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

   1 /* $Id$ */
   2
   3 /***
   4     This file is part of PulseAudio.
   5
   6     Copyright 2008 Colin Guthrie
   7
   8     PulseAudio is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU Lesser General Public License as published
  10     by the Free Software Foundation; either version 2 of the License,
  11     or (at your option) any later version.
  12
  13     PulseAudio is distributed in the hope that it will be useful, but
  14     WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16     General Public License for more details.
  17
  18     You should have received a copy of the GNU Lesser General Public License
  19     along with PulseAudio; if not, write to the Free Software
  20     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21     USA.
  22 ***/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <pulse/xmalloc.h>
  29
  30 #include <pulsecore/core.h>
  31 #include <pulsecore/sink-input.h>
  32 #include <pulsecore/modargs.h>
  33 #include <pulsecore/log.h>
  34 #include <pulsecore/namereg.h>
  35 #include <pulsecore/core-util.h>
  36
  37 #include "module-always-sink-symdef.h"
  38
  39 PA_MODULE_AUTHOR("Colin Guthrie");
  40 PA_MODULE_DESCRIPTION("Always keeps at least one sink loaded even if it's a null one");
  41 PA_MODULE_VERSION(PACKAGE_VERSION);
  42 PA_MODULE_LOAD_ONCE(TRUE);
  43 PA_MODULE_USAGE(
  44         "sink_name=<name of sink>");
  45
  46 #define DEFAULT_SINK_NAME "auto_null"
  47
  48 static const char* const valid_modargs[] = {
  49     "sink_name",
  50     NULL,
  51 };
  52
  53 struct userdata {
  54     pa_hook_slot *put_slot, *unlink_slot;
  55     pa_module* null_module;
  56     pa_bool_t ignore;
  57     char *sink_name;
  58 };
  59
  60 static void load_null_sink_if_needed(pa_core *c, pa_sink *sink, struct userdata* u) {
  61     pa_sink *target;
  62     uint32_t idx;
  63     char *t;
  64
  65     pa_assert(c);
  66     pa_assert(u);
  67     pa_assert(!u->null_module);
  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", u->sink_name);
  83     u->null_module = pa_module_load(c, "module-null-sink", t);
  84     pa_xfree(t);
  85
  86     u->ignore = FALSE;
  87
  88     if (!u->null_module)
  89         pa_log_warn("Unable to load module-null-sink");
  90 }
  91
  92 static pa_hook_result_t put_hook_callback(pa_core *c, pa_sink *sink, void* userdata) {
  93     struct userdata *u = userdata;
  94
  95     pa_assert(c);
  96     pa_assert(sink);
  97     pa_assert(u);
  98
  99     /* This is us detecting ourselves on load... just ignore this. */
 100     if (u->ignore)
 101         return PA_HOOK_OK;
 102
 103     /* Auto-loaded null-sink not active, so ignoring newly detected sink. */
 104     if (!u->null_module)
 105         return PA_HOOK_OK;
 106
 107     /* This is us detecting ourselves on load in a different way... just ignore this too. */
 108     if (sink->module == u->null_module)
 109         return PA_HOOK_OK;
 110
 111     pa_log_info("A new sink has been discovered. Unloading null-sink.");
 112
 113     pa_module_unload_request(u->null_module);
 114     u->null_module = NULL;
 115
 116     return PA_HOOK_OK;
 117 }
 118
 119 static pa_hook_result_t unlink_hook_callback(pa_core *c, pa_sink *sink, void* userdata) {
 120     struct userdata *u = userdata;
 121
 122     pa_assert(c);
 123     pa_assert(sink);
 124     pa_assert(u);
 125
 126     /* First check to see if it's our own null-sink that's been removed... */
 127     if (u->null_module && sink->module == u->null_module) {
 128         pa_log_debug("Autoloaded null-sink removed");
 129         u->null_module = NULL;
 130         return PA_HOOK_OK;
 131     }
 132
 133     load_null_sink_if_needed(c, sink, u);
 134
 135     return PA_HOOK_OK;
 136 }
 137
 138 int pa__init(pa_module*m) {
 139     pa_modargs *ma = NULL;
 140     struct userdata *u;
 141
 142     pa_assert(m);
 143
 144     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 145         pa_log("Failed to parse module arguments");
 146         return -1;
 147     }
 148
 149     m->userdata = u = pa_xnew(struct userdata, 1);
 150     u->sink_name = pa_xstrdup(pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME));
 151     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);
 152     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);
 153     u->null_module = NULL;
 154     u->ignore = FALSE;
 155
 156     pa_modargs_free(ma);
 157
 158     load_null_sink_if_needed(m->core, NULL, u);
 159
 160     return 0;
 161 }
 162
 163 void pa__done(pa_module*m) {
 164     struct userdata *u;
 165
 166     pa_assert(m);
 167
 168     if (!(u = m->userdata))
 169         return;
 170
 171     if (u->put_slot)
 172         pa_hook_slot_free(u->put_slot);
 173     if (u->unlink_slot)
 174         pa_hook_slot_free(u->unlink_slot);
 175     if (u->null_module)
 176         pa_module_unload_request(u->null_module);
 177
 178     pa_xfree(u->sink_name);
 179     pa_xfree(u);
 180 }