From 1624a5eb8deda2ed9453a0f0391a929042814c81 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@musicpd.org>
Date: Sat, 23 Jun 2018 19:11:48 +0200
Subject: [PATCH] output/Control: add another Cond attribute, replacing
 audio_output_client_notify

---
 src/output/Control.cxx         |  9 ++-------
 src/output/Control.hxx         |  6 ++++++
 src/output/Filtered.hxx        |  6 ------
 src/output/MultipleOutputs.cxx | 16 +++-------------
 src/output/MultipleOutputs.hxx |  5 +----
 src/output/Thread.cxx          |  4 +---
 6 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/src/output/Control.cxx b/src/output/Control.cxx
index 86235ed4d..1c63f110f 100644
--- a/src/output/Control.cxx
+++ b/src/output/Control.cxx
@@ -22,7 +22,6 @@
 #include "Filtered.hxx"
 #include "Domain.hxx"
 #include "mixer/MixerControl.hxx"
-#include "notify.hxx"
 #include "filter/plugins/ReplayGainFilterPlugin.hxx"
 #include "config/Block.hxx"
 #include "Log.hxx"
@@ -35,8 +34,6 @@
     automatically reopening the device */
 static constexpr PeriodClock::Duration REOPEN_AFTER = std::chrono::seconds(10);
 
-struct notify audio_output_client_notify;
-
 AudioOutputControl::AudioOutputControl(std::unique_ptr<FilteredAudioOutput> _output,
 				       AudioOutputClient &_client) noexcept
 	:output(std::move(_output)), client(_client),
@@ -116,10 +113,8 @@ AudioOutputControl::LockToggleEnabled() noexcept
 void
 AudioOutputControl::WaitForCommand() noexcept
 {
-	while (!IsCommandFinished()) {
-		const ScopeUnlock unlock(mutex);
-		audio_output_client_notify.Wait();
-	}
+	while (!IsCommandFinished())
+		client_cond.wait(mutex);
 }
 
 void
diff --git a/src/output/Control.hxx b/src/output/Control.hxx
index caf9260ac..711f86382 100644
--- a/src/output/Control.hxx
+++ b/src/output/Control.hxx
@@ -93,6 +93,12 @@ class AudioOutputControl {
 	 */
 	Cond wake_cond;
 
+	/**
+	 * This condition object signals #command completion to the
+	 * client.
+	 */
+	Cond client_cond;
+
 	/**
 	 * Additional data for #command.  Protected by #mutex.
 	 */
diff --git a/src/output/Filtered.hxx b/src/output/Filtered.hxx
index 3d79c193b..ed9d51e71 100644
--- a/src/output/Filtered.hxx
+++ b/src/output/Filtered.hxx
@@ -228,12 +228,6 @@ public:
 	}
 };
 
-/**
- * Notify object used by the thread's client, i.e. we will send a
- * notify signal to this object, expecting the caller to wait on it.
- */
-extern struct notify audio_output_client_notify;
-
 /**
  * Throws #std::runtime_error on error.
  */
diff --git a/src/output/MultipleOutputs.cxx b/src/output/MultipleOutputs.cxx
index ab4756d5d..5e8a2acea 100644
--- a/src/output/MultipleOutputs.cxx
+++ b/src/output/MultipleOutputs.cxx
@@ -26,7 +26,6 @@
 #include "config/Block.hxx"
 #include "config/ConfigGlobal.hxx"
 #include "config/ConfigOption.hxx"
-#include "notify.hxx"
 #include "util/RuntimeError.hxx"
 
 #include <stdexcept>
@@ -155,23 +154,14 @@ MultipleOutputs::EnableDisable()
 	}
 }
 
-bool
-MultipleOutputs::AllFinished() const noexcept
+void
+MultipleOutputs::WaitAll() noexcept
 {
 	for (auto *ao : outputs) {
 		const std::lock_guard<Mutex> protect(ao->mutex);
 		if (ao->IsBusy())
-			return false;
+			ao->WaitForCommand();
 	}
-
-	return true;
-}
-
-void
-MultipleOutputs::WaitAll() noexcept
-{
-	while (!AllFinished())
-		audio_output_client_notify.Wait();
 }
 
 void
diff --git a/src/output/MultipleOutputs.hxx b/src/output/MultipleOutputs.hxx
index aeb8d1c81..a01c78cfe 100644
--- a/src/output/MultipleOutputs.hxx
+++ b/src/output/MultipleOutputs.hxx
@@ -145,12 +145,9 @@ public:
 
 private:
 	/**
-	 * Determine if all (active) outputs have finished the current
+	 * Wait until all (active) outputs have finished the current
 	 * command.
 	 */
-	gcc_pure
-	bool AllFinished() const noexcept;
-
 	void WaitAll() noexcept;
 
 	/**
diff --git a/src/output/Thread.cxx b/src/output/Thread.cxx
index 0ea35aa39..58b5abcfc 100644
--- a/src/output/Thread.cxx
+++ b/src/output/Thread.cxx
@@ -22,7 +22,6 @@
 #include "Filtered.hxx"
 #include "Client.hxx"
 #include "Domain.hxx"
-#include "notify.hxx"
 #include "mixer/MixerInternal.hxx"
 #include "thread/Util.hxx"
 #include "thread/Slack.hxx"
@@ -41,8 +40,7 @@ AudioOutputControl::CommandFinished() noexcept
 	assert(command != Command::NONE);
 	command = Command::NONE;
 
-	const ScopeUnlock unlock(mutex);
-	audio_output_client_notify.Signal();
+	client_cond.signal();
 }
 
 inline void