cosmopolitan/libc/calls/now.c
Justine Tunney 072e1d2910 Make signal handling work well across platforms
- Fix sigsuspend() on XNU
- Fix strsignal() on non-Linux
- Add unit tests for strsignal()
- Add unit tests for setitimer()
- Add unit tests for sigsuspend()
- Rewrite setitimer() for New Technology
- Rewrite nanosleep() for New Technology
- Polyfill SIGALRM on the New Technology
- select(0,0,0,0) on NT now calls pause()
- Remove some NTDLL calls that aren't needed
- Polyfill SA_NOCLDWAIT on the New Technology
- Polyfill SA_RESETHAND on the New Technology
- Polyfill sigprocmask() on the New Technology
- Polyfill SIGCHLD+SIG_IGN on the New Technology
- Polyfill SA_RESTART masking on the New Technology
- Deliver console signals from main thread on New Technology
- Document SA_RESTART behavior w/ @sarestartable / @norestart
- System call trace in MODE=dbg now prints inherited FDs and signal mask
2022-03-25 07:28:57 -07:00

94 lines
3.6 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 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/bits/bits.h"
#include "libc/bits/initializer.internal.h"
#include "libc/bits/safemacros.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/strace.internal.h"
#include "libc/dce.h"
#include "libc/macros.internal.h"
#include "libc/nexgen32e/rdtsc.h"
#include "libc/nexgen32e/x86feature.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/clock.h"
#include "libc/time/time.h"
static struct Now {
bool once;
uint64_t k0;
long double r0, cpn;
} g_now;
static long double GetTimeSample(void) {
uint64_t tick1, tick2;
long double time1, time2;
sched_yield();
time1 = dtime(CLOCK_REALTIME);
tick1 = rdtsc();
nanosleep(&(struct timespec){0, 1000000}, NULL);
time2 = dtime(CLOCK_REALTIME);
tick2 = rdtsc();
return (time2 - time1) * 1e9 / MAX(1, tick2 - tick1);
}
static long double MeasureNanosPerCycle(void) {
bool tc;
int i, n;
long double avg, samp;
tc = __time_critical;
__time_critical = true;
if (IsWindows()) {
n = 10;
} else {
n = 5;
}
for (avg = 1.0L, i = 1; i < n; ++i) {
samp = GetTimeSample();
avg += (samp - avg) / i;
}
__time_critical = tc;
STRACE("MeasureNanosPerCycle cpn*1000=%d", (long)(avg * 1000));
return avg;
}
void RefreshTime(void) {
struct Now now;
now.cpn = MeasureNanosPerCycle();
now.r0 = dtime(CLOCK_REALTIME);
now.k0 = rdtsc();
now.once = true;
memcpy(&g_now, &now, sizeof(now));
}
long double ConvertTicksToNanos(uint64_t ticks) {
if (!g_now.once) RefreshTime();
return ticks * g_now.cpn; /* pico scale */
}
long double nowl_sys(void) {
return dtime(CLOCK_REALTIME);
}
long double nowl_art(void) {
uint64_t ticks;
if (!g_now.once) RefreshTime();
ticks = unsignedsubtract(rdtsc(), g_now.k0);
return g_now.r0 + (1 / 1e9L * (ticks * g_now.cpn));
}