Re: [ros-dev] [ros-diffs] [dchapyshev] 42012: - Samplify SwitchToThread and QueueUserWorkItem - Remove unneeded InternalWorkItemTrampoline function and QUEUE_USER_WORKITEM_CONTEXT structure - Other small changes

[Thomas Bluemel]

Just because Wine and Windows do it that way doesn't make it any more 
correct or portable.

RtlQueueWorkItem expects a function of this type:
typedef VOID (NTAPI *WORKERCALLBACKFUNC)(IN PVOID Context);

The supplied function is of this type:
typedef ULONG (NTAPI *PTHREAD_START_ROUTINE)(PVOID Parameter);

This doesn't crash on x86 and "works" because the return value is simply 
ignored, but it's definitely not portable and MAY crash on another 
architecture where it does make a difference.  I don't know if it would 
matter on ARM/PPC/... but the old code at least implemented it 
correctly/portable.  It's not really an issue but IMO a bad hack. 
Typecasting a function pointer to a function with a different signature 
is hardly ever good practice.

- Thomas

Dmitry Chapyshev wrote:
>   On Fri, 17 Jul 2009 23:03:18 +0400, Thomas Bluemel
> <thomas(a)reactsoft.com>  
>  wrote:
>  
> >   This explains why we are using a trampoline
> > function and not just
> >  typecast there...  Is there a reason you changed this?
> >
> >  - Thomas
> >
> >  dchapyshev(a)svn.reactos.org wrote:
> > >   -    /* NOTE: Don't use Function directly
> > > since the callback signature
> > >  -             differs. This might cause problems on certain  
> > >  platforms... */
> > >  -    Status = RtlQueueWorkItem(InternalWorkItemTrampoline,
> > >  -                              WorkItemContext, 
> > _______________________________________________
> >  Ros-dev mailing list
> >  Ros-dev(a)reactos.org
> >  http://www.reactos.org/mailman/listinfo/ros-dev 
>  
>  
>  
>  Wine and Windows do so. Why we should do in another way? Other reasons are  
>  necessary?
>