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* OsrList_lock = NULL; 98 Mutex* NMethodSweeperStats_lock = NULL; 99 #ifndef PRODUCT 100 Mutex* FullGCALot_lock = NULL; 101 #endif 102 103 Mutex* Debug1_lock = NULL; 104 Mutex* Debug2_lock = NULL; 105 Mutex* Debug3_lock = NULL; 106 107 Mutex* tty_lock = NULL; 108 109 Mutex* RawMonitor_lock = NULL; 110 Mutex* PerfDataMemAlloc_lock = NULL; 111 Mutex* PerfDataManager_lock = NULL; 112 Mutex* OopMapCacheAlloc_lock = NULL; 113 114 Mutex* FreeList_lock = NULL; 115 Mutex* OldSets_lock = NULL; 116 Monitor* RootRegionScan_lock = NULL; 117 118 Mutex* Management_lock = NULL; 119 Monitor* Service_lock = NULL; 120 Monitor* PeriodicTask_lock = NULL; 121 Monitor* RedefineClasses_lock = NULL; 122 123 #if INCLUDE_JFR 124 Mutex* JfrStacktrace_lock = NULL; 125 Monitor* JfrMsg_lock = NULL; 126 Mutex* JfrBuffer_lock = NULL; 127 Mutex* JfrStream_lock = NULL; 128 Monitor* JfrThreadSampler_lock = NULL; 129 #endif 130 131 #ifndef SUPPORTS_NATIVE_CX8 132 Mutex* UnsafeJlong_lock = NULL; 133 #endif 134 Mutex* CodeHeapStateAnalytics_lock = NULL; 135 136 Mutex* MetaspaceExpand_lock = NULL; 137 Mutex* ClassLoaderDataGraph_lock = NULL; 138 Monitor* ThreadsSMRDelete_lock = NULL; 139 Mutex* SharedDecoder_lock = NULL; 140 Mutex* DCmdFactory_lock = NULL; 141 #if INCLUDE_NMT 142 Mutex* NMTQuery_lock = NULL; 143 #endif 144 #if INCLUDE_CDS 145 #if INCLUDE_JVMTI 146 Mutex* CDSClassFileStream_lock = NULL; 147 #endif 148 Mutex* DumpTimeTable_lock = NULL; 149 #endif // INCLUDE_CDS 150 151 #if INCLUDE_JVMCI 152 Monitor* JVMCI_lock = NULL; 153 #endif 154 155 156 #define MAX_NUM_MUTEX 128 157 static Mutex* _mutex_array[MAX_NUM_MUTEX]; 158 static int _num_mutex; 159 160 #ifdef ASSERT 161 void assert_locked_or_safepoint(const Mutex* lock) { 162 // check if this thread owns the lock (common case) 163 if (IgnoreLockingAssertions) return; 164 assert(lock != NULL, "Need non-NULL lock"); 165 if (lock->owned_by_self()) return; 166 if (SafepointSynchronize::is_at_safepoint()) return; 167 if (!Universe::is_fully_initialized()) return; 168 // see if invoker of VM operation owns it 169 VM_Operation* op = VMThread::vm_operation(); 170 if (op != NULL && op->calling_thread() == lock->owner()) return; 171 fatal("must own lock %s", lock->name()); 172 } 173 174 // a weaker assertion than the above 175 void assert_locked_or_safepoint_weak(const Mutex* lock) { 176 if (IgnoreLockingAssertions) return; 177 assert(lock != NULL, "Need non-NULL lock"); 178 if (lock->is_locked()) return; 179 if (SafepointSynchronize::is_at_safepoint()) return; 180 if (!Universe::is_fully_initialized()) return; 181 fatal("must own lock %s", lock->name()); 182 } 183 184 // a stronger assertion than the above 185 void assert_lock_strong(const Mutex* lock) { 186 if (IgnoreLockingAssertions) return; 187 assert(lock != NULL, "Need non-NULL lock"); 188 if (lock->owned_by_self()) return; 189 fatal("must own lock %s", lock->name()); 190 } 191 #endif 192 193 #define def(var, type, pri, vm_block, safepoint_check_allowed ) { \ 194 var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \ 195 assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX"); \ 196 _mutex_array[_num_mutex++] = var; \ 197 } 198 199 // Using Padded subclasses to prevent false sharing of these global monitors and mutexes. 200 void mutex_init() { 201 def(tty_lock , PaddedMutex , tty, true, Monitor::_safepoint_check_never); // allow to lock in VM 202 203 def(CGC_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // coordinate between fore- and background GC 204 def(STS_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 205 206 def(FullGCCount_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); // in support of ExplicitGCInvokesConcurrent 207 if (UseG1GC) { 208 def(DirtyCardQ_CBL_mon , PaddedMonitor, access, true, Monitor::_safepoint_check_never); 209 def(Shared_DirtyCardQ_lock , PaddedMutex , access + 1, true, Monitor::_safepoint_check_never); 210 211 def(FreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 212 def(OldSets_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 213 def(RootRegionScan_lock , PaddedMonitor, leaf , true, Monitor::_safepoint_check_never); 214 215 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 216 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 217 218 def(MarkStackFreeList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 219 