From 82050d6ac16eab3ea1164037b9e7ba4a69f77645 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 23 Jan 2021 23:11:15 +0900
Subject: [PATCH] audio: Bug fix: Deadlock at acquiring the semaphore

Closes #1469
---
 audio/audio.go | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/audio/audio.go b/audio/audio.go
index c3b0bc2f4..ac27dc021 100644
--- a/audio/audio.go
+++ b/audio/audio.go
@@ -389,9 +389,6 @@ func (p *playerImpl) loop() {
 }
 
 func (p *playerImpl) read() ([]byte, bool) {
-	p.m.Lock()
-	defer p.m.Unlock()
-
 	if p.context.hasError() {
 		return nil, false
 	}
@@ -400,18 +397,20 @@ func (p *playerImpl) read() ([]byte, bool) {
 		return nil, false
 	}
 
+	p.context.semaphore <- struct{}{}
+	defer func() {
+		<-p.context.semaphore
+	}()
+
+	p.m.Lock()
+	defer p.m.Unlock()
+
 	// playing can be false when pausing.
 	if !p.playing {
 		return nil, false
 	}
 
 	const bufSize = 2048
-
-	p.context.semaphore <- struct{}{}
-	defer func() {
-		<-p.context.semaphore
-	}()
-
 	newBuf := make([]byte, bufSize-len(p.buf))
 	n, err := p.src.Read(newBuf)
 	if err != nil {