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trafshow

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