我收到了以下的崩溃日志，而且我在查看应用程序的哪个部分时遇到了一些麻烦。
Hardware Model: iPad2,4
Process: MYAPP [129]
Path: /var/mobile/Applications/FC5BD37F-838A-4CDD-8158-5A2B6F34C3AB/MYAPP.app/MYAPP
Identifier: com.myapp
Version: 4.0
Code Type: ARM
Parent Process: launchd [1]
Exception Type: SIGSEGV
Exception Codes: SEGV_ACCERR at 0x8
Crashed Thread: 6
Thread 0:
0 libz.1.dylib 0x38b9a3c8 _zError + 1159
1 ImageIO 0x2e9755b9 <redacted> + 308
2 ImageIO 0x2e973155 <redacted> + 2400
3 ImageIO 0x2e97227f <redacted> + 542
4 CoreGraphics 0x2dcaf44d _CGImageProviderCopyImageBlockSetWithOptions + 136
5 QuartzCore 0x300e9105 <redacted> + 684
6 QuartzCore 0x300e85af <redacted> + 290
7 QuartzCore 0x300e8e47 <redacted> + 18
8 QuartzCore 0x300bd201 <redacted> + 384
9 QuartzCore 0x300bc6e7 <redacted> + 238
10 QuartzCore 0x300bc4ef <redacted> + 314
11 QuartzCore 0x300b621d <redacted> + 56
12 CoreFoundation 0x2dbf32a5 <redacted> + 20
13 CoreFoundation 0x2dbf0c49 <redacted> + 284
14 CoreFoundation 0x2dbf0f8b <redacted> + 730
15 CoreFoundation 0x2db5bf0f _CFRunLoopRunSpecific + 522
16 CoreFoundation 0x2db5bcf3 _CFRunLoopRunInMode + 106
17 GraphicsServices 0x32a55663 _GSEventRunModal + 138
18 UIKit 0x304a716d _UIApplicationMain + 1136
19 MYAPP 0x000b7177 __mh_execute_header + 29047
20 libdyld.dylib 0x38c19ab7 <redacted> + 2
Thread 1:
0 libsystem_kernel.dylib 0x38cbc808 _kevent64 + 24
1 libdispatch.dylib 0x38bfde03 <redacted> + 38
Thread 2:
0 libsystem_kernel.dylib 0x38ccfc70 ___workq_kernreturn + 8
1 libsystem_pthread.dylib 0x38d36a98 _start_wqthread + 8
Thread 3:
0 libsystem_kernel.dylib 0x38ccfc70 ___workq_kernreturn + 8
1 libsystem_pthread.dylib 0x38d36a98 _start_wqthread + 8
Thread 4:
0 libsystem_kernel.dylib 0x38cbca58 _mach_msg_trap + 20
1 CoreFoundation 0x2dbf289b <redacted> + 154
2 CoreFoundation 0x2dbf0fc1 <redacted> + 784
3 CoreFoundation 0x2db5bf0f _CFRunLoopRunSpecific + 522
4 CoreFoundation 0x2db5bcf3 _CFRunLoopRunInMode + 106
5 Foundation 0x2e59b087 +[NSURLConnection _resourceLoadLoop:] + 318
6 Foundation 0x2e610a5f <redacted> + 1062
7 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
8 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
9 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 5:
0 libsystem_kernel.dylib 0x38ccfc70 ___workq_kernreturn + 8
1 libsystem_pthread.dylib 0x38d36a98 _start_wqthread + 8
Thread 6 Crashed:
0 QuartzCore 0x300c0376 <redacted> + 5
1 QuartzCore 0x300bfe63 <redacted> + 142
2 QuartzCore 0x300bfb13 -[CALayer dealloc] + 142
3 QuartzCore 0x300bf881 <redacted> + 136
4 QuartzCore 0x300bc547 <redacted> + 402
5 QuartzCore 0x3011dfa1 <redacted> + 576
6 libdispatch.dylib 0x38bfbad7 <redacted> + 222
7 libdispatch.dylib 0x38bfbd29 <redacted> + 56
8 libsystem_pthread.dylib 0x38d36bd3 __pthread_wqthread + 298
9 libsystem_pthread.dylib 0x38d36a98 _start_wqthread + 8
Thread 7:
0 libsystem_kernel.dylib 0x38cbca58 _mach_msg_trap + 20
1 CoreFoundation 0x2dbf289b <redacted> + 154
2 CoreFoundation 0x2dbf0fc1 <redacted> + 784
3 CoreFoundation 0x2db5bf0f _CFRunLoopRunSpecific + 522
4 CoreFoundation 0x2db5bcf3 _CFRunLoopRunInMode + 106
5 WebCore 0x3603011b <redacted> + 418
6 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
7 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
8 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 8:
0 libsystem_kernel.dylib 0x38cbca58 _mach_msg_trap + 20
1 CoreFoundation 0x2dbf289b <redacted> + 154
2 CoreFoundation 0x2dbf0fc1 <redacted> + 784
3 CoreFoundation 0x2db5bf0f _CFRunLoopRunSpecific + 522
4 CoreFoundation 0x2db5bcf3 _CFRunLoopRunInMode + 106
5 Foundation 0x2e54e1eb -[NSRunLoop runMode:beforeDate:] + 254
6 Foundation 0x2e59f0a1 -[NSRunLoop run] + 80
