iphone - StoreKit SKProductsRequest Crash

Question

I use the following code to request a list of products as per the In-App Purchase Programming Guide. It used to work fine in my iPhone application, however now it crashes every time the product list is requested. The delegate method (void)productsRequest:(SKProductsRequest **)request didReceiveResponse:(SKProductsResponse **)response is never called.

SKProductsRequest *request = [[SKProductsRequest alloc] initWithProductIdentifiers:[NSSet setWithObject:@"my.product.identifier"]];
[request setDelegate:self];
[request start];

As I said, it worked perfectly fine, then just stopped working. This is the crash which occurs when the above code is called.

Exception Type:  EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00000011
Crashed Thread:  0

Thread 0 Crashed:
0   libobjc.A.dylib                 0x000034f8 objc_msgSend + 24
1   StoreKit                        0x00003e18 -[SKProductsRequest handleFinishResponse:returningError:] + 40
2   StoreKit                        0x000050c4 -[SKRequest _requestFinishedNotification:] + 152
3   Foundation                      0x00019b9a _nsnote_callback + 150
4   CoreFoundation                  0x0006c2de __CFXNotificationPost_old + 390
5   CoreFoundation                  0x0001ab32 _CFXNotificationPostNotification + 122
6   Foundation                      0x000048e4 -[NSNotificationCenter postNotificationName:object:userInfo:] + 64
7   AppSupport                      0x0000bb42 -[CPDistributedNotificationCenter deliverNotification:userInfo:] + 38
8   AppSupport                      0x0000cf66 _CPDNDeliverNotification + 198
9   AppSupport                      0x0000ba4a _XDeliverNotification + 110
10  AppSupport                      0x00002e82 migHelperRecievePortCallout + 122
11  CoreFoundation                  0x000742ac __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 22
12  CoreFoundation                  0x000761d6 __CFRunLoopDoSource1 + 158
13  CoreFoundation                  0x0007718e __CFRunLoopRun + 574
14  CoreFoundation                  0x0001e0bc CFRunLoopRunSpecific + 220
15  CoreFoundation                  0x0001dfca CFRunLoopRunInMode + 54
16  GraphicsServices                0x00003f88 GSEventRunModal + 188
17  UIKit                           0x00007b40 -[UIApplication _run] + 564
18  UIKit                           0x00005fb8 UIApplicationMain + 964
19  myapp                           0x00002fae main (main.m:13)
20  myapp                           0x00002f58 start + 32

Thread 1:
0   libSystem.B.dylib               0x00034e84 kevent + 24
1   libSystem.B.dylib               0x00102a48 _dispatch_mgr_invoke + 88
2   libSystem.B.dylib               0x00102494 _dispatch_queue_invoke + 96
3   libSystem.B.dylib               0x00102634 _dispatch_worker_thread2 + 120
4   libSystem.B.dylib               0x0008b53c _pthread_wqthread + 392
5   libSystem.B.dylib               0x00082b6c start_wqthread + 0

Thread 2:
0   libSystem.B.dylib               0x00000ab0 mach_msg_trap + 20
1   libSystem.B.dylib               0x00002f94 mach_msg + 60
2   CoreFoundation                  0x00074b18 __CFRunLoopServiceMachPort + 88
3   CoreFoundation                  0x000770e0 __CFRunLoopRun + 400
4   CoreFoundation                  0x0001e0bc CFRunLoopRunSpecific + 220
5   CoreFoundation                  0x0001dfca CFRunLoopRunInMode + 54
6   WebCore                         0x0000370c RunWebThread(void*) + 552
7   libSystem.B.dylib               0x0008af80 _pthread_start + 364
8   libSystem.B.dylib               0x0007d014 thread_start + 0

Thread 3:
0   libSystem.B.dylib               0x00000ab0 mach_msg_trap + 20
1   libSystem.B.dylib               0x00002f94 mach_msg + 60
2   CoreFoundation                  0x00074b18 __CFRunLoopServiceMachPort + 88
3   CoreFoundation                  0x000770e0 __CFRunLoopRun + 400
4   CoreFoundation                  0x0001e0bc CFRunLoopRunSpecific + 220
5   CoreFoundation                  0x0001dfca CFRunLoopRunInMode + 54
6   Foundation                      0x0003c316 +[NSURLConnection(NSURLConnectionReallyInternal) _resourceLoadLoop:] + 210
7   Foundation                      0x0000c612 -[NSThread main] + 42
8   Foundation                      0x00092140 __NSThread__main__ + 908
9   libSystem.B.dylib               0x0008af80 _pthread_start + 364
10  libSystem.B.dylib               0x0007d014 thread_start + 0

Thread 4:
0   libSystem.B.dylib               0x00029f24 select$DARWIN_EXTSN + 20
1   CoreFoundation                  0x0007aa54 __CFSocketManager + 340
2   libSystem.B.dylib               0x0008af80 _pthread_start + 364
3   libSystem.B.dylib               0x0007d014 thread_start + 0

I don't know what is causing the objc_msgSend crash, or how it is related to StoreKit. I also have no idea what I added or changed which caused this simple code to stop working.

Answer 1

A very likely explanation is whether the object you set as a delegate for the SKProductRequest object might have been deallocated already.

It is quite possible for the request to take a few seconds to complete, and this might be past the lifetime of your delegate object, so you may want to make sure it sticks around for long enough.