From 12eaaef210dda959c8a1717914870ef4fcfde69b Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@gmail.com>
Date: Mon, 29 Jul 2024 16:44:37 +0200
Subject: [PATCH] output/Thread: allow Delay() to return duration::max()
Eliminate the periodic wakeups while paused in some output plugins.
---
src/output/Interface.hxx | 4 ++++
src/output/Thread.cxx | 5 ++++-
src/output/plugins/AlsaOutputPlugin.cxx | 2 +-
src/output/plugins/JackOutputPlugin.cxx | 2 +-
src/output/plugins/PulseOutputPlugin.cxx | 2 +-
src/output/plugins/wasapi/WasapiOutputPlugin.cxx | 2 +-
6 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/src/output/Interface.hxx b/src/output/Interface.hxx
index 8c679f66c..c3aeef2c1 100644
--- a/src/output/Interface.hxx
+++ b/src/output/Interface.hxx
@@ -136,6 +136,10 @@ public:
* instead of doing a sleep inside the plugin, because this
* allows MPD to listen to commands meanwhile.
*
+ * As a special case, this method is allowed to return
+ * std::chrono::steady_clock::duration::max() which lets MPD
+ * sleep forever until a command is received.
+ *
* @return the duration to wait
*/
virtual std::chrono::steady_clock::duration Delay() const noexcept {
diff --git a/src/output/Thread.cxx b/src/output/Thread.cxx
index b8f5e38e3..e1c3ed477 100644
--- a/src/output/Thread.cxx
+++ b/src/output/Thread.cxx
@@ -197,7 +197,10 @@ AudioOutputControl::WaitForDelay(std::unique_lock<Mutex> &lock) noexcept
if (delay <= std::chrono::steady_clock::duration::zero())
return true;
- (void)wake_cond.wait_for(lock, delay);
+ if (delay >= std::chrono::steady_clock::duration::max())
+ wake_cond.wait(lock);
+ else
+ (void)wake_cond.wait_for(lock, delay);
if (command != Command::NONE)
return false;
diff --git a/src/output/plugins/AlsaOutputPlugin.cxx b/src/output/plugins/AlsaOutputPlugin.cxx
index f6bb22432..c986c787e 100644
--- a/src/output/plugins/AlsaOutputPlugin.cxx
+++ b/src/output/plugins/AlsaOutputPlugin.cxx
@@ -883,7 +883,7 @@ std::chrono::steady_clock::duration
AlsaOutput::Delay() const noexcept
{
if (paused)
- return std::chrono::hours{1};
+ return std::chrono::steady_clock::duration::max();
return AudioOutput::Delay();
}
diff --git a/src/output/plugins/JackOutputPlugin.cxx b/src/output/plugins/JackOutputPlugin.cxx
index c393267d4..8b88bdc7f 100644
--- a/src/output/plugins/JackOutputPlugin.cxx
+++ b/src/output/plugins/JackOutputPlugin.cxx
@@ -155,7 +155,7 @@ public:
std::chrono::steady_clock::duration Delay() const noexcept override {
return pause && !LockWasShutdown()
- ? std::chrono::seconds(1)
+ ? std::chrono::steady_clock::duration::max()
: std::chrono::steady_clock::duration::zero();
}
diff --git a/src/output/plugins/PulseOutputPlugin.cxx b/src/output/plugins/PulseOutputPlugin.cxx
index 7b35b8271..67e905817 100644
--- a/src/output/plugins/PulseOutputPlugin.cxx
+++ b/src/output/plugins/PulseOutputPlugin.cxx
@@ -762,7 +762,7 @@ PulseOutput::Delay() const noexcept
if (pa_stream_is_corked(stream) &&
pa_stream_get_state(stream) == PA_STREAM_READY)
/* idle while paused */
- result = std::chrono::seconds(1);
+ result = std::chrono::steady_clock::duration::max();
return result;
}
diff --git a/src/output/plugins/wasapi/WasapiOutputPlugin.cxx b/src/output/plugins/wasapi/WasapiOutputPlugin.cxx
index fcc0d5320..31c9d9544 100644
--- a/src/output/plugins/wasapi/WasapiOutputPlugin.cxx
+++ b/src/output/plugins/wasapi/WasapiOutputPlugin.cxx
@@ -684,7 +684,7 @@ WasapiOutput::Delay() const noexcept
{
if (paused) {
// idle while paused
- return std::chrono::seconds(1);
+ return std::chrono::steady_clock::duration::max();
}
return std::chrono::steady_clock::duration::zero();