1 /* 2 * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/systemDictionary.hpp" 27 #include "classfile/vmSymbols.hpp" 28 #include "oops/oop.inline.hpp" 29 #include "runtime/handles.inline.hpp" 30 #include "runtime/javaCalls.hpp" 31 #include "runtime/orderAccess.inline.hpp" 32 #include "services/lowMemoryDetector.hpp" 33 #include "services/management.hpp" 34 #include "services/memoryManager.hpp" 35 #include "services/memoryPool.hpp" 36 #include "services/memoryService.hpp" 37 #include "services/gcNotifier.hpp" 38 #include "utilities/dtrace.hpp" 39 40 MemoryManager::MemoryManager() { 41 _num_pools = 0; 42 (void)const_cast<instanceOop&>(_memory_mgr_obj = instanceOop(NULL)); 43 } 44 45 void MemoryManager::add_pool(MemoryPool* pool) { 46 assert(_num_pools < MemoryManager::max_num_pools, "_num_pools exceeds the max"); 47 if (_num_pools < MemoryManager::max_num_pools) { 48 _pools[_num_pools] = pool; 49 _num_pools++; 50 } 51 pool->add_manager(this); 52 } 53 54 MemoryManager* MemoryManager::get_code_cache_memory_manager() { 55 return (MemoryManager*) new CodeCacheMemoryManager(); 56 } 57 58 MemoryManager* MemoryManager::get_metaspace_memory_manager() { 59 return (MemoryManager*) new MetaspaceMemoryManager(); 60 } 61 62 instanceOop MemoryManager::get_memory_manager_instance(TRAPS) { 63 // Must do an acquire so as to force ordering of subsequent 64 // loads from anything _memory_mgr_obj points to or implies. 65 instanceOop mgr_obj = OrderAccess::load_acquire(&_memory_mgr_obj); 66 if (mgr_obj == NULL) { 67 // It's ok for more than one thread to execute the code up to the locked region. 68 // Extra manager instances will just be gc'ed. 69 Klass* k = Management::sun_management_ManagementFactoryHelper_klass(CHECK_0); 70 71 Handle mgr_name = java_lang_String::create_from_str(name(), CHECK_0); 72 73 JavaValue result(T_OBJECT); 74 JavaCallArguments args; 75 args.push_oop(mgr_name); // Argument 1 76 77 Symbol* method_name = NULL; 78 Symbol* signature = NULL; 79 if (is_gc_memory_manager()) { 80 Klass* extKlass = Management::com_sun_management_internal_GarbageCollectorExtImpl_klass(CHECK_0); 81 // com.sun.management.GarbageCollectorMXBean is in jdk.management module which may not be present. 82 if (extKlass != NULL) { 83 k = extKlass; 84 } 85 86 method_name = vmSymbols::createGarbageCollector_name(); 87 88 signature = vmSymbols::createGarbageCollector_signature(); 89 args.push_oop(Handle()); // Argument 2 (for future extension) 90 } else { 91 method_name = vmSymbols::createMemoryManager_name(); 92 signature = vmSymbols::createMemoryManager_signature(); 93 } 94 95 InstanceKlass* ik = InstanceKlass::cast(k); 96 97 JavaCalls::call_static(&result, 98 ik, 99 method_name, 100 signature, 101 &args, 102 CHECK_0); 103 104 instanceOop m = (instanceOop) result.get_jobject(); 105 instanceHandle mgr(THREAD, m); 106 107 { 108 // Get lock before setting _memory_mgr_obj 109 // since another thread may have created the instance 110 MutexLocker ml(Management_lock); 111 112 // Check if another thread has created the management object. We reload 113 // _memory_mgr_obj here because some other thread may have initialized 114 // it while we were executing the code before the lock. 115 // 116 // The lock has done an acquire, so the load can't float above it, but 117 // we need to do a load_acquire as above. 118 mgr_obj = OrderAccess::load_acquire(&_memory_mgr_obj); 119 if (mgr_obj != NULL) { 120 return mgr_obj; 121 } 122 123 // Get the address of the object we created via call_special. 124 mgr_obj = mgr(); 125 126 // Use store barrier to make sure the memory accesses associated 127 // with creating the management object are visible before publishing 128 // its address. The unlock will publish the store to _memory_mgr_obj 129 // because it does a release first. 130 OrderAccess::release_store(&_memory_mgr_obj, mgr_obj); 131 } 132 } 133 134 return mgr_obj; 135 } 136 137 void MemoryManager::oops_do(OopClosure* f) { 138 f->do_oop((oop*) &_memory_mgr_obj); 139 } 140 141 GCStatInfo::GCStatInfo(int num_pools) { 142 // initialize the arrays for memory usage 143 _before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools, mtInternal); 144 _after_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools, mtInternal); 145 _usage_array_size = num_pools; 146 clear(); 147 } 148 149 GCStatInfo::~GCStatInfo() { 150 FREE_C_HEAP_ARRAY(MemoryUsage*, _before_gc_usage_array); 151 FREE_C_HEAP_ARRAY(MemoryUsage*, _after_gc_usage_array); 152 } 153 154 void GCStatInfo::set_gc_usage(int pool_index, MemoryUsage usage, bool before_gc) { 155 MemoryUsage* gc_usage_array; 156 if (before_gc) { 157 gc_usage_array = _before_gc_usage_array; 158 } else { 159 gc_usage_array = _after_gc_usage_array; 160 } 161 gc_usage_array[pool_index] = usage; 162 } 163 164 void GCStatInfo::clear() { 165 _index = 0; 166 _start_time = 0L; 167 _end_time = 0L; 168 size_t len = _usage_array_size * sizeof(MemoryUsage); 