iOS: App is hanging when trying to close the stream - ios

Question

I created NSStreams to transfer something using the below code:
dispatch_async(dispatch_get_main_queue(), ^{
// open input
[self.inputStream setDelegate:controller];
[self.inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[self.inputStream open];
// open output
[self.outputStream setDelegate:controller];
[self.outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[self.outputStream open];
});
At some point, I want to close the streams using the below code:
// Shut down input
[self.inputStream close];
self.inputStream = nil;
// Shut down output
[self.outputStream close];
self.outputStream = nil;
NSLog(#"input streams status:%i", [self.inputStream streamStatus]);
NSLog(#"output streams status:%i", [self.outputStream streamStatus]);
NSLog(#"input streams status:%#", [self.inputStream streamError]);
NSLog(#"output streams status:%#", [self.outputStream streamError]);
All input/output streams are strong properties.
Stream status return zero, but my app hangs. When I put device in debug mode, the monitor shows that my device CPU start running in 98+% after close method called. It seems like it's waiting for something to finish, but I still don't know what that is.
Does anyone know what may cause this issues?

Answer 1

Try removing the streams from the run loop.
// Shut down input
[self.inputStream close];
[self.inputStream removeFromRunLoop: [NSRunLoop currentRunLoop] forMode: NSDefaultRunLoopMode];
self.inputStream = nil;
// Shut down output
[self.outputStream close];
[self.outputStream removeFromRunLoop: [NSRunLoop currentRunLoop] forMode: NSDefaultRunLoopMode];
self.outputStream = nil;
More information can be found here.