从回调调用时，如何为非托管代码返回委托？
我遇到了一种情况，我正在单步执行非/托管代码，并且我认为我的方法导致我收到“FatalExecutionEngineError”。具体来说，我有一个 C# 回调（“X”），它将另一个回调（“Y”）返回到 C# 中，其中 X 和 Y 均由非托管 C++ 代码（由 C# 调用）调用。从回调 Y 返回时抛出错误。Dll
导入语句：
[DllImport ("SearchDLL.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern unsafe bool Dll_Search_Text (..., delegate_add_result Fn);
非托管 C 代码：
extern "C" {
__declspec(dllexport) bool Dll_Search_Text (..., bool (*Add_Result (int, int)) (int, int, int)) {
bool (*Add_Result_Word) (int, int, int);
bool Add_Word_Ret;
...
Add_Result_Word = Add_Result ([int param], [int param]);
if (0 == Add_Result_Word) return false;
...
for (Itr=Set->begin (); Itr != Set->end (); Itr++) {
...
Add_Word_Ret = Add_Result_Word ([int param], [int param], [int param]);
}
}
return true;
}
}
委托定义：
public delegate bool delegate_add_result_word (int A, int B, int C);
public delegate delegate_add_result_word delegate_add_result (int D, int E);
错误消息：
"Managed Debugging Assistant 'FatalExecutionEngineError' has detected a
problem in 'C:\Neuric\bin\Search.exe'. Additional Information: The
runtime has encountered a fatal error. The address of the error was
at 0x6ea2ceca, on thread 0x744. The error code is 0xc0000005. This
error may be a bug in the CLR or in the unsafe or non-verifiable
portions of user code. Common sources of this bug include user marshaling
errors for COM-interop or PInvoke, which may corrupt the stack."
代码有时可以工作（在添加嵌套回调之前工作得很好），但抛出此异常其余时间。
I have a situation where I am stepping in and out of un/managed code, and I think my methodology is causing me to get a "FatalExecutionEngineError". Specifically, I have a C# callback ("X") which returns another callback ("Y") into C#, where both X and Y are called by unmanaged C++ code (which is called by C#). The error is thrown when returning from callback Y.
Dll Import Statements:
[DllImport ("SearchDLL.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern unsafe bool Dll_Search_Text (..., delegate_add_result Fn);
The unmanaged C code:
extern "C" {
__declspec(dllexport) bool Dll_Search_Text (..., bool (*Add_Result (int, int)) (int, int, int)) {
bool (*Add_Result_Word) (int, int, int);
bool Add_Word_Ret;
...
Add_Result_Word = Add_Result ([int param], [int param]);
if (0 == Add_Result_Word) return false;
...
for (Itr=Set->begin (); Itr != Set->end (); Itr++) {
...
Add_Word_Ret = Add_Result_Word ([int param], [int param], [int param]);
}
}
return true;
}
}
Delegate definitions:
public delegate bool delegate_add_result_word (int A, int B, int C);
public delegate delegate_add_result_word delegate_add_result (int D, int E);
The error message:
"Managed Debugging Assistant 'FatalExecutionEngineError' has detected a
problem in 'C:\Neuric\bin\Search.exe'. Additional Information: The
runtime has encountered a fatal error. The address of the error was
at 0x6ea2ceca, on thread 0x744. The error code is 0xc0000005. This
error may be a bug in the CLR or in the unsafe or non-verifiable
portions of user code. Common sources of this bug include user marshaling
errors for COM-interop or PInvoke, which may corrupt the stack."
The code works some of the time (and worked just fine before I added the nested callbacks), but throws this exception the rest of the time.
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代表们通常使用 fastcall。但是c风格的函数指针使用cdecl。使用 UnamangedFuntionPointer 属性标记您的委托。
Delegates generally use fastcall. But c style function pointers use cdecl. Tag your delegate with the UnamangedFuntionPointer-attribute.
我不确定你在做什么，但我能想到有两个原因。我假设您已将委托转换为函数指针。然后...
pin_ptr是在本地执行此操作的一种方法，但是您听起来像是以复杂的方式传递东西，因此这可能意味着您需要使用GCHandle.Alloc(..., GCHandleType.Pinned)I'm unsure of exactly what you're doing, but there are two causes I can think of. I'm assuming you've converted the delegate to a function pointer. Then...
GCHandle. Of course, you may already be doing this ;-).pin_ptris one way to do that locally, but you sound like your passing things around in a complicated fashion, so that may mean you need to manually pin an object, withGCHandle.Alloc(..., GCHandleType.Pinned)