dnl Copyright © 2007 Steven G. Johnson dnl dnl This program is free software: you can redistribute it and/or modify it dnl under the terms of the GNU General Public License as published by the dnl Free Software Foundation, either version 3 of the License, or (at your dnl option) any later version. dnl dnl This program is distributed in the hope that it will be useful, but dnl WITHOUT ANY WARRANTY; without even the implied warranty of dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU dnl General Public License for more details. dnl dnl You should have received a copy of the GNU General Public License along dnl with this program. If not, see . dnl dnl As a special exception, the respective Autoconf Macro's copyright owner dnl gives unlimited permission to copy, distribute and modify the configure dnl scripts that are the output of Autoconf when processing the Macro. You dnl need not follow the terms of the GNU General Public License when using dnl or distributing such scripts, even though portions of the text of the dnl Macro appear in them. The GNU General Public License (GPL) does govern dnl all other use of the material that constitutes the Autoconf Macro. dnl dnl This special exception to the GPL applies to versions of the Autoconf dnl Macro released by the Autoconf Macro Archive. When you make and dnl distribute a modified version of the Autoconf Macro, you may extend dnl this special exception to the GPL to apply to your modified version as dnl well. dnl dnl ----------------------------------------------------------------------- dnl dnl Synopsis: ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) dnl dnl dnl This macro figures out how to build C programs using POSIX threads. It dnl sets the PTHREAD_LIBS output variable to the threads library and linker dnl flags, and the PTHREAD_CFLAGS output variable to any special C compiler dnl flags that are needed. (The user can also force certain compiler dnl flags/libs to be tested by setting these environment variables.) dnl dnl Also sets PTHREAD_CC to any special C compiler that is needed for dnl multi-threaded programs (defaults to the value of CC otherwise). (This dnl is necessary on AIX to use the special cc_r compiler alias.) dnl dnl NOTE: You are assumed to not only compile your program with these dnl flags, but also link it with them as well. e.g. you should link with dnl $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS dnl dnl If you are only building threads programs, you may wish to use these dnl variables in your default LIBS, CFLAGS, and CC: dnl dnl LIBS="$PTHREAD_LIBS $LIBS" dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS" dnl CC="$PTHREAD_CC" dnl dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant dnl has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name dnl (e.g. PTHREAD_CREATE_UNDETACHED on AIX). dnl dnl ACTION-IF-FOUND is a list of shell commands to run if a threads library dnl is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it dnl is not found. If ACTION-IF-FOUND is not specified, the default action dnl will define HAVE_PTHREAD. dnl dnl Please let the authors know if this macro fails on any platform, or if dnl you have any other suggestions or comments. This macro was based on dnl work by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros posted dnl by Alejandro Forero Cuervo to the autoconf macro repository. We are also dnl grateful for the helpful feedback of numerous users. dnl dnl ----------------------------------------------------------------------- dnl AC_DEFUN([ACX_PTHREAD], [ AC_REQUIRE([AC_CANONICAL_HOST]) AC_LANG_SAVE AC_LANG_C acx_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=$PTHREAD_CFLAGS]) AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes) AC_MSG_RESULT($acx_pthread_ok) if test x"$acx_pthread_ok" = xno; then PTHREAD_LIBS="" PTHREAD_CFLAGS="" fi LIBS="$save_LIBS" CFLAGS="$save_CFLAGS" fi # We must check for the threads library under a number of different # names; the ordering is very important because some systems # (e.g. DEC) have both -lpthread and -lpthreads, where one of the # libraries is broken (non-POSIX). # Create a list of thread flags to try. Items starting with a "-" are # C compiler flags, and other items are library names, except for "none" # which indicates that we try without any flags at all, and "pthread-config" # which is a program returning the flags for the Pth emulation library. acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" # The ordering *is* (sometimes) important. Some notes on the # individual items follow: # pthreads: AIX (must check this before -lpthread) # none: in case threads are in libc; should be tried before -Kthread and # other compiler flags to prevent continual compiler warnings # -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) # -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) # -pthreads: Solaris/gcc # -mthreads: Mingw32/gcc, Lynx/gcc # -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it # doesn't hurt to check since this sometimes defines pthreads too; # also defines -D_REENTRANT) # ... -mt is also the pthreads flag for HP/aCC # pthread: Linux, etcetera # --thread-safe: KAI C++ # pthread-config: use pthread-config program (for GNU Pth library) case "${host_cpu}-${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: acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags" ;; esac if test x"$acx_pthread_ok" = xno; then for flag in $acx_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(acx_pthread_config, pthread-config, yes, no) if test x"$acx_pthread_config" = xno; then continue; fi PTHREAD_CFLAGS="`pthread-config --cflags`" PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" ;; *) AC_MSG_CHECKING([for the pthreads library -l$flag]) PTHREAD_LIBS="-l$flag" ;; esac save_LIBS="$LIBS" save_CFLAGS="$CFLAGS" LIBS="$PTHREAD_LIBS $LIBS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS" # Check for various functions. We must include pthread.h, # since some functions may be macros. (On the Sequent, we # need a special flag -Kthread to make this header compile.) # We check for pthread_join because it is in -lpthread on IRIX # while pthread_create is in libc. We check for pthread_attr_init # due to DEC craziness with -lpthreads. We check for # pthread_cleanup_push because it is one of the few pthread # functions on Solaris that doesn't have a non-functional libc stub. # We try pthread_create on general principles. AC_TRY_LINK([#include ], [pthread_t th; pthread_join(th, 0); pthread_attr_init(0); pthread_cleanup_push(0, 0); pthread_create(0,0,0,0); pthread_cleanup_pop(0); ], [acx_pthread_ok=yes]) LIBS="$save_LIBS" CFLAGS="$save_CFLAGS" AC_MSG_RESULT($acx_pthread_ok) if test "x$acx_pthread_ok" = xyes; then break; fi PTHREAD_LIBS="" PTHREAD_CFLAGS="" done fi # Various other checks: if test "x$acx_pthread_ok" = xyes; then save_LIBS="$LIBS" LIBS="$PTHREAD_LIBS $LIBS" save_CFLAGS="$CFLAGS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS" # Detect AIX lossage: JOINABLE attribute is called UNDETACHED. AC_MSG_CHECKING([for joinable pthread attribute]) attr_name=unknown for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do AC_TRY_LINK([#include ], [int attr=$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_cpu}-${host_os}" in *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";; *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";; esac AC_MSG_RESULT(${flag}) if test "x$flag" != xno; then PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS" fi LIBS="$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="$CC" fi AC_SUBST(PTHREAD_LIBS) AC_SUBST(PTHREAD_CFLAGS) AC_SUBST(PTHREAD_CC) # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND: if test x"$acx_pthread_ok" = xyes; then ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1]) : else acx_pthread_ok=no $2 fi AC_LANG_RESTORE ])dnl ACX_PTHREAD