support: Add xclock_gettime

* support/xclock_gettime.c (xclock_gettime): New file. Provide
	clock_gettime wrapper for use in tests that fails the test rather
	than returning failure.

	* support/xtime.h: New file to declare xclock_gettime.

	* support/Makefile: Add xclock_gettime.c.

	* support/README: Mention xtime.h.

ChangeLog

@@ -1,3 +1,15 @@
+2019-05-08  Mike Crowe  <mac@mcrowe.com>
+
+	* support/xclock_gettime.c (xclock_gettime): New file. Provide
+	clock_gettime wrapper for use in tests that fails the test rather
+	than returning failure.
+
+	* support/xtime.h: New file to declare xclock_gettime.
+
+	* support/Makefile: Add xclock_gettime.c.
+
+	* support/README: Mention xtime.h.
+
 2019-05-08  Florian Weimer  <fweimer@redhat.com>
 
 	malloc/tst-mallocfork2: Use process-shared barriers.

support/Makefile

@@ -78,6 +78,7 @@ libsupport-routines = \
   xbind \
   xcalloc \
   xchroot \
+  xclock_gettime \
   xclose \
   xconnect \
   xcopy_file_range \

support/README

@@ -10,6 +10,7 @@ error.  They are declared in these header files:
 * support.h
 * xsignal.h
 * xthread.h
+* xtime.h
 
 In general, new wrappers should be added to support.h if possible.
 However, support.h must remain fully compatible with C90 and therefore

support/xclock_gettime.c

@@ -0,0 +1,31 @@
+/* clock_gettime with error checking.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xtime.h>
+#include <support/xthread.h>
+
+void
+xclock_gettime (clockid_t clockid,
+                struct timespec *ts)
+{
+  const int ret = clock_gettime (clockid, ts);
+  if (ret < 0)
+    FAIL_EXIT1 ("clock_gettime (%d): %m",
+                clockid);
+}

support/xtime.h

@@ -0,0 +1,33 @@
+/* Support functionality for using time.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_TIME_H
+#define SUPPORT_TIME_H
+
+#include <time.h>
+
+__BEGIN_DECLS
+
+/* The following functions call the corresponding libc functions and
+   terminate the process on error.  */
+
+void xclock_gettime (clockid_t clock, struct timespec *ts);
+
+__END_DECLS
+
+#endif /* SUPPORT_TIME_H */