1 /*
2 * Copyright (c) 1997, 2009, 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.
18 *
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.
22 *
23 */
24
25 // Mutexes used in the VM.
26
27 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code
28 extern Monitor* SystemDictionary_lock; // a lock on the system dictonary
29 extern Mutex* PackageTable_lock; // a lock on the class loader package table
30 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
31 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer
32 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
33 extern Mutex* JNIGlobalHandle_lock; // a lock on creating JNI global handles
34 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list
35 extern Mutex* JNICachedItableIndex_lock; // a lock on caching an itable index during JNI invoke
36 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
37 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
38 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
39 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
40 extern Monitor* JvmtiPendingEvent_lock; // a lock on the JVMTI pending events list
41 extern Monitor* Heap_lock; // a lock on the heap
42 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap
43 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
44 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
45 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
46 extern Mutex* SymbolTable_lock; // a lock on the symbol table
47 extern Mutex* StringTable_lock; // a lock on the interned string table
48 extern Mutex* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx
49 extern Mutex* MethodData_lock; // a lock on installation of method data
50 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
51 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table
52 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute
53 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate
54 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction
55 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
56 // (also used by Safepoints too to block threads creation/destruction)
57 extern Monitor* CGC_lock; // used for coordination between
58 // fore- & background GC threads.
59 extern Mutex* STS_init_lock; // coordinate initialization of SuspendibleThreadSets.
60 extern Monitor* SLT_lock; // used in CMS GC for acquiring PLL
61 extern Monitor* iCMS_lock; // CMS incremental mode start/stop notification
62 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
63 extern Monitor* CMark_lock; // used for concurrent mark thread coordination
64 extern Monitor* ZF_mon; // used for G1 conc zero-fill.
65 extern Monitor* Cleanup_mon; // used for G1 conc cleanup.
66 extern Mutex* CMRegionStack_lock; // used for protecting accesses to the CM region stack
67 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q
68 // buffer free list.
69 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q
70 // completed buffer queue.
71 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB
72 // queue shared by
73 // non-Java threads.
74
75 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q
76 // buffer free list.
77 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q
78 // completed buffer queue.
79 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card
80 // queue shared by
81 // non-Java threads.
82 // (see option ExplicitGCInvokesConcurrent)
83 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops.
84 extern Mutex* EvacFailureStack_lock; // guards the evac failure scan stack
85 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
86 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
87 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
88 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
89 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
90 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
91 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
92 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
93 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
94 extern Monitor* Interrupt_lock; // a lock used for condition variable mediated interrupt processing
95 extern Monitor* ProfileVM_lock; // a lock used for profiling the VMThread
96 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
97 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
98 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
99
100 #ifndef PRODUCT
101 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
102 #endif
103 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
104 extern Mutex* Debug2_lock; // down synchronization related bugs!
105 extern Mutex* Debug3_lock;
106
107 extern Mutex* RawMonitor_lock;
108 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
109 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
110 extern Mutex* ParkerFreeList_lock;
111 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
112
113 extern Mutex* MMUTracker_lock; // protects the MMU
114 // tracker data structures
115 extern Mutex* HotCardCache_lock; // protects the hot card cache
116
117 extern Mutex* Management_lock; // a lock used to serialize JVM management
118 extern Monitor* LowMemory_lock; // a lock used for low memory detection
119
120 // A MutexLocker provides mutual exclusion with respect to a given mutex
121 // for the scope which contains the locker. The lock is an OS lock, not
122 // an object lock, and the two do not interoperate. Do not use Mutex-based
123 // locks to lock on Java objects, because they will not be respected if a
124 // that object is locked using the Java locking mechanism.
125 //
126 // NOTE WELL!!
127 //
128 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
129 // and friends constructors do a fence, a lock and an acquire *in that
130 // order*. And that their destructors do a release and unlock, in *that*
131 // order. If their implementations change such that these assumptions
132 // are violated, a whole lot of code will break.
133
134 // Print all mutexes/monitors that are currently owned by a thread; called
135 // by fatal error handler.
136 void print_owned_locks_on_error(outputStream* st);
137
138 char *lock_name(Mutex *mutex);
139
140 class MutexLocker: StackObj {
141 private:
142 Monitor * _mutex;
143 public:
144 MutexLocker(Monitor * mutex) {
145 assert(mutex->rank() != Mutex::special,
146 "Special ranked mutex should only use MutexLockerEx");
147 _mutex = mutex;
148 _mutex->lock();
149 }
150
151 // Overloaded constructor passing current thread
152 MutexLocker(Monitor * mutex, Thread *thread) {
153 assert(mutex->rank() != Mutex::special,
154 "Special ranked mutex should only use MutexLockerEx");
155 _mutex = mutex;
156 _mutex->lock(thread);
157 }
158
159 ~MutexLocker() {
160 _mutex->unlock();
161 }
162
163 };
164
165 // for debugging: check that we're already owning this lock (or are at a safepoint)
166 #ifdef ASSERT
167 void assert_locked_or_safepoint(const Monitor * lock);
168 void assert_lock_strong(const Monitor * lock);
169 #else
170 #define assert_locked_or_safepoint(lock)
171 #define assert_lock_strong(lock)
172 #endif
173
174 // A MutexLockerEx behaves like a MutexLocker when its constructor is
175 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
176 // called with NULL, in which case the MutexLockerEx is a no-op. There
177 // is also a corresponding MutexUnlockerEx. We want to keep the
178 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
179 // without safepoint check.
