1 /* 2 * Copyright (c) 1997, 2019, 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 "memory/universe.hpp" 27 #include "runtime/mutexLocker.hpp" 28 #include "runtime/os.inline.hpp" 29 #include "runtime/safepoint.hpp" 30 #include "runtime/thread.inline.hpp" 31 #include "runtime/vmThread.hpp" 32 33 // Mutexes used in the VM (see comment in mutexLocker.hpp): 34 // 35 // Note that the following pointers are effectively final -- after having been 36 // set at JVM startup-time, they should never be subsequently mutated. 37 // Instead of using pointers to malloc()ed monitors and mutexes we should consider 38 // eliminating the indirection and using instances instead. 39 // Consider using GCC's __read_mostly. 40 41 Mutex* Patching_lock = NULL; 42 Mutex* CompiledMethod_lock = NULL; 43 Monitor* SystemDictionary_lock = NULL; 44 Mutex* ProtectionDomainSet_lock = NULL; 45 Mutex* SharedDictionary_lock = NULL; 46 Mutex* Module_lock = NULL; 47 Mutex* CompiledIC_lock = NULL; 48 Mutex* InlineCacheBuffer_lock = NULL; 49 Mutex* VMStatistic_lock = NULL; 50 Mutex* JNIHandleBlockFreeList_lock = NULL; 51 Mutex* JmethodIdCreation_lock = NULL; 52 Mutex* JfieldIdCreation_lock = NULL; 53 Monitor* JNICritical_lock = NULL; 54 Mutex* JvmtiThreadState_lock = NULL; 55 Monitor* Heap_lock = NULL; 56 Mutex* ExpandHeap_lock = NULL; 57 Mutex* AdapterHandlerLibrary_lock = NULL; 58 Mutex* SignatureHandlerLibrary_lock = NULL; 59 Mutex* VtableStubs_lock = NULL; 60 Mutex* SymbolArena_lock = NULL; 61 Monitor* StringDedupQueue_lock = NULL; 62 Mutex* StringDedupTable_lock = NULL; 63 Monitor* CodeCache_lock = NULL; 64 Mutex* MethodData_lock = NULL; 65 Mutex* TouchedMethodLog_lock = NULL; 66 Mutex* RetData_lock = NULL; 67 Monitor* VMOperationQueue_lock = NULL; 68 Monitor* VMOperationRequest_lock = NULL; 69 Monitor* SerializePage_lock = NULL; 70 Monitor* Threads_lock = NULL; 71 Mutex* NonJavaThreadsList_lock = NULL; 72 Mutex* NonJavaThreadsListSync_lock = NULL; 73 Monitor* CGC_lock = NULL; 74 Monitor* STS_lock = NULL; 75 Monitor* FullGCCount_lock = NULL; 76 Monitor* DirtyCardQ_CBL_mon = NULL; 77 Mutex* Shared_DirtyCardQ_lock = NULL; 78 Mutex* MarkStackFreeList_lock = NULL; 79 Mutex* MarkStackChunkList_lock = NULL; 80 Mutex* MonitoringSupport_lock = NULL; 81 Mutex* ParGCRareEvent_lock = NULL; 82 Monitor* CGCPhaseManager_lock = NULL; 83 Mutex* Compile_lock = NULL; 84 Monitor* MethodCompileQueue_lock = NULL; 85 Monitor* CompileThread_lock = NULL; 86 Monitor* Compilation_lock = NULL; 87 Mutex* CompileTaskAlloc_lock = NULL; 88 Mutex* CompileStatistics_lock = NULL; 89 Mutex* DirectivesStack_lock = NULL; 90 Mutex* MultiArray_lock = NULL; 91 Monitor* Terminator_lock = NULL; 92 Monitor* InitCompleted_lock = NULL; 93 Monitor* BeforeExit_lock = NULL; 94 Monitor* Notify_lock = NULL; 95 Mutex* ProfilePrint_lock = NULL; 96 Mutex* ExceptionCache_lock = NULL; 97 Mutex* NMethodSweeperStats_lock = NULL; 98 #ifndef PRODUCT 99 Mutex* FullGCALot_lock = NULL; 100 #endif 101 102 Mutex* Debug1_lock = NULL; 103 Mutex* Debug2_lock = NULL; 104 Mutex* Debug3_lock = NULL; 105 106 Mutex* tty_lock = NULL; 107 108 Mutex* RawMonitor_lock = NULL; 109 Mutex* PerfDataMemAlloc_lock = NULL; 110 Mutex* PerfDataManager_lock = NULL; 111 Mutex* OopMapCacheAlloc_lock = NULL; 112 113 Mutex* FreeList_lock = NULL; 114 Mutex* OldSets_lock = NULL; 115 Monitor* RootRegionScan_lock = NULL; 116 117 Mutex* Management_lock = NULL; 118 Monitor* Service_lock = NULL; 119 Monitor* PeriodicTask_lock = NULL; 120 Monitor* RedefineClasses_lock = NULL; 121 122 #if INCLUDE_JFR 123 Mutex* JfrStacktrace_lock = NULL; 124 Monitor* JfrMsg_lock = NULL; 125 Mutex* JfrBuffer_lock = NULL; 126 Mutex* JfrStream_lock = NULL; 127 Monitor* JfrThreadSampler_lock = NULL; 128 #endif 129 130 #ifndef SUPPORTS_NATIVE_CX8 131 Mutex* UnsafeJlong_lock = NULL; 132 #endif 133 Mutex* CodeHeapStateAnalytics_lock = NULL; 134 135 Mutex* MetaspaceExpand_lock = NULL; 136 Mutex* ClassLoaderDataGraph_lock = NULL; 137 Monitor* ThreadsSMRDelete_lock = NULL; 138 Mutex* SharedDecoder_lock = NULL; 139 Mutex* DCmdFactory_lock = NULL; 140 #if INCLUDE_NMT 141 Mutex* NMTQuery_lock = NULL; 142 #endif 143 #if INCLUDE_CDS 144 #if INCLUDE_JVMTI 145 Mutex* CDSClassFileStream_lock = NULL; 146 #endif 147 Mutex* DumpTimeTable_lock = NULL; 148 #endif // INCLUDE_CDS 149 150 #if INCLUDE_JVMCI 151 Monitor* JVMCI_lock = NULL; 152 #endif 153 154 155 #define MAX_NUM_MUTEX 128 156 static Mutex* _mutex_array[MAX_NUM_MUTEX]; 157 static int _num_mutex; 158 159 #ifdef ASSERT 160 void assert_locked_or_safepoint(const Mutex* lock) { 161 // check if this thread owns the lock (common case) 162 if (IgnoreLockingAssertions) return; 163 assert(lock != NULL, "Need non-NULL lock"); 164 if (lock->owned_by_self()) return; 165 if (SafepointSynchronize::is_at_safepoint()) return; 166 if (!Universe::is_fully_initialized()) return; 167 // see if invoker of VM operation owns it 168 VM_Operation* op = VMThread::vm_operation(); 169 