research.m1stereo.tv/gitweb/ - melted/blob - src/mvcp/mvcp_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 = calloc( 1, sizeof( valerie_notifier_t ) );
  41         if ( this != NULL )
  42         {
  43                 int index = 0;
  44                 pthread_mutex_init( &this->mutex, NULL );
  45                 pthread_cond_init( &this->cond, NULL );
  46                 for ( index = 0; index < MAX_UNITS; index ++ )
  47                         this->store[ index ].unit = index;
  48         }
  49         return this;
  50 }
  51
  52 /** Get a stored status for the specified unit.
  53 */
  54
  55 void valerie_notifier_get( valerie_notifier this, valerie_status status, int unit )
  56 {
  57         pthread_mutex_lock( &this->mutex );
  58         if ( unit >= 0 && unit < MAX_UNITS )
  59                 valerie_status_copy( status, &this->store[ unit ] );
  60         else
  61                 memset( status, 0, sizeof( valerie_status_t ) );
  62         status->unit = unit;
  63         status->dummy = time( NULL );
  64         pthread_mutex_unlock( &this->mutex );
  65 }
  66
  67 /** Wait on a new status.
  68 */
  69
  70 int valerie_notifier_wait( valerie_notifier this, valerie_status status )
  71 {
  72         struct timeval now;
  73         struct timespec timeout;
  74         int error = 0;
  75
  76         memset( status, 0, sizeof( valerie_status_t ) );
  77         gettimeofday( &now, NULL );
  78         timeout.tv_sec = now.tv_sec + 1;
  79         timeout.tv_nsec = now.tv_usec * 1000;
  80         pthread_mutex_lock( &this->mutex );
  81         pthread_cond_timedwait( &this->cond, &this->mutex, &timeout );
  82         valerie_status_copy( status, &this->last );
  83         pthread_mutex_unlock( &this->mutex );
  84
  85         return error;
  86 }
  87
  88 /** Put a new status.
  89 */
  90
  91 void valerie_notifier_put( valerie_notifier this, valerie_status status )
  92 {
  93         pthread_mutex_lock( &this->mutex );
  94         valerie_status_copy( &this->store[ status->unit ], status );
  95         valerie_status_copy( &this->last, status );
  96         pthread_mutex_unlock( &this->mutex );
  97         pthread_cond_broadcast( &this->cond );
  98 }
  99
 100 /** Communicate a disconnected status for all units to all waiting.
 101 */
 102
 103 void valerie_notifier_disconnected( valerie_notifier notifier )
 104 {
 105         int unit = 0;
 106         valerie_status_t status;
 107         for ( unit = 0; unit < MAX_UNITS; unit ++ )
 108         {
 109                 valerie_notifier_get( notifier, &status, unit );
 110                 status.status = unit_disconnected;
 111                 valerie_notifier_put( notifier, &status );
 112         }
 113 }
 114
 115 /** Close the notifier - note that all access must be stopped before we call this.
 116 */
 117
 118 void valerie_notifier_close( valerie_notifier this )
 119 {
 120         if ( this != NULL )
 121         {
 122                 pthread_mutex_destroy( &this->mutex );
 123                 pthread_cond_destroy( &this->cond );
 124                 free( this );
 125         }
 126 }