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 17 #ifndef ART_RUNTIME_THREAD_LIST_H_ 18 #define ART_RUNTIME_THREAD_LIST_H_ 19 20 #include "base/histogram.h" 21 #include "base/mutex.h" 22 #include "base/value_object.h" 23 #include "gc_root.h" 24 #include "jni.h" 25 #include "object_callbacks.h" 26 27 #include <bitset> 28 #include <list> 29 30 namespace art { 31 namespace gc { 32 namespace collector { 33 class GarbageCollector; 34 } // namespac collector 35 } // namespace gc 36 class Closure; 37 class Thread; 38 class TimingLogger; 39 40 class ThreadList { 41 public: 42 static const uint32_t kMaxThreadId = 0xFFFF; 43 static const uint32_t kInvalidThreadId = 0; 44 static const uint32_t kMainThreadId = 1; 45 46 explicit ThreadList(); 47 ~ThreadList(); 48 49 void DumpForSigQuit(std::ostream& os) 50 REQUIRES(!Locks::thread_list_lock_, !Locks::mutator_lock_); 51 // For thread suspend timeout dumps. 52 void Dump(std::ostream& os, bool dump_native_stack = true) 53 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 54 pid_t GetLockOwner(); // For SignalCatcher. 55 56 // Thread suspension support. 57 void ResumeAll() 58 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_) 59 UNLOCK_FUNCTION(Locks::mutator_lock_); 60 void Resume(Thread* thread, bool for_debugger = false) 61 REQUIRES(!Locks::thread_suspend_count_lock_); 62 63 // Suspends all threads and gets exclusive access to the mutator_lock_. 64 // If long_suspend is true, then other threads who try to suspend will never timeout. 65 // long_suspend is currenly used for hprof since large heaps take a long time. 66 void SuspendAll(const char* cause, bool long_suspend = false) 67 EXCLUSIVE_LOCK_FUNCTION(Locks::mutator_lock_) 68 REQUIRES(!Locks::thread_list_lock_, 69 !Locks::thread_suspend_count_lock_, 70 !Locks::mutator_lock_); 71 72 // Suspend a thread using a peer, typically used by the debugger. Returns the thread on success, 73 // else null. The peer is used to identify the thread to avoid races with the thread terminating. 74 // If the thread should be suspended then value of request_suspension should be true otherwise 75 // the routine will wait for a previous suspend request. If the suspension times out then *timeout 76 // is set to true. 77 Thread* SuspendThreadByPeer(jobject peer, bool request_suspension, bool debug_suspension, 78 bool* timed_out) 79 REQUIRES(!Locks::mutator_lock_, 80 !Locks::thread_list_lock_, 81 !Locks::thread_suspend_count_lock_); 82 83 // Suspend a thread using its thread id, typically used by lock/monitor inflation. Returns the 84 // thread on success else null. The thread id is used to identify the thread to avoid races with 85 // the thread terminating. Note that as thread ids are recycled this may not suspend the expected 86 // thread, that may be terminating. If the suspension times out then *timeout is set to true. 87 Thread* SuspendThreadByThreadId(uint32_t thread_id, bool debug_suspension, bool* timed_out) 88 REQUIRES(!Locks::mutator_lock_, 89 !Locks::thread_list_lock_, 90 !Locks::thread_suspend_count_lock_); 91 92 // Find an existing thread (or self) by its thread id (not tid). 93 Thread* FindThreadByThreadId(uint32_t thread_id) REQUIRES(Locks::thread_list_lock_); 94 95 // Run a checkpoint on threads, running threads are not suspended but run the checkpoint inside 96 // of the suspend check. Returns how many checkpoints that are expected to run, including for 97 // already suspended threads for b/24191051. 98 size_t RunCheckpoint(Closure* checkpoint_function) 99 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 100 101 size_t RunCheckpointOnRunnableThreads(Closure* checkpoint_function) 102 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 103 104 // Flip thread roots from from-space refs to to-space refs. Used by 105 // the concurrent copying collector. 106 size_t FlipThreadRoots(Closure* thread_flip_visitor, 107 Closure* flip_callback, 108 gc::collector::GarbageCollector* collector) 109 REQUIRES(!Locks::mutator_lock_, 110 !Locks::thread_list_lock_, 111 !Locks::thread_suspend_count_lock_); 112 113 // Suspends all threads 114 void SuspendAllForDebugger() 115 REQUIRES(!Locks::mutator_lock_, 116 !Locks::thread_list_lock_, 117 !Locks::thread_suspend_count_lock_); 118 119 void SuspendSelfForDebugger() 120 REQUIRES(!Locks::thread_suspend_count_lock_); 121 122 // Resume all threads 123 void ResumeAllForDebugger() 124 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 125 126 void UndoDebuggerSuspensions() 127 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 128 129 // Iterates over all the threads. 130 void ForEach(void (*callback)(Thread*, void*), void* context) 131 REQUIRES(Locks::thread_list_lock_); 132 133 // Add/remove current thread from list. 134 void Register(Thread* self) 135 REQUIRES(Locks::runtime_shutdown_lock_) 136 REQUIRES(!Locks::mutator_lock_, 137 !Locks::thread_list_lock_, 138 !Locks::thread_suspend_count_lock_); 139 void Unregister(Thread* self) 140 REQUIRES(!Locks::mutator_lock_, 141 !Locks::thread_list_lock_, 142 !Locks::thread_suspend_count_lock_); 143 144 void VisitRoots(RootVisitor* visitor) const 145 SHARED_REQUIRES(Locks::mutator_lock_); 146 147 // Return a copy of the thread list. 148 std::list<Thread*> GetList() REQUIRES(Locks::thread_list_lock_) { 149 return list_; 150 } 151 152 void DumpNativeStacks(std::ostream& os) 153 REQUIRES(!Locks::thread_list_lock_); 154 155 private: 156 uint32_t AllocThreadId(Thread* self); 157 void ReleaseThreadId(Thread* self, uint32_t id) REQUIRES(!Locks::allocated_thread_ids_lock_); 158 159 bool Contains(Thread* thread) REQUIRES(Locks::thread_list_lock_); 160 bool Contains(pid_t tid) REQUIRES(Locks::thread_list_lock_); 161 size_t RunCheckpoint(Closure* checkpoint_function, bool includeSuspended) 162 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 163 164 void DumpUnattachedThreads(std::ostream& os, bool dump_native_stack) 165 REQUIRES(!Locks::thread_list_lock_); 166 167 void SuspendAllDaemonThreadsForShutdown() 168 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 169 void WaitForOtherNonDaemonThreadsToExit() 170 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 171 172 void SuspendAllInternal(Thread* self, 173 Thread* ignore1, 174 Thread* ignore2 = nullptr, 175 bool debug_suspend = false) 176 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 177 178 void AssertThreadsAreSuspended(Thread* self, Thread* ignore1, Thread* ignore2 = nullptr) 179 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); 180 181 std::bitset<kMaxThreadId> allocated_ids_ GUARDED_BY(Locks::allocated_thread_ids_lock_); 182 183 // The actual list of all threads. 184 std::list<Thread*> list_ GUARDED_BY(Locks::thread_list_lock_); 185 186 // Ongoing suspend all requests, used to ensure threads added to list_ respect SuspendAll. 187 int suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_); 188 int debug_suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_); 189 190 // Number of threads unregistering, ~ThreadList blocks until this hits 0. 191 int unregistering_count_ GUARDED_BY(Locks::thread_list_lock_); 192 193 // Thread suspend time histogram. Only modified when all the threads are suspended, so guarding 194 // by mutator lock ensures no thread can read when another thread is modifying it. 195 Histogram<uint64_t> suspend_all_historam_ GUARDED_BY(Locks::mutator_lock_); 196 197 // Whether or not the current thread suspension is long. 198 bool long_suspend_; 199 200 friend class Thread; 201 202 DISALLOW_COPY_AND_ASSIGN(ThreadList); 203 }; 204 205 // Helper for suspending all threads and 206 class ScopedSuspendAll : public ValueObject { 207 public: 208 ScopedSuspendAll(const char* cause, bool long_suspend = false) 209 EXCLUSIVE_LOCK_FUNCTION(Locks::mutator_lock_) 210 REQUIRES(!Locks::thread_list_lock_, 211 !Locks::thread_suspend_count_lock_, 212 !Locks::mutator_lock_); 213 // No REQUIRES(mutator_lock_) since the unlock function already asserts this. 214 ~ScopedSuspendAll() 215 REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_) 216 UNLOCK_FUNCTION(Locks::mutator_lock_); 217 }; 218 219 } // namespace art 220 221 #endif // ART_RUNTIME_THREAD_LIST_H_ 222
