"Fossies" - the Fresh Open Source Software Archive

Member "openmpi-3.1.6/opal/mca/event/libevent2022/libevent/m4/acx_pthread.m4" (18 Mar 2020, 10928 Bytes) of package /linux/misc/openmpi-3.1.6.tar.bz2:


As a special service "Fossies" has tried to format the requested text file into HTML format (style: standard) with prefixed line numbers. Alternatively you can here view or download the uninterpreted source code file.

    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 
   86 AC_DEFUN([ACX_PTHREAD], [
   87 AC_REQUIRE([AC_CANONICAL_HOST])
   88 AC_LANG_SAVE
   89 AC_LANG_C
   90 acx_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:
   99 if 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="$save_CFLAGS"
  113 fi
  114 
  115 # We must check for the threads library under a number of different
  116 # names; the ordering is very important because some systems
  117 # (e.g. DEC) have both -lpthread and -lpthreads, where one of the
  118 # libraries is broken (non-POSIX).
  119 
  120 # Create a list of thread flags to try.  Items starting with a "-" are
  121 # C compiler flags, and other items are library names, except for "none"
  122 # which indicates that we try without any flags at all, and "pthread-config"
  123 # which is a program returning the flags for the Pth emulation library.
  124 
  125 acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
  126 
  127 # The ordering *is* (sometimes) important.  Some notes on the
  128 # individual items follow:
  129 
  130 # pthreads: AIX (must check this before -lpthread)
  131 # none: in case threads are in libc; should be tried before -Kthread and
  132 #       other compiler flags to prevent continual compiler warnings
  133 # -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
  134 # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
  135 # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
  136 # -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
  137 # -pthreads: Solaris/gcc
  138 # -mthreads: Mingw32/gcc, Lynx/gcc
  139 # -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
  140 #      doesn't hurt to check since this sometimes defines pthreads too;
  141 #      also defines -D_REENTRANT)
  142 #      ... -mt is also the pthreads flag for HP/aCC
  143 # pthread: Linux, etcetera
  144 # --thread-safe: KAI C++
  145 # pthread-config: use pthread-config program (for GNU Pth library)
  146 
  147 case "${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 $acx_pthread_flags"
  159         ;;
  160 esac
  161 
  162 if test x"$acx_pthread_ok" = xno; then
  163 for 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$acx_pthread_ok" = xyes; then
  213                 break;
  214         fi
  215 
  216         PTHREAD_LIBS=""
  217         PTHREAD_CFLAGS=""
  218 done
  219 fi
  220 
  221 # Various other checks:
  222 if test "x$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
  262 else
  263         PTHREAD_CC="$CC"
  264 fi
  265 
  266 AC_SUBST(PTHREAD_LIBS)
  267 AC_SUBST(PTHREAD_CFLAGS)
  268 AC_SUBST(PTHREAD_CC)
  269 
  270 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
  271 if test x"$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         :
  274 else
  275         acx_pthread_ok=no
  276         $2
  277 fi
  278 AC_LANG_RESTORE
  279 ])dnl ACX_PTHREAD