annotate hotspot/src/share/vm/services/memoryManager.cpp @ 11171:02c21e3d0a66

7110173: GCNotifier::pushNotification publishes stale data. Summary: GCNotifier::pushNotification() references GCMemoryManager::_last_gc_stat but is called from GCMemoryManager::gc_end() before GCMemoryManager::_last_gc_stat is set up using the values in GCMemoryManager::_current_gc_stat. As a result the GC notification code accesses unitialized or stale data. Move the notification call after GCMemoryManager::_las_gc_stat is set, but inside the same if-block. Reviewed-by: poonam, dholmes, fparain, mchung
author johnc
date Mon, 21 Nov 2011 09:24:56 -0800
parents 91935236600e
children 854c0dff3844
rev   line source
duke@1 1 /*
trims@8921 2 * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
duke@1 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1 4 *
duke@1 5 * This code is free software; you can redistribute it and/or modify it
duke@1 6 * under the terms of the GNU General Public License version 2 only, as
duke@1 7 * published by the Free Software Foundation.
duke@1 8 *
duke@1 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@1 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@1 13 * accompanied this code).
duke@1 14 *
duke@1 15 * You should have received a copy of the GNU General Public License version
duke@1 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@1 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1 18 *
trims@5547 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@5547 20 * or visit www.oracle.com if you need additional information or have any
trims@5547 21 * questions.
duke@1 22 *
duke@1 23 */
duke@1 24
stefank@7397 25 #include "precompiled.hpp"
stefank@7397 26 #include "classfile/systemDictionary.hpp"
stefank@7397 27 #include "classfile/vmSymbols.hpp"
stefank@7397 28 #include "oops/oop.inline.hpp"
stefank@7397 29 #include "runtime/handles.inline.hpp"
stefank@7397 30 #include "runtime/javaCalls.hpp"
stefank@7397 31 #include "services/lowMemoryDetector.hpp"
stefank@7397 32 #include "services/management.hpp"
stefank@7397 33 #include "services/memoryManager.hpp"
stefank@7397 34 #include "services/memoryPool.hpp"
stefank@7397 35 #include "services/memoryService.hpp"
fparain@9623 36 #include "services/gcNotifier.hpp"
stefank@7397 37 #include "utilities/dtrace.hpp"
duke@1 38
dcubed@10739 39 #ifndef USDT2
duke@1 40 HS_DTRACE_PROBE_DECL8(hotspot, mem__pool__gc__begin, char*, int, char*, int,
duke@1 41 size_t, size_t, size_t, size_t);
duke@1 42 HS_DTRACE_PROBE_DECL8(hotspot, mem__pool__gc__end, char*, int, char*, int,
duke@1 43 size_t, size_t, size_t, size_t);
dcubed@10739 44 #endif /* !USDT2 */
duke@1 45
duke@1 46 MemoryManager::MemoryManager() {
duke@1 47 _num_pools = 0;
duke@1 48 _memory_mgr_obj = NULL;
duke@1 49 }
duke@1 50
duke@1 51 void MemoryManager::add_pool(MemoryPool* pool) {
duke@1 52 assert(_num_pools < MemoryManager::max_num_pools, "_num_pools exceeds the max");
duke@1 53 if (_num_pools < MemoryManager::max_num_pools) {
duke@1 54 _pools[_num_pools] = pool;
duke@1 55 _num_pools++;
duke@1 56 }
duke@1 57 pool->add_manager(this);
duke@1 58 }
duke@1 59
duke@1 60 MemoryManager* MemoryManager::get_code_cache_memory_manager() {
duke@1 61 return (MemoryManager*) new CodeCacheMemoryManager();
duke@1 62 }
duke@1 63
duke@1 64 GCMemoryManager* MemoryManager::get_copy_memory_manager() {
