mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
8b72490431
Calls to lock/unlock functions are now NOPs by default. The first time clone() is called, they get turned into CALL instructions. Doing this caused funcctions like fputc() to shrink from 85 bytes to 45+4 bytes. Since the ANSI solution of `(__threaded && lock())` inlines os much superfluous binary content into functions all over the place.
104 lines
4.3 KiB
C
104 lines
4.3 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/bits/asmflag.h"
|
||
#include "libc/bits/bits.h"
|
||
#include "libc/calls/asan.internal.h"
|
||
#include "libc/calls/clock_gettime.h"
|
||
#include "libc/calls/internal.h"
|
||
#include "libc/calls/state.internal.h"
|
||
#include "libc/calls/strace.internal.h"
|
||
#include "libc/calls/struct/timeval.h"
|
||
#include "libc/calls/syscall_support-sysv.internal.h"
|
||
#include "libc/dce.h"
|
||
#include "libc/fmt/conv.h"
|
||
#include "libc/intrin/asan.internal.h"
|
||
#include "libc/intrin/describeflags.internal.h"
|
||
#include "libc/mem/alloca.h"
|
||
#include "libc/nt/synchronization.h"
|
||
#include "libc/sysv/errfuns.h"
|
||
|
||
/**
|
||
* 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.
|
||
*
|
||
* nowl l: 45𝑐 15𝑛𝑠
|
||
* rdtsc l: 13𝑐 4𝑛𝑠
|
||
* gettimeofday l: 44𝑐 14𝑛𝑠
|
||
* clock_gettime l: 40𝑐 13𝑛𝑠
|
||
* __clock_gettime l: 35𝑐 11𝑛𝑠
|
||
* sys_clock_gettime l: 220𝑐 71𝑛𝑠
|
||
*
|
||
* @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
|
||
*/
|
||
int clock_gettime(int clockid, struct timespec *ts) {
|
||
int rc;
|
||
char *buf;
|
||
if (IsAsan() && !__asan_is_valid_timespec(ts)) {
|
||
rc = efault();
|
||
} else {
|
||
rc = __clock_gettime(clockid, ts);
|
||
}
|
||
#if SYSDEBUG
|
||
if (!__time_critical) {
|
||
buf = alloca(45);
|
||
STRACE("clock_gettime(%d, [%s]) → %d% m", clockid,
|
||
DescribeTimespec(buf, 45, rc, ts), rc);
|
||
}
|
||
#endif
|
||
return rc;
|
||
}
|
||
|
||
/**
|
||
* Returns pointer to fastest clock_gettime().
|
||
*/
|
||
clock_gettime_f *__clock_gettime_get(bool *opt_out_isfast) {
|
||
bool isfast;
|
||
clock_gettime_f *res;
|
||
if (IsLinux() && (res = __vdsosym("LINUX_2.6", "__vdso_clock_gettime"))) {
|
||
isfast = true;
|
||
} else if (IsXnu()) {
|
||
isfast = false;
|
||
res = sys_clock_gettime_xnu;
|
||
} else if (IsWindows()) {
|
||
isfast = true;
|
||
res = sys_clock_gettime_nt;
|
||
} else {
|
||
isfast = false;
|
||
res = sys_clock_gettime;
|
||
}
|
||
if (opt_out_isfast) {
|
||
*opt_out_isfast = isfast;
|
||
}
|
||
return res;
|
||
}
|
||
|
||
hidden int __clock_gettime_init(int clockid, struct timespec *ts) {
|
||
clock_gettime_f *gettime;
|
||
__clock_gettime = gettime = __clock_gettime_get(0);
|
||
return gettime(clockid, ts);
|
||
}
|