clock_getres implementation for Linux.
authordrepper <drepper>
Mon, 3 Mar 2003 04:48:47 +0000 (04:48 +0000)
committerdrepper <drepper>
Mon, 3 Mar 2003 04:48:47 +0000 (04:48 +0000)
sysdeps/unix/sysv/linux/clock_getres.c [new file with mode: 0644]

diff --git a/sysdeps/unix/sysv/linux/clock_getres.c b/sysdeps/unix/sysv/linux/clock_getres.c
new file mode 100644 (file)
index 0000000..442fbd5
--- /dev/null
@@ -0,0 +1,76 @@
+/* Copyright (C) 2003 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+
+#include "kernel-features.h"
+
+
+#ifdef __ASSUME_POSIX_TIMERS
+/* This means the REALTIME and MONOTONIC clock are definitely
+   supported in the kernel.  */
+# define SYSDEP_GETRES \
+  case CLOCK_REALTIME:                                                       \
+  case CLOCK_MONOTONIC:                                                              \
+    retval = INLINE_SYSCALL (clock_getres, 2, clock_id, res);                \
+    break
+#elif defined __NR_clock_getres
+/* Is the syscall known to exist?  */
+extern int __libc_missing_posix_timers attribute_hidden;
+
+/* The REALTIME and MONOTONIC clock might be available.  Try the
+   syscall first.  */
+# define SYSDEP_GETRES \
+  case CLOCK_REALTIME:                                                       \
+  case CLOCK_MONOTONIC:                                                              \
+    {                                                                        \
+      int e = EINVAL;                                                        \
+                                                                             \
+      if (!__libc_missing_posix_timers)                                              \
+       {                                                                     \
+         INTERNAL_SYSCALL_DECL (err);                                        \
+         int r = INTERNAL_SYSCALL (clock_getres, err, 2, clock_id, res);     \
+         if (!INTERNAL_SYSCALL_ERROR_P (r, err))                             \
+           {                                                                 \
+             retval = 0;                                                     \
+             break;                                                          \
+           }                                                                 \
+                                                                             \
+         e = INTERNAL_SYSCALL_ERRNO (r, err);                                \
+         if (e == ENOSYS)                                                    \
+           {                                                                 \
+             __libc_missing_posix_timers = 1;                                \
+             e = EINVAL;                                                     \
+           }                                                                 \
+       }                                                                     \
+                                                                             \
+      /* Fallback code.  */                                                  \
+      if (e == EINVAL && clock_id == CLOCK_REALTIME)                         \
+       HANDLE_REALTIME;                                                      \
+      else                                                                   \
+       __set_errno (e);                                                      \
+    }                                                                        \
+    break
+#endif
+
+#ifdef __NR_clock_getres
+/* We handled the REALTIME clock here.  */
+# define HANDLED_REALTIME      1
+#endif
+
+#include <sysdeps/posix/clock_getres.c>