1 /* 2 * Copyright (c) 1997, 2024, 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 #ifndef SHARE_RUNTIME_MUTEXLOCKER_HPP 26 #define SHARE_RUNTIME_MUTEXLOCKER_HPP 27 28 #include "memory/allocation.hpp" 29 #include "runtime/flags/flagSetting.hpp" 30 #include "runtime/mutex.hpp" 31 32 // Mutexes used in the VM. 33 34 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code 35 extern Mutex* NMethodState_lock; // a lock used to guard a compiled method state 36 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary 37 extern Mutex* InvokeMethodTypeTable_lock; 38 extern Monitor* InvokeMethodIntrinsicTable_lock; 39 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary 40 extern Monitor* ClassInitError_lock; // a lock on the class initialization error table 41 extern Mutex* Module_lock; // a lock on module and package related data structures 42 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 43 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 44 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 45 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers 46 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers 47 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in 48 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data 49 extern Monitor* EscapeBarrier_lock; // a lock to sync reallocating and relocking objects because of JVMTI access 50 extern Monitor* JvmtiVTMSTransition_lock; // a lock for Virtual Thread Mount State transition (VTMS transition) management 51 extern Monitor* Heap_lock; // a lock on the heap 52 #ifdef INCLUDE_PARALLELGC 53 extern Mutex* PSOldGenExpand_lock; // a lock on expanding the heap 54 #endif 55 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 56 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 57 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 58 extern Mutex* SymbolArena_lock; // a lock on the symbol table arena 59 extern Monitor* StringDedup_lock; // a lock on the string deduplication facility 60 extern Mutex* StringDedupIntern_lock; // a lock on StringTable notification of StringDedup 61 extern Monitor* CodeCache_lock; // a lock on the CodeCache 62 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info 63 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 64 extern Monitor* VMOperation_lock; // a lock on queue of vm_operations waiting to execute 65 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads 66 // (also used by Safepoints too to block threads creation/destruction) 67 extern Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list 68 extern Mutex* NonJavaThreadsListSync_lock; // a lock for NonJavaThreads list synchronization 69 extern Monitor* CGC_lock; // used for coordination between 70 // fore- & background GC threads. 71 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 72 extern Monitor* G1OldGCCount_lock; // in support of "concurrent" full gc 73 extern Mutex* G1RareEvent_lock; // Synchronizes (rare) parallel GC operations. 74 extern Mutex* G1DetachedRefinementStats_lock; // Lock protecting detached refinement stats 75 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list. 76 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list. 77 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools and allocated memory high water mark. 78 extern Monitor* ConcurrentGCBreakpoints_lock; // Protects concurrent GC breakpoint management 79 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 80 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 81 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 82 extern Monitor* Compilation_lock; // a lock used to pause compilation 83 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 84 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 85 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives 86 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 87 extern Monitor* InitCompleted_lock; // a lock used to signal threads waiting on init completed 88 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 89 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 90 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 91 92 #ifndef PRODUCT 93 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 94 #endif // PRODUCT 95 96 extern Mutex* RawMonitor_lock; 97 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 98 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 99 100 extern Mutex* FreeList_lock; // protects the free region list during safepoints 101 extern Mutex* OldSets_lock; // protects the old region sets 102 extern Mutex* Uncommit_lock; // protects the uncommit list when not at safepoints 103 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 104 105 extern Mutex* Management_lock; // a lock used to serialize JVM management 106 extern Monitor* MonitorDeflation_lock; // a lock used for monitor deflation thread operation 107 extern Monitor* Service_lock; // a lock used for service thread operation 108 extern Monitor* Notification_lock; // a lock used for notification thread operation 109 extern Monitor* PeriodicTask_lock; // protects the periodic task structure 110 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 111 extern Mutex* Verify_lock; // synchronize initialization of verify library 112 extern Monitor* ThreadsSMRDelete_lock; // Used by ThreadsSMRSupport to take pressure off the Threads_lock 113 extern Mutex* ThreadIdTableCreate_lock; // Used by ThreadIdTable to lazily create the thread id table 114 extern Mutex* SharedDecoder_lock; // serializes access to the decoder during normal (not error reporting) use 115 extern Mutex* DCmdFactory_lock; // serialize access to DCmdFactory information 116 extern Mutex* NMTQuery_lock; // serialize NMT Dcmd queries 117 extern Mutex* NMTCompilationCostHistory_lock; // guards NMT compilation cost history 118 #if INCLUDE_CDS 119 #if INCLUDE_JVMTI 120 extern Mutex* CDSClassFileStream_lock; // FileMapInfo::open_stream_for_jvmti 121 #endif 122 extern Mutex* DumpTimeTable_lock; // SystemDictionaryShared::_dumptime_table 123 extern Mutex* CDSLambda_lock; // SystemDictionaryShared::get_shared_lambda_proxy_class 124 extern Mutex* DumpRegion_lock; // Symbol::operator new(size_t sz, int len) 125 extern Mutex* ClassListFile_lock; // ClassListWriter() 126 extern Mutex* UnregisteredClassesTable_lock; // UnregisteredClassesTableTable 127 extern Mutex* LambdaFormInvokers_lock; // Protecting LambdaFormInvokers::_lambdaform_lines 128 extern Mutex* ScratchObjects_lock; // Protecting _scratch_xxx_table in heapShared.cpp 129 #endif // INCLUDE_CDS 130 #if INCLUDE_JFR 131 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 132 extern Monitor* JfrMsg_lock; // protects JFR messaging 133 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 134 extern Monitor* JfrThreadSampler_lock; // used to suspend/resume JFR thread sampler 135 #endif 136 137 extern Mutex* Metaspace_lock; // protects Metaspace virtualspace and chunk expansions 138 extern Monitor* MetaspaceCritical_lock; // synchronizes failed metaspace allocations that risk throwing metaspace OOM 139 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading 140 141 142 extern Mutex* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 143 // Only used locally in PrintCodeCacheLayout processing. 144 145 extern Mutex* ExternalsRecorder_lock; // used to guard access to the external addresses table 146 147 extern Monitor* ContinuationRelativize_lock; 148 149 #if INCLUDE_JVMCI 150 extern Monitor* JVMCI_lock; // protects global JVMCI critical sections 151 extern Monitor* JVMCIRuntime_lock; // protects critical sections for a specific JVMCIRuntime object 152 #endif 153 154 extern Mutex* Bootclasspath_lock; 155 156 extern Mutex* tty_lock; // lock to synchronize output. 157 158 // A MutexLocker provides mutual exclusion with respect to a given mutex 159 // for the scope which contains the locker. The lock is an OS lock, not 160 // an object lock, and the two do not interoperate. Do not use Mutex-based 161 // locks to lock on Java objects, because they will not be respected if a 162 // that object is locked using the Java locking mechanism. 163 // 164 // NOTE WELL!! 165 // 166 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 167 // and friends constructors do a fence, a lock and an acquire *in that 168 // order*. And that their destructors do a release and unlock, in *that* 169 // order. If their implementations change such that these assumptions 170 // are violated, a whole lot of code will break. 171 172 // Print all mutexes/monitors that are currently owned by a thread; called 173 // by fatal error handler. 174 void print_owned_locks_on_error(outputStream* st); 175 void print_lock_ranks(outputStream* st); 176 177 // for debugging: check that we're already owning this lock (or are at a safepoint / handshake) 178 #ifdef ASSERT 179 void assert_locked_or_safepoint(const Mutex* lock); 180 void assert_lock_strong(const Mutex* lock); 181 #else 182 #define assert_locked_or_safepoint(lock) 183 #define assert_lock_strong(lock) 184 #endif 185 186 // Internal implementation. Skips on null Mutex. 187 // Subclasses enforce stronger invariants. 188 class MutexLockerImpl: public StackObj { 189 protected: 190 Mutex* _mutex; 191 192 MutexLockerImpl(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 193 _mutex(mutex) { 194 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag; 195 if (_mutex != nullptr) { 196 if (no_safepoint_check) { 197 _mutex->lock_without_safepoint_check(); 198 } else { 199 _mutex->lock(); 200 } 201 } 202 } 203 204 MutexLockerImpl(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 205 _mutex(mutex) { 206 bool no_safepoint_check = flag == Mutex::_no_safepoint_check_flag; 207 if (_mutex != nullptr) { 208 if (no_safepoint_check) { 209 _mutex->lock_without_safepoint_check(thread); 210 } else { 211 _mutex->lock(thread); 212 } 213 } 214 } 215 216 ~MutexLockerImpl() { 217 if (_mutex != nullptr) { 218 assert_lock_strong(_mutex); 219 _mutex->unlock(); 220 } 221 } 222 223 public: 224 static void post_initialize(); 225 }; 226 227 // Simplest mutex locker. 228 // Does not allow null mutexes. 229 class MutexLocker: public MutexLockerImpl { 230 public: 231 MutexLocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 232 MutexLockerImpl(mutex, flag) { 233 assert(mutex != nullptr, "null mutex not allowed"); 234 } 235 236 MutexLocker(Thread* thread, Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 237 MutexLockerImpl(thread, mutex, flag) { 238 assert(mutex != nullptr, "null mutex not allowed"); 239 } 240 }; 241 242 // Conditional mutex locker. 243 // Like MutexLocker above, but only locks when condition is true. 244 class ConditionalMutexLocker: public MutexLockerImpl { 245 public: 246 ConditionalMutexLocker(Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 247 MutexLockerImpl(condition ? mutex : nullptr, flag) { 248 assert(!condition || mutex != nullptr, "null mutex not allowed when locking"); 249 } 250 251 ConditionalMutexLocker(Thread* thread, Mutex* mutex, bool condition, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 252 MutexLockerImpl(thread, condition ? mutex : nullptr, flag) { 253 assert(!condition || mutex != nullptr, "null mutex not allowed when locking"); 254 } 255 }; 256 257 // A MonitorLocker is like a MutexLocker above, except it allows 258 // wait/notify as well which are delegated to the underlying Monitor. 259 // It also disallows null. 260 class MonitorLocker: public MutexLockerImpl { 261 Mutex::SafepointCheckFlag _flag; 262 263 protected: 264 Monitor* as_monitor() const { 265 return static_cast<Monitor*>(_mutex); 266 } 267 268 public: 269 MonitorLocker(Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 270 MutexLockerImpl(monitor, flag), _flag(flag) { 271 // Superclass constructor did locking 272 assert(monitor != nullptr, "null monitor not allowed"); 273 } 274 275 MonitorLocker(Thread* thread, Monitor* monitor, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 276 MutexLockerImpl(thread, monitor, flag), _flag(flag) { 277 // Superclass constructor did locking 278 assert(monitor != nullptr, "null monitor not allowed"); 279 } 280 281 bool wait(int64_t timeout = 0) { 282 return _flag == Mutex::_safepoint_check_flag ? 283 as_monitor()->wait(timeout) : as_monitor()->wait_without_safepoint_check(timeout); 284 } 285 286 void notify_all() { 287 as_monitor()->notify_all(); 288 } 289 290 void notify() { 291 as_monitor()->notify(); 292 } 293 }; 294 295 296 // A GCMutexLocker is usually initialized with a mutex that is 297 // automatically acquired in order to do GC. The function that 298 // synchronizes using a GCMutexLocker may be called both during and between 299 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 300 // if GC is in progress (since the mutex is already held on its behalf.) 301 302 class GCMutexLocker: public StackObj { 303 private: 304 Mutex* _mutex; 305 bool _locked; 306 public: 307 GCMutexLocker(Mutex* mutex); 308 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 309 }; 310 311 // A MutexUnlocker temporarily exits a previously 312 // entered mutex for the scope which contains the unlocker. 313 314 class MutexUnlocker: StackObj { 315 private: 316 Mutex* _mutex; 317 bool _no_safepoint_check; 318 319 public: 320 MutexUnlocker(Mutex* mutex, Mutex::SafepointCheckFlag flag = Mutex::_safepoint_check_flag) : 321 _mutex(mutex), 322 _no_safepoint_check(flag == Mutex::_no_safepoint_check_flag) { 323 _mutex->unlock(); 324 } 325 326 ~MutexUnlocker() { 327 if (_no_safepoint_check) { 328 _mutex->lock_without_safepoint_check(); 329 } else { 330 _mutex->lock(); 331 } 332 } 333 }; 334 335 // Instance of a RecursiveLock that may be held through Java heap allocation, which may include calls to Java, 336 // and JNI event notification for resource exhaustion for metaspace or heap. 337 extern RecursiveMutex* MultiArray_lock; 338 339 // RAII locker for a RecursiveMutex. See comments in mutex.hpp for more information. 340 class RecursiveLocker { 341 RecursiveMutex* _lock; 342 Thread* _thread; 343 public: 344 RecursiveLocker(RecursiveMutex* lock, Thread* current) : _lock(lock), _thread(current) { 345 _lock->lock(_thread); 346 } 347 ~RecursiveLocker() { 348 _lock->unlock(_thread); 349 } 350 }; 351 352 #endif // SHARE_RUNTIME_MUTEXLOCKER_HPP