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# 2006-05-29 52# 53# COPYLEFT 54# 55# Copyright (c) 2006 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 2 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, write to the Free Software 69# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 70# 02111-1307, USA. 71# 72# As a special exception, the respective Autoconf Macro's copyright 73# owner gives unlimited permission to copy, distribute and modify the 74# configure scripts that are the output of Autoconf when processing 75# the Macro. You need not follow the terms of the GNU General Public 76# License when using or distributing such scripts, even though 77# portions of the text of the Macro appear in them. The GNU General 78# Public License (GPL) does govern all other use of the material that 79# constitutes the Autoconf Macro. 80# 81# This special exception to the GPL applies to versions of the 82# Autoconf Macro released by the Autoconf Macro Archive. When you 83# make and distribute a modified version of the Autoconf Macro, you 84# may extend this special exception to the GPL to apply to your 85# modified version as well. 86 87AC_DEFUN([ACX_PTHREAD], [ 88AC_REQUIRE([AC_CANONICAL_HOST]) 89AC_LANG_SAVE 90AC_LANG_C 91acx_pthread_ok=no 92 93# We used to check for pthread.h first, but this fails if pthread.h 94# requires special compiler flags (e.g. on True64 or Sequent). 95# It gets checked for in the link test anyway. 96 97# First of all, check if the user has set any of the PTHREAD_LIBS, 98# etcetera environment variables, and if threads linking works using 99# them: 100if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then 101 save_CFLAGS="$CFLAGS" 102 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 103 save_LIBS="$LIBS" 104 LIBS="$PTHREAD_LIBS $LIBS" 105 AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS]) 106 AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes) 107 AC_MSG_RESULT($acx_pthread_ok) 108 if test x"$acx_pthread_ok" = xno; then 109 PTHREAD_LIBS="" 110 PTHREAD_CFLAGS="" 111 fi 112 LIBS="$save_LIBS" 113 CFLAGS="$save_CFLAGS" 114fi 115 116# We must check for the threads library under a number of different 117# names; the ordering is very important because some systems 118# (e.g. DEC) have both -lpthread and -lpthreads, where one of the 119# libraries is broken (non-POSIX). 120 121# Create a list of thread flags to try. Items starting with a "-" are 122# C compiler flags, and other items are library names, except for "none" 123# which indicates that we try without any flags at all, and "pthread-config" 124# which is a program returning the flags for the Pth emulation library. 125 126acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" 127 128# The ordering *is* (sometimes) important. Some notes on the 129# individual items follow: 130 131# pthreads: AIX (must check this before -lpthread) 132# none: in case threads are in libc; should be tried before -Kthread and 133# other compiler flags to prevent continual compiler warnings 134# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) 135# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) 136# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) 137# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) 138# -pthreads: Solaris/gcc 139# -mthreads: Mingw32/gcc, Lynx/gcc 140# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it 141# doesn't hurt to check since this sometimes defines pthreads too; 142# also defines -D_REENTRANT) 143# ... -mt is also the pthreads flag for HP/aCC 144# pthread: Linux, etcetera 145# --thread-safe: KAI C++ 146# pthread-config: use pthread-config program (for GNU Pth library) 147 148case "${host_cpu}-${host_os}" in 149 *solaris*) 150 151 # On Solaris (at least, for some versions), libc contains stubbed 152 # (non-functional) versions of the pthreads routines, so link-based 153 # tests will erroneously succeed. (We need to link with -pthreads/-mt/ 154 # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather 155 # a function called by this macro, so we could check for that, but 156 # who knows whether they'll stub that too in a future libc.) So, 157 # we'll just look for -pthreads and -lpthread first: 158 159 acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags" 160 ;; 161esac 162 163if test x"$acx_pthread_ok" = xno; then 164for flag in $acx_pthread_flags; do 165 166 case $flag in 167 none) 168 AC_MSG_CHECKING([whether pthreads work without any flags]) 169 ;; 170 171 -*) 172 AC_MSG_CHECKING([whether pthreads work with $flag]) 173 PTHREAD_CFLAGS="$flag" 174 ;; 175 176 pthread-config) 177 AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no) 178 if test x"$acx_pthread_config" = xno; then continue; fi 179 PTHREAD_CFLAGS="`pthread-config --cflags`" 180 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" 181 ;; 182 183 *) 184 AC_MSG_CHECKING([for the pthreads library -l$flag]) 185 PTHREAD_LIBS="-l$flag" 186 ;; 187 esac 188 189 save_LIBS="$LIBS" 190 save_CFLAGS="$CFLAGS" 191 LIBS="$PTHREAD_LIBS $LIBS" 192 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 193 194 # Check for various functions. We must include pthread.h, 195 # since some functions may be macros. (On the Sequent, we 196 # need a special flag -Kthread to make this header compile.) 197 # We check for pthread_join because it is in -lpthread on IRIX 198 # while pthread_create is in libc. We check for pthread_attr_init 199 # due to DEC craziness with -lpthreads. We check for 200 # pthread_cleanup_push because it is one of the few pthread 201 # functions on Solaris that doesn't have a non-functional libc stub. 202 # We try pthread_create on general principles. 203 AC_TRY_LINK([#include <pthread.h>], 204 [pthread_t th; pthread_join(th, 0); 205 pthread_attr_init(0); pthread_cleanup_push(0, 0); 206 pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], 207 [acx_pthread_ok=yes]) 208 209 LIBS="$save_LIBS" 210 CFLAGS="$save_CFLAGS" 211 212 AC_MSG_RESULT($acx_pthread_ok) 213 if test "x$acx_pthread_ok" = xyes; then 214 break; 215 fi 216 217 PTHREAD_LIBS="" 218 PTHREAD_CFLAGS="" 219done 220fi 221 222# Various other checks: 223if test "x$acx_pthread_ok" = xyes; then 224 save_LIBS="$LIBS" 225 LIBS="$PTHREAD_LIBS $LIBS" 226 save_CFLAGS="$CFLAGS" 227 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 228 229 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. 230 AC_MSG_CHECKING([for joinable pthread attribute]) 231 attr_name=unknown 232 for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do 233 AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;], 234 [attr_name=$attr; break]) 235 done 236 AC_MSG_RESULT($attr_name) 237 if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then 238 AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name, 239 [Define to necessary symbol if this constant 240 uses a non-standard name on your system.]) 241 fi 242 243 AC_MSG_CHECKING([if more special flags are required for pthreads]) 244 flag=no 245 case "${host_cpu}-${host_os}" in 246 *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";; 247 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";; 248 esac 249 AC_MSG_RESULT(${flag}) 250 if test "x$flag" != xno; then 251 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS" 252 fi 253 254 LIBS="$save_LIBS" 255 CFLAGS="$save_CFLAGS" 256 257 # More AIX lossage: must compile with xlc_r or cc_r 258 if test x"$GCC" != xyes; then 259 AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC}) 260 else 261 PTHREAD_CC=$CC 262 fi 263else 264 PTHREAD_CC="$CC" 265fi 266 267AC_SUBST(PTHREAD_LIBS) 268AC_SUBST(PTHREAD_CFLAGS) 269AC_SUBST(PTHREAD_CC) 270 271# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: 272if test x"$acx_pthread_ok" = xyes; then 273 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1]) 274 : 275else 276 acx_pthread_ok=no 277 $2 278fi 279AC_LANG_RESTORE 280])dnl ACX_PTHREAD 281