Fixed erroneous retain by NSTimer

Author: ivannador

Superpowered/OpenSource/SuperpoweredIOSAudioIO.mm

@@ -93,13 +93,35 @@ - (id)initWithDelegate:(NSObject<SuperpoweredIOSAudioIODelegate> *)d preferredBu
         externalAudioDeviceName = nil;
         audioUnit = NULL;
         inputBuffer = NULL;
-        
+
 #if (USES_AUDIO_INPUT == 1)
         if (inputEnabled) [self createInputBuffer];
 #endif
-        stopTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(everySecond) userInfo:nil repeats:YES];
 #if !__has_feature(objc_arc)
+        stopTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(everySecond) userInfo:nil repeats:YES];
         [self release]; // to prevent NSTimer retaining this
+#else
+        typeof(self) __weak weakSelf = self;
+        stopTimer = [NSTimer scheduledTimerWithTimeInterval:2.0 repeats:YES block:^(NSTimer * _Nonnull timer) {
+            __strong typeof(weakSelf) strongSelf = weakSelf;
+            if (!strongSelf) return;
+            if (strongSelf->silenceFrames > strongSelf->samplerate) {
+                [strongSelf beginInterruption];
+                strongSelf->silenceFrames = 0;
+            } else if (!strongSelf->background && strongSelf->audioUnitRunning && strongSelf->started) { // If it should run...
+                mach_timebase_info_data_t timebase;
+                mach_timebase_info(&timebase);
+                uint64_t diff = mach_absolute_time() - strongSelf->lastCallbackTime;
+                diff *= timebase.numer;
+                diff /= timebase.denom;
+                if (diff > 1000000000) { // But it didn't call the audio processing callback in the past second.
+                    strongSelf->audioUnitRunning = false;
+                    [[AVAudioSession sharedInstance] setActive:NO error:nil];
+                    [strongSelf resetAudio];
+                    [strongSelf start];
+                }
+            }
+        }];
 #endif
         [self resetAudio];
 
@@ -109,7 +131,7 @@ - (id)initWithDelegate:(NSObject<SuperpoweredIOSAudioIODelegate> *)d preferredBu
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onMediaServerReset:) name:AVAudioSessionMediaServicesWereResetNotification object:[AVAudioSession sharedInstance]];
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onAudioSessionInterrupted:) name:AVAudioSessionInterruptionNotification object:[AVAudioSession sharedInstance]];
         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onRouteChange:) name:AVAudioSessionRouteChangeNotification object:[AVAudioSession sharedInstance]];
-        
+
 #if (USES_AUDIO_INPUT == 1)
 #if __IPHONE_OS_VERSION_MIN_REQUIRED >= 170000
         if ((recordOnly || [category isEqualToString:AVAudioSessionCategoryPlayAndRecord]) && ([AVAudioApplication sharedInstance].recordPermission != AVAudioApplicationRecordPermissionGranted)) {
@@ -162,6 +184,7 @@ - (void)onMediaServerReset:(NSNotification *)notification { // The mediaserver d
     };
 }
 
+#if !__has_feature(objc_arc)
 - (void)everySecond { // If we waited for more than 1 second with silence, stop RemoteIO to save battery.
     if (silenceFrames > samplerate) {
         [self beginInterruption];
@@ -180,6 +203,7 @@ - (void)everySecond { // If we waited for more than 1 second with silence, stop
         }
     }
 }
+#endif
 
 - (void)beginInterruption { // Phone call, etc.
     if (![NSThread isMainThread]) [self performSelectorOnMainThread:@selector(beginInterruption) withObject:nil waitUntilDone:NO];
@@ -242,7 +266,7 @@ - (void)onRouteChange:(NSNotification *)notification {
         [self performSelectorOnMainThread:@selector(onRouteChange:) withObject:notification waitUntilDone:NO];
         return;
     };
-    
+
     bool receiverAvailable = false, usbOrHDMIAvailable = false;
     for (AVAudioSessionPortDescription *port in [[[AVAudioSession sharedInstance] currentRoute] outputs]) {
         if ([port.portType isEqualToString:AVAudioSessionPortUSBAudio] || [port.portType isEqualToString:AVAudioSessionPortHDMI]) {
@@ -274,7 +298,7 @@ - (void)onRouteChange:(NSNotification *)notification {
         audioDeviceType type = NSStringToAudioDeviceType(port.portType);
         [audioSystemInfo appendFormat:@"%s%@ (%i out)", first ? "" : ", ", [port.portName stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]], channels];
         first = false;
-        
+
         if (type == audioDeviceType_headphone) outputChannelMap.headphoneAvailable = true;
         else if (type == audioDeviceType_HDMI) {
             outputChannelMap.numberOfHDMIChannelsAvailable = channels;
@@ -293,7 +317,7 @@ - (void)onRouteChange:(NSNotification *)notification {
             externalAudioDeviceName = port.portName;
 #endif
         };
-        
+
         while (channels > 0) {
             RemoteIOOutputChannelMap[n++] = type;
             channels--;
@@ -303,15 +327,15 @@ - (void)onRouteChange:(NSNotification *)notification {
     if ([[AVAudioSession sharedInstance] isInputAvailable]) {
         [audioSystemInfo appendString:@", Inputs: "];
         first = true;
-        
+
         for (AVAudioSessionPortDescription *port in [[[AVAudioSession sharedInstance] currentRoute] inputs]) {
             int channels = (int)[port.channels count];
             audioDeviceType type = NSStringToAudioDeviceType(port.portType);
             [audioSystemInfo appendFormat:@"%s%@ (%i in)", first ? "" : ", ", [port.portName stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]], channels];
             first = false;
             if (type == audioDeviceType_USB) inputChannelMap.numberOfUSBChannelsAvailable = channels;
         };
-        
+
         if (first) [audioSystemInfo appendString:@"-"];
     };
 
@@ -401,7 +425,7 @@ static void streamFormatChangedCallback(void *inRefCon, AudioUnit inUnit, AudioU
 static OSStatus coreAudioProcessingCallback(void *inRefCon, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inBusNumber, UInt32 inNumberFrames, AudioBufferList *ioData) {
     __unsafe_unretained SuperpoweredIOSAudioIO *self = (__bridge SuperpoweredIOSAudioIO *)inRefCon;
     self->lastCallbackTime = mach_absolute_time();
-    
+
     if (!ioData) ioData = self->inputBuffer;
     div_t d = div(inNumberFrames, 8);
     if (d.rem != 0) {
@@ -448,7 +472,7 @@ static OSStatus coreAudioProcessingCallback(void *inRefCon, AudioUnitRenderActio
         // If the app is in the background, check if we don't output anything.
         if (self->background && self->saveBatteryInBackground) self->silenceFrames += inNumberFrames; else self->silenceFrames = 0;
     } else self->silenceFrames = 0;
-    
+
     return noErr;
 }
 
@@ -532,7 +556,7 @@ - (void)mapChannels {
     outputChannelMap.deviceChannels[0] = outputChannelMap.deviceChannels[1] = -1;
     for (int n = 0; n < 8; n++) outputChannelMap.HDMIChannels[n] = -1;
     for (int n = 0; n < 32; n++) outputChannelMap.USBChannels[n] = inputChannelMap.USBChannels[n] = -1;
-    
+
     if ([(NSObject *)self->delegate respondsToSelector:@selector(mapChannels:inputMap:externalAudioDeviceName:outputsAndInputs:)]) [delegate mapChannels:&outputChannelMap inputMap:&inputChannelMap externalAudioDeviceName:externalAudioDeviceName outputsAndInputs:audioSystemInfo];
     if (!audioUnit || (numberOfChannels <= 2)) return;
 
@@ -547,7 +571,7 @@ - (void)mapChannels {
         } else outputmap[n] = -1;
         inputmap[n] = inputChannelMap.USBChannels[n];
     };
-    
+
 #if !TARGET_IPHONE_SIMULATOR
     AudioUnitSetProperty(audioUnit, kAudioOutputUnitProperty_ChannelMap, kAudioUnitScope_Output, 0, outputmap, 128);
     AudioUnitSetProperty(audioUnit, kAudioOutputUnitProperty_ChannelMap, kAudioUnitScope_Output, 1, inputmap, 128);