[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 at 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 at 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,
>> _______________________________________________
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>> Ros-dev at 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?
>