code.delx.au - pulseaudio/blob - src/modules/module-always-sink.c

   1 /***
   2     This file is part of PulseAudio.
   3
   4     Copyright 2008 Colin Guthrie
   5
   6     PulseAudio is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU Lesser General Public License as published
   8     by the Free Software Foundation; either version 2.1 of the License,
   9     or (at your option) any later version.
  10
  11     PulseAudio is distributed in the hope that it will be useful, but
  12     WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14     General Public License for more details.
  15
  16     You should have received a copy of the GNU Lesser General Public License
  17     along with PulseAudio; if not, write to the Free Software
  18     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19     USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <pulse/xmalloc.h>
  27 #include <pulse/i18n.h>
  28
  29 #include <pulsecore/core.h>
  30 #include <pulsecore/sink-input.h>
  31 #include <pulsecore/modargs.h>
  32 #include <pulsecore/log.h>
  33 #include <pulsecore/namereg.h>
  34 #include <pulsecore/core-util.h>
  35
  36 #include "module-always-sink-symdef.h"
  37
  38 PA_MODULE_AUTHOR("Colin Guthrie");
  39 PA_MODULE_DESCRIPTION(_("Always keeps at least one sink loaded even if it's a null one"));
  40 PA_MODULE_VERSION(PACKAGE_VERSION);
  41 PA_MODULE_LOAD_ONCE(TRUE);
  42 PA_MODULE_USAGE(
  43         "sink_name=<name of sink>");
  44
  45 #define DEFAULT_SINK_NAME "auto_null"
  46
  47 static const char* const valid_modargs[] = {
  48     "sink_name",
  49     NULL,
  50 };
  51
  52 struct userdata {
  53     pa_hook_slot *put_slot, *unlink_slot;
  54     uint32_t null_module;
  55     pa_bool_t ignore;
  56     char *sink_name;
  57 };
  58
  59 static void load_null_sink_if_needed(pa_core *c, pa_sink *sink, struct userdata* u) {
  60     pa_sink *target;
  61     uint32_t idx;
  62     char *t;
  63     pa_module *m;
  64
  65     pa_assert(c);
  66     pa_assert(u);
  67     pa_assert(u->null_module == PA_INVALID_INDEX);
  68
  69     /* Loop through all sinks and check to see if we have *any*
  70      * sinks. Ignore the sink passed in (if it's not null) */
  71     for (target = pa_idxset_first(c->sinks, &idx); target; target = pa_idxset_next(c->sinks, &idx))
  72         if (!sink || target != sink)
  73             break;
  74
  75     if (target)
  76         return;
  77
  78     pa_log_debug("Autoloading null-sink as no other sinks detected.");
  79
  80     u->ignore = TRUE;
  81
  82     t = pa_sprintf_malloc("sink_name=%s sink_properties='device.description=\"%s\"'", u->sink_name,
  83                           _("Dummy Output"));
  84     m = pa_module_load(c, "module-null-sink", t);
  85     u->null_module = m ? m->index : PA_INVALID_INDEX;
  86     pa_xfree(t);
  87
  88     u->ignore = FALSE;
  89
  90     if (!m)
  91         pa_log_warn("Unable to load module-null-sink");
  92 }
  93
  94 static pa_hook_result_t put_hook_callback(pa_core *c, pa_sink *sink, void* userdata) {
  95     struct userdata *u = userdata;
  96
  97     pa_assert(c);
  98     pa_assert(sink);
  99     pa_assert(u);
 100
 101     /* This is us detecting ourselves on load... just ignore this. */
 102     if (u->ignore)
 103         return PA_HOOK_OK;
 104
 105     /* There's no point in doing anything if the core is shut down anyway */
 106     if (c->state == PA_CORE_SHUTDOWN)
 107         return PA_HOOK_OK;
 108
 109     /* Auto-loaded null-sink not active, so ignoring newly detected sink. */
 110     if (u->null_module == PA_INVALID_INDEX)
 111         return PA_HOOK_OK;
 112
 113     /* This is us detecting ourselves on load in a different way... just ignore this too. */
 114     if (sink->module && sink->module->index == u->null_module)
 115         return PA_HOOK_OK;
 116
 117     pa_log_info("A new sink has been discovered. Unloading null-sink.");
 118
 119     pa_module_unload_request_by_index(c, u->null_module, TRUE);
 120     u->null_module = PA_INVALID_INDEX;
 121
 122     return PA_HOOK_OK;
 123 }
 124
 125 static pa_hook_result_t unlink_hook_callback(pa_core *c, pa_sink *sink, void* userdata) {
 126     struct userdata *u = userdata;
 127
 128     pa_assert(c);
 129     pa_assert(sink);
 130     pa_assert(u);
 131
 132     /* First check to see if it's our own null-sink that's been removed... */
 133     if (u->null_module != PA_INVALID_INDEX && sink->module && sink->module->index == u->null_module) {
 134         pa_log_debug("Autoloaded null-sink removed");
 135         u->null_module = PA_INVALID_INDEX;
 136         return PA_HOOK_OK;
 137     }
 138
 139     /* There's no point in doing anything if the core is shut down anyway */
 140     if (c->state == PA_CORE_SHUTDOWN)
 141         return PA_HOOK_OK;
 142
 143     load_null_sink_if_needed(c, sink, u);
 144
 145     return PA_HOOK_OK;
 146 }
 147
 148 int pa__init(pa_module*m) {
 149     pa_modargs *ma = NULL;
 150     struct userdata *u;
 151
 152     pa_assert(m);
 153
 154     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 155         pa_log("Failed to parse module arguments");
 156         return -1;
 157     }
 158
 159     m->userdata = u = pa_xnew(struct userdata, 1);
 160     u->sink_name = pa_xstrdup(pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 161     u->put_slot = pa_hook_connect(&m->core->hooks[PA_CORE_HOOK_SINK_PUT], PA_HOOK_LATE, (pa_hook_cb_t) put_hook_callback, u);
 162     u->unlink_slot = pa_hook_connect(&m->core->hooks[PA_CORE_HOOK_SINK_UNLINK], PA_HOOK_EARLY, (pa_hook_cb_t) unlink_hook_callback, u);
 163     u->null_module = PA_INVALID_INDEX;
 164     u->ignore = FALSE;
 165
 166     pa_modargs_free(ma);
 167
 168     load_null_sink_if_needed(m->core, NULL, u);
 169
 170     return 0;
 171 }
 172
 173 void pa__done(pa_module*m) {
 174     struct userdata *u;
 175
 176     pa_assert(m);
 177
 178     if (!(u = m->userdata))
 179         return;
 180
 181     if (u->put_slot)
 182         pa_hook_slot_free(u->put_slot);
 183     if (u->unlink_slot)
 184         pa_hook_slot_free(u->unlink_slot);
 185     if (u->null_module != PA_INVALID_INDEX && m->core->state != PA_CORE_SHUTDOWN)
 186         pa_module_unload_request_by_index(m->core, u->null_module, TRUE);
 187
 188     pa_xfree(u->sink_name);
 189     pa_xfree(u);
 190 }