cinelerra-5.1/guicast/condition.C

   1
   2 /*
   3  * CINELERRA
   4  * Copyright (C) 2008 Adam Williams <broadcast at earthling dot net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 #include "bcsignals.h"
  23 #include "condition.h"
  24
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <stdint.h>
  28 #include <sys/time.h>
  29 #include <unistd.h>
  30
  31 Condition::Condition(int init_value, const char *title, int is_binary)
  32 {
  33         this->is_binary = is_binary;
  34         this->title = title;
  35         this->trace = 0;
  36         pthread_mutex_init(&mutex, 0);
  37         pthread_cond_init(&cond, NULL);
  38         this->value = this->init_value = init_value;
  39 }
  40
  41 Condition:: ~Condition()
  42 {
  43         pthread_cond_destroy(&cond);
  44         pthread_mutex_destroy(&mutex);
  45         UNSET_ALL_LOCKS(this);
  46 }
  47
  48 void Condition::reset()
  49 {
  50         pthread_cond_destroy(&cond);
  51         pthread_mutex_destroy(&mutex);
  52         pthread_mutex_init(&mutex, 0);
  53         pthread_cond_init(&cond, NULL);
  54         UNSET_ALL_LOCKS(this);
  55         value = init_value;
  56         trace = 0;
  57 }
  58
  59 void Condition::lock(const char *location)
  60 {
  61         SET_LOCK(this, title, location);
  62         pthread_mutex_lock(&mutex);
  63         while(value <= 0) pthread_cond_wait(&cond, &mutex);
  64         UNSET_LOCK2
  65         if(is_binary)
  66                 value = 0;
  67         else
  68                 value--;
  69         pthread_mutex_unlock(&mutex);
  70 }
  71
  72 void Condition::unlock()
  73 {
  74 // The lock trace is created and removed by the acquirer
  75 //      UNSET_LOCK(this);
  76         pthread_mutex_lock(&mutex);
  77         if(is_binary)
  78                 value = 1;
  79         else
  80                 value++;
  81         pthread_cond_signal(&cond);
  82         pthread_mutex_unlock(&mutex);
  83 }
  84
  85 int Condition::timed_lock(int microseconds, const char *location)
  86 {
  87         int result = 0;
  88
  89         SET_LOCK(this, title, location);
  90         pthread_mutex_lock(&mutex);
  91
  92         struct timeval now;
  93         gettimeofday(&now, 0);
  94 #if 1
  95         struct timespec timeout;
  96         timeout.tv_sec = now.tv_sec + microseconds / 1000000;
  97         timeout.tv_nsec = now.tv_usec * 1000 + (microseconds % 1000000) * 1000;
  98         while(value <= 0 && result != ETIMEDOUT)
  99         {
 100                 result = pthread_cond_timedwait(&cond, &mutex, &timeout);
 101         }
 102
 103         if( result )
 104                 result = result == ETIMEDOUT ? 1 : -1;
 105
 106 #else
 107         struct timeval timeout;
 108         int64_t timeout_msec = ((int64_t)microseconds / 1000);
 109 // This is based on the most common frame rate since it's mainly used in
 110 // recording.
 111         while( value <= 0 && !result ) {
 112                 pthread_mutex_unlock(&mutex);
 113                 usleep(20000);
 114                 gettimeofday(&timeout, 0);
 115                 timeout.tv_usec -= now.tv_usec;
 116                 timeout.tv_sec -= now.tv_sec;
 117                 pthread_mutex_lock(&mutex);
 118                 if( value > 0 ) break;
 119                 if( (int64_t)timeout.tv_sec * 1000 +
 120                     (int64_t)timeout.tv_usec / 1000 > timeout_msec )
 121                         result = 1;
 122         }
 123 #endif
 124
 125         UNSET_LOCK2
 126 //printf("Condition::timed_lock 2 %d %s %s\n", result, title, location);
 127         if( !result ) {
 128                 if(is_binary)
 129                         value = 0;
 130                 else
 131                         --value;
 132         }
 133         pthread_mutex_unlock(&mutex);
 134         return result;
 135 }
 136
 137
 138 int Condition::get_value()
 139 {
 140         return value;
 141 }