Xamarin Android本機調用堆棧

Question

我是新的Xamarin開發人員，我想為Xamarin開發准備診斷工具。 就我而言，我想從C＃異常中獲取托管堆棧跟蹤，並從其余庫中獲取非托管堆棧跟蹤（如果可能，則為C ++）。 我試圖調用C ++方法，使用一些奇怪的選項初始化控件，調用Java庫（谷歌地圖），但是我仍然沒有使用本機調用堆棧的堆棧跟蹤。

您能幫我解釋一下如何從Xamarin Android應用程序獲取托管和非托管堆棧框架的堆棧跟蹤嗎？

非常感謝！

Answer 1

其余庫（C ++，Java）的非托管堆棧跟蹤

就C而言，沒有異常處理，C ++確實有異常，但是它們與CIL管理的異常完全不同。 現在，您可以在NDK / C ++代碼中實現C ++異常，並在可能的情況下基於該異常以及繼續運行的能力，抑制該異常，並通過Mono運行時創建托管異常（以某種方式表示C ++異常）。 有關運行時異常傳播的更多信息，請查閱Mono文檔。 就我個人而言，我只是在C ++級別處理C ++異常，記錄它們，報告它們，等等...，並且不要嘗試將異常傳播回托管代碼（開銷太大，而付出的努力卻很少）。

關於各種Xamarin.Android / Android異常：

Mono運行時/ NDK崩潰

考慮類似libc的字符串strncpy ：

[DllImport("libc.so")]
private static extern void strncpy(StringBuilder dest, string src, uint n);

並使用null（或IntPtr.Zero）調用它：

strncpy(null, null, 1);

一個討厭的運行時崩潰：

[mono-rt] Stacktrace:
[mono-rt] 
[mono-rt]   at <unknown> <0xffffffff>
[mono-rt]   at (wrapper managed-to-native) Android_Clipboard.MainActivity.strncpy (System.Text.StringBuilder,string,uint) <0x00012>
[mono-rt]   at Android_Clipboard.MainActivity/<>c__DisplayClass5_0.<OnCreate>b__0 (object,System.EventArgs) [0x0004f] in /Volumes/Code/code/Projects/Android_Clipboard/Android_Clipboard/MainActivity.cs:57
[mono-rt]   at Android.Views.View/IOnClickListenerImplementor.OnClick (Android.Views.View) [0x00011] in <25661073a35344a89f215a4cf81af37c>:0
[mono-rt]   at Android.Views.View/IOnClickListenerInvoker.n_OnClick_Landroid_view_View_ (intptr,intptr,intptr) [0x00011] in <25661073a35344a89f215a4cf81af37c>:0
[mono-rt]   at (wrapper dynamic-method) object.cea8479a-a63b-41ac-a9f6-b0fe3b09df49 (intptr,intptr,intptr) [0x00017] in <f32579baafc1404fa37ba3ec1abdc0bd>:0
[mono-rt]   at (wrapper native-to-managed) object.cea8479a-a63b-41ac-a9f6-b0fe3b09df49 (intptr,intptr,intptr) [0x00022] in <f32579baafc1404fa37ba3ec1abdc0bd>:0
[mono-rt] /proc/self/maps:
[mono-rt] 12c00000-42c00000 rw-p 00000000 00:01 207683     /dev/ashmem/dalvik-main space (region space) (deleted)
[mono-rt] 70dca000-70f78000 rw-p 00000000 fc:00 106531     /data/dalvik-cache/x86/system@framework@boot.art
[mono-rt] 70f78000-71014000 rw-p 00000000 fc:00 106532     
~~~
[mono-rt] No native Android stacktrace (see debuggerd output).
[mono-rt] 
[mono-rt] 
[mono-rt] =================================================================
[mono-rt] Got a SIGSEGV while executing native code. This usually indicates
[mono-rt] a fatal error in the mono runtime or one of the native libraries 
[mono-rt] used by your application.
[mono-rt] =================================================================
[mono-rt] 
[libc] Fatal signal 11 (SIGSEGV), code 1, fault addr 0x0 in tid 14916 (droid_Clipboard), pid 14916 (droid_Clipboard)

Mono / CIL托管異常

從CIL Mono VM到Java的任何調用都將通過VM2VM橋（CilVM <-> Mono / JNI <-> JavaVM）傳遞，並由Mono JNIEnv處理，因此，Mono運行時會將其包裝在托管異常中。

考慮考慮不存在的Java字段（來自C＃）：

var someWidget = FindViewById<Button>(Resource.Id.myButton);
Java.Lang.Reflect.Field f = someWidget.Class.GetField("SomethingThatDoesNotExist");

產生一個基於Java的java.lang.NoSuchFieldException，將其包裝並呈現為托管異常：

MonoDroid] UNHANDLED EXCEPTION:
[MonoDroid] Java.Lang.NoSuchFieldException: SomethingThatDoesNotExist
[MonoDroid]   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <f32579baafc1404fa37ba3ec1abdc0bd>:0 
[MonoDroid]   at Java.Interop.JniEnvironment+InstanceMethods.CallObjectMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniMethodInfo method, Java.Interop.JniArgumentValue* args) [0x00069] in <09bf3e262b934ffab2ba01f9fc7fd54d>:0 
[MonoDroid]   at Java.Interop.JniPeerMembers+JniInstanceMethods.InvokeAbstractObjectMethod (System.String encodedMember, Java.Interop.IJavaPeerable self, Java.Interop.JniArgumentValue* parameters) [0x00014] in <09bf3e262b934ffab2ba01f9fc7fd54d>:0 
[MonoDroid]   at Java.Lang.Class.GetField (System.String name) [0x00029] in <25661073a35344a89f215a4cf81af37c>:0 
[MonoDroid]   at Android_Clipboard.MainActivity+<>c__DisplayClass5_0.<OnCreate>b__0 (System.Object <p0>, System.EventArgs <p1>) [0x00048] in /Volumes/Code/code/Projects/Android_Clipboard/Android_Clipboard/MainActivity.cs:53 
[MonoDroid]   at Android.Views.View+IOnClickListenerImplementor.OnClick (Android.Views.View v) [0x00011] in <25661073a35344a89f215a4cf81af37c>:0 
[MonoDroid]   at Android.Views.View+IOnClickListenerInvoker.n_OnClick_Landroid_view_View_ (System.IntPtr jnienv, System.IntPtr native__this, System.IntPtr native_v) [0x0000f] in <25661073a35344a89f215a4cf81af37c>:0 
[MonoDroid]   at (wrapper dynamic-method) System.Object.7ad62bce-4e52-4d67-9099-969546fceb57(intptr,intptr,intptr)
[MonoDroid]   --- End of managed Java.Lang.NoSuchFieldException stack trace ---
[MonoDroid] java.lang.NoSuchFieldException: SomethingThatDoesNotExist
[MonoDroid]     at java.lang.Class.getField(Class.java:1601)
[MonoDroid]     at mono.android.view.View_OnClickListenerImplementor.n_onClick(Native Method)
[MonoDroid]     at mono.android.view.View_OnClickListenerImplementor.onClick(View_OnClickListenerImplementor.java:30)
[MonoDroid]     at android.view.View.performClick(View.java:6294)
[MonoDroid]     at android.view.View$PerformClick.run(View.java:24770)
[MonoDroid]     at android.os.Handler.handleCallback(Handler.java:790)
[MonoDroid]     at android.os.Handler.dispatchMessage(Handler.java:99)
[MonoDroid]     at android.os.Looper.loop(Looper.java:164)
[MonoDroid]     at android.app.ActivityThread.main(ActivityThread.java:6494)
[MonoDroid]     at java.lang.reflect.Method.invoke(Native Method)
[MonoDroid]     at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
[MonoDroid]     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
[MonoDroid] 

“本地” Java異常

考慮一下Java異常，該異常不會在Mono / CIL調用的上下文中發生：

Java：

private static void stackOverflowLoop() {
    CrashMe.stackOverflowLoop();
}
public void stackOverflow() {
    new Handler().postDelayed(new Runnable() {
        public void run() {
            CrashMe.stackOverflowLoop();
        }
    }, 2000);
}

C＃：

new CrashMe().StackOverflow();

產生在Android運行時中捕獲的“純” Java異常（請記住， Xamarin.Android應用只是具有CIL VM並訪問Java VM的基於NDK的C應用）

AndroidRuntime] Shutting down VM
[AndroidRuntime] FATAL EXCEPTION: main
[AndroidRuntime] Process: com.sushihangover.Android_Clipboard, PID: 23664
[AndroidRuntime] java.lang.StackOverflowError: stack size 8MB
[AndroidRuntime]    at com.sushihangover.mylibrary.CrashMe.stackOverflowLoop(CrashMe.java:7)
~~~~
[AndroidRuntime]    at com.sushihangover.mylibrary.CrashMe.stackOverflowLoop(CrashMe.java:7)
[AndroidRuntime]    at com.sushihangover.mylibrary.CrashMe.access$000(CrashMe.java:5)
[AndroidRuntime]    at com.sushihangover.mylibrary.CrashMe$1.run(CrashMe.java:12)
[AndroidRuntime]    at android.os.Handler.handleCallback(Handler.java:790)
[AndroidRuntime]    at android.os.Handler.dispatchMessage(Handler.java:99)
[AndroidRuntime]    at android.os.Looper.loop(Looper.java:164)
[AndroidRuntime]    at android.app.ActivityThread.main(ActivityThread.java:6494)
[AndroidRuntime]    at java.lang.reflect.Method.invoke(Native Method)
[AndroidRuntime]    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
[AndroidRuntime]    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

基於Java的Android無響應（ ANR ）

僅被Android操作系統捕獲/捕獲。

Java：

public void androidNotReponding() {
    new Handler().postDelayed(new Runnable() {
        public void run() {
            while (true) {
            }
        }
    }, 2000);

C＃

new CrashMe().AndroidNotReponding();

ANR Logcat：

[zygote] Thread[3,tid=25575,WaitingInMainSignalCatcherLoop,Thread*=0xb224ec00,peer=0x13880020,"Signal Catcher"]: reacting to signal 3
[zygote] 
[zygote] Wrote stack traces to '[tombstoned]'
E ActivityManager: ANR in com.sushihangover.Android_Clipboard (com.sushihangover.Android_Clipboard/md58bbdf49b937b7d185e88b8dfe7516c89.MainActivity)
E ActivityManager: PID: 25886
E ActivityManager: Reason: Input dispatching timed out (Waiting to send non-key event because the touched window has not finished processing certain input events that were delivered to it over 500.0ms ago. 

ANR墓碑軌跡：

Cmd line: com.sushihangover.Android_Clipboard
~~~~
Total blocking GC count: 0
Total blocking GC time: 0
~~~~
suspend all histogram:  Sum: 576us 99% C.I. 2us-329.200us Avg: 30.315us Max: 346us
DALVIK THREADS (13):
"main" prio=5 tid=1 Runnable
  | group="main" sCount=0 dsCount=0 obj=0x73997258 self=0xb4034500
  | sysTid=4484 nice=0 cgrp=default sched=0/0 handle=0xb7728c00
  | state=R schedstat=( 0 0 0 ) utm=6486 stm=688 core=3 HZ=100
  | stack=0xbf21d000-0xbf21f000 stackSize=8MB
  | held mutexes= "mutator lock"(shared held)
  at com.sushihangover.mylibrary.CrashMe$3.run(CrashMe.java:26)
  at android.os.Handler.handleCallback(Handler.java:739)
  at android.os.Handler.dispatchMessage(Handler.java:95)
  at android.os.Looper.loop(Looper.java:148)
  at android.app.ActivityThread.main(ActivityThread.java:5417)
  at java.lang.reflect.Method.invoke!(Native method)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

"Signal Catcher" daemon prio=5 tid=2 Runnable
  | group="system" sCount=0 dsCount=0 obj=0x12c840a0 self=0xae4c2000
  | sysTid=4488 nice=0 cgrp=default sched=0/0 handle=0xb3432930
  | state=R schedstat=( 0 0 0 ) utm=0 stm=0 core=0 HZ=100
  | stack=0xb3336000-0xb3338000 stackSize=1014KB
  | held mutexes= "mutator lock"(shared held)
  native: #00 pc 0058bd02  /system/lib/libart.so (art::DumpNativeStack(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, int, char const*, art::ArtMethod*, void*)+226)
  native: #01 pc 0055194e  /system/lib/libart.so (art::Thread::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) const+286)
 ~~~~