7 MYAPP 0x002c533d +[AFURLConnectionOperation networkRequestThreadEntryPoint:] + 80
8 Foundation 0x2e610a5f <redacted> + 1062
9 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
10 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
11 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 9:
0 libsystem_kernel.dylib 0x38ccf434 ___select + 20
1 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
2 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
3 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 10:
0 libsystem_kernel.dylib 0x38ccef2c ___psynch_cvwait + 24
1 libsystem_pthread.dylib 0x38d38d65 _pthread_cond_wait + 40
2 JavaScriptCore 0x2eb88ee9 <redacted> + 208
3 JavaScriptCore 0x2eb8653b <redacted> + 14
4 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
5 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
6 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 11:
0 libsystem_kernel.dylib 0x38ccef2c ___psynch_cvwait + 24
1 libsystem_pthread.dylib 0x38d38d65 _pthread_cond_wait + 40
2 JavaScriptCore 0x2ed2440b <redacted> + 78
3 JavaScriptCore 0x2ed24465 <redacted> + 52
4 JavaScriptCore 0x2eb8653b <redacted> + 14
5 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
6 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
7 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 12:
0 libsystem_kernel.dylib 0x38cbca58 _mach_msg_trap + 20
1 CoreFoundation 0x2dbf289b <redacted> + 154
2 CoreFoundation 0x2dbf0fc1 <redacted> + 784
3 CoreFoundation 0x2db5bf0f _CFRunLoopRunSpecific + 522
4 CoreFoundation 0x2db5bcf3 _CFRunLoopRunInMode + 106
5 WebCore 0x36078b17 <redacted> + 254
6 JavaScriptCore 0x2eb8653b <redacted> + 14
7 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
8 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
9 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 13:
0 libsystem_kernel.dylib 0x38ccef2c ___psynch_cvwait + 24
1 libsystem_pthread.dylib 0x38d38d65 _pthread_cond_wait + 40
2 JavaScriptCore 0x2eb88ee9 <redacted> + 208
3 JavaScriptCore 0x2eb8653b <redacted> + 14
4 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
5 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
6 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 14:
0 libsystem_kernel.dylib 0x38ccef2c ___psynch_cvwait + 24
1 libsystem_pthread.dylib 0x38d38d65 _pthread_cond_wait + 40
2 JavaScriptCore 0x2ed2440b <redacted> + 78
3 JavaScriptCore 0x2ed24465 <redacted> + 52
4 JavaScriptCore 0x2eb8653b <redacted> + 14
5 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
6 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
7 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 15:
0 libsystem_kernel.dylib 0x38ccfc70 ___workq_kernreturn + 8
1 libsystem_pthread.dylib 0x38d36a98 _start_wqthread + 8
Thread 16:
0 libsystem_kernel.dylib 0x38cbca58 _mach_msg_trap + 20
1 CoreFoundation 0x2dbf289b <redacted> + 154
2 CoreFoundation 0x2dbf0fc1 <redacted> + 784
3 CoreFoundation 0x2db5bf0f _CFRunLoopRunSpecific + 522
4 CoreFoundation 0x2db9fa03 _CFRunLoopRun + 98
5 CoreMotion 0x2e2193ad _CLSF_thorntonUpdate_6x6 + 56957
6 libsystem_pthread.dylib 0x38d38919 <redacted> + 140
7 libsystem_pthread.dylib 0x38d3888b __pthread_start + 102
8 libsystem_pthread.dylib 0x38d36aa4 _thread_start + 8
Thread 6 crashed with ARM Thread State:
pc: 0x300c0376 r7: 0x03389d68 sp: 0x03389d0c r0: 0x00000000
r1: 0x16b1d800 r2: 0x00000002 r3: 0x300c435d r4: 0x16b1d800
r5: 0x00000000 r6: 0x17a3e820 r8: 0x03389d20 r9: 0x17200020
r10: 0x39202310 r11: 0x00000000 ip: 0x3ac7ebc8 lr: 0x300c02ab
cpsr: 0x60000030
我注意到在崩溃的线程上有一个-[CALayer dealloc]调用，所以我猜我不小心从一个辅助线程调用了一些UI更新。
所以这是我的问题：我是否正确地认为问题是从辅助线程更新UI？如果是这样，这个崩溃日志能否帮助我弄清楚我的代码中的错误在哪里？