Add uuidd daemon to prevent duplicate time-based UUID's

Also store the clock sequence information in a state file in
/var/lib/misc/uuid-clock so that if the time goes backwards the clock
sequence counter can get bumped.  This allows us to completely
correctly generate time-based (version 1) UUID's according to the
algorithm specified RFC 4122.

Addresses-Sourceforge-Bug: #1529672
Addresses-Red-Hat-Bugzilla: #233471

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 49 insertions, 0 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index 3a4c2f30..fc3ed733 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -2600,3 +2600,52 @@ AC_DEFUN([gl_XSIZE],
   AC_REQUIRE([gl_SIZE_MAX])
   AC_CHECK_HEADERS(stdint.h)
 ])
+
+# from http://autoconf-archive.cryp.to/ax_tls.html
+#
+# This was licensed under the GPL with the following exception:
+#
+# As a special exception, the respective Autoconf Macro's copyright
+# owner gives unlimited permission to copy, distribute and modify the
+# configure scripts that are the output of Autoconf when processing
+# the Macro. You need not follow the terms of the GNU General Public
+# License when using or distributing such scripts, even though
+# portions of the text of the Macro appear in them. The GNU General
+# Public License (GPL) does govern all other use of the material that
+# constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the
+# Autoconf Macro released by the Autoconf Macro Archive. When you make
+# and distribute a modified version of the Autoconf Macro, you may
+# extend this special exception to the GPL to apply to your modified
+# version as well.
+#
+AC_DEFUN([AX_TLS], [
+  AC_MSG_CHECKING(for thread local storage (TLS) class)
+  AC_CACHE_VAL(ac_cv_tls, [
+    ax_tls_keywords="__thread __declspec(thread) none"
+    for ax_tls_keyword in $ax_tls_keywords; do
+       case $ax_tls_keyword in
+          none) ac_cv_tls=none ; break ;;
+          *)
+             AC_TRY_COMPILE(
+                [#include <stdlib.h>
+                 static void
+                 foo(void) {
+                 static ] $ax_tls_keyword [ int bar;
+                 exit(1);
+                 }],
+                 [],
+                 [ac_cv_tls=$ax_tls_keyword ; break],
+                 ac_cv_tls=none
+             )
+          esac
+    done
+])
+
+  if test "$ac_cv_tls" != "none"; then
+    dnl AC_DEFINE([TLS], [], [If the compiler supports a TLS storage class define it to that here])
+    AC_DEFINE_UNQUOTED([TLS], $ac_cv_tls, [If the compiler supports a TLS storage class define it to that here])
+  fi
+  AC_MSG_RESULT($ac_cv_tls)
+])