diff options
Diffstat (limited to 'sysdeps/posix')
-rw-r--r-- | sysdeps/posix/clock_getres.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/sysdeps/posix/clock_getres.c b/sysdeps/posix/clock_getres.c new file mode 100644 index 0000000000..5043ffd0e6 --- /dev/null +++ b/sysdeps/posix/clock_getres.c @@ -0,0 +1,63 @@ +/* Copyright (C) 1999, 2000 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <errno.h> +#include <unistd.h> +#include <sys/time.h> + + +#ifndef EXTRA_CLOCK_CASES +# define EXTRA_CLOCK_CASES +#endif + +/* Get resolution of clock. */ +int +clock_getres (clockid_t clock_id, struct timespec *res) +{ + int retval; + + switch (clock_id) + { + case CLOCK_REALTIME: + { + long int clk_tck = sysconf (_SC_CLK_TCK); + + retval = -1; + if (__builtin_expect (clk_tck != -1, 1)) + { + /* This implementation assumes that the realtime clock has a + resolution higher than 1 second. This is the case for any + reasonable implementation. */ + res->tv_sec = 0; + res->tv_nsec = 1000000000 / clk_tck; + + retval = 0; + } + } + break; + + EXTRA_CLOCK_CASES + + default: + __set_errno (EINVAL); + retval = -1; + break; + } + + return retval; +} |