Message-ID: <411CA643.8050900@betrusted.com>
Date: Fri, 13 Aug 2004 13:30:11 +0200
From: =?ISO-8859-1?Q?Martin_M=FCnstermann?= <mmuenstermann@betrusted.com>
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To: =?ISO-8859-1?Q?Martin_M=FCnstermann?= <mmuenstermann@betrusted.com>
Cc: Bruce Momjian <pgman@candle.pha.pa.us>,
	Robert Treat <xzilla@users.sourceforge.net>,
	PostgreSQL-patches <pgsql-patches@postgresql.org>
Subject: Re: [BUGS] 8.0.0beta1: -lpthread missing
References: <200408121647.i7CGlEB23426@candle.pha.pa.us>
	<411C8EE0.50507@betrusted.com>
In-Reply-To: <411C8EE0.50507@betrusted.com>
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Hi!

Martin Münstermann wrote:
>> OK, we now have thread compile failure reports on Debian and Slackware.
>>
>> The config/acx_pthread.m4 script basically tests these:
>>
>>     acx_pthread_flags=3D"pthreads none -Kthread -kthread lthread -pthread
>>         -pthreads -mthreads pthread --thread-safe -mt pthread-config"
>> =09
>> in that order and exits once it finds the first one that can
>> compile/link this:
>>
>>         AC_TRY_LINK([#include <pthread.h>],
>>                     [pthread_t th; pthread_join(th, 0);
>>                      pthread_attr_init(0); pthread_cleanup_push(0, 0);
>>                      pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
>>                     [acx_pthread_ok=3Dyes])
>>
>> Now, the big question is why -pthread can compile/link this successfully
>> but -pthread isn't enough to build a library that uses threads.
> 
> 
> I suspect that on Solaris, without "-lpthread" the pthread-stubs in 
> /usr/lib/libc.so might be called at runtime instead of the functional 
> ones in libpthread.so.
> 
> Could this easily be checked?

I can confirm this suspect for Solaris8/gcc 3.2.3.
How to reproduce it:
Add a line like
      printf("### NOTE: check_sigpipe_handler called.\n");
to check_sigpipe_handler() in fe-secure.c and rebuild libpq.so.

The line is only dumped out (indicating that check_sigpipe_handler() is 
being called), when the library is linked with -lpthread.
Without -lpthread no complains from the compiler or linker, but 
check_sigpipe_handler() is not called, because the stub of 
pthread_once() in libc.so does nothing.

--> We need -lpthread on solaris, too.

Regards,
  Martin