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.
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.
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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 #ifdef TARGET_OS_FAMILY_linux
31 # include "os_linux.inline.hpp"
32 #endif
33 #ifdef TARGET_OS_FAMILY_solaris
34 # include "os_solaris.inline.hpp"
35 #endif
36 #ifdef TARGET_OS_FAMILY_windows
37 # include "os_windows.inline.hpp"
38 #endif
39 #ifdef TARGET_OS_FAMILY_aix
40 # include "os_aix.inline.hpp"
41 #endif
42 #ifdef TARGET_OS_FAMILY_bsd
43 # include "os_bsd.inline.hpp"
44 #endif
45
46 // Mutexes used in the VM.
47
48 extern Mutex* Patching_lock; // a lock used to guard code patching of compiled code
49 extern Monitor* SystemDictionary_lock; // a lock on the system dictonary
50 extern Mutex* PackageTable_lock; // a lock on the class loader package table
51 extern Mutex* CompiledIC_lock; // a lock used to guard compiled IC patching and access
52 extern Mutex* InlineCacheBuffer_lock; // a lock used to guard the InlineCacheBuffer
53 extern Mutex* VMStatistic_lock; // a lock used to guard statistics count increment
54 extern Mutex* JNIGlobalHandle_lock; // a lock on creating JNI global handles
55 extern Mutex* JNIHandleBlockFreeList_lock; // a lock on the JNI handle block free list
56 extern Mutex* MemberNameTable_lock; // a lock on the MemberNameTable updates
57 extern Mutex* JmethodIdCreation_lock; // a lock on creating JNI method identifiers
58 extern Mutex* JfieldIdCreation_lock; // a lock on creating JNI static field identifiers
59 extern Monitor* JNICritical_lock; // a lock used while entering and exiting JNI critical regions, allows GC to sometimes get in
60 extern Mutex* JvmtiThreadState_lock; // a lock on modification of JVMTI thread data
61 extern Monitor* JvmtiPendingEvent_lock; // a lock on the JVMTI pending events list
62 extern Monitor* Heap_lock; // a lock on the heap
63 extern Mutex* ExpandHeap_lock; // a lock on expanding the heap
64 extern Mutex* AdapterHandlerLibrary_lock; // a lock on the AdapterHandlerLibrary
65 extern Mutex* SignatureHandlerLibrary_lock; // a lock on the SignatureHandlerLibrary
66 extern Mutex* VtableStubs_lock; // a lock on the VtableStubs
67 extern Mutex* SymbolTable_lock; // a lock on the symbol table
68 extern Mutex* StringTable_lock; // a lock on the interned string table
69 extern Monitor* StringDedupQueue_lock; // a lock on the string deduplication queue
70 extern Mutex* StringDedupTable_lock; // a lock on the string deduplication table
71 extern Mutex* CodeCache_lock; // a lock on the CodeCache, rank is special, use MutexLockerEx
72 extern Mutex* MethodData_lock; // a lock on installation of method data
73 extern Mutex* RetData_lock; // a lock on installation of RetData inside method data
74 extern Mutex* DerivedPointerTableGC_lock; // a lock to protect the derived pointer table
75 extern Monitor* VMOperationQueue_lock; // a lock on queue of vm_operations waiting to execute
76 extern Monitor* VMOperationRequest_lock; // a lock on Threads waiting for a vm_operation to terminate
77 extern Monitor* Safepoint_lock; // a lock used by the safepoint abstraction
78 extern Monitor* Threads_lock; // a lock on the Threads table of active Java threads
79 // (also used by Safepoints too to block threads creation/destruction)
80 extern Monitor* CGC_lock; // used for coordination between
81 // fore- & background GC threads.
82 extern Monitor* STS_lock; // used for joining/leaving SuspendibleThreadSet.
83 extern Monitor* SLT_lock; // used in CMS GC for acquiring PLL
84 extern Monitor* iCMS_lock; // CMS incremental mode start/stop notification
85 extern Monitor* FullGCCount_lock; // in support of "concurrent" full gc
86 extern Monitor* CMark_lock; // used for concurrent mark thread coordination
87 extern Mutex* CMRegionStack_lock; // used for protecting accesses to the CM region stack
88 extern Mutex* SATB_Q_FL_lock; // Protects SATB Q
89 // buffer free list.
