Re: When to call code after the GC

MethodDesc::Call is used in the EE itself to call the managed code. Here
is an example from comutilnative.cpp:

        MethodDesc *pMD =
g_Mscorlib.GetMethod(METHOD__EXCEPTION__GET_MESSAGE);

        ARG_SLOT GetMessageArgs[] = { ObjToArgSlot(objException) };
        MessageString =
(STRINGREF)ArgSlotToObj(pMD->Call(GetMessageArgs,
METHOD__EXCEPTION__GET_MESSAGE));


In order to call your own method from the EE code, you need to add an
entry in clr\src\vm\mscorlib.h. Entry in mscorlib.h will give you the
METHOD__XXX constant. If your method has unusual signature, you may also
need to add an entry to clr\src\vm\metasig.h in order to complete the
entry in mscorlib.h.

MethodDesc::Call should be used inside
HELPER_METHOD_FRAME_BEGIN/HELPER_METHOD_FRAME_END since it needs a valid
frame to be erected.

If your method is not in mscorlib, I would recommend adding a small
method to mscorlib that will call your non-mscorlib method. Check
LoadISymWrapper method in
clr\src\BCL\System\Reflection\Emit\AssemblyBuilder.cs to see how to do
it.

-Jan

This posting is provided "AS IS" with no warranties, and confers no
rights.

-----Original Message-----
From: Discussion of the Rotor Shared Source CLI implementation
[mailto:[email protected]] On Behalf Of Ricardo Mendes
Sent: Monday, July 07, 2003 8:13 AM
To: [email protected]
Subject: [DOTNET-ROTOR] When to call code after the GC

Hello all,

What is the best place to call managed code after a GC? I tried to call
managed code after the
HELPER_METHOD_FRAME_END(); call in the
FCIMPL1(void, GCInterface::CollectGeneration, INT32 generation) method
(in
the comutilnative.cpp file)
but it just keeps on firing assertions. I want to call managed code
using
something like FFI. It would be great
to call the code I want from managed code but I don't know if it's
possible.
Any ideas regarding a place in which I can call managed code safely
after a
GC?

Thanks in advance for any help...

Ricardo Mendes
Distributed Systems Group
INESC-ID Lisbon, Portugal