Re: [RFC] MERGEPID macro wrong ?

[Kevin Buettner <kevinb at cygnus dot com>]

On May 28,  1:31pm, Pierre Muller wrote:

> The definition of MERGEPID macro currently on CVS seems
> wrong to me:
> 
> the macro is the following,
> 
>    #define MERGEPID(PID,TID) ptid_build(PID,TID, 0)

I think the comment in defs.h sort of explains this...

/* Provide default definitions of PIDGET, TIDGET, and MERGEPID.
   The name ``TIDGET'' is a historical accident.  Many uses of TIDGET
   in the code actually refer to a lightweight process id, i.e,
   something that can be considered a process id in its own right for
   certain purposes.  */

I.e, for MERGEPID, the TID parameter is actually a lightweight process
id in most cases.

> but ptid_build is defined as
> 
> ptid_t
> ptid_build (int pid, long lwp, long tid)
> 
> So I think that the right macro should be
> 
> #define MERGEPID(PID,TID) ptid_build(PID, 0, TID)

If this is done, then the TIDGET macro would also have to change.  Some
of the low level thread code might also have to change.  For the short
term, I think it would be better to change the MERGEPID define to read
as follows:

#define MERGEPID(PID,LWP) ptid_build(PID, LWP, 0)

Now that we have ptid_t with separate pid, tid, and lwp components we
should able to clean up a lot of code which used to overload PIDs, LWPs
and TIDs onto an int.

Kevin