cinelerra-5.1/guicast/mutex.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 <stdio.h>
  23 #include <errno.h>
  24
  25 #ifndef NO_GUICAST
  26 #include "bcsignals.h"
  27 #endif
  28 #include "mutex.h"
  29
  30
  31 Mutex::Mutex(const char *title, int recursive)
  32 {
  33         this->title = title;
  34         pthread_mutexattr_t attr;
  35         pthread_mutexattr_init(&attr);
  36         pthread_mutex_init(&mutex, &attr);
  37         pthread_mutex_init(&recursive_lock, &attr);
  38         count = 0;
  39         this->recursive = recursive;
  40         thread_id = 0;
  41         thread_id_valid = 0;
  42 }
  43
  44 Mutex::~Mutex()
  45 {
  46         pthread_mutex_destroy(&mutex);
  47         pthread_mutex_destroy(&recursive_lock);
  48 #ifndef NO_GUICAST
  49         UNSET_ALL_LOCKS(this);
  50 #endif
  51 }
  52
  53 int Mutex::lock(const char *location)
  54 {
  55 // Test recursive owner and give up if we already own it
  56         if(recursive)
  57         {
  58                 pthread_mutex_lock(&recursive_lock);
  59                 if(thread_id_valid && pthread_self() == thread_id)
  60                 {
  61                         count++;
  62                         pthread_mutex_unlock(&recursive_lock);
  63                         return 0;
  64                 }
  65                 pthread_mutex_unlock(&recursive_lock);
  66         }
  67
  68
  69 #ifndef NO_GUICAST
  70         SET_LOCK(this, title, location);
  71 #endif
  72         if(pthread_mutex_lock(&mutex)) perror("Mutex::lock");
  73
  74
  75
  76 // Update recursive status for the first lock
  77         if(recursive)
  78         {
  79                 pthread_mutex_lock(&recursive_lock);
  80                 count = 1;
  81                 thread_id = pthread_self();
  82                 thread_id_valid = 1;
  83                 pthread_mutex_unlock(&recursive_lock);
  84         }
  85         else
  86         {
  87                 count = 1;
  88         }
  89
  90
  91 #ifndef NO_GUICAST
  92         SET_LOCK2
  93 #endif
  94         return 0;
  95 }
  96
  97 int Mutex::unlock()
  98 {
  99 // Remove from recursive status
 100         if(recursive)
 101         {
 102                 pthread_mutex_lock(&recursive_lock);
 103                 count--;
 104 // Still locked
 105                 if(count > 0)
 106                 {
 107                         pthread_mutex_unlock(&recursive_lock);
 108                         return 0;
 109                 }
 110 // Not owned anymore
 111                 thread_id = 0;
 112                 thread_id_valid = 0;
 113                 pthread_mutex_unlock(&recursive_lock);
 114         }
 115         else
 116                 count = 0;
 117
 118
 119 #ifndef NO_GUICAST
 120         UNSET_LOCK(this);
 121 #endif
 122
 123         if(pthread_mutex_unlock(&mutex)) perror("Mutex::unlock");
 124         return 0;
 125 }
 126
 127 int Mutex::trylock(const char *location)
 128 {
 129         if( count ) return EBUSY;
 130         int ret = pthread_mutex_trylock(&mutex);
 131         if( ret ) return ret;
 132
 133 // Update recursive status for the first lock
 134         if(recursive) {
 135                 pthread_mutex_lock(&recursive_lock);
 136                 count = 1;
 137                 thread_id = pthread_self();
 138                 thread_id_valid = 1;
 139                 pthread_mutex_unlock(&recursive_lock);
 140         }
 141         else
 142                 count = 1;
 143
 144 #ifndef NO_GUICAST
 145         SET_LOCK(this, title, location);
 146         SET_LOCK2
 147 #endif
 148         return 0;
 149 }
 150
 151 int Mutex::is_locked()
 152 {
 153         return count;
 154 }
 155
 156 int Mutex::reset()
 157 {
 158         pthread_mutex_destroy(&mutex);
 159         pthread_mutexattr_t attr;
 160         pthread_mutexattr_init(&attr);
 161         pthread_mutex_init(&mutex, &attr);
 162         count = 0;
 163         thread_id = 0;
 164         thread_id_valid = 0;
 165 #ifndef NO_GUICAST
 166         UNSET_ALL_LOCKS(this)
 167 #endif
 168         return 0;
 169 }