def(MarkStackChunkList_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_never); 220 221 def(MonitoringSupport_lock , PaddedMutex , native , true, Monitor::_safepoint_check_never); // used for serviceability monitoring support 222 } 223 if (UseShenandoahGC) { 224 def(StringDedupQueue_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 225 def(StringDedupTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 226 } 227 def(ParGCRareEvent_lock , PaddedMutex , leaf , true, Monitor::_safepoint_check_always); 228 def(CGCPhaseManager_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_always); 229 def(CodeCache_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); 230 def(RawMonitor_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 231 def(OopMapCacheAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for oop_map_cache allocation. 232 233 def(MetaspaceExpand_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); 234 def(ClassLoaderDataGraph_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always); 235 236 def(Patching_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); // used for safepointing and code patching. 237 def(OsrList_lock , PaddedMutex , special-1, true, Monitor::_safepoint_check_never); 238 def(CompiledMethod_lock , PaddedMutex , special-1, true, Monitor::_safepoint_check_never); 239 def(Service_lock , PaddedMonitor, special, true, Monitor::_safepoint_check_never); // used for service thread operations 240 def(JmethodIdCreation_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for creating jmethodIDs. 241 242 def(SystemDictionary_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); 243 def(ProtectionDomainSet_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); 244 def(SharedDictionary_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); 245 def(Module_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_always); 246 def(InlineCacheBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 247 def(VMStatistic_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); 248 def(ExpandHeap_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // Used during compilation by VM thread 249 def(JNIHandleBlockFreeList_lock , PaddedMutex , leaf-1, true, Monitor::_safepoint_check_never); // handles are used by VM thread 250 def(SignatureHandlerLibrary_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); 251 def(SymbolArena_lock , PaddedMutex , leaf+2, true, Monitor::_safepoint_check_never); 252 def(ProfilePrint_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing 253 def(ExceptionCache_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // serial profile printing 254 def(Debug1_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 255 #ifndef PRODUCT 256 def(FullGCALot_lock , PaddedMutex , leaf, false, Monitor::_safepoint_check_always); // a lock to make FullGCALot MT safe 257 #endif 258 def(BeforeExit_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); 259 def(PerfDataMemAlloc_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for allocating PerfData memory for performance data 260 def(PerfDataManager_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_always); // used for synchronized access to PerfDataManager resources 261 262 // CMS_modUnionTable_lock leaf 263 // CMS_bitMap_lock leaf 1 264 // CMS_freeList_lock leaf 2 265 266 def(Threads_lock , PaddedMonitor, barrier, true, Monitor::_safepoint_check_always); // Used for safepoint protocol. 267 def(NonJavaThreadsList_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never); 268 def(NonJavaThreadsListSync_lock , PaddedMutex, leaf, true, Monitor::_safepoint_check_never); 269 270 def(VMOperationQueue_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_never); // VM_thread allowed to block on these 271 def(VMOperationRequest_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); 272 def(RetData_lock , PaddedMutex , nonleaf, false, Monitor::_safepoint_check_always); 273 def(Terminator_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); 274 def(InitCompleted_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 275 def(VtableStubs_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_never); 276 def(Notify_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); 277 def(JNICritical_lock , PaddedMonitor, nonleaf, true, Monitor::_safepoint_check_always); // used for JNI critical regions 278 def(AdapterHandlerLibrary_lock , PaddedMutex , nonleaf, true, Monitor::_safepoint_check_always); 279 280 def(Heap_lock , PaddedMonitor, nonleaf+1, false, Monitor::_safepoint_check_sometimes); // Doesn't safepoint check during termination. 281 def(JfieldIdCreation_lock , PaddedMutex , nonleaf+1, true, Monitor::_safepoint_check_always); // jfieldID, Used in VM_Operation 282 283 def(CompiledIC_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_never); // locks VtableStubs_lock, InlineCacheBuffer_lock 284 def(CompileTaskAlloc_lock , PaddedMutex , nonleaf+2, true, Monitor::_safepoint_check_always); 285 def(CompileStatistics_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); 286 def(DirectivesStack_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 287 def(MultiArray_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); 288 289 def(JvmtiThreadState_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // Used by JvmtiThreadState/JvmtiEventController 290 def(Management_lock , PaddedMutex , nonleaf+2, false, Monitor::_safepoint_check_always); // used for JVM management 291 292 def(Compile_lock , PaddedMutex , nonleaf+3, true, Monitor::_safepoint_check_always); 293 def(MethodData_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always); 294 def(TouchedMethodLog_lock , PaddedMutex , nonleaf+3, false, Monitor::_safepoint_check_always); 295 296 def(MethodCompileQueue_lock , PaddedMonitor, nonleaf+4, true, Monitor::_safepoint_check_always); 297 def(Debug2_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never); 298 def(Debug3_lock , PaddedMutex , nonleaf+4, true, Monitor::_safepoint_check_never); 299 def(CompileThread_lock , PaddedMonitor, nonleaf+5, false, Monitor::_safepoint_check_always); 300 def(PeriodicTask_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always); 301 def(RedefineClasses_lock , PaddedMonitor, nonleaf+5, true, Monitor::_safepoint_check_always); 302 303 if (WhiteBoxAPI) { 304 def(Compilation_lock , PaddedMonitor, leaf, false, Monitor::_safepoint_check_never); 305 } 306 307 #if INCLUDE_JFR 308 def(JfrMsg_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_always); 309 def(JfrBuffer_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 310 def(JfrStream_lock , PaddedMutex , leaf+1, true, Monitor::_safepoint_check_never); // ensure to rank lower than 'safepoint' 311 def(JfrStacktrace_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 312 def(JfrThreadSampler_lock , PaddedMonitor, leaf, true, Monitor::_safepoint_check_never); 313 #endif 314 315 #ifndef SUPPORTS_NATIVE_CX8 316 def(UnsafeJlong_lock , PaddedMutex , special, false, Monitor::_safepoint_check_never); 317 #endif 318 319 def(CodeHeapStateAnalytics_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 320 def(NMethodSweeperStats_lock , PaddedMutex , special, true, Monitor::_safepoint_check_never); 321 def(ThreadsSMRDelete_lock , PaddedMonitor, special, false, Monitor::_safepoint_check_never); 322 def(SharedDecoder_lock , PaddedMutex , native, false, Monitor::_safepoint_check_never); 323 def(DCmdFactory_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 324 #if INCLUDE_NMT 325 def(NMTQuery_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always); 326 #endif 327 #if INCLUDE_CDS 328 #if INCLUDE_JVMTI 329 def(CDSClassFileStream_lock , PaddedMutex , max_nonleaf, false, Monitor::_safepoint_check_always); 330 #endif 331 332 #if INCLUDE_JVMCI 333 def(JVMCI_lock , PaddedMonitor, nonleaf+2, true, Monitor::_safepoint_check_always); 334 #endif 335 def(DumpTimeTable_lock , PaddedMutex , leaf, true, Monitor::_safepoint_check_never); 336 #endif // INCLUDE_CDS 337 } 338 339 GCMutexLocker::GCMutexLocker(Mutex* mutex) { 340 if (SafepointSynchronize::is_at_safepoint()) { 341 _locked = false; 342 } else { 343 _mutex = mutex; 344 _locked = true; 345 _mutex->lock(); 346 } 347 } 348 349 // Print all mutexes/monitors that are currently owned by a thread; called 350 // by fatal error handler. 351 void print_owned_locks_on_error(outputStream* st) { 352 st->print("VM Mutex/Monitor currently owned by a thread: "); 353 bool none = true; 354 for (int i = 0; i < _num_mutex; i++) { 355 // see if it has an owner 356 if (_mutex_array[i]->owner() != NULL) { 357 if (none) { 358 // print format used by Mutex::print_on_error() 359 st->print_cr(" ([mutex/lock_event])"); 360 none = false; 361 } 362 _mutex_array[i]->print_on_error(st); 363 st->cr(); 364 } 365 } 366 if (none) st->print_cr("None"); 367 }