m4/pthread_sigmask.m4

   1 # pthread_sigmask.m4 serial 7
   2 dnl Copyright (C) 2011 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 AC_DEFUN([gl_FUNC_PTHREAD_SIGMASK],
   8 [
   9   AC_CHECK_FUNCS_ONCE([pthread_sigmask])
  10   LIB_PTHREAD_SIGMASK=
  11   m4_ifdef([gl_THREADLIB], [
  12     AC_REQUIRE([gl_THREADLIB])
  13     if test "$gl_threads_api" = posix; then
  14       if test $ac_cv_func_pthread_sigmask = yes; then
  15         dnl pthread_sigmask is available without -lpthread.
  16         :
  17       else
  18         if test -n "$LIBMULTITHREAD"; then
  19           AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
  20             [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
  21             [gl_save_LIBS="$LIBS"
  22              LIBS="$LIBS $LIBMULTITHREAD"
  23              AC_LINK_IFELSE(
  24                [AC_LANG_PROGRAM(
  25                   [[#include <pthread.h>
  26                     #include <signal.h>
  27                   ]],
  28                   [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
  29                ],
  30                [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
  31                [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
  32              LIBS="$gl_save_LIBS"
  33             ])
  34           if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
  35             dnl pthread_sigmask is available with -lpthread.
  36             LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
  37           else
  38             dnl pthread_sigmask is not available at all.
  39             HAVE_PTHREAD_SIGMASK=0
  40           fi
  41         else
  42           dnl pthread_sigmask is not available at all.
  43           HAVE_PTHREAD_SIGMASK=0
  44         fi
  45       fi
  46     else
  47       dnl pthread_sigmask may exist but does not interoperate with the chosen
  48       dnl multithreading facility.
  49       dnl If "$gl_threads_api" = pth, we could use the function pth_sigmask,
  50       dnl but it is equivalent to sigprocmask, so we choose to emulate
  51       dnl pthread_sigmask with sigprocmask also in this case. This yields fewer
  52       dnl link dependencies.
  53       if test $ac_cv_func_pthread_sigmask = yes; then
  54         REPLACE_PTHREAD_SIGMASK=1
  55       else
  56         HAVE_PTHREAD_SIGMASK=0
  57       fi
  58     fi
  59   ] ,[
  60     dnl gl_THREADLIB is not in use.  Assume the application wants
  61     dnl POSIX semantics.
  62     if test $ac_cv_func_pthread_sigmask != yes; then
  63       gl_save_LIBS=$LIBS
  64       AC_SEARCH_LIBS([pthread_sigmask], [pthread c_r])
  65       LIBS=$gl_save_LIBS
  66       if test "$ac_cv_search_pthread_sigmask" = no; then
  67         HAVE_PTHREAD_SIGMASK=0
  68       elif test "$ac_cv_search_pthread_sigmask" != 'none required'; then
  69         LIB_PTHREAD_SIGMASK=$ac_cv_search_pthread_sigmask
  70       fi
  71     fi
  72   ])
  73   AC_SUBST([LIB_PTHREAD_SIGMASK])
  74   dnl We don't need a variable LTLIB_PTHREAD_SIGMASK, because when
  75   dnl "$gl_threads_api" = posix, $LTLIBMULTITHREAD and $LIBMULTITHREAD are the
  76   dnl same: either both empty or both "-lpthread".
  77 ])