From d417d245f40f490e2f5260ce206c5c7b7b02b1c0 Mon Sep 17 00:00:00 2001
From: Christopher Snowhill <kode54@gmail.com>
Date: Thu, 14 Jul 2022 03:16:21 -0700
Subject: [PATCH] [Audio Output] Make toggling DSPs safe

The DSPs should not be deinitialized from another thread, possibly while
they are currently processing.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>
---
 Audio/Output/OutputAVFoundation.h |  2 ++
 Audio/Output/OutputAVFoundation.m | 15 ++++++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/Audio/Output/OutputAVFoundation.h b/Audio/Output/OutputAVFoundation.h
index bbf9c64d4..3728b36a5 100644
--- a/Audio/Output/OutputAVFoundation.h
+++ b/Audio/Output/OutputAVFoundation.h
@@ -113,6 +113,8 @@ using std::atomic_long;
 	BOOL enableFSurround;
 	FSurroundFilter *fsurround;
 
+	BOOL resetStreamFormat;
+
 	float *samplePtr;
 	float tempBuffer[512 * 32];
 	float inputBuffer[4096 * 32]; // 4096 samples times maximum supported channel count
diff --git a/Audio/Output/OutputAVFoundation.m b/Audio/Output/OutputAVFoundation.m
index be61cbf64..5e4150c1b 100644
--- a/Audio/Output/OutputAVFoundation.m
+++ b/Audio/Output/OutputAVFoundation.m
@@ -304,12 +304,10 @@ current_device_listener(AudioObjectID inObjectID, UInt32 inNumberAddresses, cons
 		eqPreamp = pow(10.0, preamp / 20.0);
 	} else if([keyPath isEqualToString:@"values.enableHrtf"]) {
 		enableHrtf = [[[NSUserDefaultsController sharedUserDefaultsController] defaults] boolForKey:@"enableHrtf"];
-		if(streamFormatStarted)
-			[self updateStreamFormat];
+		resetStreamFormat = YES;
 	} else if([keyPath isEqualToString:@"values.enableFSurround"]) {
 		enableFSurround = [[[NSUserDefaultsController sharedUserDefaultsController] defaults] boolForKey:@"enableFSurround"];
-		if(streamFormatStarted)
-			[self updateStreamFormat];
+		resetStreamFormat = YES;
 	}
 }
 
@@ -606,6 +604,7 @@ current_device_listener(AudioObjectID inObjectID, UInt32 inNumberAddresses, cons
 - (void)updateStreamFormat {
 	/* Set the channel layout for the audio queue */
 	streamFormatChanged = YES;
+	resetStreamFormat = NO;
 
 	uint32_t channels = realStreamFormat.mChannelsPerFrame;
 	uint32_t channelConfig = realStreamChannelConfig;
@@ -746,6 +745,10 @@ current_device_listener(AudioObjectID inObjectID, UInt32 inNumberAddresses, cons
 	status = CMBlockBufferCreateEmpty(kCFAllocatorDefault, 0, 0, &blockListBuffer);
 	if(status != noErr || !blockListBuffer) return 0;
 
+	if(resetStreamFormat) {
+		[self updateStreamFormat];
+	}
+
 	int inputRendered = 0;
 	int bytesRendered = 0;
 	do {
@@ -898,7 +901,9 @@ current_device_listener(AudioObjectID inObjectID, UInt32 inNumberAddresses, cons
 		commandStop = NO;
 
 		audioFormatDescription = NULL;
-		
+
+		resetStreamFormat = NO;
+
 		running = NO;
 		stopping = NO;
 		stopped = NO;