replace sink/source SET_STATE handlers with callbacks

There are no behaviour changes, the code from almost all the SET_STATE
handlers is moved with minimal changes to the newly introduced
set_state_in_io_thread() callback. The only exception is module-tunnel,
which has to call pa_sink_render() after pa_sink.thread_info.state has
been updated. The set_state_in_io_thread() callback is called before
updating that variable, so moving the SET_STATE handler code to the
callback isn't possible.

The purpose of this change is to make it easier to get state change
handling right in modules. Hooking to the SET_STATE messages in modules
required care in calling pa_sink/source_process_msg() at the right time
(or not calling it at all, as was the case on resume failures), and
there were a few bugs (fixed before this patch). Now the core takes care
of ordering things correctly.

Another motivation for this change is that there was some talk about
adding a suspend_cause variable to pa_sink/source.thread_info. The
variable would be updated in the core SET_STATE handler, but that would
not work with the old design, because in case of resume failures modules
didn't call the core message handler.
This commit is contained in:
Tanu Kaskinen 2018-03-13 19:40:38 +02:00
parent 73b8a57078
commit b2537a8f38
25 changed files with 874 additions and 658 deletions

View file

@ -89,13 +89,6 @@ static int source_process_msg(pa_msgobject *o, int code, void *data, int64_t off
struct userdata *u = PA_SOURCE(o)->userdata;
switch (code) {
case PA_SOURCE_MESSAGE_SET_STATE:
if (PA_PTR_TO_UINT(data) == PA_SOURCE_RUNNING)
u->timestamp = pa_rtclock_now();
break;
case PA_SOURCE_MESSAGE_GET_LATENCY: {
pa_usec_t now;
@ -109,6 +102,19 @@ static int source_process_msg(pa_msgobject *o, int code, void *data, int64_t off
return pa_source_process_msg(o, code, data, offset, chunk);
}
/* Called from the IO thread. */
static int source_set_state_in_io_thread_cb(pa_source *s, pa_source_state_t new_state) {
struct userdata *u;
pa_assert(s);
pa_assert_se(u = s->userdata);
if (new_state == PA_SOURCE_RUNNING)
u->timestamp = pa_rtclock_now();
return 0;
}
static void source_update_requested_latency_cb(pa_source *s) {
struct userdata *u;
@ -229,6 +235,7 @@ int pa__init(pa_module*m) {
u->latency_time = latency_time;
u->source->parent.process_msg = source_process_msg;
u->source->set_state_in_io_thread = source_set_state_in_io_thread_cb;
u->source->update_requested_latency = source_update_requested_latency_cb;
u->source->userdata = u;