From bad3283182927332bf3f39084ad1a047def95b7f Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@musicpd.org>
Date: Fri, 24 Sep 2021 11:33:09 +0200
Subject: [PATCH] output/pipewire: add flag "active", replaces some uses of
 "paused"

This way, we know whether we're explicitly "paused" or "not yet
activated because the ring buffer hasn't been filled yet".
---
 src/output/plugins/PipeWireOutputPlugin.cxx | 28 +++++++++++++++------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/output/plugins/PipeWireOutputPlugin.cxx b/src/output/plugins/PipeWireOutputPlugin.cxx
index 5e4938589..9cea7fdb8 100644
--- a/src/output/plugins/PipeWireOutputPlugin.cxx
+++ b/src/output/plugins/PipeWireOutputPlugin.cxx
@@ -93,6 +93,12 @@ class PipeWireOutput final : AudioOutput {
 	bool interrupted;
 	bool paused;
 
+	/**
+	 * Is the PipeWire stream active, i.e. has
+	 * pw_stream_set_active() been called successfully?
+	 */
+	bool active;
+
 	/**
 	 * Has Drain() been called?  This causes Process() to invoke
 	 * pw_stream_flush() to drain PipeWire as soon as the
@@ -353,11 +359,11 @@ PipeWireOutput::Open(AudioFormat &audio_format)
 	disconnected = false;
 	restore_volume = true;
 
-	/* we're paused (inactive) now because of the flag
-	   PW_STREAM_FLAG_INACTIVE; this way, we can fill the
-	   ring_buffer before activating the stream, to avoid
-	   underruns */
-	paused = true;
+	paused = false;
+
+	/* stay inactive (PW_STREAM_FLAG_INACTIVE) until the ring
+	   buffer has been filled */
+	active = false;
 
 	drain_requested = false;
 	drained = true;
@@ -492,6 +498,8 @@ PipeWireOutput::Play(const void *chunk, size_t size)
 {
 	const PipeWire::ThreadLoopLock lock(thread_loop);
 
+	paused = false;
+
 	while (true) {
 		CheckThrowError();
 
@@ -502,11 +510,11 @@ PipeWireOutput::Play(const void *chunk, size_t size)
 			return bytes_written;
 		}
 
-		if (paused) {
+		if (!active) {
 			/* now that the ring_buffer is full, there is
 			   enough data for Process(), so let's resume
 			   the stream now */
-			paused = false;
+			active = true;
 			pw_stream_set_active(stream, true);
 		}
 
@@ -547,7 +555,11 @@ PipeWireOutput::Pause() noexcept
 	interrupted = false;
 
 	paused = true;
-	pw_stream_set_active(stream, false);
+
+	if (active) {
+		active = false;
+		pw_stream_set_active(stream, false);
+	}
 
 	return true;
 }