MyApp 98%的时间运行良好，但有时会崩溃.太随机了.
坠机报告显示了以下内容.
Thread : Crashed: com.apple.main-thread
0 libobjc.A.dylib 0x3b1ae626 objc_msgSend + 5
1 Foundation 0x310e2381 _netServiceMonitorCallBack + 104
2 CFNetwork 0x302ea3b5 _QueryRecordReply(_DNSServiceRef_t*, unsigned int, unsigned int, int, char const*, unsigned short, unsigned short, unsigned short, void const*, unsigned int, void*) + 324
3 libsystem_dnssd.dylib 0x3b7289d9 handle_query_response + 168
4 libsystem_dnssd.dylib 0x3b72773f DNSServiceProcessResult + 582
5 CFNetwork 0x302ea3e5 _SocketCallBack_Mon(__CFSocket*, unsigned long, __CFData const*, void const*, void*) + 20
6 CoreFoundation 0x30691189 __CFSocketPerformV0 + 580
7 CoreFoundation 0x3068efaf __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 14
8 CoreFoundation 0x3068e477 __CFRunLoopDoSources0 + 206
9 CoreFoundation 0x3068cc67 __CFRunLoopRun + 630
10 CoreFoundation 0x305f7729 CFRunLoopRunSpecific + 524
11 CoreFoundation 0x305f750b CFRunLoopRunInMode + 106
12 GraphicsServices 0x355336d3 GSEventRunModal + 138
13 UIKit 0x32f58871 UIApplicationMain + 1136
14 MyApp 0x0013f813 main (main.m:16)
所有这些看起来都像是内部方法.我在运行iOS 7.1.2的iPad 4上经历过这些崩溃.