1 /* 2 * Copyright (c) 1997, 2014, 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/mutex.hpp" 30 31 // Mutexes used in the VM. 32 33 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code 34 extern Monitor* SystemDictionary_lock; // a lock on the system dictionary 35 extern Mutex* PackageTable_lock; // a lock on the class loader package table 36 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 37 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 38 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 39 extern Mutex* JNIGlobalHandle_lock; // a lock on creating JNI global handles 40 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 41 extern Mutex* MemberNameTable_lock; // a lock on the MemberNameTable updates 42 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers 43 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers 44 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in 45 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data 46 extern Monitor* JvmtiPendingEvent_lock; // a lock on the JVMTI pending events list 47 extern Monitor* Heap_lock; // a lock on the heap 48 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 49 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 50 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 51 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 52 extern Mutex* SymbolTable_lock; // a lock on the symbol table 53 extern Mutex* StringTable_lock; // a lock on the interned string table 54 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue 55 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table 56 extern Mutex* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx 57 extern Mutex* MethodData_lock; // a lock on installation of method data 58 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 59 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table 60 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute 61 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate 62 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction 63 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads 64 // (also used by Safepoints too to block threads creation/destruction) 65 extern Monitor* CGC_lock; // used for coordination between 66 // fore- & background GC threads. 67 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 68 extern Monitor* SLT_lock; // used in CMS GC for acquiring PLL 69 extern Monitor* iCMS_lock; // CMS incremental mode start/stop notification 70 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 71 extern Monitor* CMark_lock; // used for concurrent mark thread coordination 72 extern Mutex* CMRegionStack_lock; // used for protecting accesses to the CM region stack 73 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q 74 // buffer free list. 75 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q 76 // completed buffer queue. 77 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB 78 // queue shared by 79 // non-Java threads. 80 81 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q 82 // buffer free list. 83 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 84 // completed buffer queue. 85 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 86 // queue shared by 87 // non-Java threads. 88 // (see option ExplicitGCInvokesConcurrent) 89 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 90 extern Mutex* EvacFailureStack_lock; // guards the evac failure scan stack 91 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 92 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 93 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 94 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 95 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 96 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 97 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 98 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 99 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 100 extern Monitor* Interrupt_lock; // a lock used for condition variable mediated interrupt processing 101 extern Monitor* ProfileVM_lock; // a lock used for profiling the VMThread 102 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 103 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 104 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 105 106 #ifndef PRODUCT 107 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 108 #endif // PRODUCT 109 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 110 extern Mutex* Debug2_lock; // down synchronization related bugs! 111 extern Mutex* Debug3_lock; 112 113 extern Mutex* RawMonitor_lock; 114 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 115 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 116 extern Mutex* ParkerFreeList_lock; 117 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 118 119 extern Mutex* FreeList_lock; // protects the free region list during safepoints 120 extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list 121 extern Mutex* OldSets_lock; // protects the old region sets 122 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 123 extern Mutex* MMUTracker_lock; // protects the MMU 124 // tracker data structures 125 extern Mutex* HotCardCache_lock; // protects the hot card cache 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 130 131 #ifdef INCLUDE_TRACE 132 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 133 extern Monitor* JfrMsg_lock; // protects JFR messaging 134 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 135 extern Mutex* JfrStream_lock; // protects JFR stream access 136 extern Mutex* JfrThreadGroups_lock; // protects JFR access to Thread Groups 137 #endif 138 139 // A MutexLocker provides mutual exclusion with respect to a given mutex 140 // for the scope which contains the locker. The lock is an OS lock, not 141 // an object lock, and the two do not interoperate. Do not use Mutex-based 142 // locks to lock on Java objects, because they will not be respected if a 143 // that object is locked using the Java locking mechanism. 