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
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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* InitCompleted_lock; // a lock used to signal threads waiting on init completed
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 Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
110 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
111 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
112
113 #ifndef PRODUCT
114 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
115 #endif // PRODUCT
116 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
117 extern Mutex* Debug2_lock; // down synchronization related bugs!
118 extern Mutex* Debug3_lock;
119
120 extern Mutex* RawMonitor_lock;
121 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
122 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
123 extern Mutex* ParkerFreeList_lock;
124 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
125
126 extern Mutex* FreeList_lock; // protects the free region list during safepoints
127 extern Mutex* OldSets_lock; // protects the old region sets
128 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
129
130 extern Mutex* Management_lock; // a lock used to serialize JVM management
131 extern Monitor* Service_lock; // a lock used for service thread operation
132 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
133 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
134 extern Mutex* ThreadHeapSampler_lock; // protects the static data for initialization.
135
136 #if INCLUDE_JFR
137 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
138 extern Monitor* JfrMsg_lock; // protects JFR messaging
139 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
140 extern Mutex* JfrStream_lock; // protects JFR stream access
141 #endif
142
143 #ifndef SUPPORTS_NATIVE_CX8
144 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
145 #endif
146
147 extern Mutex* MetaspaceExpand_lock; // protects Metaspace virtualspace and chunk expansions
148
149
150 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions.
151 // Only used locally in PrintCodeCacheLayout processing.
152
153 // A MutexLocker provides mutual exclusion with respect to a given mutex
154 // for the scope which contains the locker. The lock is an OS lock, not
155 // an object lock, and the two do not interoperate. Do not use Mutex-based
156 // locks to lock on Java objects, because they will not be respected if a
157 // that object is locked using the Java locking mechanism.
158 //
159 // NOTE WELL!!
160 //
161 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
162 // and friends constructors do a fence, a lock and an acquire *in that
163 // order*. And that their destructors do a release and unlock, in *that*
164 // order. If their implementations change such that these assumptions
165 // are violated, a whole lot of code will break.
166
167 // Print all mutexes/monitors that are currently owned by a thread; called
168 // by fatal error handler.
169 void print_owned_locks_on_error(outputStream* st);
170
171 char *lock_name(Mutex *mutex);
172
173 class MutexLocker: StackObj {
174 private:
175 Monitor * _mutex;
176 public:
177 MutexLocker(Monitor * mutex) {
178 assert(mutex->rank() != Mutex::special,
179 "Special ranked mutex should only use MutexLockerEx");
180 _mutex = mutex;
181 _mutex->lock();
182 }
183
184 // Overloaded constructor passing current thread
185 MutexLocker(Monitor * mutex, Thread *thread) {
186 assert(mutex->rank() != Mutex::special,
187 "Special ranked mutex should only use MutexLockerEx");
188 _mutex = mutex;
189 _mutex->lock(thread);
190 }
191
192 ~MutexLocker() {
193 _mutex->unlock();
194 }
195
196 };
197
198 // for debugging: check that we're already owning this lock (or are at a safepoint)
199 #ifdef ASSERT
200 void assert_locked_or_safepoint(const Monitor * lock);
201 void assert_lock_strong(const Monitor * lock);
202 #else
203 #define assert_locked_or_safepoint(lock)
204 #define assert_lock_strong(lock)
205 #endif
206
207 // A MutexLockerEx behaves like a MutexLocker when its constructor is
208 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
209 // called with NULL, in which case the MutexLockerEx is a no-op. There
210 // is also a corresponding MutexUnlockerEx. We want to keep the
211 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
212 // without safepoint check.
213
214 class MutexLockerEx: public StackObj {
215 private:
216 Monitor * _mutex;
217 public:
218 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
219 _mutex = mutex;
220 if (_mutex != NULL) {
221 assert(mutex->rank() > Mutex::special || no_safepoint_check,
222 "Mutexes with rank special or lower should not do safepoint checks");
223 if (no_safepoint_check)
224 _mutex->lock_without_safepoint_check();
225 else
226 _mutex->lock();
227 }
228 }
229
230 ~MutexLockerEx() {
231 if (_mutex != NULL) {
232 _mutex->unlock();
233 }
234 }
235 };
236
237 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
238 // a possibly null Monitor, and allows wait/notify as well which are
239 // delegated to the underlying Monitor.
240
241 class MonitorLockerEx: public MutexLockerEx {
242 private:
243 Monitor * _monitor;
244 public:
245 MonitorLockerEx(Monitor* monitor,
246 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
247 MutexLockerEx(monitor, no_safepoint_check),
248 _monitor(monitor) {
249 // Superclass constructor did locking
250 }
251
252 ~MonitorLockerEx() {
253 #ifdef ASSERT
254 if (_monitor != NULL) {
255 assert_lock_strong(_monitor);
256 }
257 #endif // ASSERT
258 // Superclass destructor will do unlocking
259 }
260
261 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
262 long timeout = 0,
263 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
264 if (_monitor != NULL) {
265 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
266 }
267 return false;
268 }
269
270 bool notify_all() {
271 if (_monitor != NULL) {
272 return _monitor->notify_all();
273 }
274 return true;
275 }
276
277 bool notify() {
278 if (_monitor != NULL) {
279 return _monitor->notify();
280 }
281 return true;
282 }
283 };
284
285
286
287 // A GCMutexLocker is usually initialized with a mutex that is
288 // automatically acquired in order to do GC. The function that
289 // synchronizes using a GCMutexLocker may be called both during and between
290 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
291 // if GC is in progress (since the mutex is already held on its behalf.)
292
293 class GCMutexLocker: public StackObj {
294 private:
295 Monitor * _mutex;
296 bool _locked;
297 public:
298 GCMutexLocker(Monitor * mutex);
299 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
300 };
301
302
303
304 // A MutexUnlocker temporarily exits a previously
305 // entered mutex for the scope which contains the unlocker.
306
307 class MutexUnlocker: StackObj {
308 private:
309 Monitor * _mutex;
310
311 public:
312 MutexUnlocker(Monitor * mutex) {
313 _mutex = mutex;
314 _mutex->unlock();
315 }
316
317 ~MutexUnlocker() {
318 _mutex->lock();
319 }
320 };
321
322 // A MutexUnlockerEx temporarily exits a previously
323 // entered mutex for the scope which contains the unlocker.
324
325 class MutexUnlockerEx: StackObj {
326 private:
327 Monitor * _mutex;
328 bool _no_safepoint_check;
329
330 public:
331 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
332 _mutex = mutex;
333 _no_safepoint_check = no_safepoint_check;
334 _mutex->unlock();
335 }
336
337 ~MutexUnlockerEx() {
338 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
339 _mutex->lock_without_safepoint_check();
340 } else {
341 _mutex->lock();
342 }
343 }
344 };
345
346 #ifndef PRODUCT
347 //
348 // A special MutexLocker that allows:
349 // - reentrant locking
350 // - locking out of order
351 //
352 // Only to be used for verify code, where we can relax out dead-lock
353 // detection code a bit (unsafe, but probably ok). This code is NEVER to
354 // be included in a product version.
355 //
356 class VerifyMutexLocker: StackObj {
357 private:
358 Monitor * _mutex;
359 bool _reentrant;
360 public:
361 VerifyMutexLocker(Monitor * mutex) {
362 _mutex = mutex;
363 _reentrant = mutex->owned_by_self();
364 if (!_reentrant) {
365 // We temp. disable strict safepoint checking, while we require the lock
366 FlagSetting fs(StrictSafepointChecks, false);
367 _mutex->lock();
368 }
369 }
370
371 ~VerifyMutexLocker() {
372 if (!_reentrant) {
373 _mutex->unlock();
374 }
375 }
376 };
377
378 #endif
379
380 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP