Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Brian Carlstrom | fc0e321 | 2013-07-17 14:40:12 -0700 | [diff] [blame] | 17 | #ifndef ART_RUNTIME_BASE_MUTEX_H_ |
| 18 | #define ART_RUNTIME_BASE_MUTEX_H_ |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 19 | |
| 20 | #include <pthread.h> |
Brian Carlstrom | cd74c4b | 2012-01-23 13:21:00 -0800 | [diff] [blame] | 21 | #include <stdint.h> |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 22 | |
| 23 | #include <iosfwd> |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 24 | #include <string> |
| 25 | |
Ian Rogers | ef7d42f | 2014-01-06 12:55:46 -0800 | [diff] [blame] | 26 | #include "atomic.h" |
Elliott Hughes | 07ed66b | 2012-12-12 18:34:25 -0800 | [diff] [blame] | 27 | #include "base/logging.h" |
Elliott Hughes | 7616005 | 2012-12-12 16:31:20 -0800 | [diff] [blame] | 28 | #include "base/macros.h" |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 29 | #include "globals.h" |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 30 | |
Ian Rogers | ab47016 | 2012-09-29 23:06:53 -0700 | [diff] [blame] | 31 | #if defined(__APPLE__) |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 32 | #define ART_USE_FUTEXES 0 |
Ian Rogers | ab47016 | 2012-09-29 23:06:53 -0700 | [diff] [blame] | 33 | #else |
Chris Dearman | c014178 | 2013-11-14 17:29:21 -0800 | [diff] [blame] | 34 | #define ART_USE_FUTEXES 1 |
Ian Rogers | ab47016 | 2012-09-29 23:06:53 -0700 | [diff] [blame] | 35 | #endif |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 36 | |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 37 | // Currently Darwin doesn't support locks with timeouts. |
| 38 | #if !defined(__APPLE__) |
| 39 | #define HAVE_TIMED_RWLOCK 1 |
| 40 | #else |
| 41 | #define HAVE_TIMED_RWLOCK 0 |
| 42 | #endif |
| 43 | |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 44 | namespace art { |
| 45 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 46 | class LOCKABLE ReaderWriterMutex; |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 47 | class ScopedContentionRecorder; |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 48 | class Thread; |
| 49 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 50 | // LockLevel is used to impose a lock hierarchy [1] where acquisition of a Mutex at a higher or |
| 51 | // equal level to a lock a thread holds is invalid. The lock hierarchy achieves a cycle free |
| 52 | // partial ordering and thereby cause deadlock situations to fail checks. |
| 53 | // |
| 54 | // [1] http://www.drdobbs.com/parallel/use-lock-hierarchies-to-avoid-deadlock/204801163 |
| 55 | enum LockLevel { |
| 56 | kLoggingLock = 0, |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 57 | kMemMapsLock, |
Raghu Gandham | 7de77dd | 2014-06-13 15:16:31 -0700 | [diff] [blame] | 58 | kSwapMutexesLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 59 | kUnexpectedSignalLock, |
| 60 | kThreadSuspendCountLock, |
| 61 | kAbortLock, |
| 62 | kJdwpSocketLock, |
Mathieu Chartier | a5a53ef | 2014-09-12 12:58:05 -0700 | [diff] [blame] | 63 | kReferenceQueueSoftReferencesLock, |
| 64 | kReferenceQueuePhantomReferencesLock, |
| 65 | kReferenceQueueFinalizerReferencesLock, |
| 66 | kReferenceQueueWeakReferencesLock, |
| 67 | kReferenceQueueClearedReferencesLock, |
| 68 | kReferenceProcessorLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 69 | kRosAllocGlobalLock, |
| 70 | kRosAllocBracketLock, |
| 71 | kRosAllocBulkFreeLock, |
| 72 | kAllocSpaceLock, |
| 73 | kDexFileMethodInlinerLock, |
| 74 | kDexFileToMethodInlinerMapLock, |
| 75 | kMarkSweepMarkStackLock, |
| 76 | kTransactionLogLock, |
| 77 | kInternTableLock, |
Vladimir Marko | 3f5838d | 2014-08-07 18:07:18 +0100 | [diff] [blame] | 78 | kOatFileSecondaryLookupLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 79 | kDefaultMutexLevel, |
| 80 | kMarkSweepLargeObjectLock, |
| 81 | kPinTableLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 82 | kJdwpObjectRegistryLock, |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 83 | kModifyLdtLock, |
| 84 | kAllocatedThreadIdsLock, |
Andreas Gampe | 7424081 | 2014-04-17 10:35:09 -0700 | [diff] [blame] | 85 | kMonitorPoolLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 86 | kClassLinkerClassesLock, |
| 87 | kBreakpointLock, |
| 88 | kMonitorLock, |
Mathieu Chartier | 440e4ce | 2014-03-31 16:36:35 -0700 | [diff] [blame] | 89 | kMonitorListLock, |
Ian Rogers | 68d8b42 | 2014-07-17 11:09:10 -0700 | [diff] [blame] | 90 | kJniLoadLibraryLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 91 | kThreadListLock, |
| 92 | kBreakpointInvokeLock, |
Brian Carlstrom | 306db81 | 2014-09-05 13:01:41 -0700 | [diff] [blame] | 93 | kAllocTrackerLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 94 | kDeoptimizationLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 95 | kProfilerLock, |
| 96 | kJdwpEventListLock, |
| 97 | kJdwpAttachLock, |
| 98 | kJdwpStartLock, |
| 99 | kRuntimeShutdownLock, |
Jeff Hao | 69dbec6 | 2014-09-15 18:03:41 -0700 | [diff] [blame] | 100 | kTraceLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 101 | kHeapBitmapLock, |
| 102 | kMutatorLock, |
Mathieu Chartier | 9ef78b5 | 2014-09-25 17:03:12 -0700 | [diff] [blame] | 103 | kInstrumentEntrypointsLock, |
Ian Rogers | f3d874c | 2014-07-17 18:52:42 -0700 | [diff] [blame] | 104 | kThreadListSuspendThreadLock, |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 105 | kZygoteCreationLock, |
| 106 | |
| 107 | kLockLevelCount // Must come last. |
| 108 | }; |
| 109 | std::ostream& operator<<(std::ostream& os, const LockLevel& rhs); |
| 110 | |
Brian Carlstrom | 2e250c8 | 2013-08-14 18:08:52 -0700 | [diff] [blame] | 111 | const bool kDebugLocking = kIsDebugBuild; |
Ian Rogers | 25fd14b | 2012-09-05 10:56:38 -0700 | [diff] [blame] | 112 | |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 113 | // Record Log contention information, dumpable via SIGQUIT. |
| 114 | #ifdef ART_USE_FUTEXES |
Jeff Hao | 08f2e7b | 2013-09-09 16:44:02 -0700 | [diff] [blame] | 115 | // To enable lock contention logging, set this to true. |
| 116 | const bool kLogLockContentions = false; |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 117 | #else |
| 118 | // Keep this false as lock contention logging is supported only with |
| 119 | // futex. |
| 120 | const bool kLogLockContentions = false; |
| 121 | #endif |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 122 | const size_t kContentionLogSize = 4; |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 123 | const size_t kContentionLogDataSize = kLogLockContentions ? 1 : 0; |
| 124 | const size_t kAllMutexDataSize = kLogLockContentions ? 1 : 0; |
| 125 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 126 | // Base class for all Mutex implementations |
| 127 | class BaseMutex { |
| 128 | public: |
Ian Rogers | bab7496 | 2013-04-19 10:04:10 -0700 | [diff] [blame] | 129 | const char* GetName() const { |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 130 | return name_; |
| 131 | } |
| 132 | |
| 133 | virtual bool IsMutex() const { return false; } |
| 134 | virtual bool IsReaderWriterMutex() const { return false; } |
| 135 | |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 136 | virtual void Dump(std::ostream& os) const = 0; |
| 137 | |
| 138 | static void DumpAll(std::ostream& os); |
| 139 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 140 | protected: |
| 141 | friend class ConditionVariable; |
| 142 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 143 | BaseMutex(const char* name, LockLevel level); |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 144 | virtual ~BaseMutex(); |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 145 | void RegisterAsLocked(Thread* self); |
| 146 | void RegisterAsUnlocked(Thread* self); |
| 147 | void CheckSafeToWait(Thread* self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 148 | |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 149 | friend class ScopedContentionRecorder; |
| 150 | |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 151 | void RecordContention(uint64_t blocked_tid, uint64_t owner_tid, uint64_t nano_time_blocked); |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 152 | void DumpContention(std::ostream& os) const; |
| 153 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 154 | const LockLevel level_; // Support for lock hierarchy. |
Ian Rogers | bab7496 | 2013-04-19 10:04:10 -0700 | [diff] [blame] | 155 | const char* const name_; |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 156 | |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 157 | // A log entry that records contention but makes no guarantee that either tid will be held live. |
| 158 | struct ContentionLogEntry { |
| 159 | ContentionLogEntry() : blocked_tid(0), owner_tid(0) {} |
| 160 | uint64_t blocked_tid; |
| 161 | uint64_t owner_tid; |
| 162 | AtomicInteger count; |
| 163 | }; |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 164 | struct ContentionLogData { |
| 165 | ContentionLogEntry contention_log[kContentionLogSize]; |
| 166 | // The next entry in the contention log to be updated. Value ranges from 0 to |
| 167 | // kContentionLogSize - 1. |
| 168 | AtomicInteger cur_content_log_entry; |
| 169 | // Number of times the Mutex has been contended. |
| 170 | AtomicInteger contention_count; |
| 171 | // Sum of time waited by all contenders in ns. |
Ian Rogers | 37f3c96 | 2014-07-17 11:25:30 -0700 | [diff] [blame] | 172 | Atomic<uint64_t> wait_time; |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 173 | void AddToWaitTime(uint64_t value); |
| 174 | ContentionLogData() : wait_time(0) {} |
| 175 | }; |
Ian Rogers | 3e5cf30 | 2014-05-20 16:40:37 -0700 | [diff] [blame] | 176 | ContentionLogData contention_log_data_[kContentionLogDataSize]; |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 177 | |
| 178 | public: |
| 179 | bool HasEverContended() const { |
| 180 | if (kLogLockContentions) { |
Ian Rogers | 3e5cf30 | 2014-05-20 16:40:37 -0700 | [diff] [blame] | 181 | return contention_log_data_->contention_count.LoadSequentiallyConsistent() > 0; |
Hiroshi Yamauchi | 1afde13 | 2013-08-06 17:09:30 -0700 | [diff] [blame] | 182 | } |
| 183 | return false; |
| 184 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 185 | }; |
| 186 | |
| 187 | // A Mutex is used to achieve mutual exclusion between threads. A Mutex can be used to gain |
| 188 | // exclusive access to what it guards. A Mutex can be in one of two states: |
| 189 | // - Free - not owned by any thread, |
| 190 | // - Exclusive - owned by a single thread. |
| 191 | // |
| 192 | // The effect of locking and unlocking operations on the state is: |
| 193 | // State | ExclusiveLock | ExclusiveUnlock |
| 194 | // ------------------------------------------- |
| 195 | // Free | Exclusive | error |
| 196 | // Exclusive | Block* | Free |
| 197 | // * Mutex is not reentrant and so an attempt to ExclusiveLock on the same thread will result in |
| 198 | // an error. Being non-reentrant simplifies Waiting on ConditionVariables. |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 199 | std::ostream& operator<<(std::ostream& os, const Mutex& mu); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 200 | class LOCKABLE Mutex : public BaseMutex { |
| 201 | public: |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 202 | explicit Mutex(const char* name, LockLevel level = kDefaultMutexLevel, bool recursive = false); |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 203 | ~Mutex(); |
| 204 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 205 | virtual bool IsMutex() const { return true; } |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 206 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 207 | // Block until mutex is free then acquire exclusive access. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 208 | void ExclusiveLock(Thread* self) EXCLUSIVE_LOCK_FUNCTION(); |
| 209 | void Lock(Thread* self) EXCLUSIVE_LOCK_FUNCTION() { ExclusiveLock(self); } |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 210 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 211 | // Returns true if acquires exclusive access, false otherwise. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 212 | bool ExclusiveTryLock(Thread* self) EXCLUSIVE_TRYLOCK_FUNCTION(true); |
| 213 | bool TryLock(Thread* self) EXCLUSIVE_TRYLOCK_FUNCTION(true) { return ExclusiveTryLock(self); } |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 214 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 215 | // Release exclusive access. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 216 | void ExclusiveUnlock(Thread* self) UNLOCK_FUNCTION(); |
| 217 | void Unlock(Thread* self) UNLOCK_FUNCTION() { ExclusiveUnlock(self); } |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 218 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 219 | // Is the current thread the exclusive holder of the Mutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 220 | bool IsExclusiveHeld(const Thread* self) const; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 221 | |
| 222 | // Assert that the Mutex is exclusively held by the current thread. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 223 | void AssertExclusiveHeld(const Thread* self) { |
Anwar Ghuloum | 3c539ff | 2013-06-20 08:58:23 -0700 | [diff] [blame] | 224 | if (kDebugLocking && (gAborting == 0)) { |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 225 | CHECK(IsExclusiveHeld(self)) << *this; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 226 | } |
| 227 | } |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 228 | void AssertHeld(const Thread* self) { AssertExclusiveHeld(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 229 | |
| 230 | // Assert that the Mutex is not held by the current thread. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 231 | void AssertNotHeldExclusive(const Thread* self) { |
Anwar Ghuloum | 3c539ff | 2013-06-20 08:58:23 -0700 | [diff] [blame] | 232 | if (kDebugLocking && (gAborting == 0)) { |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 233 | CHECK(!IsExclusiveHeld(self)) << *this; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 234 | } |
| 235 | } |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 236 | void AssertNotHeld(const Thread* self) { AssertNotHeldExclusive(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 237 | |
Ian Rogers | c719069 | 2014-07-08 23:50:26 -0700 | [diff] [blame] | 238 | // Id associated with exclusive owner. No memory ordering semantics if called from a thread other |
| 239 | // than the owner. |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 240 | uint64_t GetExclusiveOwnerTid() const; |
| 241 | |
| 242 | // Returns how many times this Mutex has been locked, it is better to use AssertHeld/NotHeld. |
| 243 | unsigned int GetDepth() const { |
| 244 | return recursion_count_; |
| 245 | } |
Elliott Hughes | accd83d | 2011-10-17 14:25:58 -0700 | [diff] [blame] | 246 | |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 247 | virtual void Dump(std::ostream& os) const; |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 248 | |
Elliott Hughes | accd83d | 2011-10-17 14:25:58 -0700 | [diff] [blame] | 249 | private: |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 250 | #if ART_USE_FUTEXES |
| 251 | // 0 is unheld, 1 is held. |
Ian Rogers | c719069 | 2014-07-08 23:50:26 -0700 | [diff] [blame] | 252 | AtomicInteger state_; |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 253 | // Exclusive owner. |
| 254 | volatile uint64_t exclusive_owner_; |
| 255 | // Number of waiting contenders. |
Ian Rogers | b122a4b | 2013-11-19 18:00:50 -0800 | [diff] [blame] | 256 | AtomicInteger num_contenders_; |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 257 | #else |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 258 | pthread_mutex_t mutex_; |
Ian Rogers | c5f1773 | 2014-06-05 20:48:42 -0700 | [diff] [blame] | 259 | volatile uint64_t exclusive_owner_; // Guarded by mutex_. |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 260 | #endif |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 261 | const bool recursive_; // Can the lock be recursively held? |
| 262 | unsigned int recursion_count_; |
Elliott Hughes | f149843 | 2012-03-28 19:34:27 -0700 | [diff] [blame] | 263 | friend class ConditionVariable; |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 264 | DISALLOW_COPY_AND_ASSIGN(Mutex); |
| 265 | }; |
| 266 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 267 | // A ReaderWriterMutex is used to achieve mutual exclusion between threads, similar to a Mutex. |
| 268 | // Unlike a Mutex a ReaderWriterMutex can be used to gain exclusive (writer) or shared (reader) |
| 269 | // access to what it guards. A flaw in relation to a Mutex is that it cannot be used with a |
| 270 | // condition variable. A ReaderWriterMutex can be in one of three states: |
| 271 | // - Free - not owned by any thread, |
| 272 | // - Exclusive - owned by a single thread, |
| 273 | // - Shared(n) - shared amongst n threads. |
| 274 | // |
| 275 | // The effect of locking and unlocking operations on the state is: |
| 276 | // |
| 277 | // State | ExclusiveLock | ExclusiveUnlock | SharedLock | SharedUnlock |
| 278 | // ---------------------------------------------------------------------------- |
| 279 | // Free | Exclusive | error | SharedLock(1) | error |
| 280 | // Exclusive | Block | Free | Block | error |
| 281 | // Shared(n) | Block | error | SharedLock(n+1)* | Shared(n-1) or Free |
| 282 | // * for large values of n the SharedLock may block. |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 283 | std::ostream& operator<<(std::ostream& os, const ReaderWriterMutex& mu); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 284 | class LOCKABLE ReaderWriterMutex : public BaseMutex { |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 285 | public: |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 286 | explicit ReaderWriterMutex(const char* name, LockLevel level = kDefaultMutexLevel); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 287 | ~ReaderWriterMutex(); |
| 288 | |
| 289 | virtual bool IsReaderWriterMutex() const { return true; } |
| 290 | |
| 291 | // Block until ReaderWriterMutex is free then acquire exclusive access. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 292 | void ExclusiveLock(Thread* self) EXCLUSIVE_LOCK_FUNCTION(); |
| 293 | void WriterLock(Thread* self) EXCLUSIVE_LOCK_FUNCTION() { ExclusiveLock(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 294 | |
| 295 | // Release exclusive access. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 296 | void ExclusiveUnlock(Thread* self) UNLOCK_FUNCTION(); |
| 297 | void WriterUnlock(Thread* self) UNLOCK_FUNCTION() { ExclusiveUnlock(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 298 | |
| 299 | // Block until ReaderWriterMutex is free and acquire exclusive access. Returns true on success |
| 300 | // or false if timeout is reached. |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 301 | #if HAVE_TIMED_RWLOCK |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 302 | bool ExclusiveLockWithTimeout(Thread* self, int64_t ms, int32_t ns) |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 303 | EXCLUSIVE_TRYLOCK_FUNCTION(true); |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 304 | #endif |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 305 | |
| 306 | // Block until ReaderWriterMutex is shared or free then acquire a share on the access. |
Ian Rogers | 1ffa32f | 2013-02-05 18:29:08 -0800 | [diff] [blame] | 307 | void SharedLock(Thread* self) SHARED_LOCK_FUNCTION() ALWAYS_INLINE; |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 308 | void ReaderLock(Thread* self) SHARED_LOCK_FUNCTION() { SharedLock(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 309 | |
| 310 | // Try to acquire share of ReaderWriterMutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 311 | bool SharedTryLock(Thread* self) EXCLUSIVE_TRYLOCK_FUNCTION(true); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 312 | |
| 313 | // Release a share of the access. |
Ian Rogers | 1ffa32f | 2013-02-05 18:29:08 -0800 | [diff] [blame] | 314 | void SharedUnlock(Thread* self) UNLOCK_FUNCTION() ALWAYS_INLINE; |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 315 | void ReaderUnlock(Thread* self) UNLOCK_FUNCTION() { SharedUnlock(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 316 | |
| 317 | // Is the current thread the exclusive holder of the ReaderWriterMutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 318 | bool IsExclusiveHeld(const Thread* self) const; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 319 | |
| 320 | // Assert the current thread has exclusive access to the ReaderWriterMutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 321 | void AssertExclusiveHeld(const Thread* self) { |
Sebastien Hertz | 702a85b | 2013-08-05 16:37:51 +0200 | [diff] [blame] | 322 | if (kDebugLocking && (gAborting == 0)) { |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 323 | CHECK(IsExclusiveHeld(self)) << *this; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 324 | } |
| 325 | } |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 326 | void AssertWriterHeld(const Thread* self) { AssertExclusiveHeld(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 327 | |
| 328 | // Assert the current thread doesn't have exclusive access to the ReaderWriterMutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 329 | void AssertNotExclusiveHeld(const Thread* self) { |
Sebastien Hertz | 702a85b | 2013-08-05 16:37:51 +0200 | [diff] [blame] | 330 | if (kDebugLocking && (gAborting == 0)) { |
Ian Rogers | e3359f7 | 2013-06-11 15:14:11 -0700 | [diff] [blame] | 331 | CHECK(!IsExclusiveHeld(self)) << *this; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 332 | } |
| 333 | } |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 334 | void AssertNotWriterHeld(const Thread* self) { AssertNotExclusiveHeld(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 335 | |
| 336 | // Is the current thread a shared holder of the ReaderWriterMutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 337 | bool IsSharedHeld(const Thread* self) const; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 338 | |
| 339 | // Assert the current thread has shared access to the ReaderWriterMutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 340 | void AssertSharedHeld(const Thread* self) { |
Sebastien Hertz | 702a85b | 2013-08-05 16:37:51 +0200 | [diff] [blame] | 341 | if (kDebugLocking && (gAborting == 0)) { |
Ian Rogers | 23055dc | 2013-04-18 16:29:16 -0700 | [diff] [blame] | 342 | // TODO: we can only assert this well when self != NULL. |
| 343 | CHECK(IsSharedHeld(self) || self == NULL) << *this; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 344 | } |
| 345 | } |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 346 | void AssertReaderHeld(const Thread* self) { AssertSharedHeld(self); } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 347 | |
| 348 | // Assert the current thread doesn't hold this ReaderWriterMutex either in shared or exclusive |
| 349 | // mode. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 350 | void AssertNotHeld(const Thread* self) { |
Anwar Ghuloum | 3c539ff | 2013-06-20 08:58:23 -0700 | [diff] [blame] | 351 | if (kDebugLocking && (gAborting == 0)) { |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 352 | CHECK(!IsSharedHeld(self)) << *this; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 353 | } |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 354 | } |
| 355 | |
Ian Rogers | c719069 | 2014-07-08 23:50:26 -0700 | [diff] [blame] | 356 | // Id associated with exclusive owner. No memory ordering semantics if called from a thread other |
| 357 | // than the owner. |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 358 | uint64_t GetExclusiveOwnerTid() const; |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 359 | |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 360 | virtual void Dump(std::ostream& os) const; |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 361 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 362 | private: |
Ian Rogers | 51d212e | 2014-10-23 17:48:20 -0700 | [diff] [blame] | 363 | #if ART_USE_FUTEXES |
Ian Rogers | cf7f191 | 2014-10-22 22:06:39 -0700 | [diff] [blame] | 364 | // Out-of-inline path for handling contention for a SharedLock. |
| 365 | void HandleSharedLockContention(Thread* self, int32_t cur_state); |
| 366 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 367 | // -1 implies held exclusive, +ve shared held by state_ many owners. |
Ian Rogers | c719069 | 2014-07-08 23:50:26 -0700 | [diff] [blame] | 368 | AtomicInteger state_; |
| 369 | // Exclusive owner. Modification guarded by this mutex. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 370 | volatile uint64_t exclusive_owner_; |
Ian Rogers | c719069 | 2014-07-08 23:50:26 -0700 | [diff] [blame] | 371 | // Number of contenders waiting for a reader share. |
| 372 | AtomicInteger num_pending_readers_; |
| 373 | // Number of contenders waiting to be the writer. |
Ian Rogers | b122a4b | 2013-11-19 18:00:50 -0800 | [diff] [blame] | 374 | AtomicInteger num_pending_writers_; |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 375 | #else |
| 376 | pthread_rwlock_t rwlock_; |
Ian Rogers | c5f1773 | 2014-06-05 20:48:42 -0700 | [diff] [blame] | 377 | volatile uint64_t exclusive_owner_; // Guarded by rwlock_. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 378 | #endif |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 379 | DISALLOW_COPY_AND_ASSIGN(ReaderWriterMutex); |
| 380 | }; |
| 381 | |
| 382 | // ConditionVariables allow threads to queue and sleep. Threads may then be resumed individually |
| 383 | // (Signal) or all at once (Broadcast). |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 384 | class ConditionVariable { |
| 385 | public: |
Ian Rogers | 23055dc | 2013-04-18 16:29:16 -0700 | [diff] [blame] | 386 | explicit ConditionVariable(const char* name, Mutex& mutex); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 387 | ~ConditionVariable(); |
| 388 | |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 389 | void Broadcast(Thread* self); |
| 390 | void Signal(Thread* self); |
| 391 | // TODO: No thread safety analysis on Wait and TimedWait as they call mutex operations via their |
| 392 | // pointer copy, thereby defeating annotalysis. |
| 393 | void Wait(Thread* self) NO_THREAD_SAFETY_ANALYSIS; |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 394 | bool TimedWait(Thread* self, int64_t ms, int32_t ns) NO_THREAD_SAFETY_ANALYSIS; |
Ian Rogers | 1d54e73 | 2013-05-02 21:10:01 -0700 | [diff] [blame] | 395 | // Variant of Wait that should be used with caution. Doesn't validate that no mutexes are held |
| 396 | // when waiting. |
| 397 | // TODO: remove this. |
| 398 | void WaitHoldingLocks(Thread* self) NO_THREAD_SAFETY_ANALYSIS; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 399 | |
| 400 | private: |
Ian Rogers | 23055dc | 2013-04-18 16:29:16 -0700 | [diff] [blame] | 401 | const char* const name_; |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 402 | // The Mutex being used by waiters. It is an error to mix condition variables between different |
| 403 | // Mutexes. |
| 404 | Mutex& guard_; |
| 405 | #if ART_USE_FUTEXES |
| 406 | // A counter that is modified by signals and broadcasts. This ensures that when a waiter gives up |
Ian Rogers | d45f201 | 2012-11-28 11:46:23 -0800 | [diff] [blame] | 407 | // their Mutex and another thread takes it and signals, the waiting thread observes that sequence_ |
| 408 | // changed and doesn't enter the wait. Modified while holding guard_, but is read by futex wait |
| 409 | // without guard_ held. |
Ian Rogers | b122a4b | 2013-11-19 18:00:50 -0800 | [diff] [blame] | 410 | AtomicInteger sequence_; |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 411 | // Number of threads that have come into to wait, not the length of the waiters on the futex as |
Ian Rogers | 5bd97c4 | 2012-11-27 02:38:26 -0800 | [diff] [blame] | 412 | // waiters may have been requeued onto guard_. Guarded by guard_. |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 413 | volatile int32_t num_waiters_; |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 414 | #else |
| 415 | pthread_cond_t cond_; |
| 416 | #endif |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 417 | DISALLOW_COPY_AND_ASSIGN(ConditionVariable); |
| 418 | }; |
| 419 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 420 | // Scoped locker/unlocker for a regular Mutex that acquires mu upon construction and releases it |
| 421 | // upon destruction. |
| 422 | class SCOPED_LOCKABLE MutexLock { |
| 423 | public: |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 424 | explicit MutexLock(Thread* self, Mutex& mu) EXCLUSIVE_LOCK_FUNCTION(mu) : self_(self), mu_(mu) { |
| 425 | mu_.ExclusiveLock(self_); |
| 426 | } |
| 427 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 428 | ~MutexLock() UNLOCK_FUNCTION() { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 429 | mu_.ExclusiveUnlock(self_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 430 | } |
| 431 | |
| 432 | private: |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 433 | Thread* const self_; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 434 | Mutex& mu_; |
| 435 | DISALLOW_COPY_AND_ASSIGN(MutexLock); |
| 436 | }; |
| 437 | // Catch bug where variable name is omitted. "MutexLock (lock);" instead of "MutexLock mu(lock)". |
Andreas Gampe | 575e78c | 2014-11-03 23:41:03 -0800 | [diff] [blame^] | 438 | #define MutexLock(x) static_assert(0, "MutexLock declaration missing variable name") |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 439 | |
| 440 | // Scoped locker/unlocker for a ReaderWriterMutex that acquires read access to mu upon |
| 441 | // construction and releases it upon destruction. |
| 442 | class SCOPED_LOCKABLE ReaderMutexLock { |
| 443 | public: |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 444 | explicit ReaderMutexLock(Thread* self, ReaderWriterMutex& mu) EXCLUSIVE_LOCK_FUNCTION(mu) : |
| 445 | self_(self), mu_(mu) { |
| 446 | mu_.SharedLock(self_); |
| 447 | } |
| 448 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 449 | ~ReaderMutexLock() UNLOCK_FUNCTION() { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 450 | mu_.SharedUnlock(self_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 451 | } |
| 452 | |
| 453 | private: |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 454 | Thread* const self_; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 455 | ReaderWriterMutex& mu_; |
| 456 | DISALLOW_COPY_AND_ASSIGN(ReaderMutexLock); |
| 457 | }; |
| 458 | // Catch bug where variable name is omitted. "ReaderMutexLock (lock);" instead of |
| 459 | // "ReaderMutexLock mu(lock)". |
Andreas Gampe | 575e78c | 2014-11-03 23:41:03 -0800 | [diff] [blame^] | 460 | #define ReaderMutexLock(x) static_assert(0, "ReaderMutexLock declaration missing variable name") |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 461 | |
| 462 | // Scoped locker/unlocker for a ReaderWriterMutex that acquires write access to mu upon |
| 463 | // construction and releases it upon destruction. |
| 464 | class SCOPED_LOCKABLE WriterMutexLock { |
| 465 | public: |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 466 | explicit WriterMutexLock(Thread* self, ReaderWriterMutex& mu) EXCLUSIVE_LOCK_FUNCTION(mu) : |
| 467 | self_(self), mu_(mu) { |
| 468 | mu_.ExclusiveLock(self_); |
| 469 | } |
| 470 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 471 | ~WriterMutexLock() UNLOCK_FUNCTION() { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 472 | mu_.ExclusiveUnlock(self_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 473 | } |
| 474 | |
| 475 | private: |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 476 | Thread* const self_; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 477 | ReaderWriterMutex& mu_; |
| 478 | DISALLOW_COPY_AND_ASSIGN(WriterMutexLock); |
| 479 | }; |
| 480 | // Catch bug where variable name is omitted. "WriterMutexLock (lock);" instead of |
| 481 | // "WriterMutexLock mu(lock)". |
Andreas Gampe | 575e78c | 2014-11-03 23:41:03 -0800 | [diff] [blame^] | 482 | #define WriterMutexLock(x) static_assert(0, "WriterMutexLock declaration missing variable name") |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 483 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 484 | // Global mutexes corresponding to the levels above. |
| 485 | class Locks { |
| 486 | public: |
| 487 | static void Init(); |
| 488 | |
Ian Rogers | f3d874c | 2014-07-17 18:52:42 -0700 | [diff] [blame] | 489 | // There's a potential race for two threads to try to suspend each other and for both of them |
| 490 | // to succeed and get blocked becoming runnable. This lock ensures that only one thread is |
| 491 | // requesting suspension of another at any time. As the the thread list suspend thread logic |
| 492 | // transitions to runnable, if the current thread were tried to be suspended then this thread |
| 493 | // would block holding this lock until it could safely request thread suspension of the other |
| 494 | // thread without that thread having a suspension request against this thread. This avoids a |
| 495 | // potential deadlock cycle. |
| 496 | static Mutex* thread_list_suspend_thread_lock_; |
| 497 | |
Mathieu Chartier | 9ef78b5 | 2014-09-25 17:03:12 -0700 | [diff] [blame] | 498 | // Guards allocation entrypoint instrumenting. |
| 499 | static Mutex* instrument_entrypoints_lock_ ACQUIRED_AFTER(thread_list_suspend_thread_lock_); |
| 500 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 501 | // The mutator_lock_ is used to allow mutators to execute in a shared (reader) mode or to block |
| 502 | // mutators by having an exclusive (writer) owner. In normal execution each mutator thread holds |
| 503 | // a share on the mutator_lock_. The garbage collector may also execute with shared access but |
| 504 | // at times requires exclusive access to the heap (not to be confused with the heap meta-data |
| 505 | // guarded by the heap_lock_ below). When the garbage collector requires exclusive access it asks |
| 506 | // the mutators to suspend themselves which also involves usage of the thread_suspend_count_lock_ |
| 507 | // to cover weaknesses in using ReaderWriterMutexes with ConditionVariables. We use a condition |
| 508 | // variable to wait upon in the suspension logic as releasing and then re-acquiring a share on |
| 509 | // the mutator lock doesn't necessarily allow the exclusive user (e.g the garbage collector) |
| 510 | // chance to acquire the lock. |
| 511 | // |
| 512 | // Thread suspension: |
| 513 | // Shared users | Exclusive user |
| 514 | // (holding mutator lock and in kRunnable state) | .. running .. |
| 515 | // .. running .. | Request thread suspension by: |
| 516 | // .. running .. | - acquiring thread_suspend_count_lock_ |
| 517 | // .. running .. | - incrementing Thread::suspend_count_ on |
| 518 | // .. running .. | all mutator threads |
| 519 | // .. running .. | - releasing thread_suspend_count_lock_ |
| 520 | // .. running .. | Block trying to acquire exclusive mutator lock |
| 521 | // Poll Thread::suspend_count_ and enter full | .. blocked .. |
| 522 | // suspend code. | .. blocked .. |
| 523 | // Change state to kSuspended | .. blocked .. |
| 524 | // x: Release share on mutator_lock_ | Carry out exclusive access |
| 525 | // Acquire thread_suspend_count_lock_ | .. exclusive .. |
| 526 | // while Thread::suspend_count_ > 0 | .. exclusive .. |
| 527 | // - wait on Thread::resume_cond_ | .. exclusive .. |
| 528 | // (releases thread_suspend_count_lock_) | .. exclusive .. |
| 529 | // .. waiting .. | Release mutator_lock_ |
| 530 | // .. waiting .. | Request thread resumption by: |
| 531 | // .. waiting .. | - acquiring thread_suspend_count_lock_ |
| 532 | // .. waiting .. | - decrementing Thread::suspend_count_ on |
| 533 | // .. waiting .. | all mutator threads |
| 534 | // .. waiting .. | - notifying on Thread::resume_cond_ |
| 535 | // - re-acquire thread_suspend_count_lock_ | - releasing thread_suspend_count_lock_ |
| 536 | // Release thread_suspend_count_lock_ | .. running .. |
| 537 | // Acquire share on mutator_lock_ | .. running .. |
| 538 | // - This could block but the thread still | .. running .. |
| 539 | // has a state of kSuspended and so this | .. running .. |
| 540 | // isn't an issue. | .. running .. |
| 541 | // Acquire thread_suspend_count_lock_ | .. running .. |
| 542 | // - we poll here as we're transitioning into | .. running .. |
| 543 | // kRunnable and an individual thread suspend | .. running .. |
| 544 | // request (e.g for debugging) won't try | .. running .. |
| 545 | // to acquire the mutator lock (which would | .. running .. |
| 546 | // block as we hold the mutator lock). This | .. running .. |
| 547 | // poll ensures that if the suspender thought | .. running .. |
| 548 | // we were suspended by incrementing our | .. running .. |
| 549 | // Thread::suspend_count_ and then reading | .. running .. |
| 550 | // our state we go back to waiting on | .. running .. |
| 551 | // Thread::resume_cond_. | .. running .. |
| 552 | // can_go_runnable = Thread::suspend_count_ == 0 | .. running .. |
| 553 | // Release thread_suspend_count_lock_ | .. running .. |
| 554 | // if can_go_runnable | .. running .. |
| 555 | // Change state to kRunnable | .. running .. |
| 556 | // else | .. running .. |
| 557 | // Goto x | .. running .. |
| 558 | // .. running .. | .. running .. |
Mathieu Chartier | 9ef78b5 | 2014-09-25 17:03:12 -0700 | [diff] [blame] | 559 | static ReaderWriterMutex* mutator_lock_ ACQUIRED_AFTER(instrument_entrypoints_lock_); |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 560 | |
| 561 | // Allow reader-writer mutual exclusion on the mark and live bitmaps of the heap. |
| 562 | static ReaderWriterMutex* heap_bitmap_lock_ ACQUIRED_AFTER(mutator_lock_); |
| 563 | |
| 564 | // Guards shutdown of the runtime. |
| 565 | static Mutex* runtime_shutdown_lock_ ACQUIRED_AFTER(heap_bitmap_lock_); |
| 566 | |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 567 | // Guards background profiler global state. |
| 568 | static Mutex* profiler_lock_ ACQUIRED_AFTER(runtime_shutdown_lock_); |
| 569 | |
| 570 | // Guards trace (ie traceview) requests. |
| 571 | static Mutex* trace_lock_ ACQUIRED_AFTER(profiler_lock_); |
| 572 | |
Brian Carlstrom | 306db81 | 2014-09-05 13:01:41 -0700 | [diff] [blame] | 573 | // Guards debugger recent allocation records. |
| 574 | static Mutex* alloc_tracker_lock_ ACQUIRED_AFTER(trace_lock_); |
| 575 | |
| 576 | // Guards updates to instrumentation to ensure mutual exclusion of |
| 577 | // events like deoptimization requests. |
| 578 | // TODO: improve name, perhaps instrumentation_update_lock_. |
| 579 | static Mutex* deoptimization_lock_ ACQUIRED_AFTER(alloc_tracker_lock_); |
| 580 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 581 | // The thread_list_lock_ guards ThreadList::list_. It is also commonly held to stop threads |
| 582 | // attaching and detaching. |
Brian Carlstrom | 306db81 | 2014-09-05 13:01:41 -0700 | [diff] [blame] | 583 | static Mutex* thread_list_lock_ ACQUIRED_AFTER(deoptimization_lock_); |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 584 | |
Ian Rogers | 68d8b42 | 2014-07-17 11:09:10 -0700 | [diff] [blame] | 585 | // Guards maintaining loading library data structures. |
| 586 | static Mutex* jni_libraries_lock_ ACQUIRED_AFTER(thread_list_lock_); |
| 587 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 588 | // Guards breakpoints. |
Sebastien Hertz | ed2be17 | 2014-08-19 15:33:43 +0200 | [diff] [blame] | 589 | static ReaderWriterMutex* breakpoint_lock_ ACQUIRED_AFTER(jni_libraries_lock_); |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 590 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 591 | // Guards lists of classes within the class linker. |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 592 | static ReaderWriterMutex* classlinker_classes_lock_ ACQUIRED_AFTER(breakpoint_lock_); |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 593 | |
| 594 | // When declaring any Mutex add DEFAULT_MUTEX_ACQUIRED_AFTER to use annotalysis to check the code |
| 595 | // doesn't try to hold a higher level Mutex. |
| 596 | #define DEFAULT_MUTEX_ACQUIRED_AFTER ACQUIRED_AFTER(Locks::classlinker_classes_lock_) |
| 597 | |
Andreas Gampe | 7424081 | 2014-04-17 10:35:09 -0700 | [diff] [blame] | 598 | static Mutex* allocated_monitor_ids_lock_ ACQUIRED_AFTER(classlinker_classes_lock_); |
| 599 | |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 600 | // Guard the allocation/deallocation of thread ids. |
Andreas Gampe | 7424081 | 2014-04-17 10:35:09 -0700 | [diff] [blame] | 601 | static Mutex* allocated_thread_ids_lock_ ACQUIRED_AFTER(allocated_monitor_ids_lock_); |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 602 | |
| 603 | // Guards modification of the LDT on x86. |
| 604 | static Mutex* modify_ldt_lock_ ACQUIRED_AFTER(allocated_thread_ids_lock_); |
| 605 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 606 | // Guards intern table. |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 607 | static Mutex* intern_table_lock_ ACQUIRED_AFTER(modify_ldt_lock_); |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 608 | |
Mathieu Chartier | a5a53ef | 2014-09-12 12:58:05 -0700 | [diff] [blame] | 609 | // Guards reference processor. |
| 610 | static Mutex* reference_processor_lock_ ACQUIRED_AFTER(intern_table_lock_); |
| 611 | |
| 612 | // Guards cleared references queue. |
| 613 | static Mutex* reference_queue_cleared_references_lock_ ACQUIRED_AFTER(reference_processor_lock_); |
| 614 | |
| 615 | // Guards weak references queue. |
| 616 | static Mutex* reference_queue_weak_references_lock_ ACQUIRED_AFTER(reference_queue_cleared_references_lock_); |
| 617 | |
| 618 | // Guards finalizer references queue. |
| 619 | static Mutex* reference_queue_finalizer_references_lock_ ACQUIRED_AFTER(reference_queue_weak_references_lock_); |
| 620 | |
| 621 | // Guards phantom references queue. |
| 622 | static Mutex* reference_queue_phantom_references_lock_ ACQUIRED_AFTER(reference_queue_finalizer_references_lock_); |
| 623 | |
| 624 | // Guards soft references queue. |
| 625 | static Mutex* reference_queue_soft_references_lock_ ACQUIRED_AFTER(reference_queue_phantom_references_lock_); |
| 626 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 627 | // Have an exclusive aborting thread. |
Mathieu Chartier | a5a53ef | 2014-09-12 12:58:05 -0700 | [diff] [blame] | 628 | static Mutex* abort_lock_ ACQUIRED_AFTER(reference_queue_soft_references_lock_); |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 629 | |
| 630 | // Allow mutual exclusion when manipulating Thread::suspend_count_. |
| 631 | // TODO: Does the trade-off of a per-thread lock make sense? |
| 632 | static Mutex* thread_suspend_count_lock_ ACQUIRED_AFTER(abort_lock_); |
| 633 | |
| 634 | // One unexpected signal at a time lock. |
| 635 | static Mutex* unexpected_signal_lock_ ACQUIRED_AFTER(thread_suspend_count_lock_); |
| 636 | |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 637 | // Guards the maps in mem_map. |
| 638 | static Mutex* mem_maps_lock_ ACQUIRED_AFTER(unexpected_signal_lock_); |
| 639 | |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 640 | // Have an exclusive logging thread. |
| 641 | static Mutex* logging_lock_ ACQUIRED_AFTER(unexpected_signal_lock_); |
| 642 | }; |
| 643 | |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 644 | } // namespace art |
| 645 | |
Brian Carlstrom | fc0e321 | 2013-07-17 14:40:12 -0700 | [diff] [blame] | 646 | #endif // ART_RUNTIME_BASE_MUTEX_H_ |