research.m1stereo.tv/gitweb/ - melted/blob - src/valerie/valerie_notifier.c

   1 /*
   2  * valerie_notifier.c -- Unit Status Notifier Handling
   3  * Copyright (C) 2002-2003 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include <config.h>
  23 #endif
  24
  25 /* System header files */
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <errno.h>
  30 #include <sys/time.h>
  31
  32 /* Application header files */
  33 #include "valerie_notifier.h"
  34
  35 /** Notifier initialisation.
  36 */
  37
  38 valerie_notifier valerie_notifier_init( )
  39 {
  40         valerie_notifier this = malloc( sizeof( valerie_notifier_t ) );
  41         if ( this != NULL )
  42         {
  43                 int index = 0;
  44                 memset( this, 0, sizeof( valerie_notifier_t ) );
  45                 pthread_mutex_init( &this->mutex, NULL );
  46                 pthread_cond_init( &this->cond, NULL );
  47                 pthread_mutex_init( &this->cond_mutex, NULL );
  48                 for ( index = 0; index < MAX_UNITS; index ++ )
  49                         this->store[ index ].unit = index;
  50         }
  51         return this;
  52 }
  53
  54 /** Get a stored status for the specified unit.
  55 */
  56
  57 void valerie_notifier_get( valerie_notifier this, valerie_status status, int unit )
  58 {
  59         pthread_mutex_lock( &this->mutex );
  60         if ( unit >= 0 && unit < MAX_UNITS )
  61         {
  62                 valerie_status_copy( status, &this->store[ unit ] );
  63         }
  64         else
  65         {
  66                 memset( status, 0, sizeof( valerie_status_t ) );
  67                 status->unit = unit;
  68         }
  69         status->dummy = time( NULL );
  70         pthread_mutex_unlock( &this->mutex );
  71 }
  72
  73 /** Wait on a new status.
  74 */
  75
  76 int valerie_notifier_wait( valerie_notifier this, valerie_status status )
  77 {
  78         struct timeval now;
  79         struct timespec timeout;
  80         int error = 0;
  81
  82         memset( status, 0, sizeof( valerie_status_t ) );
  83
  84         pthread_mutex_lock( &this->cond_mutex );
  85         gettimeofday( &now, NULL );
  86         timeout.tv_sec = now.tv_sec + 1;
  87         timeout.tv_nsec = now.tv_usec * 1000;
  88         if ( pthread_cond_timedwait( &this->cond, &this->cond_mutex, &timeout ) != ETIMEDOUT )
  89         {
  90                 pthread_mutex_lock( &this->mutex );
  91                 valerie_status_copy( status, &this->last );
  92                 pthread_mutex_unlock( &this->mutex );
  93         }
  94         else
  95         {
  96                 pthread_mutex_lock( &this->mutex );
  97                 valerie_status_copy( status, &this->last );
  98                 pthread_mutex_unlock( &this->mutex );
  99         }
 100         pthread_mutex_unlock( &this->cond_mutex );
 101
 102         return error;
 103 }
 104
 105 /** Put a new status.
 106 */
 107
 108 void valerie_notifier_put( valerie_notifier this, valerie_status status )
 109 {
 110         pthread_mutex_lock( &this->mutex );
 111         valerie_status_copy( &this->store[ status->unit ], status );
 112         valerie_status_copy( &this->last, status );
 113         pthread_mutex_unlock( &this->mutex );
 114         pthread_cond_broadcast( &this->cond );
 115 }
 116
 117 /** Communicate a disconnected status for all units to all waiting.
 118 */
 119
 120 void valerie_notifier_disconnected( valerie_notifier notifier )
 121 {
 122         int unit = 0;
 123         valerie_status_t status;
 124         for ( unit = 0; unit < MAX_UNITS; unit ++ )
 125         {
 126                 valerie_notifier_get( notifier, &status, unit );
 127                 status.status = unit_disconnected;
 128                 valerie_notifier_put( notifier, &status );
 129         }
 130 }
 131
 132 /** Close the notifier - note that all access must be stopped before we call this.
 133 */
 134
 135 void valerie_notifier_close( valerie_notifier this )
 136 {
 137         if ( this != NULL )
 138         {
 139                 pthread_mutex_destroy( &this->mutex );
 140                 pthread_mutex_destroy( &this->cond_mutex );
 141                 pthread_cond_destroy( &this->cond );
 142                 free( this );
 143         }
 144 }