169 memset(_before_gc_usage_array, 0, len); 170 memset(_after_gc_usage_array, 0, len); 171 } 172 173 174 GCMemoryManager::GCMemoryManager() : MemoryManager() { 175 _num_collections = 0; 176 _last_gc_stat = NULL; 177 _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true, 178 Monitor::_safepoint_check_never); 179 _current_gc_stat = NULL; 180 _num_gc_threads = 1; 181 _notification_enabled = false; 182 } 183 184 GCMemoryManager::~GCMemoryManager() { 185 delete _last_gc_stat; 186 delete _last_gc_lock; 187 delete _current_gc_stat; 188 } 189 190 void GCMemoryManager::initialize_gc_stat_info() { 191 assert(MemoryService::num_memory_pools() > 0, "should have one or more memory pools"); 192 _last_gc_stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(MemoryService::num_memory_pools()); 193 _current_gc_stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(MemoryService::num_memory_pools()); 194 // tracking concurrent collections we need two objects: one to update, and one to 195 // hold the publicly available "last (completed) gc" information. 196 } 197 198 void GCMemoryManager::gc_begin(bool recordGCBeginTime, bool recordPreGCUsage, 199 bool recordAccumulatedGCTime) { 200 assert(_last_gc_stat != NULL && _current_gc_stat != NULL, "Just checking"); 201 if (recordAccumulatedGCTime) { 202 _accumulated_timer.start(); 203 } 204 // _num_collections now increases in gc_end, to count completed collections 205 if (recordGCBeginTime) { 206 _current_gc_stat->set_index(_num_collections+1); 207 _current_gc_stat->set_start_time(Management::timestamp()); 208 } 209 210 if (recordPreGCUsage) { 211 // Keep memory usage of all memory pools 212 for (int i = 0; i < MemoryService::num_memory_pools(); i++) { 213 MemoryPool* pool = MemoryService::get_memory_pool(i); 214 MemoryUsage usage = pool->get_memory_usage(); 215 _current_gc_stat->set_before_gc_usage(i, usage); 216 HOTSPOT_MEM_POOL_GC_BEGIN( 217 (char *) name(), strlen(name()), 218 (char *) pool->name(), strlen(pool->name()), 219 usage.init_size(), usage.used(), 220 usage.committed(), usage.max_size()); 221 } 222 } 223 } 224 225 // A collector MUST, even if it does not complete for some reason, 226 // make a TraceMemoryManagerStats object where countCollection is true, 227 // to ensure the current gc stat is placed in _last_gc_stat. 228 void GCMemoryManager::gc_end(bool recordPostGCUsage, 229 bool recordAccumulatedGCTime, 230 bool recordGCEndTime, bool countCollection, 231 GCCause::Cause cause) { 232 if (recordAccumulatedGCTime) { 233 _accumulated_timer.stop(); 234 } 235 if (recordGCEndTime) { 236 _current_gc_stat->set_end_time(Management::timestamp()); 237 } 238 239 if (recordPostGCUsage) { 240 int i; 241 // keep the last gc statistics for all memory pools 242 for (i = 0; i < MemoryService::num_memory_pools(); i++) { 243 MemoryPool* pool = MemoryService::get_memory_pool(i); 244 MemoryUsage usage = pool->get_memory_usage(); 245 246 HOTSPOT_MEM_POOL_GC_END( 247 (char *) name(), strlen(name()), 248 (char *) pool->name(), strlen(pool->name()), 249 usage.init_size(), usage.used(), 250 usage.committed(), usage.max_size()); 251 252 _current_gc_stat->set_after_gc_usage(i, usage); 253 } 254 255 // Set last collection usage of the memory pools managed by this collector 256 for (i = 0; i < num_memory_pools(); i++) { 257 MemoryPool* pool = get_memory_pool(i); 258 MemoryUsage usage = pool->get_memory_usage(); 259 260 // Compare with GC usage threshold 261 pool->set_last_collection_usage(usage); 262 LowMemoryDetector::detect_after_gc_memory(pool); 263 } 264 } 265 266 if (countCollection) { 267 _num_collections++; 268 // alternately update two objects making one public when complete 269 { 270 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag); 271 GCStatInfo *tmp = _last_gc_stat; 272 _last_gc_stat = _current_gc_stat; 273 _current_gc_stat = tmp; 274 // reset the current stat for diagnosability purposes 275 _current_gc_stat->clear(); 276 } 277 278 if (is_notification_enabled()) { 279 bool isMajorGC = this == MemoryService::get_major_gc_manager(); 280 GCNotifier::pushNotification(this, isMajorGC ? "end of major GC" : "end of minor GC", 281 GCCause::to_string(cause)); 282 } 283 } 284 } 285 286 size_t GCMemoryManager::get_last_gc_stat(GCStatInfo* dest) { 287 MutexLockerEx ml(_last_gc_lock, Mutex::_no_safepoint_check_flag); 288 if (_last_gc_stat->gc_index() != 0) { 289 dest->set_index(_last_gc_stat->gc_index()); 290 dest->set_start_time(_last_gc_stat->start_time()); 291 dest->set_end_time(_last_gc_stat->end_time()); 292 assert(dest->usage_array_size() == _last_gc_stat->usage_array_size(), 293 "Must have same array size"); 294 size_t len = dest->usage_array_size() * sizeof(MemoryUsage); 295 memcpy(dest->before_gc_usage_array(), _last_gc_stat->before_gc_usage_array(), len); 296 memcpy(dest->after_gc_usage_array(), _last_gc_stat->after_gc_usage_array(), len); 297 } 298 return _last_gc_stat->gc_index(); 299 }