90 extern Monitor* SATB_Q_CBL_mon; // Protects SATB Q
91 // completed buffer queue.
92 extern Mutex* Shared_SATB_Q_lock; // Lock protecting SATB
93 // queue shared by
94 // non-Java threads.
95
96 extern Mutex* DirtyCardQ_FL_lock; // Protects dirty card Q
97 // buffer free list.
98 extern Monitor* DirtyCardQ_CBL_mon; // Protects dirty card Q
99 // completed buffer queue.
100 extern Mutex* Shared_DirtyCardQ_lock; // Lock protecting dirty card
101 // queue shared by
102 // non-Java threads.
103 // (see option ExplicitGCInvokesConcurrent)
104 extern Mutex* ParGCRareEvent_lock; // Synchronizes various (rare) parallel GC ops.
105 extern Mutex* EvacFailureStack_lock; // guards the evac failure scan stack
106 extern Mutex* Compile_lock; // a lock held when Compilation is updating code (used to block CodeCache traversal, CHA updates, etc)
107 extern Monitor* MethodCompileQueue_lock; // a lock held when method compilations are enqueued, dequeued
108 extern Monitor* CompileThread_lock; // a lock held by compile threads during compilation system initialization
109 extern Mutex* CompileTaskAlloc_lock; // a lock held when CompileTasks are allocated
110 extern Mutex* CompileStatistics_lock; // a lock held when updating compilation statistics
111 extern Mutex* MultiArray_lock; // a lock used to guard allocation of multi-dim arrays
112 extern Monitor* Terminator_lock; // a lock used to guard termination of the vm
113 extern Monitor* BeforeExit_lock; // a lock used to guard cleanups and shutdown hooks
114 extern Monitor* Notify_lock; // a lock used to synchronize the start-up of the vm
115 extern Monitor* Interrupt_lock; // a lock used for condition variable mediated interrupt processing
116 extern Monitor* ProfileVM_lock; // a lock used for profiling the VMThread
117 extern Mutex* ProfilePrint_lock; // a lock used to serialize the printing of profiles
118 extern Mutex* ExceptionCache_lock; // a lock used to synchronize exception cache updates
119 extern Mutex* OsrList_lock; // a lock used to serialize access to OSR queues
120
121 #ifndef PRODUCT
122 extern Mutex* FullGCALot_lock; // a lock to make FullGCALot MT safe
123 #endif // PRODUCT
124 extern Mutex* Debug1_lock; // A bunch of pre-allocated locks that can be used for tracing
125 extern Mutex* Debug2_lock; // down synchronization related bugs!
126 extern Mutex* Debug3_lock;
127
128 extern Mutex* RawMonitor_lock;
129 extern Mutex* PerfDataMemAlloc_lock; // a lock on the allocator for PerfData memory for performance data
130 extern Mutex* PerfDataManager_lock; // a long on access to PerfDataManager resources
131 extern Mutex* ParkerFreeList_lock;
132 extern Mutex* OopMapCacheAlloc_lock; // protects allocation of oop_map caches
133
134 extern Mutex* FreeList_lock; // protects the free region list during safepoints
135 extern Monitor* SecondaryFreeList_lock; // protects the secondary free region list
136 extern Mutex* OldSets_lock; // protects the old region sets
137 extern Monitor* RootRegionScan_lock; // used to notify that the CM threads have finished scanning the IM snapshot regions
138 extern Mutex* MMUTracker_lock; // protects the MMU
139 // tracker data structures
140
141 extern Mutex* Management_lock; // a lock used to serialize JVM management
142 extern Monitor* Service_lock; // a lock used for service thread operation
143 extern Monitor* PeriodicTask_lock; // protects the periodic task structure
144
145 #ifdef INCLUDE_JFR
146 extern Mutex* JfrStacktrace_lock; // used to guard access to the JFR stacktrace table
147 extern Monitor* JfrMsg_lock; // protects JFR messaging
148 extern Mutex* JfrBuffer_lock; // protects JFR buffer operations
149 extern Mutex* JfrStream_lock; // protects JFR stream access
150 extern Mutex* JfrThreadGroups_lock; // protects JFR access to Thread Groups
151
152 #ifndef SUPPORTS_NATIVE_CX8
153 extern Mutex* JfrCounters_lock; // provides atomic updates of JFR counters
154 #endif
155
156 #endif
157
158 #ifndef SUPPORTS_NATIVE_CX8
159 extern Mutex* UnsafeJlong_lock; // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
160 #endif
161
162 // A MutexLocker provides mutual exclusion with respect to a given mutex
163 // for the scope which contains the locker. The lock is an OS lock, not
164 // an object lock, and the two do not interoperate. Do not use Mutex-based
165 // locks to lock on Java objects, because they will not be respected if a
166 // that object is locked using the Java locking mechanism.
