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30
31 //////////////////////////////////////////////////////////////////////////
32 // SemaphoreLinux.cpp
33 //
34 // This file contains the linux implementation of the Semaphore class
35 //////////////////////////////////////////////////////////////////////////
36 #ifdef HAVE_CONFIG_H
37 #include "config.h"
38 #endif
39 #include "Semaphore.h"
40 #include <semaphore.h>
41
42 class OSSemaphore {
43 public:
44 sem_t _sem;
45 };
46
Semaphore(int maxval)47 Semaphore::Semaphore(int maxval)
48 {
49 _osSemaphore = new OSSemaphore;
50 sem_init(&_osSemaphore->_sem, 0, maxval);
51 }
52
~Semaphore()53 Semaphore::~Semaphore()
54 {
55 sem_destroy(&_osSemaphore->_sem);
56 delete _osSemaphore;
57 }
58
acquire()59 void Semaphore::acquire()
60 {
61 // blocks until value !=0, and decrements the value
62 sem_wait(&_osSemaphore->_sem);
63 }
64
release()65 void Semaphore::release()
66 {
67 // increments the value by 1
68 sem_post(&_osSemaphore->_sem);
69 }
70
acquireTry()71 bool Semaphore::acquireTry()
72 {
73 // try to acquire the semaphore: return 'true' if succeded
74 return (sem_trywait(&_osSemaphore->_sem) == 0);
75 }
76
77