michael@0: # ===========================================================================
michael@0: #           http://www.nongnu.org/autoconf-archive/ax_pthread.html
michael@0: # ===========================================================================
michael@0: #
michael@0: # SYNOPSIS
michael@0: #
michael@0: #   AX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
michael@0: #
michael@0: # DESCRIPTION
michael@0: #
michael@0: #   This macro figures out how to build C programs using POSIX threads. It
michael@0: #   sets the PTHREAD_LIBS output variable to the threads library and linker
michael@0: #   flags, and the PTHREAD_CFLAGS output variable to any special C compiler
michael@0: #   flags that are needed. (The user can also force certain compiler
michael@0: #   flags/libs to be tested by setting these environment variables.)
michael@0: #
michael@0: #   Also sets PTHREAD_CC to any special C compiler that is needed for
michael@0: #   multi-threaded programs (defaults to the value of CC otherwise). (This
michael@0: #   is necessary on AIX to use the special cc_r compiler alias.)
michael@0: #
michael@0: #   NOTE: You are assumed to not only compile your program with these flags,
michael@0: #   but also link it with them as well. e.g. you should link with
michael@0: #   $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
michael@0: #
michael@0: #   If you are only building threads programs, you may wish to use these
michael@0: #   variables in your default LIBS, CFLAGS, and CC:
michael@0: #
michael@0: #     LIBS="$PTHREAD_LIBS $LIBS"
michael@0: #     CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
michael@0: #     CC="$PTHREAD_CC"
michael@0: #
michael@0: #   In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant
michael@0: #   has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name
michael@0: #   (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
michael@0: #
michael@0: #   ACTION-IF-FOUND is a list of shell commands to run if a threads library
michael@0: #   is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it
michael@0: #   is not found. If ACTION-IF-FOUND is not specified, the default action
michael@0: #   will define HAVE_PTHREAD.
michael@0: #
michael@0: #   Please let the authors know if this macro fails on any platform, or if
michael@0: #   you have any other suggestions or comments. This macro was based on work
michael@0: #   by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with help
michael@0: #   from M. Frigo), as well as ac_pthread and hb_pthread macros posted by
michael@0: #   Alejandro Forero Cuervo to the autoconf macro repository. We are also
michael@0: #   grateful for the helpful feedback of numerous users.
michael@0: #
michael@0: # LICENSE
michael@0: #
michael@0: #   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
michael@0: #
michael@0: #   This program is free software: you can redistribute it and/or modify it
michael@0: #   under the terms of the GNU General Public License as published by the
michael@0: #   Free Software Foundation, either version 3 of the License, or (at your
michael@0: #   option) any later version.
michael@0: #
michael@0: #   This program is distributed in the hope that it will be useful, but
michael@0: #   WITHOUT ANY WARRANTY; without even the implied warranty of
michael@0: #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
michael@0: #   Public License for more details.
michael@0: #
michael@0: #   You should have received a copy of the GNU General Public License along
michael@0: #   with this program. If not, see <http://www.gnu.org/licenses/>.
michael@0: #
michael@0: #   As a special exception, the respective Autoconf Macro's copyright owner
michael@0: #   gives unlimited permission to copy, distribute and modify the configure
michael@0: #   scripts that are the output of Autoconf when processing the Macro. You
michael@0: #   need not follow the terms of the GNU General Public License when using
michael@0: #   or distributing such scripts, even though portions of the text of the
michael@0: #   Macro appear in them. The GNU General Public License (GPL) does govern
michael@0: #   all other use of the material that constitutes the Autoconf Macro.
michael@0: #
michael@0: #   This special exception to the GPL applies to versions of the Autoconf
michael@0: #   Macro released by the Autoconf Archive. When you make and distribute a
michael@0: #   modified version of the Autoconf Macro, you may extend this special
michael@0: #   exception to the GPL to apply to your modified version as well.
michael@0: 
michael@0: #serial 6
michael@0: 
michael@0: AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
michael@0: AC_DEFUN([AX_PTHREAD], [
michael@0: AC_REQUIRE([AC_CANONICAL_HOST])
michael@0: AC_LANG_SAVE
michael@0: AC_LANG_C
michael@0: ax_pthread_ok=no
michael@0: 
michael@0: # We used to check for pthread.h first, but this fails if pthread.h
michael@0: # requires special compiler flags (e.g. on True64 or Sequent).
michael@0: # It gets checked for in the link test anyway.
