hvirtual/guicast/condition.C

   1 #include "condition.h"
   2
   3 #include <errno.h>
   4 #include <sys/time.h>
   5
   6 Condition::Condition(int init_value)
   7 {
   8         pthread_mutex_init(&mutex, 0);
   9         pthread_cond_init(&cond, NULL);
  10         value = init_value;
  11 }
  12
  13 Condition:: ~Condition()
  14 {
  15     pthread_cond_destroy(&cond);
  16     pthread_mutex_destroy(&mutex);
  17 }
  18
  19
  20 void Condition::lock()
  21 {
  22     pthread_mutex_lock(&mutex);
  23     while(value <= 0) pthread_cond_wait(&cond, &mutex);
  24         value--;
  25     pthread_mutex_unlock(&mutex);
  26 }
  27
  28 void Condition::unlock()
  29 {
  30     pthread_mutex_lock(&mutex);
  31     value++;
  32     pthread_cond_signal(&cond);
  33     pthread_mutex_unlock(&mutex);
  34 }
  35
  36 int Condition::timed_lock(int milliseconds)
  37 {
  38     struct timeval now;
  39     struct timespec timeout;
  40     int result = 0;
  41
  42     pthread_mutex_lock(&mutex);
  43     gettimeofday(&now, 0);
  44     timeout.tv_sec = now.tv_sec + milliseconds / 1000000;
  45     timeout.tv_nsec = now.tv_usec * 1000 + (milliseconds % 1000000) * 1000;
  46
  47     while(value <= 0 && result != ETIMEDOUT)
  48         {
  49                 result = pthread_cond_timedwait(&cond, &mutex, &timeout);
  50     }
  51
  52     if(result == ETIMEDOUT)
  53         {
  54                 result = 1;
  55     }
  56         else
  57         {
  58                 value--;
  59                 result = 0;
  60     }
  61     pthread_mutex_unlock(&mutex);
  62         return result;
  63 }
  64
  65