1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) 2007 Denys Vlasenko
7 * Licensed under GPL version 2, see file LICENSE in this tarball for details.
12 #if ENABLE_MONOTONIC_SYSCALL
13 #include <sys/syscall.h>
15 /* Old glibc (< 2.3.4) does not provide this constant. We use syscall
16 * directly so this definition is safe. */
17 #ifndef CLOCK_MONOTONIC
18 #define CLOCK_MONOTONIC 1
21 /* libc has incredibly messy way of doing this,
22 * typically requiring -lrt. We just skip all this mess */
23 unsigned long long monotonic_us(void)
26 if (syscall(__NR_clock_gettime, CLOCK_MONOTONIC, &ts))
27 bb_error_msg_and_die("clock_gettime(MONOTONIC) failed");
28 return ts.tv_sec * 1000000ULL + ts.tv_nsec/1000;
30 unsigned monotonic_sec(void)
33 if (syscall(__NR_clock_gettime, CLOCK_MONOTONIC, &ts))
34 bb_error_msg_and_die("clock_gettime(MONOTONIC) failed");
38 unsigned long long monotonic_us(void)
41 gettimeofday(&tv, NULL);
42 return tv.tv_sec * 1000000ULL + tv.tv_usec;
45 unsigned monotonic_sec(void)