mirror of
https://github.com/jart/cosmopolitan.git
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bcf9af94bf
- Now using 10x better GCD semaphores - We now generate Linux-like thread ids - We now use fast system clock / sleep libraries - The APE M1 loader now generates Linux-like stacks
106 lines
4.1 KiB
C
106 lines
4.1 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=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2022 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/cp.internal.h"
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#include "libc/calls/struct/timespec.internal.h"
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#include "libc/calls/syscall-sysv.internal.h"
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#include "libc/dce.h"
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#include "libc/errno.h"
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#include "libc/intrin/strace.internal.h"
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#include "libc/str/str.h"
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#include "libc/sysv/consts/f.h"
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#include "third_party/nsync/mu_semaphore.h"
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#include "third_party/nsync/time.h"
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// clang-format off
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/**
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* @fileoverview Semaphores w/ POSIX Semaphores API.
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*/
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#define ASSERT(x) _npassert(x)
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struct sem {
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int64_t id;
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};
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static nsync_semaphore *sem_big_enough_for_sem = (nsync_semaphore *) (uintptr_t)(1 /
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(sizeof (struct sem) <= sizeof (*sem_big_enough_for_sem)));
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/* Initialize *s; the initial value is 0. */
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void nsync_mu_semaphore_init_sem (nsync_semaphore *s) {
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int newfd;
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struct sem *f = (struct sem *) s;
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f->id = 0;
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ASSERT (!sys_sem_init (0, &f->id));
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STRACE ("sem_init(0, [%ld]) → 0", f->id);
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ASSERT ((newfd = __sys_fcntl (f->id, F_DUPFD_CLOEXEC, 100)) != -1);
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ASSERT (!sys_sem_destroy (f->id));
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f->id = newfd;
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}
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/* Wait until the count of *s exceeds 0, and decrement it. */
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errno_t nsync_mu_semaphore_p_sem (nsync_semaphore *s) {
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int e, rc;
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errno_t result;
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struct sem *f = (struct sem *) s;
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e = errno;
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BEGIN_CANCELLATION_POINT;
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rc = sys_sem_wait (f->id);
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END_CANCELLATION_POINT;
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STRACE ("sem_wait(%ld) → %d% m", f->id, rc);
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if (!rc) {
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result = 0;
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} else {
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result = errno;
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errno = e;
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ASSERT (result == ECANCELED);
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}
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return result;
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}
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/* Wait until one of:
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the count of *s is non-zero, in which case decrement *s and return 0;
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or abs_deadline expires, in which case return ETIMEDOUT. */
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errno_t nsync_mu_semaphore_p_with_deadline_sem (nsync_semaphore *s, nsync_time abs_deadline) {
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int e, rc;
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errno_t result;
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struct sem *f = (struct sem *) s;
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e = errno;
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BEGIN_CANCELLATION_POINT;
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rc = sys_sem_timedwait (f->id, &abs_deadline);
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END_CANCELLATION_POINT;
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STRACE ("sem_timedwait(%ld, %s) → %d% m", f->id,
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DescribeTimespec(0, &abs_deadline), rc);
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if (!rc) {
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result = 0;
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} else {
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result = errno;
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errno = e;
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ASSERT (result == ETIMEDOUT ||
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result == ECANCELED);
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}
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return result;
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}
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/* Ensure that the count of *s is at least 1. */
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void nsync_mu_semaphore_v_sem (nsync_semaphore *s) {
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struct sem *f = (struct sem *) s;
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ASSERT (!sys_sem_post (f->id));
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STRACE ("sem_post(%ld) → 0% m", f->id);
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}
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