output/Thread: skip WaitForDelay() after resuming playback

This allows removing the "base.pause" check from the JACK output
plugin, and will allow removing similar accesses from other plugins.

src/output/Control.hxx

@@ -167,6 +167,13 @@ class AudioOutputControl {
 	 */
 	bool woken_for_play = false;
 
+	/**
+	 * If this flag is set, then the next WaitForDelay() call is
+	 * skipped.  This is used to avoid delays after resuming
+	 * playback.
+	 */
+	bool skip_delay;
+
 public:
 	Mutex &mutex;
 

src/output/Thread.cxx

@@ -209,6 +209,7 @@ AudioOutputControl::InternalOpen(const AudioFormat audio_format,
 {
 	last_error = nullptr;
 	fail_timer.Reset();
+	skip_delay = true;
 
 	try {
 		output->Open(audio_format, pipe);
@@ -304,7 +305,9 @@ AudioOutputControl::PlayChunk() noexcept
 		if (data.IsEmpty())
 			break;
 
-		if (!WaitForDelay())
+		if (skip_delay)
+			skip_delay = false;
+		else if (!WaitForDelay())
 			break;
 
 		size_t nbytes;
@@ -425,6 +428,8 @@ AudioOutputControl::InternalPause() noexcept
 	} while (command == Command::NONE);
 
 	output->EndPause();
+
+	skip_delay = true;
 }
 
 void

src/output/plugins/JackOutputPlugin.cxx

@@ -129,7 +129,7 @@ struct JackOutput {
 	size_t WriteSamples(const float *src, size_t n_frames);
 
 	std::chrono::steady_clock::duration Delay() const noexcept {
-		return base.pause && pause && !shutdown
+		return pause && !shutdown
 			? std::chrono::seconds(1)
 			: std::chrono::steady_clock::duration::zero();
 	}