dbus/audio_reserve.c

   1 /*
   2     Copyright (C) 2009 Grame
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License.
   7
   8     This program is distributed in the hope that it will be useful,
   9     but WITHOUT ANY WARRANTY; without even the implied warranty of
  10     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11     GNU General Public License for more details.
  12
  13     You should have received a copy of the GNU General Public License
  14     along with this program; if not, write to the Free Software
  15     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  16
  17 */
  18
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <assert.h>
  25 #include <stdint.h>
  26
  27 #include "reserve.h"
  28 #include "audio_reserve.h"
  29 #include "jack/control.h"
  30
  31 #define DEVICE_MAX 2
  32
  33 typedef struct reserved_audio_device {
  34
  35      char device_name[64];
  36      rd_device * reserved_device;
  37
  38 } reserved_audio_device;
  39
  40 static DBusConnection* gConnection = NULL;
  41 static reserved_audio_device gReservedDevice[DEVICE_MAX];
  42 static int gReserveCount = 0;
  43
  44 SERVER_EXPORT int audio_reservation_init()
  45 {
  46     DBusError error;
  47     dbus_error_init(&error);
  48
  49     if (!(gConnection = dbus_bus_get(DBUS_BUS_SESSION, &error))) {
  50         jack_error("Failed to connect to session bus for device reservation: %s\n", error.message);
  51         jack_info("To bypass device reservation via session bus, set JACK_NO_AUDIO_RESERVATION=1 prior to starting jackd.\n");
  52         return -1;
  53     }
  54
  55     jack_info("audio_reservation_init");
  56     return 0;
  57 }
  58
  59 SERVER_EXPORT int audio_reservation_finish()
  60 {
  61     if (gConnection) {
  62         dbus_connection_unref(gConnection);
  63         gConnection = NULL;
  64         jack_info("audio_reservation_finish");
  65     }
  66     return 0;
  67 }
  68
  69 SERVER_EXPORT bool audio_acquire(const char * device_name)
  70 {
  71     DBusError error;
  72     int ret;
  73
  74     // Open DBus connection first time
  75     if (gReserveCount == 0) {
  76         if (audio_reservation_init() != 0) {
  77             return false;
  78         }
  79     }
  80
  81     assert(gReserveCount < DEVICE_MAX);
  82
  83     dbus_error_init(&error);
  84
  85     if ((ret= rd_acquire(
  86                  &gReservedDevice[gReserveCount].reserved_device,
  87                  gConnection,
  88                  device_name,
  89                  "Jack audio server",
  90                  INT32_MAX,
  91                  NULL,
  92                  &error)) < 0) {
  93
  94         jack_error("Failed to acquire device name : %s error : %s", device_name, (error.message ? error.message : strerror(-ret)));
  95         dbus_error_free(&error);
  96         return false;
  97     }
  98
  99     strcpy(gReservedDevice[gReserveCount].device_name, device_name);
 100     gReserveCount++;
 101     jack_info("Acquire audio card %s", device_name);
 102     return true;
 103 }
 104
 105 SERVER_EXPORT void audio_release(const char * device_name)
 106 {
 107     int i;
 108
 109     // Look for corresponding reserved device
 110     for (i = 0; i < DEVICE_MAX; i++) {
 111         if (strcmp(gReservedDevice[i].device_name, device_name) == 0)
 112             break;
 113     }
 114
 115     if (i < DEVICE_MAX) {
 116         jack_info("Released audio card %s", device_name);
 117         rd_release(gReservedDevice[i].reserved_device);
 118     } else {
 119         jack_error("Audio card %s not found!!", device_name);
 120     }
 121
 122     // Close DBus connection last time
 123     gReserveCount--;
 124     if (gReserveCount == 0)
 125         audio_reservation_finish();
 126 }
 127
 128 SERVER_EXPORT void audio_reserve_loop()
 129 {
 130     if (gConnection != NULL) {
 131        dbus_connection_read_write_dispatch (gConnection, 200);
 132     }
 133 }
 134