thread_list.h revision 87f8b4cf0c1d6aab3eb5d1e99cc4e7cf175ef772 
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/mutex.h"
21#include "jni.h"
22#include "object_callbacks.h"
23
24#include <bitset>
25#include <list>
26
27namespace art {
28class Closure;
29class Thread;
30class TimingLogger;
31
32class ThreadList {
33 public:
34  static const uint32_t kMaxThreadId = 0xFFFF;
35  static const uint32_t kInvalidThreadId = 0;
36  static const uint32_t kMainThreadId = 1;
37
38  explicit ThreadList();
39  ~ThreadList();
40
41  void DumpForSigQuit(std::ostream& os)
42      LOCKS_EXCLUDED(Locks::thread_list_lock_)
43      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
44  void DumpLocked(std::ostream& os)  // For thread suspend timeout dumps.
45      EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_)
46      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
47  pid_t GetLockOwner();  // For SignalCatcher.
48
49  // Thread suspension support.
50  void ResumeAll()
51      UNLOCK_FUNCTION(Locks::mutator_lock_)
52      LOCKS_EXCLUDED(Locks::thread_list_lock_,
53                     Locks::thread_suspend_count_lock_);
54  void Resume(Thread* thread, bool for_debugger = false)
55      LOCKS_EXCLUDED(Locks::thread_suspend_count_lock_);
56
57  // Suspends all threads and gets exclusive access to the mutator_lock_.
58  void SuspendAll()
59      EXCLUSIVE_LOCK_FUNCTION(Locks::mutator_lock_)
60      LOCKS_EXCLUDED(Locks::thread_list_lock_,
61                     Locks::thread_suspend_count_lock_);
62
63
64  // Suspend a thread using a peer, typically used by the debugger. Returns the thread on success,
65  // else NULL. The peer is used to identify the thread to avoid races with the thread terminating.
66  // If the thread should be suspended then value of request_suspension should be true otherwise
67  // the routine will wait for a previous suspend request. If the suspension times out then *timeout
68  // is set to true.
69  static Thread* SuspendThreadByPeer(jobject peer, bool request_suspension, bool debug_suspension,
70                                     bool* timed_out)
71      LOCKS_EXCLUDED(Locks::mutator_lock_,
72                     Locks::thread_list_lock_,
73                     Locks::thread_suspend_count_lock_);
74
75  // Suspend a thread using its thread id, typically used by lock/monitor inflation. Returns the
76  // thread on success else NULL. The thread id is used to identify the thread to avoid races with
77  // the thread terminating. Note that as thread ids are recycled this may not suspend the expected
78  // thread, that may be terminating. If the suspension times out then *timeout is set to true.
79  Thread* SuspendThreadByThreadId(uint32_t thread_id, bool debug_suspension, bool* timed_out)
80      LOCKS_EXCLUDED(Locks::mutator_lock_,
81                     Locks::thread_list_lock_,
82                     Locks::thread_suspend_count_lock_);
83
84  // Find an already suspended thread (or self) by its id.
85  Thread* FindThreadByThreadId(uint32_t thin_lock_id);
86
87  // Run a checkpoint on threads, running threads are not suspended but run the checkpoint inside
88  // of the suspend check. Returns how many checkpoints we should expect to run.
89  size_t RunCheckpoint(Closure* checkpoint_function)
90      LOCKS_EXCLUDED(Locks::thread_list_lock_,
91                     Locks::thread_suspend_count_lock_);
92
93  size_t RunCheckpointOnRunnableThreads(Closure* checkpoint_function)
94      LOCKS_EXCLUDED(Locks::thread_list_lock_, Locks::thread_suspend_count_lock_);
95
96  // Suspends all threads
97  void SuspendAllForDebugger()
98      LOCKS_EXCLUDED(Locks::mutator_lock_,
99                     Locks::thread_list_lock_,
100                     Locks::thread_suspend_count_lock_);
101
102  void SuspendSelfForDebugger()
103      LOCKS_EXCLUDED(Locks::thread_suspend_count_lock_);
104
105  void UndoDebuggerSuspensions()
106      LOCKS_EXCLUDED(Locks::thread_list_lock_,
107                     Locks::thread_suspend_count_lock_);
108
109  // Iterates over all the threads.
110  void ForEach(void (*callback)(Thread*, void*), void* context)
111      EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_);
112
113  // Add/remove current thread from list.
114  void Register(Thread* self)
115      EXCLUSIVE_LOCKS_REQUIRED(Locks::runtime_shutdown_lock_)
116      LOCKS_EXCLUDED(Locks::mutator_lock_, Locks::thread_list_lock_);
117  void Unregister(Thread* self) LOCKS_EXCLUDED(Locks::mutator_lock_, Locks::thread_list_lock_);
118
119  void VisitRoots(RootCallback* callback, void* arg) const
120      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
121
122  void VerifyRoots(VerifyRootCallback* callback, void* arg) const
123      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
124
125  // Return a copy of the thread list.
126  std::list<Thread*> GetList() EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_) {
127    return list_;
128  }
129
130  void DumpNativeStacks(std::ostream& os)
131      LOCKS_EXCLUDED(Locks::thread_list_lock_);
132
133 private:
134  uint32_t AllocThreadId(Thread* self);
135  void ReleaseThreadId(Thread* self, uint32_t id) LOCKS_EXCLUDED(allocated_ids_lock_);
136
137  bool Contains(Thread* thread) EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_);
138  bool Contains(pid_t tid) EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_);
139
140  void DumpUnattachedThreads(std::ostream& os)
141      LOCKS_EXCLUDED(Locks::thread_list_lock_);
142
143  void SuspendAllDaemonThreads()
144      LOCKS_EXCLUDED(Locks::thread_list_lock_,
145                     Locks::thread_suspend_count_lock_);
146  void WaitForOtherNonDaemonThreadsToExit()
147      LOCKS_EXCLUDED(Locks::thread_list_lock_,
148                     Locks::thread_suspend_count_lock_);
149
150  void AssertThreadsAreSuspended(Thread* self, Thread* ignore1, Thread* ignore2 = NULL)
151      LOCKS_EXCLUDED(Locks::thread_list_lock_,
152                     Locks::thread_suspend_count_lock_);
153
154  mutable Mutex allocated_ids_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
155  std::bitset<kMaxThreadId> allocated_ids_ GUARDED_BY(allocated_ids_lock_);
156
157  // The actual list of all threads.
158  std::list<Thread*> list_ GUARDED_BY(Locks::thread_list_lock_);
159
160  // Ongoing suspend all requests, used to ensure threads added to list_ respect SuspendAll.
161  int suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_);
162  int debug_suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_);
163
164  // Signaled when threads terminate. Used to determine when all non-daemons have terminated.
165  ConditionVariable thread_exit_cond_ GUARDED_BY(Locks::thread_list_lock_);
166
167  friend class Thread;
168
169  DISALLOW_COPY_AND_ASSIGN(ThreadList);
170};
171
172}  // namespace art
173
174#endif  // ART_RUNTIME_THREAD_LIST_H_
175