Singelton implementation to read / write from server - iphone

Question

I am trying to implement a singelton to read / write from a simple chat server. Im using a singelton model so that i can access the data and write from all of my viewControllers.
My singelton code:
#import "ChatDataController.h"
#implementation ChatDataController
{
ChatDataController * anotherSingles;
}
#synthesize enString;
#synthesize enInt;
+(ChatDataController *) singlOjb {
static ChatDataController * single=nil;
#synchronized(self)
{
if(!single)
{
single = [[ChatDataController alloc] init];
}
}
return single;
}
// We can still have a regular init method, that will get called the first time the Singleton is used.
- (id)init
{
self = [super init];
if (self) {
// Work your initialising magic here as you normally would
[self initNetworkCommunication];
}
return self;
}
// Open connection to server
- (void)initNetworkCommunication {
CFReadStreamRef readStream;
CFWriteStreamRef writeStream;
CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)#"localhost", 8080, &readStream, &writeStream);
inputStream = (__bridge NSInputStream *)readStream;
outputStream = (__bridge NSOutputStream *)writeStream;
[inputStream setDelegate:self];
[outputStream setDelegate:self];
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream open];
[outputStream open];
}
- (void) sendMsg {
NSString *response = [NSString stringWithFormat:#"iam:TestString"];
NSData *data = [[NSData alloc] initWithData:[response dataUsingEncoding:NSASCIIStringEncoding]];
[outputStream write:[data bytes] maxLength:[data length]];
}
#end
The problem is that when i run [self initNetworkCommunication]; from my init method my app crashes with the error: (lldb)
A break is detected at the line:
inputStream = (__bridge NSInputStream *)readStream;
Any ideas what i am doing wrong?
EDIT: Is this the way i should be doing it?

Answer 1

First, your singleton code should be like this...
+ (ChatDataController *)sharedInstance
{
static dispatch_once_t once;
static ChatDataController *chatDataController;
dispatch_once(&once, ^ { chatDataController = [[ChatDataController alloc] init];});
return chatDataController;
}
Next, and I'm not sure is this will fix as I'm not sure of the exact problem but I would do it this way...
In your AppDelegate (or wherever you need to start the stream) do this...
[[ChatDataController sharedInstance] initNetworkCommunication];
This makes sure the singleton object is fully instantiated before calling its instance methods.