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,
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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* SymbolArena_lock; // a lock on the symbol table arena
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 Mutex* NonJavaThreadsList_lock; // a lock on the NonJavaThreads list
76 extern Monitor* CGC_lock; // used for coordination between
77 // fore- & background GC threads.
78 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
79 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
80 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q
81 // buffer free list.
82 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q
83 // completed buffer queue.
84 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB
85 // queue shared by
86 // non-Java threads.
87
88 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q
89 // buffer free list.
90 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q
91 // completed buffer queue.
92 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card
93 // queue shared by
94 // non-Java threads.
95 extern Mutex* MarkStackFreeList_lock; // Protects access to the global mark stack free list.
96 extern Mutex* MarkStackChunkList_lock; // Protects access to the global mark stack chunk list.
97 extern Mutex* MonitoringSupport_lock; // Protects updates to the serviceability memory pools.
98 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops.
99 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
100 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
101 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
102 extern Monitor* Compilation_lock; // a lock used to pause compilation
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* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
106 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
107 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
108 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
109 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
110 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
111 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
112 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
113
114 #ifndef PRODUCT
115 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
116 #endif // PRODUCT
117 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
118 extern Mutex* Debug2_lock; // down synchronization related bugs!
119 extern Mutex* Debug3_lock;
120
121 extern Mutex* RawMonitor_lock;
122 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
123 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
124 extern Mutex* ParkerFreeList_lock;
125 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
126
127 extern Mutex* FreeList_lock; // protects the free region list during safepoints
128 extern Mutex* OldSets_lock; // protects the old region sets
129 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
130
131 extern Mutex* Management_lock; // a lock used to serialize JVM management
132 extern Monitor* Service_lock; // a lock used for service thread operation
133 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
134 extern Monitor* RedefineClasses_lock; // locks classes from parallel redefinition
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 extern Mutex* ClassLoaderDataGraph_lock; // protects CLDG list, needed for concurrent unloading
149
150
151 extern Monitor* CodeHeapStateAnalytics_lock; // lock print functions against concurrent analyze functions.
152 // Only used locally in PrintCodeCacheLayout processing.
153
154 // A MutexLocker provides mutual exclusion with respect to a given mutex
155 // for the scope which contains the locker. The lock is an OS lock, not
156 // an object lock, and the two do not interoperate. Do not use Mutex-based
157 // locks to lock on Java objects, because they will not be respected if a
158 // that object is locked using the Java locking mechanism.
159 //
160 // NOTE WELL!!
161 //
162 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
163 // and friends constructors do a fence, a lock and an acquire *in that
164 // order*. And that their destructors do a release and unlock, in *that*
165 // order. If their implementations change such that these assumptions
166 // are violated, a whole lot of code will break.
167
168 // Print all mutexes/monitors that are currently owned by a thread; called
169 // by fatal error handler.
170 void print_owned_locks_on_error(outputStream* st);
171
172 char *lock_name(Mutex *mutex);
173
174 class MutexLocker: StackObj {
175 private:
176 Monitor * _mutex;
177 public:
178 MutexLocker(Monitor * mutex) {
179 assert(mutex->rank() != Mutex::special,
180 "Special ranked mutex should only use MutexLockerEx");
181 _mutex = mutex;
182 _mutex->lock();
183 }
184
185 // Overloaded constructor passing current thread
186 MutexLocker(Monitor * mutex, Thread *thread) {
187 assert(mutex->rank() != Mutex::special,
188 "Special ranked mutex should only use MutexLockerEx");
189 _mutex = mutex;
190 _mutex->lock(thread);
191 }
192
193 ~MutexLocker() {
194 _mutex->unlock();
195 }
196
197 };
198
199 // for debugging: check that we're already owning this lock (or are at a safepoint)
200 #ifdef ASSERT
201 void assert_locked_or_safepoint(const Monitor * lock);
202 void assert_lock_strong(const Monitor * lock);
203 #else
204 #define assert_locked_or_safepoint(lock)
205 #define assert_lock_strong(lock)
206 #endif
207
208 // A MutexLockerEx behaves like a MutexLocker when its constructor is
209 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
210 // called with NULL, in which case the MutexLockerEx is a no-op. There
211 // is also a corresponding MutexUnlockerEx. We want to keep the
212 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
213 // without safepoint check.
