From 76de766cd84101e9304c1ff347478f2728794870 Mon Sep 17 00:00:00 2001
From: Demi Marie Obenour <demiobenour@gmail.com>
Date: Wed, 3 Jan 2024 14:16:20 -0500
Subject: [PATCH] Draft: Allow calling trigger_done from the RT thread

This allows streams to know when the graph is finished and they can
safely drive it again.

Fixes: #3759
---
 src/pipewire/stream.c | 12 ++++++++++--
 src/pipewire/stream.h |  8 +++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/pipewire/stream.c b/src/pipewire/stream.c
index ee35c4f0a..7a7a6216b 100644
--- a/src/pipewire/stream.c
+++ b/src/pipewire/stream.c
@@ -158,6 +158,7 @@ struct stream {
 	unsigned int using_trigger:1;
 	unsigned int trigger:1;
 	unsigned int early_process:1;
+	unsigned int trigger_done_rt:1;
 	int in_set_param;
 	int in_emit_param_changed;
 };
@@ -499,8 +500,14 @@ do_call_trigger_done(struct spa_loop *loop,
 
 static void call_trigger_done(struct stream *impl)
 {
-	pw_loop_invoke(impl->main_loop,
-		do_call_trigger_done, 1, NULL, 0, false, impl);
+	pw_log_trace_fp("%p: call trigger_done rt:%u", impl, impl->trigger_done_rt);
+	if (impl->trigger_done_rt) {
+		if (impl->rt_callbacks.funcs)
+			spa_callbacks_call(&impl->rt_callbacks, struct pw_stream_events, trigger_done, 2);
+	} else {
+		pw_loop_invoke(impl->main_loop,
+			do_call_trigger_done, 1, NULL, 0, false, impl);
+	}
 }
 
 static int
@@ -1921,6 +1928,7 @@ pw_stream_connect(struct pw_stream *stream,
 		impl->node_methods.process = impl_node_process_output;
 
 	impl->process_rt = SPA_FLAG_IS_SET(flags, PW_STREAM_FLAG_RT_PROCESS);
+	impl->trigger_done_rt = SPA_FLAG_IS_SET(flags, PW_STREAM_FLAG_RT_TRIGGER_DONE);
 	impl->early_process = SPA_FLAG_IS_SET(flags, PW_STREAM_FLAG_EARLY_PROCESS);
 
 	impl->impl_node.iface = SPA_INTERFACE_INIT(
diff --git a/src/pipewire/stream.h b/src/pipewire/stream.h
index 3508d92a2..5a1fa1913 100644
--- a/src/pipewire/stream.h
+++ b/src/pipewire/stream.h
@@ -356,7 +356,10 @@ struct pw_stream_events {
 	/** A command notify, Since 0.3.39:1 */
 	void (*command) (void *data, const struct spa_command *command);
 
-	/** a trigger_process completed. Since version 0.3.40:2 */
+	/** a trigger_process completed. Since version 0.3.40:2.
+	 *  This is normally called from the mainloop but since 1.1.0 it
+	 *  can also be called directly from the realtime data
+	 *  thread if the user is prepared to deal with this. */
 	void (*trigger_done) (void *data);
 };
 
@@ -401,6 +404,9 @@ enum pw_stream_flags {
 							  *  playback and when not using RT_PROCESS. It
 							  *  can be used to keep the maximum number of
 							  *  buffers queued. Since 0.3.81 */
+	PW_STREAM_FLAG_RT_TRIGGER_DONE	= (1 << 12),	/**< Call trigger_done from the realtime
+							  *  thread. You MUST use RT safe functions
+							  *  in the trigger_done callback. Since 1.1.0 */
 };
 
 /** Create a new unconneced \ref pw_stream