記一次 .NET 某光放測(cè)試系統(tǒng) 崩潰分析

一：背景

1. 講故事

微信好友里有位朋友找到我，說(shuō)他部署在windows上的程序，用debug模式正常，但用 release 模式跑程序就崩潰，如果把程序切到 .NET6 的話又都正常，所以很迷茫，讓我看看怎么回事，哈哈，這種問(wèn)題直接抓dump分析就好了。

二：崩潰分析

1. 為什么會(huì)崩潰

分析過(guò)崩潰程序的朋友應(yīng)該知道，不管是托管還是非托管崩潰，先用 !analyze -v 命令開(kāi)路，簡(jiǎn)化輸出如下：


0:000> !analyze -v
*******************************************************************************
*                                                                             *
*                        Exception Analysis                                   *
*                                                                             *
*******************************************************************************

CONTEXT:  (.ecxr)
rax=0000000000000004 rbx=000001e34b283ec0 rcx=0000000000000228
rdx=0000000000000000 rsi=000001e34ac2f4e0 rdi=000001e34ab58e70
rip=00007ff95ac53659 rsp=0000007735d7e1c0 rbp=0000007735d7e1e0
 r8=0000000000000000  r9=000001e3464ba1c0 r10=0000000000000228
r11=0000000000000228 r12=0000000000000000 r13=000001e34880eae8
r14=000001e34ab58e70 r15=0000000000000008
iopl=0         nv up di pl nz na pe nc
cs=0000  ss=0000  ds=0000  es=0000  fs=0000  gs=0000             efl=00000000
System_Private_CoreLib!System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw+0x39:
00007ff9`5ac53659 cc              int     3
Resetting default scope

EXCEPTION_RECORD:  (.exr -1)
ExceptionAddress: 00007ff95ac53659 (System_Private_CoreLib!System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw+0x0000000000000039)
   ExceptionCode: e0434f4d (CLR exception)
  ExceptionFlags: 00000000
NumberParameters: 0
...

從卦中的 ExceptionCode: e0434f4d (CLR exception) 來(lái)看，這是一個(gè)經(jīng)典的托管異常，既然是托管異常，這個(gè)問(wèn)題就比較簡(jiǎn)單了，使用 !t 找下到底是哪一個(gè)托管線程拋的，輸出如下：


0:000> !t
ThreadCount:      15
UnstartedThread:  0
BackgroundThread: 11
PendingThread:    0
DeadThread:       3
Hosted Runtime:   no
                                                                                                            Lock  
 DBG   ID     OSID ThreadOBJ           State GC Mode     GC Alloc Context                  Domain           Count Apt Exception
   0    1     81d8 000001E3464BA1C0    a6028 Preemptive  000001E34ABA2340:000001E34ABA3D30 000001e347fc40b0 -00001 STA Prism.Ioc.ContainerResolutionException 000001e34a986608
   6    2     448c 000001E34803A440    2b228 Preemptive  000001E34A876980:000001E34A8784B0 000001e347fc40b0 -00001 MTA (Finalizer) 
   ...

從卦中的 Prism.Ioc.ContainerResolutionException 來(lái)看，貌似是和 Prism 有關(guān)，接下來(lái)可以用 !pe 命令觀察調(diào)用棧詳情。


0:000> !pe
Exception object: 000001e34a986608
Exception type:   Prism.Ioc.ContainerResolutionException
Message:          An unexpected error occurred while resolving 'xxx.Views.LoginWindow'
InnerException:   Unity.ResolutionFailedException, Use !PrintException 000001E34A986228 to see more.
StackTrace (generated):
    SP               IP               Function
    0000007735D668E0 00007FF95A64DEC8 Prism_Unity_Wpf!Prism.Unity.UnityContainerExtension.Resolve(System.Type, System.ValueTuple`2<System.Type,System.Object>[])+0x2a8
    0000007735D7DC60 00007FF95A64DBFD Prism_Unity_Wpf!Prism.Unity.UnityContainerExtension.Resolve(System.Type)+0x3d
    0000007735D7DCA0 00007FF95A64DB88 Prism!Prism.Ioc.IContainerProviderExtensions.Resolve[[System.__Canon, System.Private.CoreLib]](Prism.Ioc.IContainerProvider)+0x48
    0000007735D7DCF0 00007FF95A956742 xxx!xxx.App.InitializeShell(System.Windows.Window)+0x42
    0000007735D7DD40 00007FF959B21148 Prism_Wpf!Prism.PrismApplicationBase.Initialize()+0x208
    0000007735D7DDA0 00007FF959B20F17 xxx!xxx.App.<>n__0()+0x17
    ....

從卦象來(lái)看，這不是最原始的異常，言外之意就是下面還有子異常，也只有找到最里層的異常才能發(fā)現(xiàn)災(zāi)難的禍根，經(jīng)過(guò)一層層的下鉆，最后找到了最原始的異常，參考如下：


0:000> !PrintException /d 000001E34A97E940
Exception object: 000001e34a97e940
Exception type:   System.PlatformNotSupportedException
Message:          System.IO.Ports is currently only supported on Windows.
InnerException:   <none>
StackTrace (generated):
    SP               IP               Function
    0000007735D7B580 00007FF95A9588E7 System_IO_Ports!System.IO.Ports.SerialPort.GetPortNames()+0x47
    0000007735D7B5C0 00007FF95A958859 xxx!xxx.ViewModels.LoginWindowViewModel.RefreshComs()+0x19
    0000007735D7B600 00007FF95A957FBC xxx!xxx.ViewModels.LoginWindowViewModel..ctor()+0x14c
    0000007735D7B9D0 0000000000000000 System_Private_CoreLib!System.RuntimeMethodHandle.InvokeMethod(System.Object, Void**, System.Signature, Boolean)+0x46a770b0
    0000007735D7B9D0 00007FF9B8C03106 System_Private_CoreLib!System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(System.Object, System.Reflection.BindingFlags)+0x36

StackTraceString: <none>
HResult: 80131539

從卦中來(lái)看是 GetPortNames() 方法拋出來(lái)的平臺(tái)不支持異常，這就很迷惑了。