Re: Concurrent extraction of convenience-library components on OS X

[Peter O'Gorman]

Hi Ralf,

Ralf Wildenhues wrote:
> Hi Peter,
> 
> * Peter O'Gorman wrote on Tue, May 19, 2009 at 02:26:04AM CEST:
>> Ralf Wildenhues wrote:
>>> * Akim Demaille wrote on Mon, May 18, 2009 at 02:22:56PM CEST:
>>>> I have two dlopen-modules that use a common convenience library.  If I'm 
>>>> unlucky, libtool will try to extract the objects from the convenience 
>>>> library at the same moment, which ar does not seem to like.
>>> Wow.  What in the world does Darwin's ar do to a library that it is
>>> extracting from?
>> It flock()'s it.
>> http://opensource.apple.com/source/cctools/cctools-698.1/ar/archive.c
>>
>> Will file a bug later.
> 
> Thanks; has anything come from that yet?

Won't hear back until it's fixed, but I doubt that it will ever be fixed
for current OSes.

> 
> Anyway; what about this patch?  Please note that the patch requires that
> the second argument to func_extract_an_archive has an absolute path; not
> sure whether that is universally true.
> 
> Thanks,
> Ralf
> 
>     Fix concurrent extraction of convenience libraries on Darwin.
>     
>     * libltdl/m4/libtool.m4 (_LT_CMD_OLD_ARCHIVE): New libtool
>     variable `lock_old_archive_extraction', set to `yes' on darwin.
>     * doc/libtool.texi (libtool script contents): Document it.
>     * libltdl/config/ltmain.m4sh (func_extract_an_archive): Lock
>     `ar x' invocation if `lock_old_archive_extraction' is yes.
>     * tests/darwin.at (darwin concurrent library extraction): New
>     test.
>     * NEWS: Update.
>     Report by Akim Demaille.


I wonder if the archive for the test could be a little larger. When I
applied the test suite change without the other changes, I found that it
passed 2 of the 4 times I ran the test, ar completes unpacking that
small archive pretty fast, it would take a bit longer if the archive
were significantly larger.

Otherwise, this is ok.

Peter
-- 
Peter O'Gorman
http://pogma.com