iOS 8崩溃日志（AVPlayer）

Question

I am unable to diagnose this crash log, which occurs when using the AVPlayer class-- sometimes it happens right away, and sometimes it happens when trying to play the 2nd or 3rd video..

Incident Identifier: 4E82E665-228D-4A97-8B85-6F5B65E2B457
CrashReporter Key:   46be3f0cd4d380b2ce08823fedd6d6d22c38df2f
Hardware Model:      iPad4,2
Process:             App [2433]
Path:                /private/var/mobile/Containers/Bundle/Application/66E1EFE7-1BD0-4CE3-8FEF-47D58C36ADF7/App.app/App
Identifier:          SXX.app
Version:             1.3 (1.3)
Code Type:           ARM-64 (Native)
Parent Process:      launchd [1]

Date/Time:           2015-03-31 15:59:07.361 -0700
Launch Time:         2015-03-31 15:57:50.272 -0700
OS Version:          iOS 8.2 (12D508)
Report Version:      105

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Triggered by Thread:  6

Last Exception Backtrace:
0   CoreFoundation                  0x18530a530 __exceptionPreprocess + 132
1   libobjc.A.dylib                 0x1964280e4 objc_exception_throw + 60
2   CoreFoundation                  0x18530a470 +[NSException raise:format:] + 128
3   Foundation                      0x1861865e0 NSKVODeallocate + 340
4   AVFoundation                    0x183b27b38 __destroy_helper_block_1474 + 28
5   libsystem_blocks.dylib          0x196ad1910 _Block_release + 256
6   libdispatch.dylib               0x196a79954 _dispatch_client_callout + 16
7   libdispatch.dylib               0x196a7e20c _dispatch_main_queue_callback_4CF + 1608
8   CoreFoundation                  0x1852c22ec __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12
9   CoreFoundation                  0x1852c0394 __CFRunLoopRun + 1492
10  CoreFoundation                  0x1851ed1f4 CFRunLoopRunSpecific + 396
11  GraphicsServices                0x18e51f6fc GSEventRunModal + 168
12  UIKit                           0x189b7e10c UIApplicationMain + 1488
13  App                             0x10001d4ac main (main.m:8)
14  libdyld.dylib                   0x196aa6a08 start + 4


Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0:
0   libsystem_kernel.dylib          0x0000000196bbf594 __semwait_signal_nocancel + 8
1   libsystem_c.dylib               0x0000000196aef1a0 nanosleep$NOCANCEL + 200
2   libsystem_c.dylib               0x0000000196b142b8 usleep$NOCANCEL + 64
3   libsystem_c.dylib               0x0000000196b36b1c abort + 116
4   App                             0x0000000100042b50 uncaught_exception_handler + 32
5   CoreFoundation                  0x000000018530a8ec __handleUncaughtException + 688
6   libobjc.A.dylib                 0x00000001964283b0 _objc_terminate() + 112
7   libc++abi.dylib                 0x0000000195c25bb0 std::__terminate(void (*)()) + 12
8   libc++abi.dylib                 0x0000000195c25474 __cxa_throw + 132
9   libobjc.A.dylib                 0x0000000196428200 objc_exception_throw + 344
10  CoreFoundation                  0x000000018530a46c +[NSException raise:format:] + 124
11  Foundation                      0x00000001861865dc NSKVODeallocate + 336
12  AVFoundation                    0x0000000183b27b34 __destroy_helper_block_1474 + 24
13  libsystem_blocks.dylib          0x0000000196ad190c _Block_release + 252
14  libdispatch.dylib               0x0000000196a79950 _dispatch_client_callout + 12
15  libdispatch.dylib               0x0000000196a7e208 _dispatch_main_queue_callback_4CF + 1604
16  CoreFoundation                  0x00000001852c22e8 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8
17  CoreFoundation                  0x00000001852c0390 __CFRunLoopRun + 1488
18  CoreFoundation                  0x00000001851ed1f0 CFRunLoopRunSpecific + 392
19  GraphicsServices                0x000000018e51f6f8 GSEventRunModal + 164
20  UIKit                           0x0000000189b7e108 UIApplicationMain + 1484
21  App                             0x000000010001d4a8 main (main.m:8)
22  libdyld.dylib                   0x0000000196aa6a04 start + 0

Thread 1 name:  Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0   libsystem_kernel.dylib          0x0000000196ba4c24 kevent64 + 8
1   libdispatch.dylib               0x0000000196a89e6c _dispatch_mgr_invoke + 272
2   libdispatch.dylib               0x0000000196a7b998 _dispatch_mgr_thread + 48

Thread 2 name:  com.apple.NSURLConnectionLoader
Thread 2:
0   libsystem_kernel.dylib          0x0000000196ba4e0c mach_msg_trap + 8
1   libsystem_kernel.dylib          0x0000000196ba4c84 mach_msg + 68
2   CoreFoundation                  0x00000001852c2214 __CFRunLoopServiceMachPort + 196
3   CoreFoundation                  0x00000001852c0168 __CFRunLoopRun + 936
4   CoreFoundation                  0x00000001851ed1f0 CFRunLoopRunSpecific + 392
5   CFNetwork                       0x0000000184cee2a0 +[NSURLConnection(Loader) _resourceLoadLoop:] + 436
6   Foundation                      0x0000000186202304 __NSThread__main__ + 1068
7   libsystem_pthread.dylib         0x0000000196c5bdc4 _pthread_body + 160
8   libsystem_pthread.dylib         0x0000000196c5bd20 _pthread_start + 156
9   libsystem_pthread.dylib         0x0000000196c58ef4 thread_start + 0