214
215 class MutexLockerEx: public StackObj {
216 private:
217 Monitor * _mutex;
218 public:
219 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
220 _mutex = mutex;
221 if (_mutex != NULL) {
222 assert(mutex->rank() > Mutex::special || no_safepoint_check,
223 "Mutexes with rank special or lower should not do safepoint checks");
224 if (no_safepoint_check)
225 _mutex->lock_without_safepoint_check();
226 else
227 _mutex->lock();
228 }
229 }
230
231 ~MutexLockerEx() {
232 if (_mutex != NULL) {
233 _mutex->unlock();
234 }
235 }
236 };
237
238 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
239 // a possibly null Monitor, and allows wait/notify as well which are
240 // delegated to the underlying Monitor.
241
242 class MonitorLockerEx: public MutexLockerEx {
243 private:
244 Monitor * _monitor;
245 public:
246 MonitorLockerEx(Monitor* monitor,
247 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
248 MutexLockerEx(monitor, no_safepoint_check),
249 _monitor(monitor) {
250 // Superclass constructor did locking
251 }
252
253 ~MonitorLockerEx() {
254 #ifdef ASSERT
255 if (_monitor != NULL) {
256 assert_lock_strong(_monitor);
257 }
258 #endif // ASSERT
259 // Superclass destructor will do unlocking
260 }
261
262 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
263 long timeout = 0,
264 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
265 if (_monitor != NULL) {
266 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
267 }
268 return false;
269 }
270
271 bool notify_all() {
272 if (_monitor != NULL) {
273 return _monitor->notify_all();
274 }
275 return true;
276 }
277
278 bool notify() {
279 if (_monitor != NULL) {
280 return _monitor->notify();
281 }
282 return true;
283 }
284 };
285
286
287
288 // A GCMutexLocker is usually initialized with a mutex that is
289 // automatically acquired in order to do GC. The function that
290 // synchronizes using a GCMutexLocker may be called both during and between
291 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
292 // if GC is in progress (since the mutex is already held on its behalf.)
293
294 class GCMutexLocker: public StackObj {
295 private:
296 Monitor * _mutex;
297 bool _locked;
298 public:
299 GCMutexLocker(Monitor * mutex);
300 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
301 };
302
303
304
305 // A MutexUnlocker temporarily exits a previously
306 // entered mutex for the scope which contains the unlocker.
307
308 class MutexUnlocker: StackObj {
309 private:
310 Monitor * _mutex;
311
312 public:
313 MutexUnlocker(Monitor * mutex) {
314 _mutex = mutex;
315 _mutex->unlock();
316 }
317
318 ~MutexUnlocker() {
319 _mutex->lock();
320 }
321 };
322
323 // A MutexUnlockerEx temporarily exits a previously
324 // entered mutex for the scope which contains the unlocker.
325
326 class MutexUnlockerEx: StackObj {
327 private:
328 Monitor * _mutex;
329 bool _no_safepoint_check;
330
331 public:
332 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
333 _mutex = mutex;
334 _no_safepoint_check = no_safepoint_check;
335 _mutex->unlock();
336 }
337
338 ~MutexUnlockerEx() {
339 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
340 _mutex->lock_without_safepoint_check();
341 } else {
342 _mutex->lock();
343 }
344 }
345 };
346
347 #ifndef PRODUCT
348 //
349 // A special MutexLocker that allows:
350 // - reentrant locking
351 // - locking out of order
352 //
353 // Only to be used for verify code, where we can relax out dead-lock
354 // detection code a bit (unsafe, but probably ok). This code is NEVER to
355 // be included in a product version.
356 //
357 class VerifyMutexLocker: StackObj {
358 private:
359 Monitor * _mutex;
360 bool _reentrant;
361 public:
362 VerifyMutexLocker(Monitor * mutex) {
363 _mutex = mutex;
364 _reentrant = mutex->owned_by_self();
365 if (!_reentrant) {
366 // We temp. disable strict safepoint checking, while we require the lock
367 FlagSetting fs(StrictSafepointChecks, false);
368 _mutex->lock();
369 }
370 }
371
372 ~VerifyMutexLocker() {
373 if (!_reentrant) {
374 _mutex->unlock();
375 }
376 }
377 };
378
379 #endif
380
381 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP