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.
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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* Heap_lock; // a lock on the heap
47 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap
48 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
49 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
50 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
51 extern Mutex* SymbolTable_lock; // a lock on the symbol table
52 extern Mutex* StringTable_lock; // a lock on the interned string table
53 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue
54 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table
55 extern Monitor* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx
56 extern Mutex* MethodData_lock; // a lock on installation of method data
57 extern Mutex* TouchedMethodLog_lock; // a lock on allocation of LogExecutedMethods info
58 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
59 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table
60 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute
61 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate
62 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction
63 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
64 // (also used by Safepoints too to block threads creation/destruction)
65 extern Monitor* CGC_lock; // used for coordination between
66 // fore- & background GC threads.
67 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
68 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
69 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q
70 // buffer free list.
71 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q
72 // completed buffer queue.
73 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB
74 // queue shared by
75 // non-Java threads.
76
77 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q
78 // buffer free list.
79 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q
80 // completed buffer queue.
81 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card
82 // queue shared by
83 // non-Java threads.
84 // (see option ExplicitGCInvokesConcurrent)
85 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops.
86 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
87 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
88 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
89 extern Monitor* Compilation_lock; // a lock used to pause compilation
90 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
91 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
92 extern Mutex* DirectivesStack_lock; // a lock held when mutating the dirstack and ref counting directives
93 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
94 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
95 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
96 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
97 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
98 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
99 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
100
101 #ifndef PRODUCT
102 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
103 #endif // PRODUCT
104 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
105 extern Mutex* Debug2_lock; // down synchronization related bugs!
106 extern Mutex* Debug3_lock;
107
108 extern Mutex* RawMonitor_lock;
109 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
110 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
111 extern Mutex* ParkerFreeList_lock;
112 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
113
114 extern Mutex* FreeList_lock; // protects the free region list during safepoints
115 extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list
116 extern Mutex* OldSets_lock; // protects the old region sets
117 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
118 extern Mutex* MMUTracker_lock; // protects the MMU
119 // tracker data structures
120
121 extern Mutex* Management_lock; // a lock used to serialize JVM management
122 extern Monitor* Service_lock; // a lock used for service thread operation
123 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
124
125 #ifdef INCLUDE_TRACE
126 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
127 extern Monitor* JfrMsg_lock; // protects JFR messaging
128 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
129 extern Mutex* JfrStream_lock; // protects JFR stream access
130 extern Mutex* JfrThreadGroups_lock; // protects JFR access to Thread Groups
131 #endif
132
133 #ifndef SUPPORTS_NATIVE_CX8
134 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
135 #endif
136
137 // A MutexLocker provides mutual exclusion with respect to a given mutex
138 // for the scope which contains the locker. The lock is an OS lock, not
139 // an object lock, and the two do not interoperate. Do not use Mutex-based
140 // locks to lock on Java objects, because they will not be respected if a
141 // that object is locked using the Java locking mechanism.
142 //
143 // NOTE WELL!!
144 //
145 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
146 // and friends constructors do a fence, a lock and an acquire *in that
147 // order*. And that their destructors do a release and unlock, in *that*
148 // order. If their implementations change such that these assumptions
149 // are violated, a whole lot of code will break.
150
151 // Print all mutexes/monitors that are currently owned by a thread; called
152 // by fatal error handler.
153 void print_owned_locks_on_error(outputStream* st);
154
155 char *lock_name(Mutex *mutex);
156
157 class MutexLocker: StackObj {
158 private:
159 Monitor * _mutex;
160 public:
161 MutexLocker(Monitor * mutex) {
162 assert(mutex->rank() != Mutex::special,
163 "Special ranked mutex should only use MutexLockerEx");
164 _mutex = mutex;
165 _mutex->lock();
166 }
167
168 // Overloaded constructor passing current thread
169 MutexLocker(Monitor * mutex, Thread *thread) {
170 assert(mutex->rank() != Mutex::special,
171 "Special ranked mutex should only use MutexLockerEx");
172 _mutex = mutex;
173 _mutex->lock(thread);
174 }
175
176 ~MutexLocker() {
177 _mutex->unlock();
178 }
179
180 };
181
182 // for debugging: check that we're already owning this lock (or are at a safepoint)
183 #ifdef ASSERT
184 void assert_locked_or_safepoint(const Monitor * lock);
185 void assert_lock_strong(const Monitor * lock);
186 #else
187 #define assert_locked_or_safepoint(lock)
188 #define assert_lock_strong(lock)
189 #endif
190
191 // A MutexLockerEx behaves like a MutexLocker when its constructor is
192 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
193 // called with NULL, in which case the MutexLockerEx is a no-op. There
194 // is also a corresponding MutexUnlockerEx. We want to keep the
195 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
196 // without safepoint check.
