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         unset_owner();
  56         value = init_value;
  57         trace = 0;
  58 }
  59
  60 void Condition::lock(const char *location)
  61 {
  62         SET_LOCK(this, title, location);
  63         pthread_mutex_lock(&mutex);
  64         while(value <= 0) pthread_cond_wait(&cond, &mutex);
  65         UNSET_LOCK2
  66         if(is_binary)
  67                 value = 0;
  68         else
  69                 value--;
  70         if( !value )
  71                 set_owner();
  72         pthread_mutex_unlock(&mutex);
  73 }
  74
  75 void Condition::unlock()
  76 {
  77 // The lock trace is created and removed by the acquirer
  78 //      UNSET_LOCK(this);
  79         pthread_mutex_lock(&mutex);
  80         if(is_binary)
  81                 value = 1;
  82         else
  83                 value++;
  84         unset_owner();
  85         pthread_cond_signal(&cond);
  86         pthread_mutex_unlock(&mutex);
  87 }
  88
  89 int Condition::timed_lock(int microseconds, const char *location)
  90 {
  91         int result = 0;
  92
  93         SET_LOCK(this, title, location);
  94         pthread_mutex_lock(&mutex);
  95
  96         struct timeval now;
  97         gettimeofday(&now, 0);
  98 #if 1
  99         int64_t nsec = now.tv_usec * 1000 + (microseconds % 1000000) * 1000;
 100         int64_t sec = nsec / 1000000000;  nsec %= 1000000000;
 101         sec += now.tv_sec + microseconds / 1000000;
 102         struct timespec timeout;  timeout.tv_sec = sec;   timeout.tv_nsec = nsec;
 103         while( value <= 0 && result != ETIMEDOUT ) {
 104                 result = pthread_cond_timedwait(&cond, &mutex, &timeout);
 105         }
 106
 107         if( result )
 108                 result = result == ETIMEDOUT ? 1 : -1;
 109
 110 #else
 111         struct timeval timeout;
 112         int64_t timeout_msec = ((int64_t)microseconds / 1000);
 113 // This is based on the most common frame rate since it's mainly used in
 114 // recording.
 115         while( value <= 0 && !result ) {
 116                 pthread_mutex_unlock(&mutex);
 117                 usleep(20000);
 118                 gettimeofday(&timeout, 0);
 119                 timeout.tv_usec -= now.tv_usec;
 120                 timeout.tv_sec -= now.tv_sec;
 121                 pthread_mutex_lock(&mutex);
 122                 if( value > 0 ) break;
 123                 if( (int64_t)timeout.tv_sec * 1000 +
 124                     (int64_t)timeout.tv_usec / 1000 > timeout_msec )
 125                         result = 1;
 126         }
 127 #endif
 128
 129         UNSET_LOCK2
 130 //printf("Condition::timed_lock 2 %d %s %s\n", result, title, location);
 131         if( !result ) {
 132                 if(is_binary)
 133                         value = 0;
 134                 else
 135                         --value;
 136         }
 137         if( !value )
 138                 set_owner();
 139         pthread_mutex_unlock(&mutex);
 140         return result;
 141 }
 142
 143
 144 int Condition::get_value()
 145 {
 146         return value;
 147 }