michael@0: 
michael@0: # First of all, check if the user has set any of the PTHREAD_LIBS,
michael@0: # etcetera environment variables, and if threads linking works using
michael@0: # them:
michael@0: if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
michael@0:         save_CFLAGS="$CFLAGS"
michael@0:         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
michael@0:         save_LIBS="$LIBS"
michael@0:         LIBS="$PTHREAD_LIBS $LIBS"
michael@0:         AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
michael@0:         AC_TRY_LINK_FUNC(pthread_join, ax_pthread_ok=yes)
michael@0:         AC_MSG_RESULT($ax_pthread_ok)
michael@0:         if test x"$ax_pthread_ok" = xno; then
michael@0:                 PTHREAD_LIBS=""
michael@0:                 PTHREAD_CFLAGS=""
michael@0:         fi
michael@0:         LIBS="$save_LIBS"
michael@0:         CFLAGS="$save_CFLAGS"
michael@0: fi
michael@0: 
michael@0: # We must check for the threads library under a number of different
michael@0: # names; the ordering is very important because some systems
michael@0: # (e.g. DEC) have both -lpthread and -lpthreads, where one of the
michael@0: # libraries is broken (non-POSIX).
michael@0: 
michael@0: # Create a list of thread flags to try.  Items starting with a "-" are
michael@0: # C compiler flags, and other items are library names, except for "none"
michael@0: # which indicates that we try without any flags at all, and "pthread-config"
michael@0: # which is a program returning the flags for the Pth emulation library.
michael@0: 
michael@0: ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
michael@0: 
michael@0: # The ordering *is* (sometimes) important.  Some notes on the
michael@0: # individual items follow:
michael@0: 
michael@0: # pthreads: AIX (must check this before -lpthread)
michael@0: # none: in case threads are in libc; should be tried before -Kthread and
michael@0: #       other compiler flags to prevent continual compiler warnings
michael@0: # -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
michael@0: # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
michael@0: # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
michael@0: # -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
michael@0: # -pthreads: Solaris/gcc
michael@0: # -mthreads: Mingw32/gcc, Lynx/gcc
michael@0: # -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
michael@0: #      doesn't hurt to check since this sometimes defines pthreads too;
michael@0: #      also defines -D_REENTRANT)
michael@0: #      ... -mt is also the pthreads flag for HP/aCC
michael@0: # pthread: Linux, etcetera
michael@0: # --thread-safe: KAI C++
michael@0: # pthread-config: use pthread-config program (for GNU Pth library)
michael@0: 
michael@0: case "${host_cpu}-${host_os}" in
michael@0:         *solaris*)
michael@0: 
michael@0:         # On Solaris (at least, for some versions), libc contains stubbed
michael@0:         # (non-functional) versions of the pthreads routines, so link-based
michael@0:         # tests will erroneously succeed.  (We need to link with -pthreads/-mt/
michael@0:         # -lpthread.)  (The stubs are missing pthread_cleanup_push, or rather
michael@0:         # a function called by this macro, so we could check for that, but
michael@0:         # who knows whether they'll stub that too in a future libc.)  So,
michael@0:         # we'll just look for -pthreads and -lpthread first:
michael@0: 
michael@0:         ax_pthread_flags="-pthreads pthread -mt -pthread $ax_pthread_flags"
michael@0:         ;;
michael@0: 
michael@0: 	*-darwin*)
michael@0: 	acx_pthread_flags="-pthread $acx_pthread_flags"
michael@0: 	;;
michael@0: esac
michael@0: 
michael@0: if test x"$ax_pthread_ok" = xno; then
michael@0: for flag in $ax_pthread_flags; do
michael@0: 
michael@0:         case $flag in
michael@0:                 none)
michael@0:                 AC_MSG_CHECKING([whether pthreads work without any flags])
michael@0:                 ;;
michael@0: 
michael@0:                 -*)
michael@0:                 AC_MSG_CHECKING([whether pthreads work with $flag])
michael@0:                 PTHREAD_CFLAGS="$flag"
michael@0:                 ;;
michael@0: 
michael@0: 		pthread-config)
michael@0: 		AC_CHECK_PROG(ax_pthread_config, pthread-config, yes, no)
michael@0: 		if test x"$ax_pthread_config" = xno; then continue; fi
michael@0: 		PTHREAD_CFLAGS="`pthread-config --cflags`"
michael@0: 		PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
michael@0: 		;;
michael@0: 
michael@0:                 *)
michael@0:                 AC_MSG_CHECKING([for the pthreads library -l$flag])
michael@0:                 PTHREAD_LIBS="-l$flag"
michael@0:                 ;;
michael@0:         esac
michael@0: 
michael@0:         save_LIBS="$LIBS"
michael@0:         save_CFLAGS="$CFLAGS"
michael@0:         LIBS="$PTHREAD_LIBS $LIBS"
michael@0:         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
michael@0: 
michael@0:         # Check for various functions.  We must include pthread.h,
michael@0:         # since some functions may be macros.  (On the Sequent, we
michael@0:         # need a special flag -Kthread to make this header compile.)
