Annotation of embedaddon/trafshow/aclocal.m4, revision 1.1.1.1

1.1       misho       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

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