AssemblyFactory.Execute is terribly slow

[CapitaineToinon]

I tried using MemorySharp to replace some dirty code I was using to Execute assembly from the memory.

First allocates the memory like this :

// First allocate the memory
RemoteAllocation getflagfunmem = safeHandle.Memory.Allocate(0x8000);

string[] asm =
{
    "mov eax, 0x" + (getflagfunmem.BaseAddress + 0x400).ToString("X"),
    "mov eax, [eax]",
    "push eax",
    "call 0x" + Pointers.GET_EVENT_FLAG.ToString("X"),
    "ret"
};

safeHandle.Assembly.Inject(asm, getflagfunmem.BaseAddress);

And then call it later on like this :

safeHandle.Write(getflagfunmem.BaseAddress + 0x400, eventID, false);
int flags = safeHandle.Assembly.Execute<int>(getflagfunmem.BaseAddress);
return (flags >> 7) == 1;

But I found that the Execute is terribly slow compared to my previous code, showed here :

// Note that the asm code used is a tiny bit different. Since I can't 
// automatically read the result with I can with Execute, the asm code
// writes the result in getflagfunmem.BaseAddress + 0x404 instead
safeHandle.Write(getflagfunmem.BaseAddress + 0x400, eventID, false);

IntPtr newThreadHook = (IntPtr)CreateRemoteThread(safeHandle.Handle, 0, 0, (int)getflagfunmem.BaseAddress, 0, 0, 0);
WaitForSingleObject(newThreadHook, 0xFFFFFFFFU);
CloseHandle(newThreadHook);

int flags = safeHandle.Read<int>(getflagfunmem.BaseAddress + 0x404, false);

And as you can see from the Execution times (in ms), the Execute code :

Flags function called 709 times, average duration : 5.46240267983074
Flags function called 709 times, average duration : 5.70936375176305

Is much slower than my own code, using Kernel calls :

Flags function called 709 times, average duration : 0.186416502115656
Flags function called 709 times, average duration : 0.187183215796897