1 /* 2 * Copyright (c) 1997, 2010, 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 #ifdef TARGET_OS_FAMILY_linux 31 # include "os_linux.inline.hpp" 32 #endif 33 #ifdef TARGET_OS_FAMILY_solaris 34 # include "os_solaris.inline.hpp" 35 #endif 36 #ifdef TARGET_OS_FAMILY_windows 37 # include "os_windows.inline.hpp" 38 #endif 39 40 // Mutexes used in the VM. 41 42 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code 43 extern Monitor* SystemDictionary_lock; // a lock on the system dictonary 44 extern Mutex* PackageTable_lock; // a lock on the class loader package table 45 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 46 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 47 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 48 extern Mutex* JNIGlobalHandle_lock; // a lock on creating JNI global handles 49 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 50 extern Mutex* JNICachedItableIndex_lock; // a lock on caching an itable index during JNI invoke 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* JvmtiPendingEvent_lock; // a lock on the JVMTI pending events list 56 extern Monitor* Heap_lock; // a lock on the heap 57 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 58 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 59 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 60 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 61 extern Mutex* SymbolTable_lock; // a lock on the symbol table 62 extern Mutex* StringTable_lock; // a lock on the interned string table 63 extern Mutex* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx 64 extern Mutex* MethodData_lock; // a lock on installation of method data 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* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute 68 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate 69 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction 70 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads 71 // (also used by Safepoints too to block threads creation/destruction) 72 extern Monitor* CGC_lock; // used for coordination between 73 // fore- & background GC threads. 74 extern Mutex* STS_init_lock; // coordinate initialization of SuspendibleThreadSets. 75 extern Monitor* SLT_lock; // used in CMS GC for acquiring PLL 76 extern Monitor* iCMS_lock; // CMS incremental mode start/stop notification 77 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 78 extern Monitor* CMark_lock; // used for concurrent mark thread coordination 79 extern Monitor* ZF_mon; // used for G1 conc zero-fill. 80 extern Monitor* Cleanup_mon; // used for G1 conc cleanup. 81 extern Mutex* CMRegionStack_lock; // used for protecting accesses to the CM region stack 82 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q 83 // buffer free list. 84 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q 85 // completed buffer queue. 86 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB 87 // queue shared by 88 // non-Java threads. 89 90 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q 91 // buffer free list. 92 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 93 // completed buffer queue. 94 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 95 // queue shared by 96 // non-Java threads. 97 // (see option ExplicitGCInvokesConcurrent) 98 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 99 extern Mutex* EvacFailureStack_lock; // guards the evac failure scan stack 100 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 101 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 102 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 103 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 104 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 105 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 106 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 107 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 108 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 109 extern Monitor* Interrupt_lock; // a lock used for condition variable mediated interrupt processing 110 extern Monitor* ProfileVM_lock; // a lock used for profiling the VMThread 111 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 112 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 113 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 114 115 #ifndef PRODUCT 116 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 117 #endif 118 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 119 extern Mutex* Debug2_lock; // down synchronization related bugs! 120 extern Mutex* Debug3_lock; 121 122 extern Mutex* RawMonitor_lock; 123 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 124 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 125 extern Mutex* ParkerFreeList_lock; 126 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 127 128 extern Mutex* MMUTracker_lock; // protects the MMU 129 // tracker data structures 130 extern Mutex* HotCardCache_lock; // protects the hot card cache 131 132 extern Mutex* Management_lock; // a lock used to serialize JVM management 133 extern Monitor* LowMemory_lock; // a lock used for low memory detection 134 135 // A MutexLocker provides mutual exclusion with respect to a given mutex 136 // for the scope which contains the locker. The lock is an OS lock, not 137 // an object lock, and the two do not interoperate. Do not use Mutex-based 138 // locks to lock on Java objects, because they will not be respected if a 139 // that object is locked using the Java locking mechanism. 140 // 141 // NOTE WELL!! 142 // 143 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's 144 // and friends constructors do a fence, a lock and an acquire *in that 145 // order*. And that their destructors do a release and unlock, in *that* 146 // order. If their implementations change such that these assumptions 147 // are violated, a whole lot of code will break. 148 149 // Print all mutexes/monitors that are currently owned by a thread; called 150 // by fatal error handler. 151 void print_owned_locks_on_error(outputStream* st); 152 153 char *lock_name(Mutex *mutex); 154 155 class MutexLocker: StackObj { 156 private: 157 Monitor * _mutex; 158 public: 159 MutexLocker(Monitor * mutex) { 160 assert(mutex->rank() != Mutex::special, 161 "Special ranked mutex should only use MutexLockerEx"); 162 _mutex = mutex; 163 _mutex->lock(); 164 } 165 166 // Overloaded constructor passing current thread 167 MutexLocker(Monitor * mutex, Thread *thread) { 168 assert(mutex->rank() != Mutex::special, 169 "Special ranked mutex should only use MutexLockerEx"); 170 _mutex = mutex; 171 _mutex->lock(thread); 172 } 173 174 ~MutexLocker() { 175 _mutex->unlock(); 176 } 177 178 }; 179 180 // for debugging: check that we're already owning this lock (or are at a safepoint) 181 #ifdef ASSERT 182 void assert_locked_or_safepoint(const Monitor * lock); 183 void assert_lock_strong(const Monitor * lock); 184 #else 185 #define assert_locked_or_safepoint(lock) 186 #define assert_lock_strong(lock) 187 #endif 188 189 // A MutexLockerEx behaves like a MutexLocker when its constructor is 190 // called with a Mutex. Unlike a MutexLocker, its constructor can also be 191 // called with NULL, in which case the MutexLockerEx is a no-op. There 192 // is also a corresponding MutexUnlockerEx. We want to keep the 193 // basic MutexLocker as fast as possible. MutexLockerEx can also lock 194 // without safepoint check. 195 196 class MutexLockerEx: public StackObj { 197 private: 198 Monitor * _mutex; 199 public: 200 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 201 _mutex = mutex; 202 if (_mutex != NULL) { 203 assert(mutex->rank() > Mutex::special || no_safepoint_check, 204 "Mutexes with rank special or lower should not do safepoint checks"); 205 if (no_safepoint_check) 206 _mutex->lock_without_safepoint_check(); 207 else 208 _mutex->lock(); 209 } 210 } 211 212 ~MutexLockerEx() { 213 if (_mutex != NULL) { 214 _mutex->unlock(); 215 } 216 } 217 }; 218 219 // A MonitorLockerEx is like a MutexLockerEx above, except it takes 220 // a possibly null Monitor, and allows wait/notify as well which are 221 // delegated to the underlying Monitor. 222 223 class MonitorLockerEx: public MutexLockerEx { 224 private: 225 Monitor * _monitor; 226 public: 227 MonitorLockerEx(Monitor* monitor, 228 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag): 229 MutexLockerEx(monitor, no_safepoint_check), 230 _monitor(monitor) { 231 // Superclass constructor did locking 232 } 233 234 ~MonitorLockerEx() { 235 #ifdef ASSERT 236 if (_monitor != NULL) { 237 assert_lock_strong(_monitor); 238 } 239 #endif // ASSERT 240 // Superclass destructor will do unlocking 241 } 242 243 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag, 244 long timeout = 0, 245 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) { 246 if (_monitor != NULL) { 247 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent); 248 } 249 return false; 250 } 251 252 bool notify_all() { 253 if (_monitor != NULL) { 254 return _monitor->notify_all(); 255 } 256 return true; 257 } 258 259 bool notify() { 260 if (_monitor != NULL) { 261 return _monitor->notify(); 262 } 263 return true; 264 } 265 }; 266 267 268 269 // A GCMutexLocker is usually initialized with a mutex that is 270 // automatically acquired in order to do GC. The function that 271 // synchronizes using a GCMutexLocker may be called both during and between 272 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not 273 // if GC is in progress (since the mutex is already held on its behalf.) 274 275 class GCMutexLocker: public StackObj { 276 private: 277 Monitor * _mutex; 278 bool _locked; 279 public: 280 GCMutexLocker(Monitor * mutex); 281 ~GCMutexLocker() { if (_locked) _mutex->unlock(); } 282 }; 283 284 285 286 // A MutexUnlocker temporarily exits a previously 287 // entered mutex for the scope which contains the unlocker. 288 289 class MutexUnlocker: StackObj { 290 private: 291 Monitor * _mutex; 292 293 public: 294 MutexUnlocker(Monitor * mutex) { 295 _mutex = mutex; 296 _mutex->unlock(); 297 } 298 299 ~MutexUnlocker() { 300 _mutex->lock(); 301 } 302 }; 303 304 // A MutexUnlockerEx temporarily exits a previously 305 // entered mutex for the scope which contains the unlocker. 306 307 class MutexUnlockerEx: StackObj { 308 private: 309 Monitor * _mutex; 310 bool _no_safepoint_check; 311 312 public: 313 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) { 314 _mutex = mutex; 315 _no_safepoint_check = no_safepoint_check; 316 _mutex->unlock(); 317 } 318 319 ~MutexUnlockerEx() { 320 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) { 321 _mutex->lock_without_safepoint_check(); 322 } else { 323 _mutex->lock(); 324 } 325 } 326 }; 327 328 #ifndef PRODUCT 329 // 330 // A special MutexLocker that allows: 331 // - reentrant locking 332 // - locking out of order 333 // 334 // Only too be used for verify code, where we can relaxe out dead-lock 335 // dection code a bit (unsafe, but probably ok). This code is NEVER to 336 // be included in a product version. 337 // 338 class VerifyMutexLocker: StackObj { 339 private: 340 Monitor * _mutex; 341 bool _reentrant; 342 public: 343 VerifyMutexLocker(Monitor * mutex) { 344 _mutex = mutex; 345 _reentrant = mutex->owned_by_self(); 346 if (!_reentrant) { 347 // We temp. diable strict safepoint checking, while we require the lock 348 FlagSetting fs(StrictSafepointChecks, false); 349 _mutex->lock(); 350 } 351 } 352 353 ~VerifyMutexLocker() { 354 if (!_reentrant) { 355 _mutex->unlock(); 356 } 357 } 358 }; 359 360 #endif 361 362 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP