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