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