1/* 2 * Copyright (c) 1997, 2016, 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 33extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code 34extern Monitor* SystemDictionary_lock; // a lock on the system dictionary 35extern Mutex* Module_lock; // a lock on module and package related data structures 36extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access 37extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer 38extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment 39extern Mutex* JNIGlobalHandle_lock; // a lock on creating JNI global handles 40extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list 41extern Mutex* MemberNameTable_lock; // a lock on the MemberNameTable updates 42extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers 43extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers 44extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in 45extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data 46extern Monitor* Heap_lock; // a lock on the heap 47extern Mutex* ExpandHeap_lock; // a lock on expanding the heap 48extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary 49extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary 50extern Mutex* VtableStubs_lock; // a lock on the VtableStubs 51extern Mutex* SymbolTable_lock; // a lock on the symbol table 52extern Mutex* StringTable_lock; // a lock on the interned string table 53extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue 54extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table 55extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx 56extern Mutex* MethodData_lock; // a lock on installation of method data 57extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info 58extern Mutex* RetData_lock; // a lock on installation of RetData inside method data 59extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table 60extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute 61extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate 62extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction 63extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads 64 // (also used by Safepoints too to block threads creation/destruction) 65extern Monitor* CGC_lock; // used for coordination between 66 // fore- & background GC threads. 67extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet. 68extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc 69extern Mutex* SATB_Q_FL_lock; // Protects SATB Q 70 // buffer free list. 71extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q 72 // completed buffer queue. 73extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB 74 // queue shared by 75 // non-Java threads. 76 77extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q 78 // buffer free list. 79extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q 80 // completed buffer queue. 81extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card 82 // queue shared by 83 // non-Java threads. 84extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list. 85extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list. 86extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops. 87extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc) 88extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued 89extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization 90extern Monitor* Compilation_lock; // a lock used to pause compilation 91extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated 92extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics 93extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives 94extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays 95extern Monitor* Terminator_lock; // a lock used to guard termination of the vm 96extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks 97extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm 98extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles 99extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates 100extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues 101 102#ifndef PRODUCT 103extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe 104#endif // PRODUCT 105extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing 106extern Mutex* Debug2_lock; // down synchronization related bugs! 107extern Mutex* Debug3_lock; 108 109extern Mutex* RawMonitor_lock; 110extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data 111extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources 112extern Mutex* ParkerFreeList_lock; 113extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches 114 115extern Mutex* FreeList_lock; // protects the free region list during safepoints 116extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list 117extern Mutex* OldSets_lock; // protects the old region sets 118extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions 119extern Mutex* MMUTracker_lock; // protects the MMU 120 // tracker data structures 121 122extern Mutex* Management_lock; // a lock used to serialize JVM management 123extern Monitor* Service_lock; // a lock used for service thread operation 124extern Monitor* PeriodicTask_lock; // protects the periodic task structure 125extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition 126 127#ifdef INCLUDE_TRACE 128extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table 129extern Monitor* JfrMsg_lock; // protects JFR messaging 130extern Mutex* JfrBuffer_lock; // protects JFR buffer operations 131extern Mutex* JfrStream_lock; // protects JFR stream access 132extern Mutex* JfrThreadGroups_lock; // protects JFR access to Thread Groups 133#endif 134 135#ifndef SUPPORTS_NATIVE_CX8 136extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8 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. 155void print_owned_locks_on_error(outputStream* st); 156 157char *lock_name(Mutex *mutex); 158 159class 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 186void assert_locked_or_safepoint(const Monitor * lock); 187void 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 200class 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 227class 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 279class GCMutexLocker: public StackObj { 280private: 281 Monitor * _mutex; 282 bool _locked; 283public: 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 293class 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 311class 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// 342class 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 367