source/core/semaphore.cpp

   1 /* $Id$
   2
   3 This file is part of libmspcore
   4 Copyright © 2006  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #ifndef WIN32
   9 #include <sys/time.h>
  10 #endif
  11 #include <errno.h>
  12 #include "semaphore.h"
  13 #include "../time/timestamp.h"
  14 #include "../time/units.h"
  15 #include "../time/utils.h"
  16
  17 namespace Msp {
  18
  19 Semaphore::Semaphore():
  20         mutex(new Mutex),
  21         own_mutex(true)
  22 {
  23         init();
  24 }
  25
  26 Semaphore::Semaphore(Mutex &m):
  27         mutex(&m),
  28         own_mutex(false)
  29 {
  30         init();
  31 }
  32
  33 void Semaphore::init()
  34 {
  35 #ifdef WIN32
  36         count = 0;
  37         sem = CreateSemaphore(0, 0, 32, 0);
  38 #else
  39         pthread_cond_init(&sem, 0);
  40 #endif
  41 }
  42
  43 Semaphore::~Semaphore()
  44 {
  45         if(own_mutex)
  46                 delete mutex;
  47 #ifdef WIN32
  48         CloseHandle(sem);
  49 #else
  50         pthread_cond_destroy(&sem);
  51 #endif
  52 }
  53
  54 #ifdef WIN32
  55 int Semaphore::signal()
  56 {
  57         if(count==0)
  58                 return 0;
  59
  60         int ret = !ReleaseSemaphore(sem, 1, 0);
  61
  62         unsigned old_count = count;
  63         mutex->unlock();
  64         while(count==old_count)
  65                 Sleep(0);
  66         mutex->lock();
  67
  68         return ret;
  69 }
  70
  71 int Semaphore::broadcast()
  72 {
  73         if(count==0)
  74                 return 0;
  75         int ret = !ReleaseSemaphore(sem, count, 0);
  76
  77         mutex->unlock();
  78         while(count)
  79                 Sleep(0);
  80         mutex->lock();
  81
  82         return ret;
  83 }
  84
  85 int Semaphore::wait()
  86 {
  87         ++count;
  88         mutex->unlock();
  89         DWORD ret = WaitForSingleObject(sem, INFINITE);
  90         mutex->lock();
  91         --count;
  92
  93         return ret==WAIT_OBJECT_0;
  94 }
  95 #endif
  96
  97 int Semaphore::wait(const Time::TimeDelta &d)
  98 {
  99 #ifndef WIN32
 100         Time::TimeStamp ts = Time::now()+d;
 101
 102         timespec timeout;
 103         timeout.tv_sec = ts.raw()/1000000;
 104         timeout.tv_nsec = (ts.raw()%1000000)*1000;
 105
 106         int r = pthread_cond_timedwait(&sem, &mutex->mutex, &timeout);
 107         if(r==ETIMEDOUT)
 108                 return 1;
 109         else if(r)
 110                 return -1;
 111         return 0;
 112 #else
 113         ++count;
 114         mutex->lock();
 115         DWORD ret = WaitForSingleObject(sem, (DWORD)(d/Time::usec));
 116         mutex->unlock();
 117         --count;
 118         return ret==WAIT_OBJECT_0;
 119 #endif
 120 }
 121
 122 } // namespace Msp