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