cosmopolitan/libc/calls/clock_gettime.c
Justine Tunney e7611a8476 Make improvements
- Get threads working on NetBSD
- Get threads working on OpenBSD
- Fix Emacs config for Emacs v28
- Improve --strace logging of sigset_t
- Improve --strace logging of struct stat
- Improve memory safety of DescribeThing functions
- Refactor auto stack allocation into LIBC_RUNTIME
- Introduce shell.com example which works on Windows
- Refactor __strace_thing into DescribeThing functions
- Document the CHECK macros and improve them in NDEBUG mode
- Rewrite MAP_STACK so it uses FreeBSD behavior across platforms
- Deprecate and discourage the use of MAP_GROWSDOWN (it's weird)
2022-05-12 06:45:36 -07:00

97 lines
3.9 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/calls/internal.h"
#include "libc/calls/strace.internal.h"
#include "libc/calls/struct/timeval.h"
#include "libc/dce.h"
#include "libc/fmt/conv.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/nt/synchronization.h"
#include "libc/sysv/errfuns.h"
static typeof(sys_clock_gettime) *__clock_gettime = sys_clock_gettime;
/**
* Returns nanosecond time.
*
* This is a high-precision timer that supports multiple definitions of
* time. Among the more popular is CLOCK_MONOTONIC. This function has a
* zero syscall implementation of that on modern x86.
*
* @param clockid can be CLOCK_REALTIME, CLOCK_MONOTONIC, etc.
* @param ts is where the result is stored
* @return 0 on success, or -1 w/ errno
* @error EINVAL if clockid isn't supported on this system
* @see strftime(), gettimeofday()
* @asyncsignalsafe
*/
noinstrument int clock_gettime(int clockid, struct timespec *ts) {
int rc, e;
axdx_t ad;
char buf[45];
if (!ts) {
rc = efault();
} else if (IsAsan() && !__asan_is_valid(ts, sizeof(*ts))) {
rc = efault();
} else if (clockid == -1) {
rc = einval();
} else if (!IsWindows()) {
e = errno;
if ((rc = __clock_gettime(clockid, ts))) {
errno = e;
ad = sys_gettimeofday((struct timeval *)ts, NULL, NULL);
assert(ad.ax != -1);
if (SupportsXnu() && ad.ax) {
ts->tv_sec = ad.ax;
ts->tv_nsec = ad.dx;
}
ts->tv_nsec *= 1000;
rc = 0;
}
} else {
rc = sys_clock_gettime_nt(clockid, ts);
}
if (!__time_critical) {
STRACE("clock_gettime(%d, [%s]) → %d% m", clockid,
DescribeTimespec(buf, sizeof(buf), rc, ts), rc);
}
return rc;
}
/**
* Returns fast system clock_gettime() if it exists.
*/
void *__get_clock_gettime(void) {
void *vdso;
static bool once;
static void *result;
if (!once) {
if ((vdso = __vdsofunc("__vdso_clock_gettime"))) {
__clock_gettime = result = vdso;
}
once = true;
}
return result;
}
const void *const __clock_gettime_ctor[] initarray = {
__get_clock_gettime,
};