mirror of
https://github.com/jart/cosmopolitan.git
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60cb435cb4
If threads are being used, then fork() will now acquire and release and runtime locks so that fork() may be safely used from threads. This also makes vfork() thread safe, because pthread mutexes will do nothing when the process is a child of vfork(). More torture tests have been written to confirm this all works like a charm. Additionally: - Invent hexpcpy() api - Rename nsync_malloc_() to kmalloc() - Complete posix named semaphore implementation - Make pthread_create() asynchronous signal safe - Add rm, rmdir, and touch to command interpreter builtins - Invent sigisprecious() and modify sigset functions to use it - Add unit tests for posix_spawn() attributes and fix its bugs One unresolved problem is the reclaiming of *NSYNC waiter memory in the forked child processes, within apps which have threads waiting on locks
123 lines
5.3 KiB
C
123 lines
5.3 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=8 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/assert.h"
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#include "libc/calls/asan.internal.h"
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#include "libc/calls/clock_gettime.internal.h"
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#include "libc/calls/state.internal.h"
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#include "libc/calls/struct/timespec.internal.h"
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#include "libc/calls/struct/timeval.h"
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#include "libc/calls/syscall_support-sysv.internal.h"
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#include "libc/dce.h"
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#include "libc/fmt/conv.h"
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#include "libc/intrin/asan.internal.h"
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#include "libc/intrin/asmflag.h"
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#include "libc/intrin/bits.h"
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#include "libc/intrin/describeflags.internal.h"
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#include "libc/intrin/strace.internal.h"
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#include "libc/mem/alloca.h"
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#include "libc/nt/synchronization.h"
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#include "libc/sysv/errfuns.h"
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#include "libc/thread/tls.h"
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/**
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* Returns nanosecond time.
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*
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* This is a high-precision timer that supports multiple definitions of
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* time. Among the more popular is CLOCK_MONOTONIC. This function has a
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* zero syscall implementation of that on modern x86.
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*
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* nowl l: 45𝑐 15𝑛𝑠
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* rdtsc l: 13𝑐 4𝑛𝑠
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* gettimeofday l: 44𝑐 14𝑛𝑠
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* clock_gettime l: 40𝑐 13𝑛𝑠
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* __clock_gettime l: 35𝑐 11𝑛𝑠
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* sys_clock_gettime l: 220𝑐 71𝑛𝑠
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*
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* @param clock can be one of:
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* - `CLOCK_REALTIME`: universally supported
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* - `CLOCK_REALTIME_FAST`: ditto but faster on freebsd
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* - `CLOCK_MONOTONIC`: universally supported
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* - `CLOCK_MONOTONIC_FAST`: ditto but faster on freebsd
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* - `CLOCK_MONOTONIC_RAW`: nearly universally supported
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* - `CLOCK_PROCESS_CPUTIME_ID`: linux and bsd
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* - `CLOCK_THREAD_CPUTIME_ID`: linux and bsd
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* - `CLOCK_REALTIME_COARSE`: : linux and openbsd
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* - `CLOCK_MONOTONIC_COARSE`: linux
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* - `CLOCK_PROF`: linux and netbsd
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* - `CLOCK_BOOTTIME`: linux and openbsd
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* - `CLOCK_REALTIME_ALARM`: linux-only
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* - `CLOCK_BOOTTIME_ALARM`: linux-only
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* - `CLOCK_TAI`: linux-only
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* @param ts is where the result is stored
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* @return 0 on success, or -1 w/ errno
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* @error EPERM if pledge() is in play without stdio promise
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* @error EINVAL if `clock` isn't supported on this system
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* @error EFAULT if `ts` points to bad memory
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* @see strftime(), gettimeofday()
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* @asyncsignalsafe
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* @threadsafe
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* @vforksafe
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*/
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int clock_gettime(int clock, struct timespec *ts) {
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int rc;
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if (clock == 127) {
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rc = einval(); // 127 is used by consts.sh to mean unsupported
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} else if (!ts || (IsAsan() && !__asan_is_valid_timespec(ts))) {
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rc = efault();
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} else {
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rc = __clock_gettime(clock, ts);
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}
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#if SYSDEBUG
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if (__tls_enabled && !(__get_tls()->tib_flags & TIB_FLAG_TIME_CRITICAL)) {
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STRACE("clock_gettime(%s, [%s]) → %d% m", DescribeClockName(clock),
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DescribeTimespec(rc, ts), rc);
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}
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#endif
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return rc;
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}
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/**
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* Returns pointer to fastest clock_gettime().
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*/
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clock_gettime_f *__clock_gettime_get(bool *opt_out_isfast) {
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bool isfast;
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clock_gettime_f *res;
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if (IsLinux() && (res = __vdsosym("LINUX_2.6", "__vdso_clock_gettime"))) {
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isfast = true;
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} else if (IsXnu()) {
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isfast = false;
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res = sys_clock_gettime_xnu;
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} else if (IsWindows()) {
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isfast = true;
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res = sys_clock_gettime_nt;
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} else {
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isfast = false;
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res = sys_clock_gettime;
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}
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if (opt_out_isfast) {
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*opt_out_isfast = isfast;
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}
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return res;
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}
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hidden int __clock_gettime_init(int clockid, struct timespec *ts) {
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clock_gettime_f *gettime;
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__clock_gettime = gettime = __clock_gettime_get(0);
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return gettime(clockid, ts);
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}
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