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 "root_visitor.h"
22
23#include <bitset>
24#include <list>
25
26namespace art {
27class Closure;
28class Thread;
29class TimingLogger;
30
31class ThreadList {
32 public:
33  static const uint32_t kMaxThreadId = 0xFFFF;
34  static const uint32_t kInvalidId = 0;
35  static const uint32_t kMainId = 1;
36
37  explicit ThreadList();
38  ~ThreadList();
39
40  void DumpForSigQuit(std::ostream& os)
41      LOCKS_EXCLUDED(Locks::thread_list_lock_)
42      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
43  void DumpLocked(std::ostream& os)  // For thread suspend timeout dumps.
44      EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_)
45      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
46  pid_t GetLockOwner();  // For SignalCatcher.
47
48  // Thread suspension support.
49  void ResumeAll()
50      UNLOCK_FUNCTION(Locks::mutator_lock_)
51      LOCKS_EXCLUDED(Locks::thread_list_lock_,
52                     Locks::thread_suspend_count_lock_);
53  void Resume(Thread* thread, bool for_debugger = false)
54      LOCKS_EXCLUDED(Locks::thread_suspend_count_lock_);
55
56  // Suspends all threads and gets exclusive access to the mutator_lock_.
57  void SuspendAll()
58      EXCLUSIVE_LOCK_FUNCTION(Locks::mutator_lock_)
59      LOCKS_EXCLUDED(Locks::thread_list_lock_,
60                     Locks::thread_suspend_count_lock_);
61
62  // Run a checkpoint on threads, running threads are not suspended but run the checkpoint inside
63  // of the suspend check. Returns how many checkpoints we should expect to run.
64  size_t RunCheckpoint(Closure* checkpoint_function);
65      LOCKS_EXCLUDED(Locks::thread_list_lock_,
66                     Locks::thread_suspend_count_lock_);
67
68  // Suspends all threads
69  void SuspendAllForDebugger()
70      LOCKS_EXCLUDED(Locks::mutator_lock_,
71                     Locks::thread_list_lock_,
72                     Locks::thread_suspend_count_lock_);
73
74  void SuspendSelfForDebugger()
75      LOCKS_EXCLUDED(Locks::thread_suspend_count_lock_);
76
77  void UndoDebuggerSuspensions()
78      LOCKS_EXCLUDED(Locks::thread_list_lock_,
79                     Locks::thread_suspend_count_lock_);
80
81  // Iterates over all the threads.
82  void ForEach(void (*callback)(Thread*, void*), void* context)
83      EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_);
84
85  // Add/remove current thread from list.
86  void Register(Thread* self)
87      EXCLUSIVE_LOCKS_REQUIRED(Locks::runtime_shutdown_lock_)
88      LOCKS_EXCLUDED(Locks::mutator_lock_, Locks::thread_list_lock_);
89  void Unregister(Thread* self) LOCKS_EXCLUDED(Locks::mutator_lock_, Locks::thread_list_lock_);
90
91  void VisitRoots(RootVisitor* visitor, void* arg) const
92      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
93
94  void VerifyRoots(VerifyRootVisitor* visitor, void* arg) const
95      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
96
97  // Return a copy of the thread list.
98  std::list<Thread*> GetList() EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_) {
99    return list_;
100  }
101
102  Thread* FindThreadByThinLockId(uint32_t thin_lock_id);
103
104 private:
105  uint32_t AllocThreadId(Thread* self);
106  void ReleaseThreadId(Thread* self, uint32_t id) LOCKS_EXCLUDED(allocated_ids_lock_);
107
108  bool Contains(Thread* thread) EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_);
109  bool Contains(pid_t tid) EXCLUSIVE_LOCKS_REQUIRED(Locks::thread_list_lock_);
110
111  void DumpUnattachedThreads(std::ostream& os)
112      LOCKS_EXCLUDED(Locks::thread_list_lock_);
113
114  void SuspendAllDaemonThreads()
115      LOCKS_EXCLUDED(Locks::thread_list_lock_,
116                     Locks::thread_suspend_count_lock_);
117  void WaitForOtherNonDaemonThreadsToExit()
118      LOCKS_EXCLUDED(Locks::thread_list_lock_,
119                     Locks::thread_suspend_count_lock_);
120
121  void AssertThreadsAreSuspended(Thread* self, Thread* ignore1, Thread* ignore2 = NULL)
122      LOCKS_EXCLUDED(Locks::thread_list_lock_,
123                     Locks::thread_suspend_count_lock_);
124
125  mutable Mutex allocated_ids_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
126  std::bitset<kMaxThreadId> allocated_ids_ GUARDED_BY(allocated_ids_lock_);
127
128  // The actual list of all threads.
129  std::list<Thread*> list_ GUARDED_BY(Locks::thread_list_lock_);
130
131  // Ongoing suspend all requests, used to ensure threads added to list_ respect SuspendAll.
132  int suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_);
133  int debug_suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_);
134
135  // Signaled when threads terminate. Used to determine when all non-daemons have terminated.
136  ConditionVariable thread_exit_cond_ GUARDED_BY(Locks::thread_list_lock_);
137
138  friend class Thread;
139
140  DISALLOW_COPY_AND_ASSIGN(ThreadList);
141};
142
143}  // namespace art
144
145#endif  // ART_RUNTIME_THREAD_LIST_H_
146