167 //
168 // NOTE WELL!!
169 //
170 // See orderAccess.hpp. We assume throughout the VM that MutexLocker's
171 // and friends constructors do a fence, a lock and an acquire *in that
172 // order*. And that their destructors do a release and unlock, in *that*
173 // order. If their implementations change such that these assumptions
174 // are violated, a whole lot of code will break.
175
176 // Print all mutexes/monitors that are currently owned by a thread; called
177 // by fatal error handler.
178 void print_owned_locks_on_error(outputStream* st);
179
180 char *lock_name(Mutex *mutex);
181
182 class MutexLocker: StackObj {
183 private:
184 Monitor * _mutex;
185 public:
186 MutexLocker(Monitor * mutex) {
187 assert(mutex->rank() != Mutex::special,
188 "Special ranked mutex should only use MutexLockerEx");
189 _mutex = mutex;
190 _mutex->lock();
191 }
192
193 // Overloaded constructor passing current thread
194 MutexLocker(Monitor * mutex, Thread *thread) {
195 assert(mutex->rank() != Mutex::special,
196 "Special ranked mutex should only use MutexLockerEx");
197 _mutex = mutex;
198 _mutex->lock(thread);
199 }
200
201 ~MutexLocker() {
202 _mutex->unlock();
203 }
204
205 };
206
207 // for debugging: check that we're already owning this lock (or are at a safepoint)
208 #ifdef ASSERT
209 void assert_locked_or_safepoint(const Monitor * lock);
210 void assert_lock_strong(const Monitor * lock);
211 #else
212 #define assert_locked_or_safepoint(lock)
213 #define assert_lock_strong(lock)
214 #endif
215
216 // A MutexLockerEx behaves like a MutexLocker when its constructor is
217 // called with a Mutex. Unlike a MutexLocker, its constructor can also be
218 // called with NULL, in which case the MutexLockerEx is a no-op. There
219 // is also a corresponding MutexUnlockerEx. We want to keep the
220 // basic MutexLocker as fast as possible. MutexLockerEx can also lock
221 // without safepoint check.
222
223 class MutexLockerEx: public StackObj {
224 private:
225 Monitor * _mutex;
226 public:
227 MutexLockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
228 _mutex = mutex;
229 if (_mutex != NULL) {
230 assert(mutex->rank() > Mutex::special || no_safepoint_check,
231 "Mutexes with rank special or lower should not do safepoint checks");
232 if (no_safepoint_check)
233 _mutex->lock_without_safepoint_check();
234 else
235 _mutex->lock();
236 }
237 }
238
239 ~MutexLockerEx() {
240 if (_mutex != NULL) {
241 _mutex->unlock();
242 }
243 }
244 };
245
246 // A MonitorLockerEx is like a MutexLockerEx above, except it takes
247 // a possibly null Monitor, and allows wait/notify as well which are
248 // delegated to the underlying Monitor.
