RE: [coLinux-devel] nonblocking ZwWriteFile for cobd

[DrPizza <Dr...@qu...>]

> -----Original Message-----
> From: Henry Nestler [mailto:Henry.Ne@Arcor.de] 
> Sent: 07 March 2006 19:46
> To: DrPizza
> Cc: Cooperative Linux Development
> Subject: Re: [coLinux-devel] nonblocking ZwWriteFile for cobd
> 
> DrPizza wrote:
> > pass a function pointer/context pointer (APC)
> >  
> > void CALLBACK myAPCFunction(void* context) { ...
> > }
> > ZwCreateFile(&FileHandle, ...);
> > ZwReadFile(FileHandle,
> >            NULL,
> >            &myAPCFunction,
> >            myAPCFunctionContext,
> >            &isb,
> >            linuxvm,
> >            size,
> >            &data->offset,
> >            NULL);
> 
> Exactly this I need.
> 
> We can coLinux send the finish via 'end_request' inside linux 
> kernel after block read or write request is complete.
> 
> Must I create the "myAPCFunctionContext" with a special function?
> Or can I simple use any of my (static) variable.
> It must be allocated from non swapable area?
The context is just a void*, so it can point to any (non-stack) variable.
It shouldn't even need to be non-pagable; APC_LEVEL is pagable. So, no, no
special function required.

> /I not understand, why MS means I should not use args 2,3 and 4/  :(
I think you can ignore them.  The ZwReadFile documentation even documents
the arguments so I don't think there's any problem with using them.  If I
had my IFS kit to hand I suspect they're fully documented there.