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

# http://www.gnu.org/software/autoconf-archive/ax_pthread.html

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

#

# SYNOPSIS

#

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

#

# DESCRIPTION

#

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

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

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

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

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

#

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

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

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

#

# 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

#

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

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

#

# LIBS="$PTHREAD_LIBS $LIBS"

# CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

# CC="$PTHREAD_CC"

#

# In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant

# has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name

# (e.g. PTHREAD_CREATE_UNDETACHED on AIX).

#

# Also HAVE_PTHREAD_PRIO_INHERIT is defined if pthread is found and the

# PTHREAD_PRIO_INHERIT symbol is defined when compiling with

# PTHREAD_CFLAGS.

#

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

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

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

# will define HAVE_PTHREAD.

#

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

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

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

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

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

# grateful for the helpful feedback of numerous users.

#

# Updated for Autoconf 2.68 by Daniel Richard G.

#

# LICENSE

#

# Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>

# Copyright (c) 2011 Daniel Richard G. <skunk@iSKUNK.ORG>

#

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

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

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

# option) any later version.

#

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

# WITHOUT ANY WARRANTY; without even the implied warranty of

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

# Public License for more details.

#

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

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

#

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

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

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

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

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

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

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

#

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

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

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

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

#serial 18

AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])

AC_DEFUN([AX_PTHREAD], [

AC_REQUIRE([AC_CANONICAL_HOST])

AC_LANG_PUSH([C])

ax_pthread_ok=no

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

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

# It gets checked for in the link test anyway.

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

# etcetera environment variables, and if threads linking works using

# them:

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

save_CFLAGS="$CFLAGS"

CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

save_LIBS="$LIBS"

LIBS="$PTHREAD_LIBS $LIBS"

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

AC_TRY_LINK_FUNC(pthread_join, ax_pthread_ok=yes)

AC_MSG_RESULT($ax_pthread_ok)

if test x"$ax_pthread_ok" = xno; then

PTHREAD_LIBS=""

PTHREAD_CFLAGS=""

fi

LIBS="$save_LIBS"

CFLAGS="$save_CFLAGS"

fi

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

# names; the ordering is very important because some systems

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

# libraries is broken (non-POSIX).

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

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

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

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

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

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

# individual items follow:

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

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

# other compiler flags to prevent continual compiler warnings

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

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

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

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

# -pthreads: Solaris/gcc

# -mthreads: Mingw32/gcc, Lynx/gcc

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

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

# also defines -D_REENTRANT)

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

# pthread: Linux, etcetera

# --thread-safe: KAI C++

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

case ${host_os} in

solaris*)

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

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

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

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

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

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

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

ax_pthread_flags="-pthreads pthread -mt -pthread $ax_pthread_flags"

;;

darwin*)

ax_pthread_flags="-pthread $ax_pthread_flags"

;;

esac

if test x"$ax_pthread_ok" = xno; then

for flag in $ax_pthread_flags; do

case $flag in

none)

AC_MSG_CHECKING([whether pthreads work without any flags])

;;

-*)

AC_MSG_CHECKING([whether pthreads work with $flag])

PTHREAD_CFLAGS="$flag"

;;

pthread-config)

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

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

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

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

;;

*)

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

PTHREAD_LIBS="-l$flag"

;;

esac

save_LIBS="$LIBS"

save_CFLAGS="$CFLAGS"

LIBS="$PTHREAD_LIBS $LIBS"

CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

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

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

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

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

# while pthread_create is in libc. We check for pthread_attr_init

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

# pthread_cleanup_push because it is one of the few pthread

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

# We try pthread_create on general principles.

AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>

static void routine(void *a) { a = 0; }

static void *start_routine(void *a) { return a; }],

[pthread_t th; pthread_attr_t attr;

pthread_create(&th, 0, start_routine, 0);

pthread_join(th, 0);

pthread_attr_init(&attr);

pthread_cleanup_push(routine, 0);

pthread_cleanup_pop(0) /* ; */])],

[ax_pthread_ok=yes],

[])

LIBS="$save_LIBS"

CFLAGS="$save_CFLAGS"

AC_MSG_RESULT($ax_pthread_ok)

if test "x$ax_pthread_ok" = xyes; then

break;

fi

PTHREAD_LIBS=""

PTHREAD_CFLAGS=""

done

fi

# Various other checks:

if test "x$ax_pthread_ok" = xyes; then

save_LIBS="$LIBS"

LIBS="$PTHREAD_LIBS $LIBS"

save_CFLAGS="$CFLAGS"

CFLAGS="$CFLAGS $PTHREAD_CFLAGS"

# Detect AIX lossage: JOINABLE attribute is called UNDETACHED.

AC_MSG_CHECKING([for joinable pthread attribute])

attr_name=unknown

for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do

AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>],

[int attr = $attr; return attr /* ; */])],

[attr_name=$attr; break],

[])

done

AC_MSG_RESULT($attr_name)

if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then

AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,

[Define to necessary symbol if this constant

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

fi

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

flag=no

case ${host_os} in

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

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

solaris*)

if test "$GCC" = "yes"; then

flag="-D_REENTRANT"

else

flag="-mt -D_REENTRANT"

fi

;;

esac

AC_MSG_RESULT(${flag})

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

PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"

fi

AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT],

ax_cv_PTHREAD_PRIO_INHERIT, [

AC_LINK_IFELSE([

AC_LANG_PROGRAM([[#include <pthread.h>]], [[int i = PTHREAD_PRIO_INHERIT;]])],

[ax_cv_PTHREAD_PRIO_INHERIT=yes],

[ax_cv_PTHREAD_PRIO_INHERIT=no])

])

AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes"],

AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], 1, [Have PTHREAD_PRIO_INHERIT.]))

LIBS="$save_LIBS"

CFLAGS="$save_CFLAGS"

# More AIX lossage: must compile with xlc_r or cc_r

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

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

else

PTHREAD_CC=$CC

fi

else

PTHREAD_CC="$CC"

fi

AC_SUBST(PTHREAD_LIBS)

AC_SUBST(PTHREAD_CFLAGS)

AC_SUBST(PTHREAD_CC)

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

if test x"$ax_pthread_ok" = xyes; then

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

:

else

ax_pthread_ok=no

$2

fi

AC_LANG_POP

])dnl AX_PTHREAD