mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-01 03:53:33 +00:00
9849b4c7ba
This change also fixes the clock_nanosleep() api and polyfills futexes on Windows, Mac, and NetBSD using exponential backoff.
67 lines
3.4 KiB
C
67 lines
3.4 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/errno.h"
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#include "libc/intrin/atomic.h"
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#include "libc/macros.internal.h"
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#include "libc/mem/mem.h"
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#include "libc/thread/posixthread.internal.h"
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#include "libc/thread/spawn.h"
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#include "libc/thread/thread.h"
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/**
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* Asks POSIX thread to free itself automatically on termination.
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*
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* @return 0 on success, or errno with error
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* @raise EINVAL if thread is null or already detached
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* @returnserrno
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* @threadsafe
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*/
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int pthread_detach(pthread_t thread) {
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struct PosixThread *pt;
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enum PosixThreadStatus status;
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if (!(pt = (struct PosixThread *)thread)) {
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return EINVAL;
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}
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for (;;) {
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status = atomic_load_explicit(&pt->status, memory_order_acquire);
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if (status == kPosixThreadDetached || status == kPosixThreadZombie) {
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// these two states indicate the thread was already detached, in
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// which case it's already listed under _pthread_zombies.
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return EINVAL;
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} else if (status == kPosixThreadTerminated) {
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// thread was joinable and finished running. since pthread_join
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// won't be called, it's safe to free the thread resources now.
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// POSIX says this could be reported as ESRCH but then our test
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// code would be less elegant in order for it to avoid flaking.
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_pthread_wait(pt);
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_pthread_free(pt);
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break;
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} else if (status == kPosixThreadJoinable) {
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if (atomic_compare_exchange_weak_explicit(
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&pt->status, &status, kPosixThreadDetached, memory_order_release,
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memory_order_relaxed)) {
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_pthread_zombies_add(pt);
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break;
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}
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} else {
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notpossible;
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}
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}
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return 0;
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}
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