1##### http://autoconf-archive.cryp.to/acx_pthread.html 2# 3# SYNOPSIS 4# 5# ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) 6# 7# DESCRIPTION 8# 9# This macro figures out how to build C programs using POSIX threads. 10# It sets the PTHREAD_LIBS output variable to the threads library and 11# linker flags, and the PTHREAD_CFLAGS output variable to any special 12# C compiler flags that are needed. (The user can also force certain 13# compiler flags/libs to be tested by setting these environment 14# variables.) 15# 16# Also sets PTHREAD_CC to any special C compiler that is needed for 17# multi-threaded programs (defaults to the value of CC otherwise). 18# (This is necessary on AIX to use the special cc_r compiler alias.) 19# 20# NOTE: You are assumed to not only compile your program with these 21# flags, but also link it with them as well. e.g. you should link 22# with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS 23# $LIBS 24# 25# If you are only building threads programs, you may wish to use 26# these variables in your default LIBS, CFLAGS, and CC: 27# 28# LIBS="$PTHREAD_LIBS $LIBS" 29# CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 30# CC="$PTHREAD_CC" 31# 32# In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute 33# constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to 34# that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX). 35# 36# ACTION-IF-FOUND is a list of shell commands to run if a threads 37# library is found, and ACTION-IF-NOT-FOUND is a list of commands to 38# run it if it is not found. If ACTION-IF-FOUND is not specified, the 39# default action will define HAVE_PTHREAD. 40# 41# Please let the authors know if this macro fails on any platform, or 42# if you have any other suggestions or comments. This macro was based 43# on work by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) 44# (with help from M. Frigo), as well as ac_pthread and hb_pthread 45# macros posted by Alejandro Forero Cuervo to the autoconf macro 46# repository. We are also grateful for the helpful feedback of 47# numerous users. 48# 49# LAST MODIFICATION 50# 51# 2007-07-29 52# 53# COPYLEFT 54# 55# Copyright (c) 2007 Steven G. Johnson <stevenj@alum.mit.edu> 56# 57# This program is free software: you can redistribute it and/or 58# modify it under the terms of the GNU General Public License as 59# published by the Free Software Foundation, either version 3 of the 60# License, or (at your option) any later version. 61# 62# This program is distributed in the hope that it will be useful, but 63# WITHOUT ANY WARRANTY; without even the implied warranty of 64# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 65# General Public License for more details. 66# 67# You should have received a copy of the GNU General Public License 68# along with this program. If not, see 69# <http://www.gnu.org/licenses/>. 70# 71# As a special exception, the respective Autoconf Macro's copyright 72# owner gives unlimited permission to copy, distribute and modify the 73# configure scripts that are the output of Autoconf when processing 74# the Macro. You need not follow the terms of the GNU General Public 75# License when using or distributing such scripts, even though 76# portions of the text of the Macro appear in them. The GNU General 77# Public License (GPL) does govern all other use of the material that 78# constitutes the Autoconf Macro. 79# 80# This special exception to the GPL applies to versions of the 81# Autoconf Macro released by the Autoconf Macro Archive. When you 82# make and distribute a modified version of the Autoconf Macro, you 83# may extend this special exception to the GPL to apply to your 84# modified version as well. 85 86AC_DEFUN([ACX_PTHREAD], [ 87AC_REQUIRE([AC_CANONICAL_HOST]) 88AC_LANG_SAVE 89AC_LANG([C]) 90acx_pthread_ok=no 91 92# We used to check for pthread.h first, but this fails if pthread.h 93# requires special compiler flags (e.g. on True64 or Sequent). 94# It gets checked for in the link test anyway. 95 96# First of all, check if the user has set any of the PTHREAD_LIBS, 97# etcetera environment variables, and if threads linking works using 98# them: 99if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then 100 save_CFLAGS="$CFLAGS" 101 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 102 save_LIBS="$LIBS" 103 LIBS="$PTHREAD_LIBS $LIBS" 104 AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS]) 105 AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes) 106 AC_MSG_RESULT($acx_pthread_ok) 107 if test x"$acx_pthread_ok" = xno; then 108 PTHREAD_LIBS="" 109 PTHREAD_CFLAGS="" 110 fi 111 LIBS="$save_LIBS" 112 CFLAGS="$save_CFLAGS" 113fi 114 115# We must check for the threads library under a number of different 116# names; the ordering is very important because some systems 117# (e.g. DEC) have both -lpthread and -lpthreads, where one of the 118# libraries is broken (non-POSIX). 119 120# Create a list of thread flags to try. Items starting with a "-" are 121# C compiler flags, and other items are library names, except for "none" 122# which indicates that we try without any flags at all, and "pthread-config" 123# which is a program returning the flags for the Pth emulation library. 