[pulseaudio-discuss] [PATCH] Implement module-always-source
Sebastian Dröge
slomo at coaxion.net
Thu Jun 29 21:57:36 UTC 2017
From: Sebastian Dröge <sebastian at centricular.com>
This is basically a copy of module-always-sink but doing the same for
sources. Whenever no source is available, a module-null-source is loaded
and whenever a new source is available again, module-null-source is
unloaded.
By this, anything using a source will automatically be switched to the
null source when the actual source disappears, and back to the actual
source if it appears again.
---
po/POTFILES.in | 1 +
src/Makefile.am | 8 ++
src/modules/module-always-source.c | 189 +++++++++++++++++++++++++++++++++++++
3 files changed, 198 insertions(+)
create mode 100644 src/modules/module-always-source.c
diff --git a/po/POTFILES.in b/po/POTFILES.in
index e2d6d118..d4c78cf5 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -24,6 +24,7 @@ src/modules/jack/module-jack-source.c
src/modules/macosx/module-coreaudio-device.c
src/modules/module-allow-passthrough.c
src/modules/module-always-sink.c
+src/modules/module-always-source.c
src/modules/module-cli.c
src/modules/module-combine.c
src/modules/module-console-kit.c
diff --git a/src/Makefile.am b/src/Makefile.am
index 3ff1139f..89a4b7db 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1193,6 +1193,7 @@ modlibexec_LTLIBRARIES += \
module-card-restore.la \
module-default-device-restore.la \
module-always-sink.la \
+ module-always-source.la \
module-rescue-streams.la \
module-intended-roles.la \
module-suspend-on-idle.la \
@@ -1529,6 +1530,7 @@ SYMDEF_FILES = \
module-card-restore-symdef.h \
module-default-device-restore-symdef.h \
module-always-sink-symdef.h \
+ module-always-source-symdef.h \
module-rescue-streams-symdef.h \
module-intended-roles-symdef.h \
module-suspend-on-idle-symdef.h \
@@ -2016,6 +2018,12 @@ module_always_sink_la_LDFLAGS = $(MODULE_LDFLAGS)
module_always_sink_la_LIBADD = $(MODULE_LIBADD)
module_always_sink_la_CFLAGS = $(AM_CFLAGS)
+# Always Source module
+module_always_source_la_SOURCES = modules/module-always-source.c
+module_always_source_la_LDFLAGS = $(MODULE_LDFLAGS)
+module_always_source_la_LIBADD = $(MODULE_LIBADD)
+module_always_source_la_CFLAGS = $(AM_CFLAGS)
+
# Rescue streams module
module_rescue_streams_la_SOURCES = modules/module-rescue-streams.c
module_rescue_streams_la_LDFLAGS = $(MODULE_LDFLAGS)
diff --git a/src/modules/module-always-source.c b/src/modules/module-always-source.c
new file mode 100644
index 00000000..09ac7aa5
--- /dev/null
+++ b/src/modules/module-always-source.c
@@ -0,0 +1,189 @@
+/***
+ This file is part of PulseAudio.
+
+ Copyright 2008 Colin Guthrie
+ Copyright 2017 Sebastian Dröge <sebastian at centricular.com>
+
+ PulseAudio is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation; either version 2.1 of the License,
+ or (at your option) any later version.
