Question

I’ve got an app that throws out the GKSession and makes a new one under various conditions (connection timeout, session fails, etc.). I’m getting memory leaks, though, and it sometimes crashes after a few loops through the reconnect.

Here’s my code:

- (void) netConnect:(id) sender {
     NSLog(@"allocating GKSession");

     currentSession = [[GKSession alloc] initWithSessionID:nil displayName:nil sessionMode:GKSessionModePeer];
     currentSession.delegate = self;
     currentSession.available = YES;
     currentSession.disconnectTimeout = 0;
     [currentSession setDataReceiveHandler: self withContext:nil]; 
        }

- (void) netDisconnect:(id) sender {
     NSLog(@"DISCONNECTING BY REQUEST");

     [currentSession disconnectFromAllPeers];
     [currentSession setAvailable:NO];
     [currentSession setDelegate:nil];
     [currentSession setDataReceiveHandler:nil withContext:nil];
     [currentSession release];
     currentSession = nil;
    }

There’s a timer that waits for a successful connection; if it doesn’t get one, netDisconnect is called, followed by netConnect again after a 5-second NSTimer delay.

I’m getting leaked GKList, GKTable, and GKAutoPeerIDTable objects, and crashes like this (always occurs after the alloc) :

  Date/Time:       2010-09-05 09:35:59.426 -0700
  OS Version:      iPhone OS 4.0.2 (8A400)
  Report Version:  104

  Exception Type:  EXC_BAD_ACCESS (SIGBUS)
  Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000a
  Crashed Thread:  0

  Thread 0 Crashed:
  0   libobjc.A.dylib                0x0000286c objc_msgSend + 16
  1   CoreFoundation                 0x000756ea __CFCopyFormattingDescription + 174
  2   CoreFoundation                 0x00081c8e __CFStringAppendFormatCore + 8666
  3   CoreFoundation                 0x000146ac _CFStringCreateWithFormatAndArgumentsAux + 64
  4   CoreFoundation                 0x00014660 CFStringCreateWithFormatAndArguments + 16
  5   CoreFoundation                 0x0001463c CFStringCreateWithFormat + 16
  6   SystemConfiguration            0x00003272 SCDynamicStoreCreateWithOptions + 62
  7   SystemConfiguration            0x000033d0 SCDynamicStoreCreate + 12
  8   GameKitServices                0x000020ce gckRegisterForNetworkChanges + 154
  9   GameKitServices                0x000035c0 GCKSessionCreate + 788
  10  GameKitServices                0x00035e7a -[GKSessionInternal initWithSessionID:displayName:session:sessionMode:] + 274
  11  GameKit                        0x0000fda8 -[GKSession initWithSessionID:displayName:sessionMode:] + 76

Here’s another one:

Sun Sep  5 10:28:52 thinner someapp[424] <Warning>: allocating GKSession
Sun Sep  5 10:28:52 thinner someapp[424] <Error>: -[__NSCFData UTF8String]: unrecognized selector sent to instance 0x10a710
Sun Sep  5 10:28:52 thinner someapp[424] <Error>: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFData UTF8String]: unrecognized selector sent to instance 0x10a710'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x31a9ffd3 __exceptionPreprocess + 114
    1   libobjc.A.dylib                     0x3428a8a5 objc_exception_throw + 24
    2   CoreFoundation                      0x31aa3a77 -[NSObject(NSObject) doesNotRecognizeSelector:] + 102
    3   CoreFoundation                      0x31aa2f15 ___forwarding___ + 508
    4   CoreFoundation                      0x31a35680 _CF_forwarding_prep_0 + 48
    5   GameKitServices                     0x327aff13 -[GKSessionInternal initWithSessionID:displayName:session:sessionMode:] + 426
    6   GameKit                             0x31c15daf -[GKSession initWithSessionID:displayName:sessionMode:] + 82
    7   someapp                        0x0000584b -[MainViewController netConnect:] + 126

Questions:
• Is this the right way to release and re-allocate GKSessions?
• Should I not be tearing down and re-allocating GKSessions between connections to begin with?

Answer 1

This is a known issue. The workaround is to not pass in nil for the sessionID:
[[GKSession alloc] initWithSessionID:@”com.put.something.here” displayName:nil sessionMode:GKSessionModePeer];