1dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) 2dnl 3dnl This macro figures out how to build C programs using POSIX threads. 4dnl It sets the PTHREAD_LIBS output variable to the threads library and 5dnl linker flags, and the PTHREAD_CFLAGS output variable to any special 6dnl C compiler flags that are needed. (The user can also force certain 7dnl compiler flags/libs to be tested by setting these environment 8dnl variables.) 9dnl 10dnl Also sets PTHREAD_CC to any special C compiler that is needed for 11dnl multi-threaded programs (defaults to the value of CC otherwise). 12dnl (This is necessary on AIX to use the special cc_r compiler alias.) 13dnl 14dnl NOTE: You are assumed to not only compile your program with these 15dnl flags, but also link it with them as well. e.g. you should link 16dnl with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS 17dnl $LIBS 18dnl 19dnl If you are only building threads programs, you may wish to use 20dnl these variables in your default LIBS, CFLAGS, and CC: 21dnl 22dnl LIBS="$PTHREAD_LIBS $LIBS" 23dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 24dnl CC="$PTHREAD_CC" 25dnl 26dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute 27dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to 28dnl that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX). 29dnl 30dnl ACTION-IF-FOUND is a list of shell commands to run if a threads 31dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands to 32dnl run it if it is not found. If ACTION-IF-FOUND is not specified, the 33dnl default action will define HAVE_PTHREAD. 34dnl 35dnl Please let the authors know if this macro fails on any platform, or 36dnl if you have any other suggestions or comments. This macro was based 37dnl on work by SGJ on autoconf scripts for FFTW (www.fftw.org) (with 38dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros 39dnl posted by Alejandro Forero Cuervo to the autoconf macro repository. 40dnl We are also grateful for the helpful feedback of numerous users. 41dnl 42dnl @category InstalledPackages 43dnl @author Steven G. Johnson <stevenj@alum.mit.edu> 44dnl @version 2005-01-14 45dnl @license GPLWithACException 46 47AC_DEFUN([ACX_PTHREAD], [ 48AC_REQUIRE([AC_CANONICAL_HOST]) 49AC_LANG_SAVE 50AC_LANG_C 51acx_pthread_ok=no 52 53# We used to check for pthread.h first, but this fails if pthread.h 54# requires special compiler flags (e.g. on True64 or Sequent). 55# It gets checked for in the link test anyway. 56 57# First of all, check if the user has set any of the PTHREAD_LIBS, 58# etcetera environment variables, and if threads linking works using 59# them: 60if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then 61 save_CFLAGS="$CFLAGS" 62 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 63 save_LIBS="$LIBS" 64 LIBS="$PTHREAD_LIBS $LIBS" 65 AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS]) 66 AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes) 67 AC_MSG_RESULT($acx_pthread_ok) 68 if test x"$acx_pthread_ok" = xno; then 69 PTHREAD_LIBS="" 70 PTHREAD_CFLAGS="" 71 fi 72 LIBS="$save_LIBS" 73 CFLAGS="$save_CFLAGS" 74fi 75 76# We must check for the threads library under a number of different 77# names; the ordering is very important because some systems 78# (e.g. DEC) have both -lpthread and -lpthreads, where one of the 79# libraries is broken (non-POSIX). 80 81# Create a list of thread flags to try. Items starting with a "-" are 82# C compiler flags, and other items are library names, except for "none" 83# which indicates that we try without any flags at all, and "pthread-config" 84# which is a program returning the flags for the Pth emulation library. 85 86acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" 87 88# The ordering *is* (sometimes) important. Some notes on the 89# individual items follow: 90 91# pthreads: AIX (must check this before -lpthread) 92# none: in case threads are in libc; should be tried before -Kthread and 93# other compiler flags to prevent continual compiler warnings 94# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) 95# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) 96# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) 97# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) 98# -pthreads: Solaris/gcc 99# -mthreads: Mingw32/gcc, Lynx/gcc 100# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it 