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