1 /* Copyright (c) 2015, 2020 The Linux Foundation. All rights reserved.
2  *
3  * Redistribution and use in source and binary forms, with or without
4  * modification, are permitted provided that the following conditions are
5  * met:
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7  *       notice, this list of conditions and the following disclaimer.
8  *     * Redistributions in binary form must reproduce the above
9  *       copyright notice, this list of conditions and the following
10  *       disclaimer in the documentation and/or other materials provided
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12  *     * Neither the name of The Linux Foundation, nor the names of its
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14  *       from this software without specific prior written permission.
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16  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
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28  */
29 #ifndef __LOC_THREAD__
30 #define __LOC_THREAD__
31 
32 #include <stddef.h>
33 #include <memory>
34 
35 using std::shared_ptr;
36 
37 namespace loc_util {
38 
39 // abstract class to be implemented by client to provide a runnable class
40 // which gets scheduled by LocThread
41 class LocRunnable {
42 public:
43     inline LocRunnable() = default;
44     inline virtual ~LocRunnable() = default;
45 
46     // The method to be implemented by thread clients
47     // and be scheduled by LocThread
48     // This method will be repeated called until it returns false; or
49     // until thread is stopped.
50     virtual bool run() = 0;
51 
52     // The method to be run before thread loop (conditionally repeatedly)
53     // calls run()
prerun()54     inline virtual void prerun() {}
55 
56     // The method to be run after thread loop (conditionally repeatedly)
57     // calls run()
postrun()58     inline virtual void postrun() {}
59 
60     // The method to wake up the potential blocking thread
61     // no op if not applicable
62     inline virtual void interrupt() = 0;
63 };
64 
65 // opaque class to provide service implementation.
66 class LocThreadDelegate;
67 
68 // A utility class to create a thread and run LocRunnable
69 // caller passes in.
70 class LocThread {
71     LocThreadDelegate* mThread;
72 public:
LocThread()73     inline LocThread() : mThread(NULL) {}
~LocThread()74     inline virtual ~LocThread() { stop(); }
75 
76     // client starts thread with a runnable, which implements
77     // the logics to fun in the created thread context.
78     // The thread is always detached.
79     // runnable is an obj managed by client. Client creates and
80     //          frees it (but must be after stop() is called, or
81     //          this LocThread obj is deleted).
82     //          The obj will be deleted by LocThread if start()
83     //          returns true. Else it is client's responsibility
84     //          to delete the object
85     // Returns 0 if success; false if failure.
86     bool start(const char* threadName, shared_ptr<LocRunnable> runnable);
87 
88     void stop();
89 
90     // thread status check
isRunning()91     inline bool isRunning() { return NULL != mThread; }
92 };
93 
94 } // loc_util
95 #endif //__LOC_THREAD__
96