+
+ PulseAudio is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <pulse/xmalloc.h>
+
+#include <pulsecore/core.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/i18n.h>
+#include <pulsecore/source.h>
+#include <pulsecore/modargs.h>
+#include <pulsecore/log.h>
+
+#include "module-always-source-symdef.h"
+
+PA_MODULE_AUTHOR("Sebastian Dröge");
+PA_MODULE_DESCRIPTION(_("Always keeps at least one source loaded even if it's a null one"));
+PA_MODULE_VERSION(PACKAGE_VERSION);
+PA_MODULE_LOAD_ONCE(true);
+PA_MODULE_USAGE(
+ "source_name=<name of source>");
+
+#define DEFAULT_SOURCE_NAME "auto_null"
+
+static const char* const valid_modargs[] = {
+ "source_name",
+ NULL,
+};
+
+struct userdata {
+ uint32_t null_module;
+ bool ignore;
+ char *source_name;
+};
+
+static void load_null_source_if_needed(pa_core *c, pa_source *source, struct userdata* u) {
+ pa_source *target;
+ uint32_t idx;
+ char *t;
+ pa_module *m;
+
+ pa_assert(c);
+ pa_assert(u);
+
+ if (u->null_module != PA_INVALID_INDEX)
+ return; /* We've already got a null-source loaded */
+
+ /* Loop through all sources and check to see if we have *any*
+ * sources. Ignore the source passed in (if it's not null), and
+ * don't count filter or monitor sources. */
+ PA_IDXSET_FOREACH(target, c->sources, idx)
+ if (!source || ((target != source) && !pa_source_is_filter(target) && target->monitor_of == NULL))
+ break;
+
+ if (target)
+ return;
+
+ pa_log_debug("Autoloading null-source as no other sources detected.");
+
+ u->ignore = true;
+
+ t = pa_sprintf_malloc("source_name=%s", u->source_name);
+ m = pa_module_load(c, "module-null-source", t);
+ u->null_module = m ? m->index : PA_INVALID_INDEX;
+ pa_xfree(t);
+
+ u->ignore = false;
+
+ if (!m)
+ pa_log_warn("Unable to load module-null-source");
+}
+
+static pa_hook_result_t put_hook_callback(pa_core *c, pa_source *source, void* userdata) {
+ struct userdata *u = userdata;
+
+ pa_assert(c);
+ pa_assert(source);
+ pa_assert(u);
+
+ /* This is us detecting ourselves on load... just ignore this. */
+ if (u->ignore)
+ return PA_HOOK_OK;
+
+ /* There's no point in doing anything if the core is shut down anyway */
+ if (c->state == PA_CORE_SHUTDOWN)
+ return PA_HOOK_OK;
+
+ /* Auto-loaded null-source not active, so ignoring newly detected source. */
+ if (u->null_module == PA_INVALID_INDEX)
+ return PA_HOOK_OK;
+
+ /* This is us detecting ourselves on load in a different way... just ignore this too. */
+ if (source->module && source->module->index == u->null_module)
+ return PA_HOOK_OK;
+
+ /* We don't count filter or monitor sources since they need a real source */
+ if (pa_source_is_filter(source) || source->monitor_of != NULL)
+ return PA_HOOK_OK;
+
+ pa_log_info("A new source has been discovered. Unloading null-source.");
+
+ pa_module_unload_request_by_index(c, u->null_module, true);
+ u->null_module = PA_INVALID_INDEX;
+
+ return PA_HOOK_OK;
+}
+
+static pa_hook_result_t unlink_hook_callback(pa_core *c, pa_source *source, void* userdata) {
+ struct userdata *u = userdata;
+
+ pa_assert(c);
+ pa_assert(source);
+ pa_assert(u);
+
+ /* First check to see if it's our own null-source that's been removed... */
+ if (u->null_module != PA_INVALID_INDEX && source->module && source->module->index == u->null_module) {
+ pa_log_debug("Autoloaded null-source removed");
+ u->null_module = PA_INVALID_INDEX;
+ return PA_HOOK_OK;
+ }
+
+ /* There's no point in doing anything if the core is shut down anyway */
+ if (c->state == PA_CORE_SHUTDOWN)
+ return PA_HOOK_OK;
+
+ load_null_source_if_needed(c, source, u);
+
+ return PA_HOOK_OK;
+}
+
+int pa__init(pa_module*m) {
+ pa_modargs *ma = NULL;
+ struct userdata *u;
+
+ pa_assert(m);
+
+ if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
+ pa_log("Failed to parse module arguments");
+ return -1;
+ }
+
+ m->userdata = u = pa_xnew(struct userdata, 1);
+ u->source_name = pa_xstrdup(pa_modargs_get_value(ma, "source_name", DEFAULT_SOURCE_NAME));
+ pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SOURCE_PUT], PA_HOOK_LATE, (pa_hook_cb_t) put_hook_callback, u);
+ pa_module_hook_connect(m, &m->core->hooks[PA_CORE_HOOK_SOURCE_UNLINK], PA_HOOK_EARLY, (pa_hook_cb_t) unlink_hook_callback, u);
+ u->null_module = PA_INVALID_INDEX;
+ u->ignore = false;
+
+ pa_modargs_free(ma);
+
+ load_null_source_if_needed(m->core, NULL, u);
+
+ return 0;
+}
+
+void pa__done(pa_module*m) {
+ struct userdata *u;
+
+ pa_assert(m);
+
+ if (!(u = m->userdata))
+ return;
+
+ if (u->null_module != PA_INVALID_INDEX && m->core->state != PA_CORE_SHUTDOWN)
+ pa_module_unload_request_by_index(m->core, u->null_module, true);
+
+ pa_xfree(u->source_name);
+ pa_xfree(u);
+}
--
2.13.2
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