if (op != NULL && op->calling_thread() == lock->owner()) return; 170 fatal("must own lock %s", lock->name()); 171 } 172 173 // a weaker assertion than the above 174 void assert_locked_or_safepoint_weak(const Mutex* lock) { 175 if (IgnoreLockingAssertions) return; 176 assert(lock != NULL, "Need non-NULL lock"); 177 if (lock->is_locked()) return; 178 if (SafepointSynchronize::is_at_safepoint()) return; 179 if (!Universe::is_fully_initialized()) return; 180 fatal("must own lock %s", lock->name()); 181 } 182 183 // a stronger assertion than the above 184 void assert_lock_strong(const Mutex* lock) { 185 if (IgnoreLockingAssertions) return; 186 assert(lock != NULL, "Need non-NULL lock"); 187 if (lock->owned_by_self()) return; 188 fatal("must own lock %s", lock->name()); 189 } 190 #endif 191 192 #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \ 193 var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \ 194 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \ 195 _mutex_array[_num_mutex++] = var; \ 196 } 197 198 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes. 199 void mutex_init() { 200 def(tty_lock , PaddedMutex , tty, true, Monitor::_safepoint_check_never); // allow to lock in VM 201 202 def(CGC_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // coordinate between fore- and background GC 203 def(STS_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 204 205 def(FullGCCount_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); // in support of ExplicitGCInvokesConcurrent 206 if (UseG1GC) { 207 def(DirtyCardQ_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never); 208 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never); 209 210 def(FreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 211 def(OldSets_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 212 def(RootRegionScan_lock , PaddedMonitor, leaf , true, Monitor::_safepoint_check_never); 213 214 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 215 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 216 217 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 218 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 219 220 def(MonitoringSupport_lock , PaddedMutex , native , true, Monitor::_safepoint_check_never); // used for serviceability monitoring support 221 } 222 if (UseShenandoahGC) { 223 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 224 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 225 } 226 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_always); 227 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_always); 228 def(CodeCache_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); 229 def(RawMonitor_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 230 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for oop_map_cache allocation. 231 232 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); 233 def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always); 234 235 def(Patching_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); // used for safepointing and code patching. 236 def(CompiledMethod_lock , PaddedMutex , special-1, true, Monitor::_safepoint_check_never); 237 def(Service_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // used for service thread operations 238 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for creating jmethodIDs. 239 240 def(SystemDictionary_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); 241 def(ProtectionDomainSet_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); 242 def(SharedDictionary_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); 243 def(Module_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always); 244 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 245 def(VMStatistic_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); 246 def(ExpandHeap_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // Used during compilation by VM thread 247 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); // handles are used by VM thread 248 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); 249 def(SymbolArena_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_never); 250 def(ProfilePrint_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing 251 def(ExceptionCache_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing 252 def(Debug1_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 253 #ifndef PRODUCT 254 def(FullGCALot_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // a lock to make FullGCALot MT safe 255 #endif 256 def(BeforeExit_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); 257 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for allocating PerfData memory for performance data 258 def(PerfDataManager_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for synchronized access to PerfDataManager resources 259 260 // CMS_modUnionTable_lock leaf 261 // CMS_bitMap_lock leaf 1 262 // CMS_freeList_lock leaf 2 263 264 def(Threads_lock , PaddedMonitor, barrier, true, Monitor::_safepoint_check_always); // Used for safepoint protocol. 