Thread 3:
0   libsystem_kernel.dylib          0x0000000196bbfc78 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x0000000196c592d8 _pthread_wqthread + 988
2   libsystem_pthread.dylib         0x0000000196c58eec start_wqthread + 0

Thread 4 name:  com.apple.CFSocket.private
Thread 4:
0   libsystem_kernel.dylib          0x0000000196bbf498 __select + 8
1   CoreFoundation                  0x00000001852c7c0c __CFSocketManager + 656
2   libsystem_pthread.dylib         0x0000000196c5bdc4 _pthread_body + 160
3   libsystem_pthread.dylib         0x0000000196c5bd20 _pthread_start + 156
4   libsystem_pthread.dylib         0x0000000196c58ef4 thread_start + 0

Thread 5 name:  com.apple.coremedia.player.remote
Thread 5:
0   libsystem_kernel.dylib          0x0000000196ba4e0c mach_msg_trap + 8
1   libsystem_kernel.dylib          0x0000000196ba4c84 mach_msg + 68
2   MediaToolbox                    0x00000001876efe7c FigExpressNotificationThread + 100
3   CoreMedia                       0x0000000185b22028 figThreadMain + 244
4   libsystem_pthread.dylib         0x0000000196c5bdc4 _pthread_body + 160
5   libsystem_pthread.dylib         0x0000000196c5bd20 _pthread_start + 156
6   libsystem_pthread.dylib         0x0000000196c58ef4 thread_start + 0

Thread 6 Crashed:
0   libsystem_kernel.dylib          0x0000000196bbfc78 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x0000000196c592d8 _pthread_wqthread + 988
2   libsystem_pthread.dylib         0x0000000196c58eec start_wqthread + 0

Thread 7:
0   libsystem_kernel.dylib          0x0000000196bbfc78 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x0000000196c592d8 _pthread_wqthread + 988
2   libsystem_pthread.dylib         0x0000000196c58eec start_wqthread + 0

Thread 8 name:  com.apple.coremedia.player.async
Thread 8:
0   libsystem_kernel.dylib          0x0000000196ba4e48 semaphore_wait_trap + 8
1   libdispatch.dylib               0x0000000196a87f3c _dispatch_semaphore_wait_slow + 252
2   MediaToolbox                    0x00000001876e95bc fpa_AsyncMovieControlThread + 1952
3   CoreMedia                       0x0000000185b22028 figThreadMain + 244
4   libsystem_pthread.dylib         0x0000000196c5bdc4 _pthread_body + 160
5   libsystem_pthread.dylib         0x0000000196c5bd20 _pthread_start + 156
6   libsystem_pthread.dylib         0x0000000196c58ef4 thread_start + 0

Thread 9 name:  com.apple.coremedia.player.async
Thread 9:
0   libsystem_kernel.dylib          0x0000000196ba4e48 semaphore_wait_trap + 8
1   libdispatch.dylib               0x0000000196a87f3c _dispatch_semaphore_wait_slow + 252
2   MediaToolbox                    0x00000001876e95bc fpa_AsyncMovieControlThread + 1952
3   CoreMedia                       0x0000000185b22028 figThreadMain + 244
4   libsystem_pthread.dylib         0x0000000196c5bdc4 _pthread_body + 160
5   libsystem_pthread.dylib         0x0000000196c5bd20 _pthread_start + 156
6   libsystem_pthread.dylib         0x0000000196c58ef4 thread_start + 0

Thread 10:
0   libsystem_kernel.dylib          0x0000000196bbfc78 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x0000000196c592d8 _pthread_wqthread + 988
2   libsystem_pthread.dylib         0x0000000196c58eec start_wqthread + 0

Thread 11:
0   libsystem_kernel.dylib          0x0000000196bbfc78 __workq_kernreturn + 8
1   libsystem_pthread.dylib         0x0000000196c592d8 _pthread_wqthread + 988
2   libsystem_pthread.dylib         0x0000000196c58eec start_wqthread + 0

Thread 6 crashed with ARM Thread State (64-bit):
    x0: 0x0000000000000004   x1: 0x0000000000000000   x2: 0x0000000000000000   x3: 0x0000000000000000
    x4: 0x0000000000002d1f   x5: 0x0000000000000000   x6: 0x0000000000000000   x7: 0x0000000000000000
    x8: 0x0000000000000000   x9: 0x6800a3c4679d3eb0  x10: 0x0000000000000015  x11: 0x0000000000000000
   x12: 0x000000012d0ea200  x13: 0x000000019ab850d8  x14: 0x0000000000000000  x15: 0x0000000000000001
   x16: 0x0000000000000170  x17: 0x00000001964426b8  x18: 0x0000000000000000  x19: 0x000000010469c000
   x20: 0x0000000000000009  x21: 0x00000000800002ff  x22: 0x0000000000009f0f  x23: 0x0000000000010000
   x24: 0x000000019abab000  x25: 0x0000000000000000  x26: 0x0000000000000000  x27: 0x0000000000000000
   x28: 0x0000000000000000  fp: 0x000000010469bf70   lr: 0x0000000196c592dc
    sp: 0x000000010469bf10   pc: 0x0000000196bbfc78 cpsr: 0x40000000

Answer 1

Crash logs like this can be unhelpful. The most likely culprit is a nil pointer somewhere in your code. You may have no option but to step through your code with a debugger making sure that all your variables have the values you expect them to have.