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Re: reentrant functions


On Fri, Apr 09, 2004 at 04:33:26AM +0200, Bas van Gompel wrote:
>[You left very little context. I added some.]
>
>Op Thu, 8 Apr 2004 21:00:34 -0400
>schreef Christopher Faylor <cgf-no-personal-reply-please op cygwin.com>
>in <20040409010034.GA3252@coc.bosbc.com>:
>Christopher Faylor:
>>::We also do not want to export _r functions which are unique only to
>>::newlib.  For instance, I suspect that _mallopt_r is probably not
>>::something that we want to export since no other UNIX has it.
>:>That's not what was asked...
>:
>:Aren't you glad I clarified?
>
>Yeah, sure. But this means I won't be able to help any further
>with this, as I don't know which UNIXes export which functions,.

Fair enough.

My previous message was somewhat garbled.  Let me try again.

Corinna did not provide enough guidelines in stating what was required.
I was attempting to clarify that it wasn't enough to just get a list of
all *_r from newlib which are not exported by cygwin.  Although I gave a
vague "UNIX" guideline I did not offer any clear way for you to
determine which functions should be exported.

I gave you an example of one such routine but I was too demure in my
presentation.  mallopt_r is definitely something that we do not want to
include, as is realloc_r, and malloc_r, free_r, gettimeofday_r, and
tmpfile_r.  The reason why these are not desired is that newlib defines
a number of _r type functions that do not exist on linux or in the
Single UNIX Specification.

For a reference of what is acceptable, you can use The Single Unix
Specification v3:

http://www.opengroup.org/onlinepubs/007904975/toc.htm

This reference would be adequate in determining what to include but,
if in doubt about something that seems like a useful function, then
double checking with linux should be adequate.

The SUSv3 reference does not define the mallopt function but functions
not ending in _r are not the subject of this exercise.  We are trying to
export the reentrant routines which have a UNIX analog.  We're not
trying to bloat cygwin with reentrant routines that no one else uses.

There is also another reason not to use mallopt_r -- cygwin doesn't use
the malloc version in newlib so exporting any of the _r malloc functions
from newlib would cause runtime errors for anyone who used them.

>And I asked: Why not export '_mallopt_r' when 'mallopt' is?  (I don't
>think many UNIXes have 'mallopt', and it is newlib- specific...)

Not that it matters but I found mallopt on linux, IRIX, and HP/UX.

*hold on a second*

Yep.  It's on Solaris, too.

Again, the criteria is not to export every _r function for which there
is an exported non-_r function.  We only want to export the ones that
make sense for a UNIX environment.

cgf

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