duke@1 65 return (GCMemoryManager*) new CopyMemoryManager();
duke@1 66 }
duke@1 67
duke@1 68 GCMemoryManager* MemoryManager::get_msc_memory_manager() {
duke@1 69 return (GCMemoryManager*) new MSCMemoryManager();
duke@1 70 }
duke@1 71
duke@1 72 GCMemoryManager* MemoryManager::get_parnew_memory_manager() {
duke@1 73 return (GCMemoryManager*) new ParNewMemoryManager();
duke@1 74 }
duke@1 75
duke@1 76 GCMemoryManager* MemoryManager::get_cms_memory_manager() {
duke@1 77 return (GCMemoryManager*) new CMSMemoryManager();
duke@1 78 }
duke@1 79
duke@1 80 GCMemoryManager* MemoryManager::get_psScavenge_memory_manager() {
duke@1 81 return (GCMemoryManager*) new PSScavengeMemoryManager();
duke@1 82 }
duke@1 83
duke@1 84 GCMemoryManager* MemoryManager::get_psMarkSweep_memory_manager() {
duke@1 85 return (GCMemoryManager*) new PSMarkSweepMemoryManager();
duke@1 86 }
duke@1 87
tonyp@4459 88 GCMemoryManager* MemoryManager::get_g1YoungGen_memory_manager() {
tonyp@4459 89 return (GCMemoryManager*) new G1YoungGenMemoryManager();
tonyp@4459 90 }
tonyp@4459 91
tonyp@4459 92 GCMemoryManager* MemoryManager::get_g1OldGen_memory_manager() {
tonyp@4459 93 return (GCMemoryManager*) new G1OldGenMemoryManager();
tonyp@4459 94 }
tonyp@4459 95
duke@1 96 instanceOop MemoryManager::get_memory_manager_instance(TRAPS) {
duke@1 97 // Must do an acquire so as to force ordering of subsequent
duke@1 98 // loads from anything _memory_mgr_obj points to or implies.
duke@1 99 instanceOop mgr_obj = (instanceOop)OrderAccess::load_ptr_acquire(&_memory_mgr_obj);
duke@1 100 if (mgr_obj == NULL) {
duke@1 101 // It's ok for more than one thread to execute the code up to the locked region.
duke@1 102 // Extra manager instances will just be gc'ed.
duke@1 103 klassOop k = Management::sun_management_ManagementFactory_klass(CHECK_0);
duke@1 104 instanceKlassHandle ik(THREAD, k);
duke@1 105
duke@1 106 Handle mgr_name = java_lang_String::create_from_str(name(), CHECK_0);
duke@1 107
duke@1 108 JavaValue result(T_OBJECT);
duke@1 109 JavaCallArguments args;
duke@1 110 args.push_oop(mgr_name); // Argument 1
duke@1 111
coleenp@8076 112 Symbol* method_name = NULL;
coleenp@8076 113 Symbol* signature = NULL;
duke@1 114 if (is_gc_memory_manager()) {
coleenp@8076 115 method_name = vmSymbols::createGarbageCollector_name();
coleenp@8076 116 signature = vmSymbols::createGarbageCollector_signature();
duke@1 117 args.push_oop(Handle()); // Argument 2 (for future extension)
duke@1 118 } else {
coleenp@8076 119 method_name = vmSymbols::createMemoryManager_name();
coleenp@8076 120 signature = vmSymbols::createMemoryManager_signature();
duke@1 121 }
duke@1 122
duke@1 123 JavaCalls::call_static(&result,
duke@1 124 ik,
duke@1 125 method_name,
duke@1 126 signature,
duke@1 127 &args,
duke@1 128 CHECK_0);
duke@1 129
duke@1 130 instanceOop m = (instanceOop) result.get_jobject();
duke@1 131 instanceHandle mgr(THREAD, m);
duke@1 132
duke@1 133 {
duke@1 134 // Get lock before setting _memory_mgr_obj
duke@1 135 // since another thread may have created the instance
duke@1 136 MutexLocker ml(Management_lock);
duke@1 137
duke@1 138 // Check if another thread has created the management object. We reload
duke@1 139 // _memory_mgr_obj here because some other thread may have initialized
duke@1 140 // it while we were executing the code before the lock.