144 // 145 // NOTE WELL!! 146 // 147 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 148 // and friends constructors do a fence, a lock and an acquire *in that 149 // order*. And that their destructors do a release and unlock, in *that* 150 // order. If their implementations change such that these assumptions 151 // are violated, a whole lot of code will break. 152 153 // Print all mutexes/monitors that are currently owned by a thread; called 154 // by fatal error handler. 155 void print_owned_locks_on_error(outputStream* st); 156 157 char *lock_name(Mutex *mutex); 158 159 class MutexLocker: StackObj { 160 private: 161 Monitor * _mutex; 162 public: 163 MutexLocker(Monitor * mutex) { 164 assert(mutex->rank() != Mutex::special, 165 "Special ranked mutex should only use MutexLockerEx"); 166 _mutex = mutex; 167 _mutex->lock(); 168 } 169 170 // Overloaded constructor passing current thread 171 MutexLocker(Monitor * mutex, Thread *thread) { 172 assert(mutex->rank() != Mutex::special, 173 "Special ranked mutex should only use MutexLockerEx"); 174 _mutex = mutex; 175 _mutex->lock(thread); 176 } 177 178 ~MutexLocker() { 179 _mutex->unlock(); 180 } 181 182 }; 183 184 // for debugging: check that we're already owning this lock (or are at a safepoint) 185 #ifdef ASSERT 186 void assert_locked_or_safepoint(const Monitor * lock); 187 void assert_lock_strong(const Monitor * lock); 188 #else 189 #define assert_locked_or_safepoint(lock) 190 #define assert_lock_strong(lock) 191 #endif 192 193 // A MutexLockerEx behaves like a MutexLocker when its constructor is 194 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 195 // called with NULL, in which case the MutexLockerEx is a no-op. There 196 // is also a corresponding MutexUnlockerEx. We want to keep the 197 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 198 // without safepoint check. 199 200 class MutexLockerEx: public StackObj { 201 private: 202 Monitor * _mutex; 203 public: 204 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 205 _mutex = mutex; 206 if (_mutex != NULL) { 207 assert(mutex->rank() > Mutex::special || no_safepoint_check, 208 "Mutexes with rank special or lower should not do safepoint checks"); 209 if (no_safepoint_check) 210 _mutex->lock_without_safepoint_check(); 211 else 212 _mutex->lock(); 213 } 214 } 215 216 ~MutexLockerEx() { 217 if (_mutex != NULL) { 218 _mutex->unlock(); 219 } 220 } 221 }; 222 223 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 224 // a possibly null Monitor, and allows wait/notify as well which are 225 // delegated to the underlying Monitor. 226 227 class MonitorLockerEx: public MutexLockerEx { 228 private: 229 Monitor * _monitor; 230 public: 231 MonitorLockerEx(Monitor* monitor, 232 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 233 MutexLockerEx(monitor, no_safepoint_check), 234 _monitor(monitor) { 235 // Superclass constructor did locking 236 } 237 238 ~MonitorLockerEx() { 239 #ifdef ASSERT 240 if (_monitor != NULL) { 241 assert_lock_strong(_monitor); 242 } 243 #endif // ASSERT 244 // Superclass destructor will do unlocking 245 } 246 247 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 248 long timeout = 0, 249 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 250 if (_monitor != NULL) { 251 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 252 } 253 return false; 254 } 255 256 bool notify_all() { 257 if (_monitor != NULL) { 258 return _monitor->notify_all(); 259 } 260 return true; 261 } 262 263 bool notify() { 264 if (_monitor != NULL) { 265 return _monitor->notify(); 266 } 267 return true; 268 } 269 }; 270 271 272 273 // A GCMutexLocker is usually initialized with a mutex that is 274 // automatically acquired in order to do GC. The function that 275 // synchronizes using a GCMutexLocker may be called both during and between 276 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 277 // if GC is in progress (since the mutex is already held on its behalf.) 278 279 class GCMutexLocker: public StackObj { 280 private: 281 Monitor * _mutex; 282 bool _locked; 283 public: 284 GCMutexLocker(Monitor * mutex); 285 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 286 }; 287 288 289 290 // A MutexUnlocker temporarily exits a previously 291 // entered mutex for the scope which contains the unlocker. 292 293 class MutexUnlocker: StackObj { 294 private: 295 Monitor * _mutex; 296 297 public: 298 MutexUnlocker(Monitor * mutex) { 299 _mutex = mutex; 300 _mutex->unlock(); 301 } 302 303 ~MutexUnlocker() { 304 _mutex->lock(); 305 } 306 }; 307 308 // A MutexUnlockerEx temporarily exits a previously 309 // entered mutex for the scope which contains the unlocker. 310 311 class MutexUnlockerEx: StackObj { 312 private: 313 Monitor * _mutex; 314 bool _no_safepoint_check; 315 316 public: 317 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 318 _mutex = mutex; 319 _no_safepoint_check = no_safepoint_check; 320 _mutex->unlock(); 321 } 322 323 ~MutexUnlockerEx() { 324 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 325 _mutex->lock_without_safepoint_check(); 326 } else { 327 _mutex->lock(); 328 } 329 } 330 }; 331 332 #ifndef PRODUCT 333 // 334 // A special MutexLocker that allows: 335 // - reentrant locking 336 // - locking out of order 337 // 338 // Only to be used for verify code, where we can relax out dead-lock 339 // detection code a bit (unsafe, but probably ok). This code is NEVER to 340 // be included in a product version. 341 // 342 class VerifyMutexLocker: StackObj { 343 private: 344 Monitor * _mutex; 345 bool _reentrant; 346 public: 347 VerifyMutexLocker(Monitor * mutex) { 348 _mutex = mutex; 349 _reentrant = mutex->owned_by_self(); 350 if (!_reentrant) { 351 // We temp. disable strict safepoint checking, while we require the lock 352 FlagSetting fs(StrictSafepointChecks, false); 353 _mutex->lock(); 354 } 355 } 356 357 ~VerifyMutexLocker() { 358 if (!_reentrant) { 359 _mutex->unlock(); 360 } 361 } 362 }; 363 364 #endif 365 366 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP