1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
2  *
3  *  Data Differential Utility library
4  *
5  *  Copyright (C) 2012 Data Differential, http://datadifferential.com/
6  *
7  *  Redistribution and use in source and binary forms, with or without
8  *  modification, are permitted provided that the following conditions are
9  *  met:
10  *
11  *      * Redistributions of source code must retain the above copyright
12  *  notice, this list of conditions and the following disclaimer.
13  *
14  *      * Redistributions in binary form must reproduce the above
15  *  copyright notice, this list of conditions and the following disclaimer
16  *  in the documentation and/or other materials provided with the
17  *  distribution.
18  *
19  *      * The names of its contributors may not be used to endorse or
20  *  promote products derived from this software without specific prior
21  *  written permission.
22  *
23  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
29  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
33  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  *
35  */
36 
37 #pragma once
38 
39 #include <pthread.h>
40 #include <semaphore.h>
41 
42 #ifdef HAVE_SIGNAL_H
43 #include <signal.h>
44 #endif
45 
46 #ifdef	__cplusplus
47 extern "C" {
48 #endif
49 
50 typedef void (signal_callback_fn)();
51 
52 #ifdef	__cplusplus
53 }
54 #endif
55 
56 namespace datadifferential {
57 namespace util {
58 
59 enum shutdown_t {
60   SHUTDOWN_RUNNING,
61   SHUTDOWN_GRACEFUL,
62   SHUTDOWN_FORCED
63 };
64 
65 class SignalThread {
66   bool _exit_on_signal;
67   sigset_t set;
68   sem_t lock;
69   uint64_t magic_memory;
70   volatile shutdown_t __shutdown;
71   pthread_mutex_t shutdown_mutex;
72 
73 public:
74 
75   SignalThread(bool exit_on_signal_arg= false);
76 
77   void test();
78   void post();
79   bool setup();
80 
exit_on_signal()81   bool exit_on_signal()
82   {
83     return _exit_on_signal;
84   }
85 
wait(int & sig)86   int wait(int& sig)
87   {
88     return sigwait(&set, &sig);
89   }
90 
91   ~SignalThread();
92 
93   void set_shutdown(shutdown_t arg);
94   bool is_shutdown();
95   shutdown_t get_shutdown();
96 
97   void sighup();
98   void sighup(signal_callback_fn* arg);
99 
100 private:
101   pthread_t thread;
102   signal_callback_fn* _sighup;
103 };
104 
105 } /* namespace util */
106 } /* namespace datadifferential */
107