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