1 /*
2 * Copyright (c) 1997, 2015, 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.
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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.
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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/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 Monitor* 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* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info
59 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
60 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table
61 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute
62 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate
63 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction
64 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
65 // (also used by Safepoints too to block threads creation/destruction)
66 extern Monitor* CGC_lock; // used for coordination between
67 // fore- & background GC threads.
68 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
69 extern Monitor* SLT_lock; // used in CMS GC for acquiring PLL
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 Monitor* Compilation_lock; // a lock used to pause compilation
95 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
96 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
97 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
98 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
99 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
100 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
101 extern Monitor* Interrupt_lock; // a lock used for condition variable mediated interrupt processing
102 extern Monitor* ProfileVM_lock; // a lock used for profiling the VMThread
103 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
104 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
105 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
106 extern Mutex* ImageFileReaderTable_lock; // a lock used to synchronize image readers open/close
107
108 #ifndef PRODUCT
109 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
110 #endif // PRODUCT
111 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
112 extern Mutex* Debug2_lock; // down synchronization related bugs!
113 extern Mutex* Debug3_lock;
114
115 extern Mutex* RawMonitor_lock;
116 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
117 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
118 extern Mutex* ParkerFreeList_lock;
119 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
120
121 extern Mutex* FreeList_lock; // protects the free region list during safepoints
122 extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list
123 extern Mutex* OldSets_lock; // protects the old region sets
124 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
125 extern Mutex* MMUTracker_lock; // protects the MMU
126 // tracker data structures
127
128 extern Mutex* Management_lock; // a lock used to serialize JVM management
129 extern Monitor* Service_lock; // a lock used for service thread operation
130 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
131
132 #ifdef INCLUDE_TRACE
133 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
134 extern Monitor* JfrMsg_lock; // protects JFR messaging
135 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
136 extern Mutex* JfrStream_lock; // protects JFR stream access
137 extern Mutex* JfrThreadGroups_lock; // protects JFR access to Thread Groups
138 #endif
139
140 #ifndef SUPPORTS_NATIVE_CX8
141 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
142 #endif
143
144 // A MutexLocker provides mutual exclusion with respect to a given mutex
145 // for the scope which contains the locker. The lock is an OS lock, not
146 // an object lock, and the two do not interoperate. Do not use Mutex-based
147 // locks to lock on Java objects, because they will not be respected if a
148 // that object is locked using the Java locking mechanism.
149 //
150 // NOTE WELL!!
151 //
152 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
153 // and friends constructors do a fence, a lock and an acquire *in that
154 // order*. And that their destructors do a release and unlock, in *that*
155 // order. If their implementations change such that these assumptions
156 // are violated, a whole lot of code will break.
157
158 // Print all mutexes/monitors that are currently owned by a thread; called
159 // by fatal error handler.
160 void print_owned_locks_on_error(outputStream* st);
161
162 char *lock_name(Mutex *mutex);
163
164 class MutexLocker: StackObj {
165 private:
166 Monitor * _mutex;
167 public:
168 MutexLocker(Monitor * mutex) {
169 assert(mutex->rank() != Mutex::special,
170 "Special ranked mutex should only use MutexLockerEx");
171 _mutex = mutex;
172 _mutex->lock();
173 }
174
175 // Overloaded constructor passing current thread
176 MutexLocker(Monitor * mutex, Thread *thread) {
177 assert(mutex->rank() != Mutex::special,
178 "Special ranked mutex should only use MutexLockerEx");
179 _mutex = mutex;
180 _mutex->lock(thread);
181 }
182
183 ~MutexLocker() {
184 _mutex->unlock();
185 }
186
187 };
188
189 // for debugging: check that we're already owning this lock (or are at a safepoint)
190 #ifdef ASSERT
191 void assert_locked_or_safepoint(const Monitor * lock);
192 void assert_lock_strong(const Monitor * lock);
193 #else
194 #define assert_locked_or_safepoint(lock)
195 #define assert_lock_strong(lock)
196 #endif
197
198 // A MutexLockerEx behaves like a MutexLocker when its constructor is
199 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
200 // called with NULL, in which case the MutexLockerEx is a no-op. There
201 // is also a corresponding MutexUnlockerEx. We want to keep the
202 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
203 // without safepoint check.
204
205 class MutexLockerEx: public StackObj {
206 private:
207 Monitor * _mutex;
208 public:
209 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
210 _mutex = mutex;
211 if (_mutex != NULL) {
212 assert(mutex->rank() > Mutex::special || no_safepoint_check,
213 "Mutexes with rank special or lower should not do safepoint checks");
214 if (no_safepoint_check)
215 _mutex->lock_without_safepoint_check();
216 else
217 _mutex->lock();
218 }
219 }
220
221 ~MutexLockerEx() {
222 if (_mutex != NULL) {
223 _mutex->unlock();
224 }
225 }
226 };
227
228 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
229 // a possibly null Monitor, and allows wait/notify as well which are
230 // delegated to the underlying Monitor.
231
232 class MonitorLockerEx: public MutexLockerEx {
233 private:
234 Monitor * _monitor;
235 public:
236 MonitorLockerEx(Monitor* monitor,
237 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
238 MutexLockerEx(monitor, no_safepoint_check),
239 _monitor(monitor) {
240 // Superclass constructor did locking
241 }
242
243 ~MonitorLockerEx() {
244 #ifdef ASSERT
245 if (_monitor != NULL) {
246 assert_lock_strong(_monitor);
247 }
248 #endif // ASSERT
249 // Superclass destructor will do unlocking
250 }
251
252 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
253 long timeout = 0,
254 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
255 if (_monitor != NULL) {
256 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
257 }
258 return false;
259 }
260
261 bool notify_all() {
262 if (_monitor != NULL) {
263 return _monitor->notify_all();
264 }
265 return true;
266 }
267
268 bool notify() {
269 if (_monitor != NULL) {
270 return _monitor->notify();
271 }
272 return true;
273 }
274 };
275
276
277
278 // A GCMutexLocker is usually initialized with a mutex that is
279 // automatically acquired in order to do GC. The function that
280 // synchronizes using a GCMutexLocker may be called both during and between
281 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
282 // if GC is in progress (since the mutex is already held on its behalf.)
283
284 class GCMutexLocker: public StackObj {
285 private:
286 Monitor * _mutex;
287 bool _locked;
288 public:
289 GCMutexLocker(Monitor * mutex);
290 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
291 };
292
293
294
295 // A MutexUnlocker temporarily exits a previously
296 // entered mutex for the scope which contains the unlocker.
297
298 class MutexUnlocker: StackObj {
299 private:
300 Monitor * _mutex;
301
302 public:
303 MutexUnlocker(Monitor * mutex) {
304 _mutex = mutex;
305 _mutex->unlock();
306 }
307
308 ~MutexUnlocker() {
309 _mutex->lock();
310 }
311 };
312
313 // A MutexUnlockerEx temporarily exits a previously
314 // entered mutex for the scope which contains the unlocker.
315
316 class MutexUnlockerEx: StackObj {
317 private:
318 Monitor * _mutex;
319 bool _no_safepoint_check;
320
321 public:
322 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
323 _mutex = mutex;
324 _no_safepoint_check = no_safepoint_check;
325 _mutex->unlock();
326 }
327
328 ~MutexUnlockerEx() {
329 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
330 _mutex->lock_without_safepoint_check();
331 } else {
332 _mutex->lock();
333 }
334 }
335 };
336
337 #ifndef PRODUCT
338 //
339 // A special MutexLocker that allows:
340 // - reentrant locking
341 // - locking out of order
342 //
343 // Only to be used for verify code, where we can relax out dead-lock
344 // detection code a bit (unsafe, but probably ok). This code is NEVER to
345 // be included in a product version.
346 //
347 class VerifyMutexLocker: StackObj {
348 private:
349 Monitor * _mutex;
350 bool _reentrant;
351 public:
352 VerifyMutexLocker(Monitor * mutex) {
353 _mutex = mutex;
354 _reentrant = mutex->owned_by_self();
355 if (!_reentrant) {
356 // We temp. disable strict safepoint checking, while we require the lock
357 FlagSetting fs(StrictSafepointChecks, false);
358 _mutex->lock();
359 }
360 }
361
362 ~VerifyMutexLocker() {
363 if (!_reentrant) {
364 _mutex->unlock();
365 }
366 }
367 };
368
369 #endif
370
371 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP