~drizzle-trunk/drizzle/development : revision 1992.6.11

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# ===========================================================================

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# http://autoconf-archive.cryp.to/acx_pthread.html

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# ===========================================================================

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#

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# SYNOPSIS

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#

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# ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])

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#

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# DESCRIPTION

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#

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# This macro figures out how to build C programs using POSIX threads. It

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# sets the PTHREAD_LIBS output variable to the threads library and linker

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# flags, and the PTHREAD_CFLAGS output variable to any special C compiler

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# flags that are needed. (The user can also force certain compiler

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# flags/libs to be tested by setting these environment variables.)

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#

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# Also sets PTHREAD_CC to any special C compiler that is needed for

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# multi-threaded programs (defaults to the value of CC otherwise). (This

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# is necessary on AIX to use the special cc_r compiler alias.)

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#

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# NOTE: You are assumed to not only compile your program with these flags,

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# but also link it with them as well. e.g. you should link with

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# $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS

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#

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# If you are only building threads programs, you may wish to use these

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# variables in your default LIBS, CFLAGS, and CC:

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#

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# LIBS="$PTHREAD_LIBS $LIBS"

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# CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

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# CC="$PTHREAD_CC"

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#

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# In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant

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# has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name

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# (e.g. PTHREAD_CREATE_UNDETACHED on AIX).

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#

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# ACTION-IF-FOUND is a list of shell commands to run if a threads library

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# is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it

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# is not found. If ACTION-IF-FOUND is not specified, the default action

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# will define HAVE_PTHREAD.

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#

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# Please let the authors know if this macro fails on any platform, or if

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# you have any other suggestions or comments. This macro was based on work

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# by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with help

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# from M. Frigo), as well as ac_pthread and hb_pthread macros posted by

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# Alejandro Forero Cuervo to the autoconf macro repository. We are also

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# grateful for the helpful feedback of numerous users.

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#

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# LICENSE

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#

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#

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# This program is free software: you can redistribute it and/or modify it

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# under the terms of the GNU General Public License as published by the

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# Free Software Foundation, either version 3 of the License, or (at your

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# option) any later version.

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#

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# This program is distributed in the hope that it will be useful, but

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# WITHOUT ANY WARRANTY; without even the implied warranty of

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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

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# Public License for more details.

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#

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# You should have received a copy of the GNU General Public License along

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# with this program. If not, see <http://www.gnu.org/licenses/>.

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#

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# As a special exception, the respective Autoconf Macro's copyright owner

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# gives unlimited permission to copy, distribute and modify the configure

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# scripts that are the output of Autoconf when processing the Macro. You

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# need not follow the terms of the GNU General Public License when using

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# or distributing such scripts, even though portions of the text of the

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# Macro appear in them. The GNU General Public License (GPL) does govern

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# all other use of the material that constitutes the Autoconf Macro.

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#

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# This special exception to the GPL applies to versions of the Autoconf

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# Macro released by the Autoconf Archive. When you make and distribute a

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# modified version of the Autoconf Macro, you may extend this special

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# exception to the GPL to apply to your modified version as well.

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AC_DEFUN([ACX_PTHREAD], [

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AC_REQUIRE([AC_CANONICAL_HOST])

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AC_LANG_SAVE

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AC_LANG_C

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acx_pthread_ok=no

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# We used to check for pthread.h first, but this fails if pthread.h

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# requires special compiler flags (e.g. on True64 or Sequent).

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# It gets checked for in the link test anyway.

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# First of all, check if the user has set any of the PTHREAD_LIBS,

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# etcetera environment variables, and if threads linking works using

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# them:

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if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then

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save_CFLAGS="$CFLAGS"

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CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

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save_LIBS="$LIBS"

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LIBS="$PTHREAD_LIBS $LIBS"

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AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])

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AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)

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AC_MSG_RESULT($acx_pthread_ok)

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if test x"$acx_pthread_ok" = xno; then

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PTHREAD_LIBS=""

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PTHREAD_CFLAGS=""

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fi

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LIBS="$save_LIBS"

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CFLAGS="$save_CFLAGS"

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fi

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# We must check for the threads library under a number of different

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# names; the ordering is very important because some systems

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# (e.g. DEC) have both -lpthread and -lpthreads, where one of the

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# libraries is broken (non-POSIX).

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# Create a list of thread flags to try. Items starting with a "-" are

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# C compiler flags, and other items are library names, except for "none"

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# which indicates that we try without any flags at all, and "pthread-config"

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# which is a program returning the flags for the Pth emulation library.

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acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"

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# The ordering *is* (sometimes) important. Some notes on the

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# individual items follow:

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# pthreads: AIX (must check this before -lpthread)

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# none: in case threads are in libc; should be tried before -Kthread and

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# other compiler flags to prevent continual compiler warnings

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# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)

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# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)

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# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)

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# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)

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# -pthreads: Solaris/gcc

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# -mthreads: Mingw32/gcc, Lynx/gcc

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# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it

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# doesn't hurt to check since this sometimes defines pthreads too;

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# also defines -D_REENTRANT)

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# ... -mt is also the pthreads flag for HP/aCC

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# pthread: Linux, etcetera

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# --thread-safe: KAI C++

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# pthread-config: use pthread-config program (for GNU Pth library)

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case "${host_cpu}-${host_os}" in

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*solaris*)

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# On Solaris (at least, for some versions), libc contains stubbed

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# (non-functional) versions of the pthreads routines, so link-based

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# tests will erroneously succeed. (We need to link with -pthreads/-mt/

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# -lpthread.) (The stubs are missing pthread_cleanup_push, or rather

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# a function called by this macro, so we could check for that, but

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# who knows whether they'll stub that too in a future libc.) So,

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# we'll just look for -pthreads and -lpthread first:

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acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"

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;;

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esac

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if test x"$acx_pthread_ok" = xno; then

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for flag in $acx_pthread_flags; do

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case $flag in

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none)

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AC_MSG_CHECKING([whether pthreads work without any flags])

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;;

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-*)

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AC_MSG_CHECKING([whether pthreads work with $flag])

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PTHREAD_CFLAGS="$flag"

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;;

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pthread-config)

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AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)

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if test x"$acx_pthread_config" = xno; then continue; fi

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PTHREAD_CFLAGS="`pthread-config --cflags`"

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PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"

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;;

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*)

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AC_MSG_CHECKING([for the pthreads library -l$flag])

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PTHREAD_LIBS="-l$flag"

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;;

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esac

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save_LIBS="$LIBS"

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save_CFLAGS="$CFLAGS"

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LIBS="$PTHREAD_LIBS $LIBS"

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CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

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# Check for various functions. We must include pthread.h,

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# since some functions may be macros. (On the Sequent, we

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# need a special flag -Kthread to make this header compile.)

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# We check for pthread_join because it is in -lpthread on IRIX

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# while pthread_create is in libc. We check for pthread_attr_init

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# due to DEC craziness with -lpthreads. We check for

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# pthread_cleanup_push because it is one of the few pthread

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# functions on Solaris that doesn't have a non-functional libc stub.

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# We try pthread_create on general principles.

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AC_TRY_LINK([#include <pthread.h>],

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[pthread_t th; pthread_join(th, 0);

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pthread_attr_init(0); pthread_cleanup_push(0, 0);

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pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],

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[acx_pthread_ok=yes])

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LIBS="$save_LIBS"

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CFLAGS="$save_CFLAGS"

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AC_MSG_RESULT($acx_pthread_ok)

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if test "x$acx_pthread_ok" = xyes; then

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break;

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fi

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PTHREAD_LIBS=""

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PTHREAD_CFLAGS=""

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done

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fi

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# Various other checks:

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if test "x$acx_pthread_ok" = xyes; then

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save_LIBS="$LIBS"

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LIBS="$PTHREAD_LIBS $LIBS"

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save_CFLAGS="$CFLAGS"

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CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

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# Detect AIX lossage: JOINABLE attribute is called UNDETACHED.

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AC_MSG_CHECKING([for joinable pthread attribute])

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attr_name=unknown

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for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do

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AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],

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[attr_name=$attr; break])

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done

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AC_MSG_RESULT($attr_name)

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if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then

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AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,

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[Define to necessary symbol if this constant

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uses a non-standard name on your system.])

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fi

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AC_MSG_CHECKING([if more special flags are required for pthreads])

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flag=no

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case "${host_cpu}-${host_os}" in

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*-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;

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*solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;

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esac

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AC_MSG_RESULT(${flag})

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if test "x$flag" != xno; then

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PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"

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fi

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LIBS="$save_LIBS"

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CFLAGS="$save_CFLAGS"

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# More AIX lossage: must compile with xlc_r or cc_r

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if test x"$GCC" != xyes; then

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AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})

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else

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PTHREAD_CC=$CC

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fi

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else

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PTHREAD_CC="$CC"

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fi

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AC_SUBST(PTHREAD_LIBS)

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AC_SUBST(PTHREAD_CFLAGS)

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AC_SUBST(PTHREAD_CC)

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# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:

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if test x"$acx_pthread_ok" = xyes; then

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ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])

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:

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else

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acx_pthread_ok=no

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$2

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fi

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AC_LANG_RESTORE

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])dnl ACX_PTHREAD