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* SymbolTable_lock; // a lock on the symbol table 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 133 134 #if INCLUDE_JFR 135 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 136 extern Monitor* JfrMsg_lock; // protects JFR messaging 137 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 138 extern Mutex* JfrStream_lock; // protects JFR stream access 139 #endif 140 141 #ifndef SUPPORTS_NATIVE_CX8 142 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 143 #endif 144 145 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions 146 147 148 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions. 149 // Only used locally in PrintCodeCacheLayout processing. 150 151 // A MutexLocker provides mutual exclusion with respect to a given mutex 152 // for the scope which contains the locker. The lock is an OS lock, not 153 // an object lock, and the two do not interoperate. Do not use Mutex-based 154 // locks to lock on Java objects, because they will not be respected if a 155 // that object is locked using the Java locking mechanism. 156 // 157 // NOTE WELL!! 158 // 159 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 160 // and friends constructors do a fence, a lock and an acquire *in that 161 // order*. And that their destructors do a release and unlock, in *that* 162 // order. If their implementations change such that these assumptions 163 // are violated, a whole lot of code will break. 164 165 // Print all mutexes/monitors that are currently owned by a thread; called 166 // by fatal error handler. 167 void print_owned_locks_on_error(outputStream* st); 168 169 char *lock_name(Mutex *mutex); 170 171 class MutexLocker: StackObj { 172 private: 173 Monitor * _mutex; 174 public: 175 MutexLocker(Monitor * mutex) { 176 assert(mutex->rank() != Mutex::special, 177 "Special ranked mutex should only use MutexLockerEx"); 178 _mutex = mutex; 179 _mutex->lock(); 180 } 181 182 // Overloaded constructor passing current thread 183 MutexLocker(Monitor * mutex, Thread *thread) { 184 assert(mutex->rank() != Mutex::special, 185 "Special ranked mutex should only use MutexLockerEx"); 186 _mutex = mutex; 187 _mutex->lock(thread); 188 } 189 190 ~MutexLocker() { 191 _mutex->unlock(); 192 } 193 194 }; 195 196 // for debugging: check that we're already owning this lock (or are at a safepoint) 197 #ifdef ASSERT 198 void assert_locked_or_safepoint(const Monitor * lock); 199 void assert_lock_strong(const Monitor * lock); 200 #else 201 #define assert_locked_or_safepoint(lock) 202 #define assert_lock_strong(lock) 203 #endif 204 205 // A MutexLockerEx behaves like a MutexLocker when its constructor is 206 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 207 // called with NULL, in which case the MutexLockerEx is a no-op. There 208 // is also a corresponding MutexUnlockerEx. We want to keep the 209 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 210 // without safepoint check. 211 212 class MutexLockerEx: public StackObj { 213 private: 214 Monitor * _mutex; 215 public: 216 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 217 _mutex = mutex; 218 if (_mutex != NULL) { 219 assert(mutex->rank() > Mutex::special || no_safepoint_check, 220 "Mutexes with rank special or lower should not do safepoint checks"); 221 if (no_safepoint_check) 222 _mutex->lock_without_safepoint_check(); 223 else 224 _mutex->lock(); 225 } 226 } 227 228 ~MutexLockerEx() { 229 if (_mutex != NULL) { 230 _mutex->unlock(); 231 } 232 } 233 }; 234 235 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 236 // a possibly null Monitor, and allows wait/notify as well which are 237 // delegated to the underlying Monitor. 238 239 class MonitorLockerEx: public MutexLockerEx { 240 private: 241 Monitor * _monitor; 242 public: 243 MonitorLockerEx(Monitor* monitor, 244 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 245 MutexLockerEx(monitor, no_safepoint_check), 246 _monitor(monitor) { 247 // Superclass constructor did locking 248 } 249 250 ~MonitorLockerEx() { 251 #ifdef ASSERT 252 if (_monitor != NULL) { 253 assert_lock_strong(_monitor); 254 } 255 #endif // ASSERT 256 // Superclass destructor will do unlocking 257 } 258 259 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 260 long timeout = 0, 261 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 262 if (_monitor != NULL) { 263 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 264 } 265 return false; 266 } 267 268 bool notify_all() { 269 if (_monitor != NULL) { 270 return _monitor->notify_all(); 271 } 272 return true; 273 } 274 275 bool notify() { 276 if (_monitor != NULL) { 277 return _monitor->notify(); 278 } 279 return true; 280 } 281 }; 282 283 284 285 // A GCMutexLocker is usually initialized with a mutex that is 286 // automatically acquired in order to do GC. The function that 287 // synchronizes using a GCMutexLocker may be called both during and between 288 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 289 // if GC is in progress (since the mutex is already held on its behalf.) 290 291 class GCMutexLocker: public StackObj { 292 private: 293 Monitor * _mutex; 294 bool _locked; 295 public: 296 GCMutexLocker(Monitor * mutex); 297 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 298 }; 299 300 301 302 // A MutexUnlocker temporarily exits a previously 303 // entered mutex for the scope which contains the unlocker. 304 305 class MutexUnlocker: StackObj { 306 private: 307 Monitor * _mutex; 308 309 public: 310 MutexUnlocker(Monitor * mutex) { 311 _mutex = mutex; 312 _mutex->unlock(); 313 } 314 315 ~MutexUnlocker() { 316 _mutex->lock(); 317 } 318 }; 319 320 // A MutexUnlockerEx temporarily exits a previously 321 // entered mutex for the scope which contains the unlocker. 322 323 class MutexUnlockerEx: StackObj { 324 private: 325 Monitor * _mutex; 326 bool _no_safepoint_check; 327 328 public: 329 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 330 _mutex = mutex; 331 _no_safepoint_check = no_safepoint_check; 332 _mutex->unlock(); 333 } 334 335 ~MutexUnlockerEx() { 336 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 337 _mutex->lock_without_safepoint_check(); 338 } else { 339 _mutex->lock(); 340 } 341 } 342 }; 343 344 #ifndef PRODUCT 345 // 346 // A special MutexLocker that allows: 347 // - reentrant locking 348 // - locking out of order 349 // 350 // Only to be used for verify code, where we can relax out dead-lock 351 // detection code a bit (unsafe, but probably ok). This code is NEVER to 352 // be included in a product version. 353 // 354 class VerifyMutexLocker: StackObj { 355 private: 356 Monitor * _mutex; 357 bool _reentrant; 358 public: 359 VerifyMutexLocker(Monitor * mutex) { 360 _mutex = mutex; 361 _reentrant = mutex->owned_by_self(); 362 if (!_reentrant) { 363 // We temp. disable strict safepoint checking, while we require the lock 364 FlagSetting fs(StrictSafepointChecks, false); 365 _mutex->lock(); 366 } 367 } 368 369 ~VerifyMutexLocker() { 370 if (!_reentrant) { 371 _mutex->unlock(); 372 } 373 } 374 }; 375 376 #endif 377 378 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP