doc: use ASCII in .texi files where UTF-8 isn't needed
[gnulib.git] / m4 / pthread_sigmask.m4
index 22485bd..4ba0732 100644 (file)
-# pthread_sigmask.m4 serial 1
-dnl Copyright (C) 2011 Free Software Foundation, Inc.
+# pthread_sigmask.m4 serial 13
+dnl Copyright (C) 2011-2014 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 
-AC_DEFUN([gl_PTHREAD_SIGMASK],
+AC_DEFUN([gl_FUNC_PTHREAD_SIGMASK],
 [
-  m4_ifdef([gl_THREADLIB], [
-    AC_REQUIRE([gl_THREADLIB])
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+
+  AC_CHECK_FUNCS_ONCE([pthread_sigmask])
+  LIB_PTHREAD_SIGMASK=
+
+  dnl Test whether the gnulib module 'threadlib' is in use.
+  dnl Some packages like Emacs use --avoid=threadlib.
+  dnl Write the symbol in such a way that it does not cause 'aclocal' to pick
+  dnl the threadlib.m4 file that is installed in $PREFIX/share/aclocal/.
+  m4_ifdef([gl_][THREADLIB], [
+    AC_REQUIRE([gl_][THREADLIB])
+
     if test "$gl_threads_api" = posix; then
-      gl_save_LIBS="$LIBS"
-      LIBS="$LIBS $LIBMULTITHREAD"
-      AC_CHECK_FUNCS([pthread_sigmask])
-      LIBS="$gl_save_LIBS"
+      if test $ac_cv_func_pthread_sigmask = yes; then
+        dnl pthread_sigmask is available without -lpthread.
+        :
+      else
+        if test -n "$LIBMULTITHREAD"; then
+          AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
+            [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
+            [gl_save_LIBS="$LIBS"
+             LIBS="$LIBS $LIBMULTITHREAD"
+             AC_LINK_IFELSE(
+               [AC_LANG_PROGRAM(
+                  [[#include <pthread.h>
+                    #include <signal.h>
+                  ]],
+                  [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
+               ],
+               [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
+               [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
+             LIBS="$gl_save_LIBS"
+            ])
+          if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
+            dnl pthread_sigmask is available with -lpthread.
+            LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
+          else
+            dnl pthread_sigmask is not available at all.
+            HAVE_PTHREAD_SIGMASK=0
+          fi
+        else
+          dnl pthread_sigmask is not available at all.
+          HAVE_PTHREAD_SIGMASK=0
+        fi
+      fi
+    else
+      dnl pthread_sigmask may exist but does not interoperate with the chosen
+      dnl multithreading facility.
+      dnl If "$gl_threads_api" = pth, we could use the function pth_sigmask,
+      dnl but it is equivalent to sigprocmask, so we choose to emulate
+      dnl pthread_sigmask with sigprocmask also in this case. This yields fewer
+      dnl link dependencies.
+      if test $ac_cv_func_pthread_sigmask = yes; then
+        REPLACE_PTHREAD_SIGMASK=1
+      else
+        HAVE_PTHREAD_SIGMASK=0
+      fi
     fi
   ], [
-    AC_CHECK_FUNCS_ONCE([pthread_sigmask])
+    dnl The module 'threadlib' is not in use, due to --avoid=threadlib being
+    dnl specified.
+    dnl The package either has prepared CPPFLAGS and LIBS for use of POSIX:2008
+    dnl threads, or wants to build single-threaded programs.
+    if test $ac_cv_func_pthread_sigmask = yes; then
+      dnl pthread_sigmask exists and does not require extra libraries.
+      dnl Assume that it is declared.
+      :
+    else
+      dnl pthread_sigmask either does not exist or needs extra libraries.
+      HAVE_PTHREAD_SIGMASK=0
+      dnl Define the symbol rpl_pthread_sigmask, not pthread_sigmask,
+      dnl so as to not accidentally override the system's pthread_sigmask
+      dnl symbol from libpthread. This is necessary on IRIX 6.5.
+      REPLACE_PTHREAD_SIGMASK=1
+    fi
   ])
 
-  if test $ac_cv_func_pthread_sigmask = no; then
-    REPLACE_PTHREAD_SIGMASK=0
+  AC_SUBST([LIB_PTHREAD_SIGMASK])
+  dnl We don't need a variable LTLIB_PTHREAD_SIGMASK, because when
+  dnl "$gl_threads_api" = posix, $LTLIBMULTITHREAD and $LIBMULTITHREAD are the
+  dnl same: either both empty or both "-lpthread".
+
+  dnl Now test for some bugs in the system function.
+  if test $HAVE_PTHREAD_SIGMASK = 1; then
+    AC_REQUIRE([AC_PROG_CC])
+    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+    dnl On FreeBSD 6.4, HP-UX 11.31, Solaris 9, in programs that are not linked
+    dnl with -lpthread, the pthread_sigmask() function always returns 0 and has
+    dnl no effect.
+    if test -z "$LIB_PTHREAD_SIGMASK"; then
+      AC_CACHE_CHECK([whether pthread_sigmask works without -lpthread],
+        [gl_cv_func_pthread_sigmask_in_libc_works],
+        [
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#include <pthread.h>
+#include <signal.h>
+#include <stddef.h>
+int main ()
+{
+  sigset_t set;
+  sigemptyset (&set);
+  return pthread_sigmask (1729, &set, NULL) != 0;
+}]])],
+            [gl_cv_func_pthread_sigmask_in_libc_works=no],
+            [gl_cv_func_pthread_sigmask_in_libc_works=yes],
+            [
+changequote(,)dnl
+             case "$host_os" in
+               freebsd* | hpux* | solaris | solaris2.[2-9]*)
+                 gl_cv_func_pthread_sigmask_in_libc_works="guessing no";;
+               *)
+                 gl_cv_func_pthread_sigmask_in_libc_works="guessing yes";;
+             esac
+changequote([,])dnl
+            ])
+        ])
+      case "$gl_cv_func_pthread_sigmask_in_libc_works" in
+        *no)
+          REPLACE_PTHREAD_SIGMASK=1
+          AC_DEFINE([PTHREAD_SIGMASK_INEFFECTIVE], [1],
+            [Define to 1 if pthread_sigmask() may returns 0 and have no effect.])
+          ;;
+      esac
+    fi
+
+    dnl On Cygwin 1.7.5, the pthread_sigmask() has a wrong return value
+    dnl convention: Upon failure, it returns -1 and sets errno.
+    AC_CACHE_CHECK([whether pthread_sigmask returns error numbers],
+      [gl_cv_func_pthread_sigmask_return_works],
+      [
+        gl_save_LIBS="$LIBS"
+        LIBS="$LIBS $LIB_PTHREAD_SIGMASK"
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <pthread.h>
+#include <signal.h>
+#include <stddef.h>
+int main ()
+{
+  sigset_t set;
+  sigemptyset (&set);
+  if (pthread_sigmask (1729, &set, NULL) == -1)
+    return 1;
+  return 0;
+}]])],
+          [gl_cv_func_pthread_sigmask_return_works=yes],
+          [gl_cv_func_pthread_sigmask_return_works=no],
+          [case "$host_os" in
+             cygwin*)
+               gl_cv_func_pthread_sigmask_return_works="guessing no";;
+             *)
+               gl_cv_func_pthread_sigmask_return_works="guessing yes";;
+           esac
+          ])
+        LIBS="$gl_save_LIBS"
+      ])
+    case "$gl_cv_func_pthread_sigmask_return_works" in
+      *no)
+        REPLACE_PTHREAD_SIGMASK=1
+        AC_DEFINE([PTHREAD_SIGMASK_FAILS_WITH_ERRNO], [1],
+          [Define to 1 if pthread_sigmask(), when it fails, returns -1 and sets errno.])
+        ;;
+    esac
+
+    dnl On IRIX 6.5, in a single-threaded program, pending signals are not
+    dnl immediately delivered when they are unblocked through pthread_sigmask,
+    dnl only a little while later.
+    AC_CACHE_CHECK([whether pthread_sigmask unblocks signals correctly],
+      [gl_cv_func_pthread_sigmask_unblock_works],
+      [
+        case "$host_os" in
+          irix*)
+            gl_cv_func_pthread_sigmask_unblock_works="guessing no";;
+          *)
+            gl_cv_func_pthread_sigmask_unblock_works="guessing yes";;
+        esac
+        dnl Here we link against $LIBMULTITHREAD, not only $LIB_PTHREAD_SIGMASK,
+        dnl otherwise we get a false positive on those platforms where
+        dnl $gl_cv_func_pthread_sigmask_in_libc_works is "no".
+        gl_save_LIBS="$LIBS"
+        LIBS="$LIBS $LIBMULTITHREAD"
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+static volatile int sigint_occurred;
+static void
+sigint_handler (int sig)
+{
+  sigint_occurred++;
+}
+int main ()
+{
+  sigset_t set;
+  int pid = getpid ();
+  char command[80];
+  signal (SIGINT, sigint_handler);
+  sigemptyset (&set);
+  sigaddset (&set, SIGINT);
+  if (!(pthread_sigmask (SIG_BLOCK, &set, NULL) == 0))
+    return 1;
+  sprintf (command, "sh -c 'sleep 1; kill -%d %d' &", SIGINT, pid);
+  if (!(system (command) == 0))
+    return 2;
+  sleep (2);
+  if (!(sigint_occurred == 0))
+    return 3;
+  if (!(pthread_sigmask (SIG_UNBLOCK, &set, NULL) == 0))
+    return 4;
+  if (!(sigint_occurred == 1)) /* This fails on IRIX.  */
+    return 5;
+  return 0;
+}]])],
+          [:],
+          [gl_cv_func_pthread_sigmask_unblock_works=no],
+          [:])
+        LIBS="$gl_save_LIBS"
+      ])
+    case "$gl_cv_func_pthread_sigmask_unblock_works" in
+      *no)
+        REPLACE_PTHREAD_SIGMASK=1
+        AC_DEFINE([PTHREAD_SIGMASK_UNBLOCK_BUG], [1],
+          [Define to 1 if pthread_sigmask() unblocks signals incorrectly.])
+        ;;
+    esac
+  fi
+])
+
+# Prerequisite of lib/pthread_sigmask.c.
+AC_DEFUN([gl_PREREQ_PTHREAD_SIGMASK],
+[
+  if test $HAVE_PTHREAD_SIGMASK = 1; then
+    AC_DEFINE([HAVE_PTHREAD_SIGMASK], [1],
+      [Define to 1 if the pthread_sigmask function can be used (despite bugs).])
   fi
 ])