1 /*
2  * Copyright (C) 2015 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 ANDROID_WORKER_H_
18 #define ANDROID_WORKER_H_
19 
20 #include <pthread.h>
21 #include <stdint.h>
22 #include <string>
23 
24 namespace android {
25 
26 class Worker {
27  public:
28   int Lock();
29   int Unlock();
30 
31   // Must be called with the lock acquired
32   int SignalLocked();
33   int ExitLocked();
34 
35   // Convenience versions of above, acquires the lock
36   int Signal();
37   int Exit();
38 
39  protected:
40   Worker(const char *name, int priority);
41   virtual ~Worker();
42 
43   int InitWorker();
44 
45   bool initialized() const;
46 
47   virtual void Routine() = 0;
48 
49   /*
50    * Must be called with the lock acquired. max_nanoseconds may be negative to
51    * indicate infinite timeout, otherwise it indicates the maximum time span to
52    * wait for a signal before returning.
53    * Returns -EINTR if interrupted by exit request, or -ETIMEDOUT if timed out
54    */
55   int WaitForSignalOrExitLocked(int64_t max_nanoseconds = -1);
56 
57  private:
58   static void *InternalRoutine(void *worker);
59 
60   // Must be called with the lock acquired
61   int SignalThreadLocked(bool exit);
62 
63   std::string name_;
64   int priority_;
65 
66   pthread_t thread_;
67   pthread_mutex_t lock_;
68   pthread_cond_t cond_;
69 
70   bool exit_;
71   bool initialized_;
72 };
73 }
74 
75 #endif
76