101# doesn't hurt to check since this sometimes defines pthreads too; 102# also defines -D_REENTRANT) 103# pthread: Linux, etcetera 104# --thread-safe: KAI C++ 105# pthread-config: use pthread-config program (for GNU Pth library) 106 107case "${host_cpu}-${host_os}" in 108 *solaris*) 109 110 # On Solaris (at least, for some versions), libc contains stubbed 111 # (non-functional) versions of the pthreads routines, so link-based 112 # tests will erroneously succeed. (We need to link with -pthread or 113 # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather 114 # a function called by this macro, so we could check for that, but 115 # who knows whether they'll stub that too in a future libc.) So, 116 # we'll just look for -pthreads and -lpthread first: 117 118 acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags" 119 ;; 120esac 121 122if test x"$acx_pthread_ok" = xno; then 123for flag in $acx_pthread_flags; do 124 125 case $flag in 126 none) 127 AC_MSG_CHECKING([whether pthreads work without any flags]) 128 ;; 129 130 -*) 131 AC_MSG_CHECKING([whether pthreads work with $flag]) 132 PTHREAD_CFLAGS="$flag" 133 ;; 134 135 pthread-config) 136 AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no) 137 if test x"$acx_pthread_config" = xno; then continue; fi 138 PTHREAD_CFLAGS="`pthread-config --cflags`" 139 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" 140 ;; 141 142 *) 143 AC_MSG_CHECKING([for the pthreads library -l$flag]) 144 PTHREAD_LIBS="-l$flag" 145 ;; 146 esac 147 148 save_LIBS="$LIBS" 149 save_CFLAGS="$CFLAGS" 150 LIBS="$PTHREAD_LIBS $LIBS" 151 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 152 153 # Check for various functions. We must include pthread.h, 154 # since some functions may be macros. (On the Sequent, we 155 # need a special flag -Kthread to make this header compile.) 156 # We check for pthread_join because it is in -lpthread on IRIX 157 # while pthread_create is in libc. We check for pthread_attr_init 158 # due to DEC craziness with -lpthreads. We check for 159 # pthread_cleanup_push because it is one of the few pthread 160 # functions on Solaris that doesn't have a non-functional libc stub. 161 # We try pthread_create on general principles. 162 AC_TRY_LINK([#include <pthread.h>], 163 [pthread_t th; pthread_join(th, 0); 164 pthread_attr_init(0); pthread_cleanup_push(0, 0); 165 pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], 166 [acx_pthread_ok=yes]) 167 168 LIBS="$save_LIBS" 169 CFLAGS="$save_CFLAGS" 170 171 AC_MSG_RESULT($acx_pthread_ok) 172 if test "x$acx_pthread_ok" = xyes; then 173 break; 174 fi 175 176 PTHREAD_LIBS="" 177 PTHREAD_CFLAGS="" 178done 179fi 180 181# Various other checks: 182if test "x$acx_pthread_ok" = xyes; then 183 save_LIBS="$LIBS" 184 LIBS="$PTHREAD_LIBS $LIBS" 185 save_CFLAGS="$CFLAGS" 186 CFLAGS="$CFLAGS $PTHREAD_CFLAGS" 187 188 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. 189 AC_MSG_CHECKING([for joinable pthread attribute]) 190 attr_name=unknown 191 for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do 192 AC_TRY_LINK([#include <pthread.h>], [int attr=$attr;], 193 [attr_name=$attr; break]) 194 done 195 AC_MSG_RESULT($attr_name) 196 if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then 197 AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name, 198 [Define to necessary symbol if this constant 199 uses a non-standard name on your system.]) 200 fi 201 202 AC_MSG_CHECKING([if more special flags are required for pthreads]) 203 flag=no 204 case "${host_cpu}-${host_os}" in 205 *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";; 206 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";; 207 esac 208 AC_MSG_RESULT(${flag}) 209 if test "x$flag" != xno; then 210 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS" 211 fi 212 213 LIBS="$save_LIBS" 214 CFLAGS="$save_CFLAGS" 215 216 # More AIX lossage: must compile with cc_r 217 AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC}) 218else 219 PTHREAD_CC="$CC" 220fi 221 222AC_SUBST(PTHREAD_LIBS) 223AC_SUBST(PTHREAD_CFLAGS) 224AC_SUBST(PTHREAD_CC) 225 226# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: 227if test x"$acx_pthread_ok" = xyes; then 228 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1]) 229 : 230else 231 acx_pthread_ok=no 232 $2 233fi 234AC_LANG_RESTORE 235])dnl ACX_PTHREAD 236