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