NSFileHandle function acceptConnectionInBackgroundAndNotify not working when called a second time - cocoa

Question

I'm using cocoa and i'm trying to create a tcp socket server for a program i'm writing, i'm using NSFileHandle and the method acceptConnectionInBackgroundAndNotify. I've been following the code from here.
The problem i'm having is that I can connect my client once but when I try to connect again I get a connection refused error.
Before I connect for the first time the command sudo lsof -i -P returns the following information:
RubyBeat 23964 pauljohnson 8u IPv4 0x0632c274 0t0 TCP *:1234 (LISTEN)
After connecting the first time with the client I get this:
RubyBeat 23964 pauljohnson 5u IPv4 0x06a30334 0t0 TCP localhost:1234->localhost:51579 (CLOSED)
My application doesn't seem to be reopening the socket to listen for connections after the first one comes in and gets a error number 22 when I try to connect a second time.
I'm using the garbage collection in cocoa and was wondering if that would cause problems with sockets?
My code is:
[self createSocket];
}
-(void)createSocket
{
// create socket and wait for events to come in
NSSocketPort* serverSock = [[NSSocketPort alloc] initWithTCPPort: 1234];
socketHandle = [[NSFileHandle alloc] initWithFileDescriptor: [serverSock socket]
closeOnDealloc: NO];
[[NSNotificationCenter defaultCenter] addObserver: self selector: #selector(newConnection:)
name: NSFileHandleConnectionAcceptedNotification
object: socketHandle];
[socketHandle acceptConnectionInBackgroundAndNotify];
}
- (void)newConnection:(NSNotification*)notification
{
NSLog(#"connection accepted");
NSDictionary* userInfo = [notification userInfo];
NSFileHandle* remoteFileHandle = [userInfo objectForKey:
NSFileHandleNotificationFileHandleItem];
if([[userInfo allKeys] containsObject:#"NSFileHandleError"]){
NSNumber* errorNo = [userInfo objectForKey:#"NSFileHandleError"];
if( errorNo ) {
NSLog(#"NSFileHandle Error: %#", errorNo);
return;
}
}
[socketHandle acceptConnectionInBackgroundAndNotify];
[[NSNotificationCenter defaultCenter] addObserver:self
selector: #selector(processSocketData:)
name: NSFileHandleReadCompletionNotification
object: remoteFileHandle];
// Send a message to the client, acknowledging that the connection was accepted
[remoteFileHandle writeData: [#"OK" dataUsingEncoding: NSASCIIStringEncoding]];
[remoteFileHandle readInBackgroundAndNotify];
}
/*
Handle client data
*/
- (void)processSocketData:(NSNotification *)note
{
NSData *data = [[note userInfo]
objectForKey:NSFileHandleNotificationDataItem];
NSNumber* errorNo = [[note userInfo] objectForKey:#"NSFileHandleError"];
if( errorNo ) {
NSLog(#"NSFileHandle Error: %#", errorNo);
return;
}
// Do something here with your data
// search string for \n\n that terminates event
NSString* stringData = [[NSString alloc] initWithData: data encoding: NSASCIIStringEncoding];
NSLog(#"data received: %#", stringData);
NSDictionary* lastEvent = nil;
NSRange range = [stringData rangeOfString: #"\n\n"];
if (range.location != NSNotFound) {
NSArray* subStrings = [stringData componentsSeparatedByString:#"\n\n"];
NSMutableArray* events = [[NSMutableArray alloc] init];
[eventBuffer appendString: [subStrings objectAtIndex: 0]];
// handle first event - could be in parts
NSDictionary * json = (NSDictionary*)[eventBuffer JSONValue];
[events addObject:json];
for(int i = 1; i < [subStrings count]-1; i++){
NSString* subString = [subStrings indexOfObject:i];
NSDictionary * eventJson = (NSDictionary*)[subString JSONValue];
[events addObject:eventJson];
}
// we have at least one event to draw here
for(NSDictionary* event in events){
NSLog(#"event: %#", [event objectForKey:#"type"]);
}
lastEvent = [events lastObject];
// clear eventBuffer
[eventBuffer setString:#""];
// add end of data to eventBuffer?
}else {
[eventBuffer appendString:stringData];
}
// check event if it is a program exit event then stop receiving data
if([[lastEvent objectForKey: #"type"] compare: #"exit"] != NSOrderedSame){
// Tell file handle to continue waiting for data
[[note object] readInBackgroundAndNotify];
}else {
NSLog(#"exit received stopping receiving data");
}
}

Answer 1

I have met this problem before.
Once all data is read, do another "accept connection in background" for another round of reading data.