source: vscpl/src/hu/varadiistvan/scpl/_posix/CondVar.h@ 8:7b2598d1ea55

Last change on this file since 8:7b2598d1ea55 was 6:53519b47b166, checked in by István Váradi <ivaradi@…>, 12 years ago

Imported some further stuff from the IO code

File size: 4.5 KB
Line 
1// Copyright (c) 2013 by István Váradi
2
3// This file is part of VSCPL, a simple cross-platform utility library
4
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are met:
7
8// 1. Redistributions of source code must retain the above copyright notice, this
9// list of conditions and the following disclaimer.
10// 2. Redistributions in binary form must reproduce the above copyright notice,
11// this list of conditions and the following disclaimer in the documentation
12// and/or other materials provided with the distribution.
13
14// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
15// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
18// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24
25// The views and conclusions contained in the software and documentation are those
26// of the authors and should not be interpreted as representing official policies,
27// either expressed or implied, of the FreeBSD Project.
28
29#ifndef HU_VARADIISTVAN_SCPL_POSIX_CONDVAR_H
30#define HU_VARADIISTVAN_SCPL_POSIX_CONDVAR_H
31//------------------------------------------------------------------------------
32
33#include "Mutex.h"
34
35//------------------------------------------------------------------------------
36
37namespace hu { namespace varadiistvan { namespace scpl {
38
39//------------------------------------------------------------------------------
40
41/**
42 * A condition variable for POSIX threads.
43 */
44class CondVar
45{
46private:
47 /**
48 * Fill the given timespec with the absolute time corresponding to
49 * the given relative timeout.
50 */
51 static void getAbsTime(struct ::timespec& abstime, int timeout);
52
53 /**
54 * The pthreads structure.
55 */
56 pthread_cond_t cond;
57
58public:
59 /**
60 * Construct the condition variable.
61 */
62 CondVar();
63
64 /**
65 * Destroy the condition variable.
66 */
67 ~CondVar();
68
69 /**
70 * Wait for the condition variable.
71 *
72 * @param mutex the mutex to unlock and re-lock.
73 * @param timeout the number of milliseconds to wait at most. If
74 * negative, the function will wait indefinitely.
75 *
76 * @return true, if the condition variable was signalled, false
77 * if a timeout occured
78 */
79 bool wait(Mutex& mutex, int timeout = -1);
80
81 /**
82 * Signal the condition variable to wake up one thread.
83 */
84 void signal();
85
86 /**
87 * Signal all threads waiting on the condition variable.
88 */
89 void broadcast();
90};
91
92//------------------------------------------------------------------------------
93// Inline definitions
94//------------------------------------------------------------------------------
95
96inline CondVar::CondVar()
97{
98 pthread_cond_init(&cond, 0);
99}
100
101//------------------------------------------------------------------------------
102
103inline CondVar::~CondVar()
104{
105 pthread_cond_destroy(&cond);
106}
107
108//------------------------------------------------------------------------------
109
110inline bool CondVar::wait(Mutex& mutex, int timeout)
111{
112 if (timeout<0) {
113 pthread_cond_wait(&cond, &mutex.mutex);
114 return true;
115 } else {
116 struct ::timespec abstime;
117 getAbsTime(abstime, timeout);
118 return pthread_cond_timedwait(&cond, &mutex.mutex, &abstime)==0;
119 }
120}
121
122//------------------------------------------------------------------------------
123
124inline void CondVar::signal()
125{
126 pthread_cond_signal(&cond);
127}
128
129//------------------------------------------------------------------------------
130
131inline void CondVar::broadcast()
132{
133 pthread_cond_broadcast(&cond);
134}
135
136//------------------------------------------------------------------------------
137
138} /* namespace hu::varadiistvan::scpl */ } /* namespace hu::varadiistvan */ } /* namespace hu */
139
140//------------------------------------------------------------------------------
141#endif // HU_VARADIISTVAN_SCPL_CONDVAR_H
142
143// Local Variables:
144// mode: C++
145// c-basic-offset: 4
146// indent-tabs-mode: nil
147// End:
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