197
198 class MutexLockerEx: public StackObj {
199 private:
200 Monitor * _mutex;
201 public:
202 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
203 _mutex = mutex;
204 if (_mutex != NULL) {
205 assert(mutex->rank() > Mutex::special || no_safepoint_check,
206 "Mutexes with rank special or lower should not do safepoint checks");
207 if (no_safepoint_check)
208 _mutex->lock_without_safepoint_check();
209 else
210 _mutex->lock();
211 }
212 }
213
214 ~MutexLockerEx() {
215 if (_mutex != NULL) {
216 _mutex->unlock();
217 }
218 }
219 };
220
221 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
222 // a possibly null Monitor, and allows wait/notify as well which are
223 // delegated to the underlying Monitor.
224
225 class MonitorLockerEx: public MutexLockerEx {
226 private:
227 Monitor * _monitor;
228 public:
229 MonitorLockerEx(Monitor* monitor,
230 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
231 MutexLockerEx(monitor, no_safepoint_check),
232 _monitor(monitor) {
233 // Superclass constructor did locking
234 }
235
236 ~MonitorLockerEx() {
237 #ifdef ASSERT
238 if (_monitor != NULL) {
239 assert_lock_strong(_monitor);
240 }
241 #endif // ASSERT
242 // Superclass destructor will do unlocking
243 }
244
245 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
246 long timeout = 0,
247 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
248 if (_monitor != NULL) {
249 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
250 }
251 return false;
252 }
253
254 bool notify_all() {
255 if (_monitor != NULL) {
256 return _monitor->notify_all();
257 }
258 return true;
259 }
260
261 bool notify() {
262 if (_monitor != NULL) {
263 return _monitor->notify();
264 }
265 return true;
266 }
267 };
268
269
270
271 // A GCMutexLocker is usually initialized with a mutex that is
272 // automatically acquired in order to do GC. The function that
273 // synchronizes using a GCMutexLocker may be called both during and between
274 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
275 // if GC is in progress (since the mutex is already held on its behalf.)
276
277 class GCMutexLocker: public StackObj {
278 private:
279 Monitor * _mutex;
280 bool _locked;
281 public:
282 GCMutexLocker(Monitor * mutex);
283 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
284 };
285
286
287
288 // A MutexUnlocker temporarily exits a previously
289 // entered mutex for the scope which contains the unlocker.
290
291 class MutexUnlocker: StackObj {
292 private:
293 Monitor * _mutex;
294
295 public:
296 MutexUnlocker(Monitor * mutex) {
297 _mutex = mutex;
298 _mutex->unlock();
299 }
300
301 ~MutexUnlocker() {
302 _mutex->lock();
303 }
304 };
305
306 // A MutexUnlockerEx temporarily exits a previously
307 // entered mutex for the scope which contains the unlocker.
308
309 class MutexUnlockerEx: StackObj {
310 private:
311 Monitor * _mutex;
312 bool _no_safepoint_check;
313
314 public:
315 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
316 _mutex = mutex;
317 _no_safepoint_check = no_safepoint_check;
318 _mutex->unlock();
319 }
320
321 ~MutexUnlockerEx() {
322 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
323 _mutex->lock_without_safepoint_check();
324 } else {
325 _mutex->lock();
326 }
327 }
328 };
329
330 #ifndef PRODUCT
331 //
332 // A special MutexLocker that allows:
333 // - reentrant locking
334 // - locking out of order
335 //
336 // Only to be used for verify code, where we can relax out dead-lock
337 // detection code a bit (unsafe, but probably ok). This code is NEVER to
338 // be included in a product version.
339 //
340 class VerifyMutexLocker: StackObj {
341 private:
342 Monitor * _mutex;
343 bool _reentrant;
344 public:
345 VerifyMutexLocker(Monitor * mutex) {
346 _mutex = mutex;
347 _reentrant = mutex->owned_by_self();
348 if (!_reentrant) {
349 // We temp. disable strict safepoint checking, while we require the lock
350 FlagSetting fs(StrictSafepointChecks, false);
351 _mutex->lock();
352 }
353 }
354
355 ~VerifyMutexLocker() {
356 if (!_reentrant) {
357 _mutex->unlock();
358 }
359 }
360 };
361
362 #endif
363
364 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP