1 /* 2 * Copyright (c) 1997, 2018, 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_VM_RUNTIME_MUTEXLOCKER_HPP 26 #define SHARE_VM_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 Monitor* SystemDictionary_lock; // a lock on the system dictionary 36 extern Mutex* SharedDictionary_lock; // a lock on the CDS shared dictionary 37 extern Mutex* Module_lock; // a lock on module and package related data structures 38 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 39 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 40 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 41 extern Mutex* JNIGlobalAlloc_lock; // JNI global storage allocate list lock 42 extern Mutex* JNIGlobalActive_lock; // JNI global storage active list lock 43 extern Mutex* JNIWeakAlloc_lock; // JNI weak storage allocate list lock 44 extern Mutex* JNIWeakActive_lock; // JNI weak storage active list lock 45 extern Mutex* StringTableWeakAlloc_lock; // StringTable weak storage allocate list lock 46 extern Mutex* StringTableWeakActive_lock; // STringTable weak storage active list lock 47 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 48 extern Mutex* VMWeakAlloc_lock; // VM Weak Handles storage allocate list lock 49 extern Mutex* VMWeakActive_lock; // VM Weak Handles storage active list lock 50 extern Mutex* ResolvedMethodTable_lock; // a lock on the ResolvedMethodTable updates 51 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers 52 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers 53 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in 54 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data 55 extern Monitor* Heap_lock; // a lock on the heap 56 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 57 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 58 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 59 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 60 extern Mutex* SymbolArena_lock; // a lock on the symbol table arena 61 extern Mutex* StringTable_lock; // a lock on the interned string table 62 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue 63 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table 64 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx 65 extern Mutex* MethodData_lock; // a lock on installation of method data 66 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info 67 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 68 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table 69 extern Monitor* CGCPhaseManager_lock; // a lock to protect a concurrent GC's phase management 70 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute 71 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate 72 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction 73 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads 74 // (also used by Safepoints too to block threads creation/destruction) 75 extern Monitor* CGC_lock; // used for coordination between 76 // fore- & background GC threads. 77 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 78 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 79 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q 80 // buffer free list. 81 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q 82 // completed buffer queue. 83 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB 84 // queue shared by 85 // non-Java threads. 86 87 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q 88 // buffer free list. 89 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 90 // completed buffer queue. 91 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 92 // queue shared by 93 // non-Java threads. 94 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list. 95 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list. 96 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 97 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 98 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 99 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 100 extern Monitor* Compilation_lock; // a lock used to pause compilation 101 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 102 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 103 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives 104 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 105 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 106 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 107 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 108 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 109 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 110 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 111 112 #ifndef PRODUCT 113 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 114 #endif // PRODUCT 115 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 116 extern Mutex* Debug2_lock; // down synchronization related bugs! 117 extern Mutex* Debug3_lock; 118 119 extern Mutex* RawMonitor_lock; 120 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 121 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 122 extern Mutex* ParkerFreeList_lock; 123 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 124 125 extern Mutex* FreeList_lock; // protects the free region list during safepoints 126 extern Mutex* OldSets_lock; // protects the old region sets 127 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 128 129 extern Mutex* Management_lock; // a lock used to serialize JVM management 130 extern Monitor* Service_lock; // a lock used for service thread operation 131 extern Monitor* PeriodicTask_lock; // protects the periodic task structure 132 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 133 extern Mutex* ThreadHeapSampler_lock; // protects the static data for initialization. 134 135 #if INCLUDE_JFR 136 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 137 extern Monitor* JfrMsg_lock; // protects JFR messaging 138 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 139 extern Mutex* JfrStream_lock; // protects JFR stream access 140 #endif 141 142 #ifndef SUPPORTS_NATIVE_CX8 143 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 144 #endif 145 146 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions 147 148 149 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 150 // Only used locally in PrintCodeCacheLayout processing. 151 152 // A MutexLocker provides mutual exclusion with respect to a given mutex 153 // for the scope which contains the locker. The lock is an OS lock, not 154 // an object lock, and the two do not interoperate. Do not use Mutex-based 155 // locks to lock on Java objects, because they will not be respected if a 156 // that object is locked using the Java locking mechanism. 157 // 158 // NOTE WELL!! 159 // 160 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 161 // and friends constructors do a fence, a lock and an acquire *in that 162 // order*. And that their destructors do a release and unlock, in *that* 163 // order. If their implementations change such that these assumptions 164 // are violated, a whole lot of code will break. 165 166 // Print all mutexes/monitors that are currently owned by a thread; called 167 // by fatal error handler. 168 void print_owned_locks_on_error(outputStream* st); 169 170 char *lock_name(Mutex *mutex); 171 172 class MutexLocker: StackObj { 173 private: 174 Monitor * _mutex; 175 public: 176 MutexLocker(Monitor * mutex) { 177 assert(mutex->rank() != Mutex::special, 178 "Special ranked mutex should only use MutexLockerEx"); 179 _mutex = mutex; 180 _mutex->lock(); 181 } 182 183 // Overloaded constructor passing current thread 184 MutexLocker(Monitor * mutex, Thread *thread) { 185 assert(mutex->rank() != Mutex::special, 186 "Special ranked mutex should only use MutexLockerEx"); 187 _mutex = mutex; 188 _mutex->lock(thread); 189 } 190 191 ~MutexLocker() { 192 _mutex->unlock(); 193 } 194 195 }; 196 197 // for debugging: check that we're already owning this lock (or are at a safepoint) 198 #ifdef ASSERT 199 void assert_locked_or_safepoint(const Monitor * lock); 200 void assert_lock_strong(const Monitor * lock); 201 #else 202 #define assert_locked_or_safepoint(lock) 203 #define assert_lock_strong(lock) 204 #endif 205 206 // A MutexLockerEx behaves like a MutexLocker when its constructor is 207 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 208 // called with NULL, in which case the MutexLockerEx is a no-op. There 209 // is also a corresponding MutexUnlockerEx. We want to keep the 210 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 211 // without safepoint check. 212 213 class MutexLockerEx: public StackObj { 214 private: 215 Monitor * _mutex; 216 public: 217 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 218 _mutex = mutex; 219 if (_mutex != NULL) { 220 assert(mutex->rank() > Mutex::special || no_safepoint_check, 221 "Mutexes with rank special or lower should not do safepoint checks"); 222 if (no_safepoint_check) 223 _mutex->lock_without_safepoint_check(); 224 else 225 _mutex->lock(); 226 } 227 } 228 229 ~MutexLockerEx() { 230 if (_mutex != NULL) { 231 _mutex->unlock(); 232 } 233 } 234 }; 235 236 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 237 // a possibly null Monitor, and allows wait/notify as well which are 238 // delegated to the underlying Monitor. 239 240 class MonitorLockerEx: public MutexLockerEx { 241 private: 242 Monitor * _monitor; 243 public: 244 MonitorLockerEx(Monitor* monitor, 245 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 246 MutexLockerEx(monitor, no_safepoint_check), 247 _monitor(monitor) { 248 // Superclass constructor did locking 249 } 250 251 ~MonitorLockerEx() { 252 #ifdef ASSERT 253 if (_monitor != NULL) { 254 assert_lock_strong(_monitor); 255 } 256 #endif // ASSERT 257 // Superclass destructor will do unlocking 258 } 259 260 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 261 long timeout = 0, 262 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 263 if (_monitor != NULL) { 264 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 265 } 266 return false; 267 } 268 269 bool notify_all() { 270 if (_monitor != NULL) { 271 return _monitor->notify_all(); 272 } 273 return true; 274 } 275 276 bool notify() { 277 if (_monitor != NULL) { 278 return _monitor->notify(); 279 } 280 return true; 281 } 282 }; 283 284 285 286 // A GCMutexLocker is usually initialized with a mutex that is 287 // automatically acquired in order to do GC. The function that 288 // synchronizes using a GCMutexLocker may be called both during and between 289 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 290 // if GC is in progress (since the mutex is already held on its behalf.) 291 292 class GCMutexLocker: public StackObj { 293 private: 294 Monitor * _mutex; 295 bool _locked; 296 public: 297 GCMutexLocker(Monitor * mutex); 298 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 299 }; 300 301 302 303 // A MutexUnlocker temporarily exits a previously 304 // entered mutex for the scope which contains the unlocker. 305 306 class MutexUnlocker: StackObj { 307 private: 308 Monitor * _mutex; 309 310 public: 311 MutexUnlocker(Monitor * mutex) { 312 _mutex = mutex; 313 _mutex->unlock(); 314 } 315 316 ~MutexUnlocker() { 317 _mutex->lock(); 318 } 319 }; 320 321 // A MutexUnlockerEx temporarily exits a previously 322 // entered mutex for the scope which contains the unlocker. 323 324 class MutexUnlockerEx: StackObj { 325 private: 326 Monitor * _mutex; 327 bool _no_safepoint_check; 328 329 public: 330 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 331 _mutex = mutex; 332 _no_safepoint_check = no_safepoint_check; 333 _mutex->unlock(); 334 } 335 336 ~MutexUnlockerEx() { 337 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 338 _mutex->lock_without_safepoint_check(); 339 } else { 340 _mutex->lock(); 341 } 342 } 343 }; 344 345 #ifndef PRODUCT 346 // 347 // A special MutexLocker that allows: 348 // - reentrant locking 349 // - locking out of order 350 // 351 // Only to be used for verify code, where we can relax out dead-lock 352 // detection code a bit (unsafe, but probably ok). This code is NEVER to 353 // be included in a product version. 354 // 355 class VerifyMutexLocker: StackObj { 356 private: 357 Monitor * _mutex; 358 bool _reentrant; 359 public: 360 VerifyMutexLocker(Monitor * mutex) { 361 _mutex = mutex; 362 _reentrant = mutex->owned_by_self(); 363 if (!_reentrant) { 364 // We temp. disable strict safepoint checking, while we require the lock 365 FlagSetting fs(StrictSafepointChecks, false); 366 _mutex->lock(); 367 } 368 } 369 370 ~VerifyMutexLocker() { 371 if (!_reentrant) { 372 _mutex->unlock(); 373 } 374 } 375 }; 376 377 #endif 378 379 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP