1 /*
2  * Copyright (C) 2008 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_SIGNAL_CATCHER_H_
18 #define ART_RUNTIME_SIGNAL_CATCHER_H_
19 
20 #include "base/mutex.h"
21 
22 namespace art {
23 
24 class Runtime;
25 class SignalSet;
26 class Thread;
27 
28 /*
29  * A daemon thread that catches signals and does something useful. For
30  * example, when a SIGQUIT (Ctrl-\) arrives, we suspend and dump the
31  * status of all threads.
32  */
33 class SignalCatcher {
34  public:
35   explicit SignalCatcher(const std::string& stack_trace_file);
36   ~SignalCatcher();
37 
38   void HandleSigQuit() LOCKS_EXCLUDED(Locks::mutator_lock_,
39                                       Locks::thread_list_lock_,
40                                       Locks::thread_suspend_count_lock_);
41 
42 
43  private:
44   static void* Run(void* arg);
45 
46   void HandleSigUsr1();
47   void Output(const std::string& s);
48   void SetHaltFlag(bool new_value);
49   bool ShouldHalt();
50   int WaitForSignal(Thread* self, SignalSet& signals);
51 
52   std::string stack_trace_file_;
53 
54   mutable Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
55   ConditionVariable cond_ GUARDED_BY(lock_);
56   bool halt_ GUARDED_BY(lock_);
57   pthread_t pthread_ GUARDED_BY(lock_);
58   Thread* thread_ GUARDED_BY(lock_);
59 };
60 
61 }  // namespace art
62 
63 #endif  // ART_RUNTIME_SIGNAL_CATCHER_H_
64