265 def(NonJavaThreadsList_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never); 266 def(NonJavaThreadsListSync_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never); 267 268 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_never); // VM_thread allowed to block on these 269 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); 270 def(RetData_lock , PaddedMutex , nonleaf, false, Monitor::_safepoint_check_always); 271 def(Terminator_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); 272 def(InitCompleted_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 273 def(VtableStubs_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never); 274 def(Notify_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); 275 def(JNICritical_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); // used for JNI critical regions 276 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always); 277 278 def(Heap_lock , PaddedMonitor, nonleaf+1, false, Monitor::_safepoint_check_sometimes); // Doesn't safepoint check during termination. 279 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, Monitor::_safepoint_check_always); // jfieldID, Used in VM_Operation 280 281 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock 282 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, Monitor::_safepoint_check_always); 283 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); 284 def(DirectivesStack_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 285 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); 286 287 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController 288 def(Management_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // used for JVM management 289 290 def(Compile_lock , PaddedMutex , nonleaf+3, true, Monitor::_safepoint_check_always); 291 def(MethodData_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always); 292 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always); 293 294 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, true, Monitor::_safepoint_check_always); 295 def(Debug2_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never); 296 def(Debug3_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never); 297 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, Monitor::_safepoint_check_always); 298 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always); 299 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always); 300 301 if (WhiteBoxAPI) { 302 def(Compilation_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_never); 303 } 304 305 #if INCLUDE_JFR 306 def(JfrMsg_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); 307 def(JfrBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 308 def(JfrStream_lock , PaddedMutex , leaf+1, true, Monitor::_safepoint_check_never); // ensure to rank lower than 'safepoint' 309 def(JfrStacktrace_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 310 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 311 #endif 312 313 #ifndef SUPPORTS_NATIVE_CX8 314 def(UnsafeJlong_lock , PaddedMutex , special, false, Monitor::_safepoint_check_never); 315 #endif 316 317 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 318 def(NMethodSweeperStats_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 319 def(ThreadsSMRDelete_lock , PaddedMonitor, special, false, Monitor::_safepoint_check_never); 320 def(SharedDecoder_lock , PaddedMutex , native, false, Monitor::_safepoint_check_never); 321 def(DCmdFactory_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 322 #if INCLUDE_NMT 323 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always); 324 #endif 325 #if INCLUDE_CDS 326 #if INCLUDE_JVMTI 327 def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always); 328 #endif 329 330 #if INCLUDE_JVMCI 331 def(JVMCI_lock , PaddedMonitor, nonleaf+2, true, Monitor::_safepoint_check_always); 332 #endif 333 def(DumpTimeTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 334 #endif // INCLUDE_CDS 335 } 336 337 GCMutexLocker::GCMutexLocker(Mutex* mutex) { 338 if (SafepointSynchronize::is_at_safepoint()) { 339 _locked = false; 340 } else { 341 _mutex = mutex; 342 _locked = true; 343 _mutex->lock(); 344 } 345 } 346 347 // Print all mutexes/monitors that are currently owned by a thread; called 348 // by fatal error handler. 349 void print_owned_locks_on_error(outputStream* st) { 350 st->print("VM Mutex/Monitor currently owned by a thread: "); 351 bool none = true; 352 for (int i = 0; i < _num_mutex; i++) { 353 // see if it has an owner 354 if (_mutex_array[i]->owner() != NULL) { 355 if (none) { 356 // print format used by Mutex::print_on_error() 357 st->print_cr(" ([mutex/lock_event])"); 358 none = false; 359 } 360 _mutex_array[i]->print_on_error(st); 361 st->cr(); 362 } 363 } 364 if (none) st->print_cr("None"); 365 }