michael@0:         # We check for pthread_join because it is in -lpthread on IRIX
michael@0:         # while pthread_create is in libc.  We check for pthread_attr_init
michael@0:         # due to DEC craziness with -lpthreads.  We check for
michael@0:         # pthread_cleanup_push because it is one of the few pthread
michael@0:         # functions on Solaris that doesn't have a non-functional libc stub.
michael@0:         # We try pthread_create on general principles.
michael@0:         AC_TRY_LINK([#include <pthread.h>
michael@0: 	             static void routine(void* a) {a=0;}
michael@0: 	             static void* start_routine(void* a) {return a;}],
michael@0:                     [pthread_t th; pthread_attr_t attr;
michael@0:                      pthread_join(th, 0);
michael@0:                      pthread_attr_init(&attr);
michael@0:                      pthread_cleanup_push(routine, 0);
michael@0:                      pthread_create(&th,0,start_routine,0);
michael@0:                      pthread_cleanup_pop(0); ],
michael@0:                     [ax_pthread_ok=yes])
michael@0: 
michael@0:         LIBS="$save_LIBS"
michael@0:         CFLAGS="$save_CFLAGS"
michael@0: 
michael@0:         AC_MSG_RESULT($ax_pthread_ok)
michael@0:         if test "x$ax_pthread_ok" = xyes; then
michael@0:                 break;
michael@0:         fi
michael@0: 
michael@0:         PTHREAD_LIBS=""
michael@0:         PTHREAD_CFLAGS=""
michael@0: done
michael@0: fi
michael@0: 
michael@0: # Various other checks:
michael@0: if test "x$ax_pthread_ok" = xyes; then
michael@0:         save_LIBS="$LIBS"
michael@0:         LIBS="$PTHREAD_LIBS $LIBS"
michael@0:         save_CFLAGS="$CFLAGS"
michael@0:         CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
michael@0: 
michael@0:         # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
michael@0: 	AC_MSG_CHECKING([for joinable pthread attribute])
michael@0: 	attr_name=unknown
michael@0: 	for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
michael@0: 	    AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
michael@0:                         [attr_name=$attr; break])
michael@0: 	done
michael@0:         AC_MSG_RESULT($attr_name)
michael@0:         if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
michael@0:             AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
michael@0:                                [Define to necessary symbol if this constant
michael@0:                                 uses a non-standard name on your system.])
michael@0:         fi
michael@0: 
michael@0:         AC_MSG_CHECKING([if more special flags are required for pthreads])
michael@0:         flag=no
michael@0:         case "${host_cpu}-${host_os}" in
michael@0:             *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
michael@0:             *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
michael@0:         esac
michael@0:         AC_MSG_RESULT(${flag})
michael@0:         if test "x$flag" != xno; then
michael@0:             PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
michael@0:         fi
michael@0: 
michael@0:         LIBS="$save_LIBS"
michael@0:         CFLAGS="$save_CFLAGS"
michael@0: 
michael@0:         # More AIX lossage: must compile with xlc_r or cc_r
michael@0: 	if test x"$GCC" != xyes; then
michael@0:           AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
michael@0:         else
michael@0:           PTHREAD_CC=$CC
michael@0: 	fi
michael@0: else
michael@0:         PTHREAD_CC="$CC"
michael@0: fi
michael@0: 
michael@0: AC_SUBST(PTHREAD_LIBS)
michael@0: AC_SUBST(PTHREAD_CFLAGS)
michael@0: AC_SUBST(PTHREAD_CC)
michael@0: 
michael@0: # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
michael@0: if test x"$ax_pthread_ok" = xyes; then
michael@0:         ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
michael@0:         :
michael@0: else
michael@0:         ax_pthread_ok=no
michael@0:         $2
michael@0: fi
michael@0: AC_LANG_RESTORE
michael@0: ])dnl AX_PTHREAD