_oops_do,
duke@435 43 SH_PS_JNIHandles_oops_do,
duke@435 44 SH_PS_ObjectSynchronizer_oops_do,
duke@435 45 SH_PS_FlatProfiler_oops_do,
duke@435 46 SH_PS_Management_oops_do,
duke@435 47 SH_PS_SystemDictionary_oops_do,
stefank@5194 48 SH_PS_ClassLoaderDataGraph_oops_do,
duke@435 49 SH_PS_jvmti_oops_do,
duke@435 50 SH_PS_StringTable_oops_do,
duke@435 51 SH_PS_CodeCache_oops_do,
duke@435 52 // Leave this one last.
duke@435 53 SH_PS_NumElements
duke@435 54 };
duke@435 55
duke@435 56 SharedHeap::SharedHeap(CollectorPolicy* policy_) :
duke@435 57 CollectedHeap(),
duke@435 58 _collector_policy(policy_),
coleenp@4037 59 _rem_set(NULL),
duke@435 60 _strong_roots_parity(0),
duke@435 61 _process_strong_tasks(new SubTasksDone(SH_PS_NumElements)),
jmasa@2188 62 _workers(NULL)
duke@435 63 {
duke@435 64 if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
duke@435 65 vm_exit_during_initialization("Failed necessary allocation.");
duke@435 66 }
duke@435 67 _sh = this; // ch is static, should be set only once.
duke@435 68 if ((UseParNewGC ||
ysr@777 69 (UseConcMarkSweepGC && CMSParallelRemarkEnabled) ||
ysr@777 70 UseG1GC) &&
duke@435 71 ParallelGCThreads > 0) {
jmasa@2188 72 _workers = new FlexibleWorkGang("Parallel GC Threads", ParallelGCThreads,
ysr@777 73 /* are_GC_task_threads */true,
ysr@777 74 /* are_ConcurrentGC_threads */false);
duke@435 75 if (_workers == NULL) {
duke@435 76 vm_exit_during_initialization("Failed necessary allocation.");
jmasa@2188 77 } else {
jmasa@2188 78 _workers->initialize_workers();
duke@435 79 }
duke@435 80 }
duke@435 81 }
duke@435 82
jmasa@3294 83 int SharedHeap::n_termination() {
jmasa@3294 84 return _process_strong_tasks->n_threads();
jmasa@3294 85 }
jmasa@3294 86
jmasa@3294 87 void SharedHeap::set_n_termination(int t) {
jmasa@3294 88 _process_strong_tasks->set_n_threads(t);
jmasa@3294 89 }
jmasa@3294 90
ysr@777 91 bool SharedHeap::heap_lock_held_for_gc() {
ysr@777 92 Thread* t = Thread::current();
ysr@777 93 return Heap_lock->owned_by_self()
ysr@777 94 || ( (t->is_GC_task_thread() || t->is_VM_thread())
ysr@777 95 && _thread_holds_heap_lock_for_gc);
ysr@777 96 }
duke@435 97
jmasa@3357 98 void SharedHeap::set_par_threads(uint t) {
jmasa@2188 99 assert(t == 0 || !UseSerialGC, "Cannot have parallel threads");
duke@435 100 _n_par_threads = t;
jmasa@2188 101 _process_strong_tasks->set_n_threads(t);
duke@435 102 }
duke@435 103
jmasa@2909 104 #ifdef ASSERT
jmasa@2909 105 class AssertNonScavengableClosure: public OopClosure {
jmasa@2909 106 public:
jmasa@2909 107 virtual void do_oop(oop* p) {
jmasa@2909 108 assert(!Universe::heap()->is_in_partial_collection(*p),
jmasa@2909 109 "Referent should not be scavengable."); }
jmasa@2909 110 virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
jmasa@2909 111 };
jmasa@2909 112 static AssertNonScavengableClosure assert_is_non_scavengable_closure;
jmasa@2909 113 #endif
jmasa@2909 114
duke@435 115 void SharedHeap::change_strong_roots_parity() {
duke@435 116 // Also set the new collection parity.
duke@435 117 assert(_strong_roots_parity >= 0 && _strong_roots_parity <= 2,
duke@435 118 "Not in range.");
duke@435 119 _strong_roots_parity++;
duke@435 120 if (_strong_roots_parity == 3) _strong_roots_parity = 1;
duke@435 121 assert(_strong_roots_parity >= 1 && _strong_roots_parity <= 2,
duke@435 122 "Not in range.");
duke@435 123 }
duke@435 124
jrose@1424 125 SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* outer, bool activate)
jrose@1424 126 : MarkScope(activate)
jrose@1424 127 {
jrose@1424 128 if (_active) {
jrose@1424 129 outer->change_strong_roots_parity();
jrose@1424 130 }
jrose@1424 131 }
jrose@1424 132
jrose@1424 133 SharedHeap::StrongRootsScope::~StrongRootsScope() {
jrose@1424 134 // nothing particular
jrose@1424 135 }
jrose@1424 136
jrose@1424 137 void SharedHeap::process_strong_roots(bool activate_scope,
coleenp@4037 138 bool is_scavenging,
duke@435 139 ScanningOption so,
duke@435 140 OopClosure* roots,
jrose@1424 141 CodeBlobClosure* code_roots,
coleenp@4037 142 KlassClosure* klass_closure) {
jrose@1424 143 StrongRootsScope srs(this, activate_scope);
coleenp@4037 144
duke@435 145 // General strong roots.
jrose@1424 146 assert(_strong_roots_parity != 0, "must have called prologue code");
jmasa@3294 147 // _n_termination for _process_strong_tasks should be set up stream
jmasa@3294 148 // in a method not running in a GC worker. Otherwise the GC worker
jmasa@3294 149 // could be trying to change the termination condition while the task
jmasa@3294 150 // is executing in another GC worker.
duke@435 151 if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) {
duke@435 152 Universe::oops_do(roots);
duke@435 153 }
duke@435 154 // Global (strong) JNI handles
duke@435 155 if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do))
duke@435 156 JNIHandles::oops_do(roots);
duke@435 157 // All threads execute this; the individual threads are task groups.
stefank@4298 158 CLDToOopClosure roots_from_clds(roots);
stefank@4298 159 CLDToOopClosure* roots_from_clds_p = (is_scavenging ? NULL : &roots_from_clds);
duke@435 160 if (ParallelGCThreads > 0) {
stefank@4298 161 Threads::possibly_parallel_oops_do(roots, roots_from_clds_p ,code_roots);
duke@435 162 } else {
stefank@4298 163 Threads::oops_do(roots, roots_from_clds_p, code_roots);
duke@435 164 }
duke@435 165 if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do))
duke@435 166 ObjectSynchronizer::oops_do(roots);
duke@435 167 if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do))
duke@435 168 FlatProfiler::oops_do(roots);
duke@435 169 if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do))
duke@435 170 Management::oops_do(roots);
duke@435 171 if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do))
duke@435 172 JvmtiExport::oops_do(roots);
duke@435 173
duke@435 174 if (!_process_strong_tasks->is_task_claimed(SH_PS_SystemDictionary_oops_do)) {
duke@435 175 if (so & SO_AllClasses) {
duke@435 176 SystemDictionary::oops_do(roots);
stefank@5194 177 } else if (so & SO_SystemClasses) {
stefank@5194 178 SystemDictionary::always_strong_oops_do(roots);
stefank@5194 179 } else {
stefank@5194 180 fatal("We should always have selected either SO_AllClasses or SO_SystemClasses");
stefank@5194 181 }
stefank@5194 182 }
stefank@5194 183
stefank@5194 184 if (!_process_strong_tasks->is_task_claimed(SH_PS_ClassLoaderDataGraph_oops_do)) {
stefank@5194 185 if (so & SO_AllClasses) {
coleenp@4037 186 ClassLoaderDataGraph::oops_do(roots, klass_closure, !is_scavenging);
ysr@2825 187 } else if (so & SO_SystemClasses) {
coleenp@4037 188 ClassLoaderDataGraph::always_strong_oops_do(roots, klass_closure, !is_scavenging);
ysr@2825 189 }
duke@435 190 }
duke@435 191
duke@435 192 if (!_process_strong_tasks->is_task_claimed(SH_PS_StringTable_oops_do)) {
coleenp@4037 193 if (so & SO_Strings) {
jcoomes@2661 194 StringTable::oops_do(roots);
jcoomes@2661 195 }
duke@435 196 }
duke@435 197
duke@435 198 if (!_process_strong_tasks->is_task_claimed(SH_PS_CodeCache_oops_do)) {
jrose@1424 199 if (so & SO_CodeCache) {
jrose@1424 200 assert(code_roots != NULL, "must supply closure for code cache");
coleenp@4037 201
coleenp@4037 202 if (is_scavenging) {
coleenp@4037 203 // We only visit parts of the CodeCache when scavenging.
coleenp@4037 204 CodeCache::scavenge_root_nmethods_do(code_roots);
coleenp@4037 205 } else {
coleenp@4037 206 // CMSCollector uses this to do intermediate-strength collections.
coleenp@4037 207 // We scan the entire code cache, since CodeCache::do_unloading is not called.
jrose@1424 208 CodeCache::blobs_do(code_roots);
jrose@1424 209 }
jrose@1424 210 }
jmasa@2909 211 // Verify that the code cache contents are not subject to
jmasa@2909 212 // movement by a scavenging collection.
jmasa@2909 213 DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, /*do_marking=*/ false));
jmasa@2909 214 DEBUG_ONLY(CodeCache::asserted_non_scavengable_nmethods_do(&assert_code_is_non_scavengable));
duke@435 215 }
duke@435 216
duke@435 217 _process_strong_tasks->all_tasks_completed();
duke@435 218 }
duke@435 219
duke@435 220 class AlwaysTrueClosure: public BoolObjectClosure {
duke@435 221 public:
duke@435 222 bool do_object_b(oop p) { return true; }
duke@435 223 };
duke@435 224 static AlwaysTrueClosure always_true;
duke@435 225
duke@435 226 void SharedHeap::process_weak_roots(OopClosure* root_closure,
stefank@5011 227 CodeBlobClosure* code_roots) {
duke@435 228 // Global (weak) JNI handles
duke@435 229 JNIHandles::weak_oops_do(&always_true, root_closure);
duke@435 230
jrose@1424 231 CodeCache::blobs_do(code_roots);
stefank@5011 232 StringTable::oops_do(root_closure);
stefank@5011 233 }
duke@435 234
duke@435 235 void SharedHeap::set_barrier_set(BarrierSet* bs) {
duke@435 236 _barrier_set = bs;
duke@435 237 // Cached barrier set for fast access in oops
duke@435 238 oopDesc::set_bs(bs);
duke@435 239 }
duke@435 240
duke@435 241 void SharedHeap::post_initialize() {
duke@435 242 ref_processing_init();
duke@435 243 }
duke@435 244
coleenp@4037 245 void SharedHeap::ref_processing_init() {}
duke@435 246
duke@435 247 // Some utilities.
ysr@777 248 void SharedHeap::print_size_transition(outputStream* out,
ysr@777 249 size_t bytes_before,
duke@435 250 size_t bytes_after,
duke@435 251 size_t capacity) {
ysr@777 252 out->print(" %d%s->%d%s(%d%s)",
duke@435 253 byte_size_in_proper_unit(bytes_before),
duke@435 254 proper_unit_for_byte_size(bytes_before),
duke@435 255 byte_size_in_proper_unit(bytes_after),
duke@435 256 proper_unit_for_byte_size(bytes_after),
duke@435 257 byte_size_in_proper_unit(capacity),
duke@435 258 proper_unit_for_byte_size(capacity));
duke@435 259 }

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