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