249
250 class MonitorLockerEx: public MutexLockerEx {
251 private:
252 Monitor * _monitor;
253 public:
254 MonitorLockerEx(Monitor* monitor,
255 bool no_safepoint_check = !Mutex::_no_safepoint_check_flag):
256 MutexLockerEx(monitor, no_safepoint_check),
257 _monitor(monitor) {
258 // Superclass constructor did locking
259 }
260
261 ~MonitorLockerEx() {
262 #ifdef ASSERT
263 if (_monitor != NULL) {
264 assert_lock_strong(_monitor);
265 }
266 #endif // ASSERT
267 // Superclass destructor will do unlocking
268 }
269
270 bool wait(bool no_safepoint_check = !Mutex::_no_safepoint_check_flag,
271 long timeout = 0,
272 bool as_suspend_equivalent = !Mutex::_as_suspend_equivalent_flag) {
273 if (_monitor != NULL) {
274 return _monitor->wait(no_safepoint_check, timeout, as_suspend_equivalent);
275 }
276 return false;
277 }
278
279 bool notify_all() {
280 if (_monitor != NULL) {
281 return _monitor->notify_all();
282 }
283 return true;
284 }
285
286 bool notify() {
287 if (_monitor != NULL) {
288 return _monitor->notify();
289 }
290 return true;
291 }
292 };
293
294
295
296 // A GCMutexLocker is usually initialized with a mutex that is
297 // automatically acquired in order to do GC. The function that
298 // synchronizes using a GCMutexLocker may be called both during and between
299 // GC's. Thus, it must acquire the mutex if GC is not in progress, but not
300 // if GC is in progress (since the mutex is already held on its behalf.)
301
302 class GCMutexLocker: public StackObj {
303 private:
304 Monitor * _mutex;
305 bool _locked;
306 public:
307 GCMutexLocker(Monitor * mutex);
308 ~GCMutexLocker() { if (_locked) _mutex->unlock(); }
309 };
310
311
312
313 // A MutexUnlocker temporarily exits a previously
314 // entered mutex for the scope which contains the unlocker.
315
316 class MutexUnlocker: StackObj {
317 private:
318 Monitor * _mutex;
319
320 public:
321 MutexUnlocker(Monitor * mutex) {
322 _mutex = mutex;
323 _mutex->unlock();
324 }
325
326 ~MutexUnlocker() {
327 _mutex->lock();
328 }
329 };
330
331 // A MutexUnlockerEx temporarily exits a previously
332 // entered mutex for the scope which contains the unlocker.
333
334 class MutexUnlockerEx: StackObj {
335 private:
336 Monitor * _mutex;
337 bool _no_safepoint_check;
338
339 public:
340 MutexUnlockerEx(Monitor * mutex, bool no_safepoint_check = !Mutex::_no_safepoint_check_flag) {
341 _mutex = mutex;
342 _no_safepoint_check = no_safepoint_check;
343 _mutex->unlock();
344 }
345
346 ~MutexUnlockerEx() {
347 if (_no_safepoint_check == Mutex::_no_safepoint_check_flag) {
348 _mutex->lock_without_safepoint_check();
349 } else {
350 _mutex->lock();
351 }
352 }
353 };
354
355 #ifndef PRODUCT
356 //
357 // A special MutexLocker that allows:
358 // - reentrant locking
359 // - locking out of order
360 //
361 // Only too be used for verify code, where we can relaxe out dead-lock
362 // dection code a bit (unsafe, but probably ok). This code is NEVER to
363 // be included in a product version.
364 //
365 class VerifyMutexLocker: StackObj {
366 private:
367 Monitor * _mutex;
368 bool _reentrant;
369 public:
370 VerifyMutexLocker(Monitor * mutex) {
371 _mutex = mutex;
372 _reentrant = mutex->owned_by_self();
373 if (!_reentrant) {
374 // We temp. diable strict safepoint checking, while we require the lock
375 FlagSetting fs(StrictSafepointChecks, false);
376 _mutex->lock();
377 }
378 }
379
380 ~VerifyMutexLocker() {
381 if (!_reentrant) {
382 _mutex->unlock();
383 }
384 }
385 };
386
387 #endif
388
389 #endif // SHARE_VM_RUNTIME_MUTEXLOCKER_HPP