X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fpthread_sigmask.m4;h=0346a20af21bc2218e0efefe4feba323886a2b15;hb=5191b3546cfb6c163228c23f214e325ddf60d46f;hp=c65a4ce3507cd71553a15f226137dece2c686d21;hpb=43243b5fdcf1e0c0e016cabe190f1ab29b984871;p=gnulib.git

diff --git a/m4/pthread_sigmask.m4 b/m4/pthread_sigmask.m4
index c65a4ce35..0346a20af 100644
--- a/m4/pthread_sigmask.m4
+++ b/m4/pthread_sigmask.m4
@@ -1,15 +1,23 @@
-# pthread_sigmask.m4 serial 8
-dnl Copyright (C) 2011 Free Software Foundation, Inc.
+# pthread_sigmask.m4 serial 13
+dnl Copyright (C) 2011-2013 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_FUNC_PTHREAD_SIGMASK],
 [
+  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
+
   AC_CHECK_FUNCS_ONCE([pthread_sigmask])
   LIB_PTHREAD_SIGMASK=
-  m4_ifdef([gl_THREADLIB], [
-    AC_REQUIRE([gl_THREADLIB])
+
+  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
       if test $ac_cv_func_pthread_sigmask = yes; then
         dnl pthread_sigmask is available without -lpthread.
@@ -56,20 +64,25 @@ AC_DEFUN([gl_FUNC_PTHREAD_SIGMASK],
         HAVE_PTHREAD_SIGMASK=0
       fi
     fi
-  ] ,[
-    dnl gl_THREADLIB is not in use.  Assume the application wants
-    dnl POSIX semantics.
-    if test $ac_cv_func_pthread_sigmask != yes; then
-      gl_save_LIBS=$LIBS
-      AC_SEARCH_LIBS([pthread_sigmask], [pthread c_r])
-      LIBS=$gl_save_LIBS
-      if test "$ac_cv_search_pthread_sigmask" = no; then
-        HAVE_PTHREAD_SIGMASK=0
-      elif test "$ac_cv_search_pthread_sigmask" != 'none required'; then
-        LIB_PTHREAD_SIGMASK=$ac_cv_search_pthread_sigmask
-      fi
+  ], [
+    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 $ac_cv_func_pthread_sigmask = yes; then
+      dnl pthread_sigmask exists and does not require extra libraries.
+      dnl Assume that it is declared.
+      :
+    else
+      dnl pthread_sigmask either does not exist or needs extra libraries.
+      HAVE_PTHREAD_SIGMASK=0
+      dnl Define the symbol rpl_pthread_sigmask, not pthread_sigmask,
+      dnl so as to not accidentally override the system's pthread_sigmask
+      dnl symbol from libpthread. This is necessary on IRIX 6.5.
+      REPLACE_PTHREAD_SIGMASK=1
     fi
   ])
+
   AC_SUBST([LIB_PTHREAD_SIGMASK])
   dnl We don't need a variable LTLIB_PTHREAD_SIGMASK, because when
   dnl "$gl_threads_api" = posix, $LTLIBMULTITHREAD and $LIBMULTITHREAD are the
@@ -115,7 +128,7 @@ changequote([,])dnl
         *no)
           REPLACE_PTHREAD_SIGMASK=1
           AC_DEFINE([PTHREAD_SIGMASK_INEFFECTIVE], [1],
-            [Define to 1 if pthread_mask() may returns 0 and have no effect.])
+            [Define to 1 if pthread_sigmask() may returns 0 and have no effect.])
           ;;
       esac
     fi
@@ -155,10 +168,74 @@ int main ()
       *no)
         REPLACE_PTHREAD_SIGMASK=1
         AC_DEFINE([PTHREAD_SIGMASK_FAILS_WITH_ERRNO], [1],
-          [Define to 1 if pthread_mask(), when it fails, returns -1 and sets errno.])
+          [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
 ])