C ++ / CLI DLL中的本机代码

Question

I would like to be as close to real time as possible, so my intention is to have the most critical part of the code unmanaged (I don't want GC to block execution). So I tried this:

class Native 
{
public:
    int GetValue() 
    {       
        return 1;
    }
};

ref class Managed 
{
public:
    void Test() 
    {
        Native n;
        Console::WriteLine(n.GetValue());
    }
};

ILDASM shows Native::GetValue compiled to IL. Is it possible to keep this class/function unmanaged? Is a dedicated unmanaged dll the only way to do it?

Answer 1

It looks like I need #pragma directives:

#pragma unmanaged

class Native 
{
public:
    int GetValue() 
    {       
        return 1;
    }
};

#pragma managed

ref class Managed 
{
public:
    void Test() 
    {
        Native n;
        Console::WriteLine(n.GetValue());
    }
};

Answer 2

C++-CLI are managed extensions that allow you to directly use .NET functions such as Console.WriteLine that you have shown in your example. It is compiled into a managed assembly. If you want unmanaged code you will have to instruct the compiler to produce unmanaged code. But in this case obviously you will have to forget about the .NET functions.

Answer 3

Hm, I probably misunderstood you requirement but I am choking on the this:

I don't want GC to block execution

It depends on the interop scenario you are using, but in general you will not be able to prevent suspension of execution threads by simply making parts of application unmanaged. Any thread which has CLR roots along its call stack could be hijacked and halted by the GC, no matter if this thread just happens to execute "unmanaged" code.