From: Bruce Momjian <pgman@candle.pha.pa.us>
Message-Id: <200408111554.i7BFsa609431@candle.pha.pa.us>
Subject: Re: 8.0.0beta1: -lpthread missing
In-Reply-To: <4119D11C.5010206@betrusted.com>
To: =?ISO-8859-1?Q?Martin_M=FCnstermann?= <mmuenstermann@betrusted.com>
Date: Wed, 11 Aug 2004 11:54:36 -0400 (EDT)
Cc: Robert Treat <xzilla@users.sourceforge.net>,
	pgsql-bugs@postgresql.org
MIME-Version: 1.0
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OK, I have some more information.  Basically, the config/acx_pthread.m4
manual page (http://www.gnu.org/software/ac-archive/htmldoc/acx_pthread.html)
says:
	
	NOTE: You are assumed to not only compile your program with these flags,
	but also link it with them as well. e.g. you should link with
	$PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS

meaning if -lpthread is defined in PTHREAD_CFLAGS, it also has to be
included in the link.  Now, from your reports you said -lpthread was in
PTHREAD_CFLAGS, so why isn't it also included in the libpq link line.  I
need to see your link line output for libpq.

If I add -g3 in interfaces/libpq/Makefile:

	override CFLAGS += $(PTHREAD_CFLAGS) -g3

I see -g3 in the libpq link line:
	
	gcc -O2 -fno-strict-aliasing -Wall -Wmissing-prototypes
	-Wmissing-declarations -O1 -Wall -Wmissing-prototypes
	-Wmissing-declarations -Wpointer-arith -Wcast-align -D_REENTRANT
	-D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS -g3 -fpic -shared

                                                  ^^^
	-Wl,-x,-soname,libpq.so.3 fe-auth.o fe-connect.o fe-exec.o fe-misc.o
	fe-print.o fe-lobj.o fe-protocol2.o fe-protocol3.o pqexpbuffer.o
	pqsignal.o fe-secure.o dllist.o md5.o ip.o wchar.o encnames.o noblock.o
	pgstrcasecmp.o thread.o  -L../../../src/port -L/usr/local/lib
	-L/usr/contrib/lib -lintl -lssl -lcrypto  -lc
	-Wl,-rpath,/usr/local/pgsql/lib -o libpq.so.3.2

Do you see similar behavior in Slackware?  I assumed all compilers would
use $CFLAGS in their link lines.

---------------------------------------------------------------------------

Martin Münstermann wrote:
> Hello!
> 
> Bruce Momjian wrote:
> > Robert Treat wrote:
> > 
> >>>`pthread_once'
> >>>../../../src/interfaces/libpq/libpq.so: undefined reference to
> >>>`pthread_key_create'
> >>>../../../src/interfaces/libpq/libpq.so: undefined reference to
> >>>`pthread_setspecific'
> >>>collect2: ld returned 1 exit status
> >>>
> >>>
> >>>
> >>>Please describe a way to repeat the problem.   Please try to provide a
> >>>concise reproducible example, if at all possible:
> >>>----------------------------------------------------------------------
> >>># ./configure --prefix=/opt/postgresql-800beta1 --enable-thread-safety
> >>># make
> >>>
> >>>
> >>>If you know how this problem might be fixed, list the solution below:
> >>>---------------------------------------------------------------------
> >>>The binaries must be linked with pthread (-lpthread).
> >>>
> >>
> >>Can you take a look at the thread below and report back if that fixes your 
> >>problem?  http://archives.postgresql.org/pgsql-hackers/2004-08/msg00525.php
> 
> Yes, adding -lpthread to PTHREAD_LIBS and rebuilding solved the problem.
> Note: when doing so, libpq.so is built with -lpthread, PTHREAD_LIBS is 
> *not* used in the makefiles of the client binaries like initdb and psql.
> 
> > I looked at that.  The line that does the tests is in
> > config/acx_pthread.m4:
> > 	
> > 	acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread
> > 	-pthreads -mthreads pthread --thread-safe -mt pthread-conf ig"
> > 
> > so you should see that list tried.  Does that help?
> > 
> > I am majorly concerned that Slackware has the same problem as Unixware,
> > meaning that if you use threading in the lib, you now need the flags on
> > every applicaiton that uses the lib.  
> 
> At least on debian this is not the case (see above):
> -lpthread is used when building libpq.so.3.2.
> So the shared library contains a dependency on libpthread.so.
> Then the client apps do not need a -lpthread at build time. The dynamic 
> linker will resolve the dependency on libpthread.so (via libpq.so) at 
> runtime.
> 
> Regards,
>   Martin
> 

-- 
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