duke@1 141 //
duke@1 142 // The lock has done an acquire, so the load can't float above it, but
duke@1 143 // we need to do a load_acquire as above.
duke@1 144 mgr_obj = (instanceOop)OrderAccess::load_ptr_acquire(&_memory_mgr_obj);
duke@1 145 if (mgr_obj != NULL) {
duke@1 146 return mgr_obj;
duke@1 147 }
duke@1 148
duke@1 149 // Get the address of the object we created via call_special.
duke@1 150 mgr_obj = mgr();
duke@1 151
duke@1 152 // Use store barrier to make sure the memory accesses associated
duke@1 153 // with creating the management object are visible before publishing
duke@1 154 // its address. The unlock will publish the store to _memory_mgr_obj
duke@1 155 // because it does a release first.
duke@1 156 OrderAccess::release_store_ptr(&_memory_mgr_obj, mgr_obj);
duke@1 157 }
duke@1 158 }
duke@1 159
duke@1 160 return mgr_obj;
duke@1 161 }
duke@1 162
duke@1 163 void MemoryManager::oops_do(OopClosure* f) {
duke@1 164 f->do_oop((oop*) &_memory_mgr_obj);
duke@1 165 }
duke@1 166
duke@1 167 GCStatInfo::GCStatInfo(int num_pools) {
duke@1 168 // initialize the arrays for memory usage
duke@1 169 _before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
duke@1 170 _after_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
duke@1 171 _usage_array_size = num_pools;
johnc@11171 172 clear();
duke@1 173 }
duke@1 174
duke@1 175 GCStatInfo::~GCStatInfo() {
duke@1 176 FREE_C_HEAP_ARRAY(MemoryUsage*, _before_gc_usage_array);
duke@1 177 FREE_C_HEAP_ARRAY(MemoryUsage*, _after_gc_usage_array);
duke@1 178 }
duke@1 179
duke@1 180 void GCStatInfo::set_gc_usage(int pool_index, MemoryUsage usage, bool before_gc) {
duke@1 181 MemoryUsage* gc_usage_array;
duke@1 182 if (before_gc) {
duke@1 183 gc_usage_array = _before_gc_usage_array;
duke@1 184 } else {
duke@1 185 gc_usage_array = _after_gc_usage_array;
duke@1 186 }
duke@1 187 gc_usage_array[pool_index] = usage;
duke@1 188 }
duke@1 189
kevinw@6245 190 void GCStatInfo::clear() {
kevinw@6245 191 _index = 0;
kevinw@6245 192 _start_time = 0L;
kevinw@6245 193 _end_time = 0L;
kevinw@6245 194 size_t len = _usage_array_size * sizeof(MemoryUsage);
kevinw@6245 195 memset(_before_gc_usage_array, 0, len);
kevinw@6245 196 memset(_after_gc_usage_array, 0, len);
kevinw@6245 197 }
kevinw@6245 198
kevinw@6245 199
duke@1 200 GCMemoryManager::GCMemoryManager() : MemoryManager() {
duke@1 201 _num_collections = 0;
duke@1 202 _last_gc_stat = NULL;
kevinw@6245 203 _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true);
kevinw@6245 204 _current_gc_stat = NULL;
duke@1 205 _num_gc_threads = 1;
fparain@9623 206 _notification_enabled = false;
duke@1 207 }
duke@1 208
duke@1 209 GCMemoryManager::~GCMemoryManager() {
duke@1 210 delete _last_gc_stat;
kevinw@6245 211 delete _last_gc_lock;
kevinw@6245 212 delete _current_gc_stat;
duke@1 213 }
duke@1 214
duke@1 215 void GCMemoryManager::initialize_gc_stat_info() {
duke@1 216 assert(MemoryService::num_memory_pools() > 0, "should have one or more memory pools");
duke@1 217 _last_gc_stat = new GCStatInfo(MemoryService::num_memory_pools());
kevinw@6245 218 _current_gc_stat = new GCStatInfo(MemoryService::num_memory_pools());
kevinw@6245 219 // tracking concurrent collections we need two objects: one to update, and one to
kevinw@6245 220 // hold the publicly available "last (completed) gc" information.
duke@1 221 }
duke@1 222
kevinw@6245 223 void GCMemoryManager::gc_begin(bool recordGCBeginTime, bool recordPreGCUsage,
kevinw@6245 224 bool recordAccumulatedGCTime) {
kevinw@6245 225 assert(_last_gc_stat != NULL && _current_gc_stat != NULL, "Just checking");
kevinw@6245 226 if (recordAccumulatedGCTime) {
kevinw@6245 227 _accumulated_timer.start();
kevinw@6245 228 }
kevinw@6245 229 // _num_collections now increases in gc_end, to count completed collections
kevinw@6245 230 if (recordGCBeginTime) {
kevinw@6245 231 _current_gc_stat->set_index(_num_collections+1);
kevinw@6245 232 _current_gc_stat->set_start_time(Management::timestamp());
kevinw@6245 233 }
duke@1 234
kevinw@6245 235 if (recordPreGCUsage) {
kevinw@6245 236 // Keep memory usage of all memory pools
kevinw@6245 237 for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
kevinw@6245 238 MemoryPool* pool = MemoryService::get_memory_pool(i);
kevinw@6245 239 MemoryUsage usage = pool->get_memory_usage();
kevinw@6245 240 _current_gc_stat->set_before_gc_usage(i, usage);
dcubed@10739 241 #ifndef USDT2
kevinw@6245 242 HS_DTRACE_PROBE8(hotspot, mem__pool__gc__begin,
kevinw@6245 243 name(), strlen(name()),
kevinw@6245 244 pool->name(), strlen(pool->name()),
kevinw@6245 245 usage.init_size(), usage.used(),
kevinw@6245 246 usage.committed(), usage.max_size());
dcubed@10739 247 #else /* USDT2 */
dcubed@10739 248 HOTSPOT_MEM_POOL_GC_BEGIN(
dcubed@10739 249 (char *) name(), strlen(name()),
dcubed@10739 250 (char *) pool->name(), strlen(pool->name()),
dcubed@10739 251 usage.init_size(), usage.used(),
dcubed@10739 252 usage.committed(), usage.max_size());
dcubed@10739 253 #endif /* USDT2 */
kevinw@6245 254 }
duke@1 255 }
duke@1 256 }
duke@1 257
kevinw@6245 258 // A collector MUST, even if it does not complete for some reason,
kevinw@6245 259 // make a TraceMemoryManagerStats object where countCollection is true,
kevinw@6245 260 // to ensure the current gc stat is placed in _last_gc_stat.