180
181 class MutexLockerEx: public StackObj {
182 private:
183 Monitor * _mutex;
184 public:
185 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
186 _mutex = mutex;
187 if (_mutex != NULL) {
188 assert(mutex->rank() > Mutex::special || no_safepoint_check,
189 "Mutexes with rank special or lower should not do safepoint checks");
190 if (no_safepoint_check)
191 _mutex->lock_without_safepoint_check();
192 else
193 _mutex->lock();
194 }
195 }
196
197 ~MutexLockerEx() {
198 if (_mutex != NULL) {
199 _mutex->unlock();
200 }
201 }
202 };
203
204 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
205 // a possibly null Monitor, and allows wait/notify as well which are
206 // delegated to the underlying Monitor.
207
208 class MonitorLockerEx: public MutexLockerEx {
209 private:
210 Monitor * _monitor;
211 public:
212 MonitorLockerEx(Monitor* monitor,
213 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
214 MutexLockerEx(monitor, no_safepoint_check),
215 _monitor(monitor) {
216 // Superclass constructor did locking
217 }
218
219 ~MonitorLockerEx() {
220 #ifdef ASSERT
221 if (_monitor != NULL) {
222 assert_lock_strong(_monitor);
223 }
224 #endif // ASSERT
225 // Superclass destructor will do unlocking
226 }
227
228 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
229 long timeout = 0,
230 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
231 if (_monitor != NULL) {
232 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
233 }
234 return false;
235 }
236
237 bool notify_all() {
238 if (_monitor != NULL) {
239 return _monitor->notify_all();
240 }
241 return true;
242 }
243
244 bool notify() {
245 if (_monitor != NULL) {
246 return _monitor->notify();
247 }
248 return true;
249 }
250 };
251
252
253
254 // A GCMutexLocker is usually initialized with a mutex that is
255 // automatically acquired in order to do GC. The function that
256 // synchronizes using a GCMutexLocker may be called both during and between
257 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
258 // if GC is in progress (since the mutex is already held on its behalf.)
259
260 class GCMutexLocker: public StackObj {
261 private:
262 Monitor * _mutex;
263 bool _locked;
264 public:
265 GCMutexLocker(Monitor * mutex);
266 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
267 };
268
269
270
271 // A MutexUnlocker temporarily exits a previously
272 // entered mutex for the scope which contains the unlocker.
273
274 class MutexUnlocker: StackObj {
275 private:
276 Monitor * _mutex;
277
278 public:
279 MutexUnlocker(Monitor * mutex) {
280 _mutex = mutex;
281 _mutex->unlock();
282 }
283
284 ~MutexUnlocker() {
285 _mutex->lock();
286 }
287 };
288
289 // A MutexUnlockerEx temporarily exits a previously
290 // entered mutex for the scope which contains the unlocker.
291
292 class MutexUnlockerEx: StackObj {
293 private:
294 Monitor * _mutex;
295 bool _no_safepoint_check;
296
297 public:
298 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
299 _mutex = mutex;
300 _no_safepoint_check = no_safepoint_check;
301 _mutex->unlock();
302 }
303
304 ~MutexUnlockerEx() {
305 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
306 _mutex->lock_without_safepoint_check();
307 } else {
308 _mutex->lock();
309 }
310 }
311 };
312
313 #ifndef PRODUCT
314 //
315 // A special MutexLocker that allows:
316 // - reentrant locking
317 // - locking out of order
318 //
319 // Only too be used for verify code, where we can relaxe out dead-lock
320 // dection code a bit (unsafe, but probably ok). This code is NEVER to
321 // be included in a product version.
322 //
323 class VerifyMutexLocker: StackObj {
324 private:
325 Monitor * _mutex;
326 bool _reentrant;
327 public:
328 VerifyMutexLocker(Monitor * mutex) {
329 _mutex = mutex;
330 _reentrant = mutex->owned_by_self();
331 if (!_reentrant) {
332 // We temp. diable strict safepoint checking, while we require the lock
333 FlagSetting fs(StrictSafepointChecks, false);
334 _mutex->lock();
335 }
336 }
337
338 ~VerifyMutexLocker() {
339 if (!_reentrant) {
340 _mutex->unlock();
341 }
342 }
343 };
344
345 #endif