124 125acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" 126 127# The ordering *is* (sometimes) important. Some notes on the 128# individual items follow: 129 130# pthreads: AIX (must check this before -lpthread) 131# none: in case threads are in libc; should be tried before -Kthread and 132# other compiler flags to prevent continual compiler warnings 133# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) 134# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) 135# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) 136# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) 137# -pthreads: Solaris/gcc 138# -mthreads: Mingw32/gcc, Lynx/gcc 139# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it 140# doesn't hurt to check since this sometimes defines pthreads too; 141# also defines -D_REENTRANT) 142# ... -mt is also the pthreads flag for HP/aCC 143# pthread: Linux, etcetera 144# --thread-safe: KAI C++ 145# pthread-config: use pthread-config program (for GNU Pth library) 146 147case "${host_cpu}-${host_os}" in 148 *solaris*) 149 150 # On Solaris (at least, for some versions), libc contains stubbed 151 # (non-functional) versions of the pthreads routines, so link-based 152 # tests will erroneously succeed. (We need to link with -pthreads/-mt/ 153 # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather 154 # a function called by this macro, so we could check for that, but 155 # who knows whether they'll stub that too in a future libc.) So, 156 # we'll just look for -pthreads and -lpthread first: 157 158 acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags" 159 ;; 160esac 161 162if test x"$acx_pthread_ok" = xno; then 163for flag in $acx_pthread_flags; do 164 165 case $flag in 166 none) 167 AC_MSG_CHECKING([whether pthreads work without any flags]) 168 ;; 169 170 -*) 171 AC_MSG_CHECKING([whether pthreads work with $flag]) 172 PTHREAD_CFLAGS="$flag" 173 ;; 174 175 pthread-config) 176 AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no) 177 if test x"$acx_pthread_config" = xno; then continue; fi 178 PTHREAD_CFLAGS="`pthread-config --cflags`" 179 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" 180 ;; 181 182 *) 183 AC_MSG_CHECKING([for the pthreads library -l$flag]) 184 PTHREAD_LIBS="-l$flag" 185 ;; 186 esac 187 188 save_LIBS="$LIBS" 189 save_CFLAGS="$CFLAGS" 190 LIBS="$PTHREAD_LIBS $LIBS" 191 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 192 193 # Check for various functions. We must include pthread.h, 194 # since some functions may be macros. (On the Sequent, we 195 # need a special flag -Kthread to make this header compile.) 196 # We check for pthread_join because it is in -lpthread on IRIX 197 # while pthread_create is in libc. We check for pthread_attr_init 198 # due to DEC craziness with -lpthreads. We check for 199 # pthread_cleanup_push because it is one of the few pthread 200 # functions on Solaris that doesn't have a non-functional libc stub. 201 # We try pthread_create on general principles. 202 AC_TRY_LINK([#include <pthread.h>], 203 [pthread_t th; pthread_join(th, 0); 204 pthread_attr_init(0); pthread_cleanup_push(0, 0); 205 pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], 206 [acx_pthread_ok=yes]) 207 208 LIBS="$save_LIBS" 209 CFLAGS="$save_CFLAGS" 210 211 AC_MSG_RESULT($acx_pthread_ok) 212 if test "x$acx_pthread_ok" = xyes; then 213 break; 214 fi 215 216 PTHREAD_LIBS="" 217 PTHREAD_CFLAGS="" 218done 219fi 220 221# Various other checks: 222if test "x$acx_pthread_ok" = xyes; then 223 save_LIBS="$LIBS" 224 LIBS="$PTHREAD_LIBS $LIBS" 225 save_CFLAGS="$CFLAGS" 226 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 227 228 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. 229 AC_MSG_CHECKING([for joinable pthread attribute]) 230 attr_name=unknown 231 for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do 232 AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;], 233 [attr_name=$attr; break]) 234 done 235 AC_MSG_RESULT($attr_name) 236 if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then 237 AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name, 238 [Define to necessary symbol if this constant 239 uses a non-standard name on your system.]) 240 fi 241 242 AC_MSG_CHECKING([if more special flags are required for pthreads]) 243 flag=no 244 case "${host_cpu}-${host_os}" in 245 *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";; 246 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";; 247 esac 248 AC_MSG_RESULT(${flag}) 249 if test "x$flag" != xno; then 250 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS" 251 fi 252 253 LIBS="$save_LIBS" 254 CFLAGS="$save_CFLAGS" 255 256 # More AIX lossage: must compile with xlc_r or cc_r 257 if test x"$GCC" != xyes; then 258 AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC}) 259 else 260 PTHREAD_CC=$CC 261 fi 262else 263 PTHREAD_CC="$CC" 264fi 265 266AC_SUBST(PTHREAD_LIBS) 267AC_SUBST(PTHREAD_CFLAGS) 268AC_SUBST(PTHREAD_CC) 269 270# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: 271if test x"$acx_pthread_ok" = xyes; then 272 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1]) 273 : 274else 275 acx_pthread_ok=no 276 $2 277fi 278AC_LANG_RESTORE 279])dnl ACX_PTHREAD 280