kevinw@6245 261 void GCMemoryManager::gc_end(bool recordPostGCUsage,
kevinw@6245 262 bool recordAccumulatedGCTime,
fparain@9623 263 bool recordGCEndTime, bool countCollection,
fparain@9623 264 GCCause::Cause cause) {
kevinw@6245 265 if (recordAccumulatedGCTime) {
kevinw@6245 266 _accumulated_timer.stop();
kevinw@6245 267 }
kevinw@6245 268 if (recordGCEndTime) {
kevinw@6245 269 _current_gc_stat->set_end_time(Management::timestamp());
duke@1 270 }
duke@1 271
kevinw@6245 272 if (recordPostGCUsage) {
kevinw@6245 273 int i;
kevinw@6245 274 // keep the last gc statistics for all memory pools
kevinw@6245 275 for (i = 0; i < MemoryService::num_memory_pools(); i++) {
kevinw@6245 276 MemoryPool* pool = MemoryService::get_memory_pool(i);
kevinw@6245 277 MemoryUsage usage = pool->get_memory_usage();
duke@1 278
dcubed@10739 279 #ifndef USDT2
kevinw@6245 280 HS_DTRACE_PROBE8(hotspot, mem__pool__gc__end,
kevinw@6245 281 name(), strlen(name()),
kevinw@6245 282 pool->name(), strlen(pool->name()),
kevinw@6245 283 usage.init_size(), usage.used(),
kevinw@6245 284 usage.committed(), usage.max_size());
dcubed@10739 285 #else /* USDT2 */
dcubed@10739 286 HOTSPOT_MEM_POOL_GC_END(
dcubed@10739 287 (char *) name(), strlen(name()),
dcubed@10739 288 (char *) pool->name(), strlen(pool->name()),
dcubed@10739 289 usage.init_size(), usage.used(),
dcubed@10739 290 usage.committed(), usage.max_size());
dcubed@10739 291 #endif /* USDT2 */
kevinw@6245 292
kevinw@6245 293 _current_gc_stat->set_after_gc_usage(i, usage);
kevinw@6245 294 }
kevinw@6245 295
kevinw@6245 296 // Set last collection usage of the memory pools managed by this collector
kevinw@6245 297 for (i = 0; i < num_memory_pools(); i++) {
kevinw@6245 298 MemoryPool* pool = get_memory_pool(i);
kevinw@6245 299 MemoryUsage usage = pool->get_memory_usage();
kevinw@6245 300
kevinw@6245 301 // Compare with GC usage threshold
kevinw@6245 302 pool->set_last_collection_usage(usage);
kevinw@6245 303 LowMemoryDetector::detect_after_gc_memory(pool);
kevinw@6245 304 }
kevinw@6245 305 }
johnc@11171 306
kevinw@6245 307 if (countCollection) {
kevinw@6245 308 _num_collections++;
kevinw@6245 309 // alternately update two objects making one public when complete
kevinw@6245 310 {
kevinw@6245 311 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
kevinw@6245 312 GCStatInfo *tmp = _last_gc_stat;
kevinw@6245 313 _last_gc_stat = _current_gc_stat;
kevinw@6245 314 _current_gc_stat = tmp;
kevinw@6245 315 // reset the current stat for diagnosability purposes
kevinw@6245 316 _current_gc_stat->clear();
kevinw@6245 317 }
johnc@11171 318
johnc@11171 319 if (is_notification_enabled()) {
johnc@11171 320 bool isMajorGC = this == MemoryService::get_major_gc_manager();
johnc@11171 321 GCNotifier::pushNotification(this, isMajorGC ? "end of major GC" : "end of minor GC",
johnc@11171 322 GCCause::to_string(cause));
johnc@11171 323 }
duke@1 324 }
duke@1 325 }
kevinw@6245 326
kevinw@6245 327 size_t GCMemoryManager::get_last_gc_stat(GCStatInfo* dest) {
kevinw@6245 328 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag);
kevinw@6245 329 if (_last_gc_stat->gc_index() != 0) {
kevinw@6245 330 dest->set_index(_last_gc_stat->gc_index());
kevinw@6245 331 dest->set_start_time(_last_gc_stat->start_time());
kevinw@6245 332 dest->set_end_time(_last_gc_stat->end_time());
kevinw@6245 333 assert(dest->usage_array_size() == _last_gc_stat->usage_array_size(),
kevinw@6245 334 "Must have same array size");
kevinw@6245 335 size_t len = dest->usage_array_size() * sizeof(MemoryUsage);
kevinw@6245 336 memcpy(dest->before_gc_usage_array(), _last_gc_stat->before_gc_usage_array(), len);
kevinw@6245 337 memcpy(dest->after_gc_usage_array(), _last_gc_stat->after_gc_usage_array(), len);
kevinw@6245 338 }
kevinw@6245 339 return _last_gc_stat->gc_index();
kevinw@6245 340 }