1# URL: http://autoconf-archive.cryp.to/acx_pthread.html 2# Author: Steven G. Johnson <stevenj@alum.mit.edu> 3# Revised: 2007-07-29 4# 5# Copyright �� 2007 Steven G. Johnson <stevenj@alum.mit.edu> 6# 7# This program is free software: you can redistribute it and/or modify 8# it under the terms of the GNU General Public License as published by 9# the Free Software Foundation, either version 3 of the License, or 10# (at your option) any later version. 11 12 13AC_DEFUN([ACX_PTHREAD], [ 14AC_REQUIRE([AC_CANONICAL_HOST]) 15AC_LANG_SAVE 16AC_LANG_C 17acx_pthread_ok=no 18 19# We used to check for pthread.h first, but this fails if pthread.h 20# requires special compiler flags (e.g. on True64 or Sequent). 21# It gets checked for in the link test anyway. 22 23# First of all, check if the user has set any of the PTHREAD_LIBS, 24# etcetera environment variables, and if threads linking works using 25# them: 26if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then 27 save_CFLAGS="$CFLAGS" 28 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 29 save_LIBS="$LIBS" 30 LIBS="$PTHREAD_LIBS $LIBS" 31 AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS]) 32 AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes) 33 AC_MSG_RESULT($acx_pthread_ok) 34 if test x"$acx_pthread_ok" = xno; then 35 PTHREAD_LIBS="" 36 PTHREAD_CFLAGS="" 37 fi 38 LIBS="$save_LIBS" 39 CFLAGS="$save_CFLAGS" 40fi 41 42# We must check for the threads library under a number of different 43# names; the ordering is very important because some systems 44# (e.g. DEC) have both -lpthread and -lpthreads, where one of the 45# libraries is broken (non-POSIX). 46 47# Create a list of thread flags to try. Items starting with a "-" are 48# C compiler flags, and other items are library names, except for "none" 49# which indicates that we try without any flags at all, and "pthread-config" 50# which is a program returning the flags for the Pth emulation library. 51 52acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" 53 54# The ordering *is* (sometimes) important. Some notes on the 55# individual items follow: 56 57# pthreads: AIX (must check this before -lpthread) 58# none: in case threads are in libc; should be tried before -Kthread and 59# other compiler flags to prevent continual compiler warnings 60# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) 61# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) 62# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) 63# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) 64# -pthreads: Solaris/gcc 65# -mthreads: Mingw32/gcc, Lynx/gcc 66# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it 67# doesn't hurt to check since this sometimes defines pthreads too; 68# also defines -D_REENTRANT) 69# ... -mt is also the pthreads flag for HP/aCC 70# pthread: Linux, etcetera 71# --thread-safe: KAI C++ 72# pthread-config: use pthread-config program (for GNU Pth library) 73 74case "${host_cpu}-${host_os}" in 75 *solaris*) 76 77 # On Solaris (at least, for some versions), libc contains stubbed 78 # (non-functional) versions of the pthreads routines, so link-based 79 # tests will erroneously succeed. (We need to link with -pthreads/-mt/ 80 # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather 81 # a function called by this macro, so we could check for that, but 82 # who knows whether they'll stub that too in a future libc.) So, 83 # we'll just look for -pthreads and -lpthread first: 84 85 acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags" 86 ;; 87esac 88 89if test x"$acx_pthread_ok" = xno; then 90for flag in $acx_pthread_flags; do 91 92 case $flag in 93 none) 94 AC_MSG_CHECKING([whether pthreads work without any flags]) 95 ;; 96 97 -*) 98 AC_MSG_CHECKING([whether pthreads work with $flag]) 99 PTHREAD_CFLAGS="$flag" 100 ;; 101 102 pthread-config) 103 AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no) 104 if test x"$acx_pthread_config" = xno; then continue; fi 105 PTHREAD_CFLAGS="`pthread-config --cflags`" 106 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" 107 ;; 108 109 *) 110 AC_MSG_CHECKING([for the pthreads library -l$flag]) 111 PTHREAD_LIBS="-l$flag" 112 ;; 113 esac 114 115 save_LIBS="$LIBS" 116 save_CFLAGS="$CFLAGS" 117 LIBS="$PTHREAD_LIBS $LIBS" 118 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 119 120 # Check for various functions. We must include pthread.h, 121 # since some functions may be macros. (On the Sequent, we 122 # need a special flag -Kthread to make this header compile.) 123 # We check for pthread_join because it is in -lpthread on IRIX 124 # while pthread_create is in libc. We check for pthread_attr_init 125 # due to DEC craziness with -lpthreads. We check for 126 # pthread_cleanup_push because it is one of the few pthread 127 # functions on Solaris that doesn't have a non-functional libc stub. 128 # We try pthread_create on general principles. 129 AC_TRY_LINK([#include <pthread.h>], 130 [pthread_t th; pthread_join(th, 0); 131 pthread_attr_init(0); pthread_cleanup_push(0, 0); 132 pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], 133 [acx_pthread_ok=yes]) 134 135 LIBS="$save_LIBS" 136 CFLAGS="$save_CFLAGS" 137 138 AC_MSG_RESULT($acx_pthread_ok) 139 if test "x$acx_pthread_ok" = xyes; then 140 break; 141 fi 142 143 PTHREAD_LIBS="" 144 PTHREAD_CFLAGS="" 145done 146fi 147 148# Various other checks: 149if test "x$acx_pthread_ok" = xyes; then 150 save_LIBS="$LIBS" 151 LIBS="$PTHREAD_LIBS $LIBS" 152 save_CFLAGS="$CFLAGS" 153 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 154 155 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. 156 AC_MSG_CHECKING([for joinable pthread attribute]) 157 attr_name=unknown 158 for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do 159 AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;], 160 [attr_name=$attr; break]) 161 done 162 AC_MSG_RESULT($attr_name) 163 if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then 164 AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name, 165 [Define to necessary symbol if this constant 166 uses a non-standard name on your system.]) 167 fi 168 169 AC_MSG_CHECKING([if more special flags are required for pthreads]) 170 flag=no 171 case "${host_cpu}-${host_os}" in 172 *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";; 173 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";; 174 esac 175 AC_MSG_RESULT(${flag}) 176 if test "x$flag" != xno; then 177 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS" 178 fi 179 180 LIBS="$save_LIBS" 181 CFLAGS="$save_CFLAGS" 182 183 # More AIX lossage: must compile with xlc_r or cc_r 184 if test x"$GCC" != xyes; then 185 AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC}) 186 else 187 PTHREAD_CC=$CC 188 fi 189else 190 PTHREAD_CC="$CC" 191fi 192 193AC_SUBST(PTHREAD_LIBS) 194AC_SUBST(PTHREAD_CFLAGS) 195AC_SUBST(PTHREAD_CC) 196 197# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: 198if test x"$acx_pthread_ok" = xyes; then 199 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1]) 200 : 201else 202 acx_pthread_ok=no 203 $2 204fi 205AC_LANG_RESTORE 206])dnl ACX_PTHREAD 207 208 209