mirror of
https://github.com/jart/cosmopolitan.git
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101 lines
3.7 KiB
C
101 lines
3.7 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│ vi: set et 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/atomic.h"
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#include "libc/calls/state.internal.h"
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#include "libc/cosmo.h"
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#include "libc/dce.h"
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#include "libc/errno.h"
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#include "libc/intrin/atomic.h"
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#include "libc/intrin/dll.h"
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#include "libc/intrin/strace.h"
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#include "libc/macros.h"
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#include "libc/proc/proc.internal.h"
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#include "libc/runtime/runtime.h"
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#include "libc/str/str.h"
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#include "libc/thread/posixthread.internal.h"
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#include "libc/thread/thread.h"
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#include "libc/thread/tls.h"
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struct AtFork {
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struct AtFork *p[2];
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atfork_f f[3];
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};
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static struct AtForks {
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pthread_spinlock_t lock;
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struct AtFork *list;
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struct AtFork pool[64];
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atomic_int allocated;
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} _atforks;
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static void _pthread_onfork(int i, const char *op) {
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struct AtFork *a;
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if (!i)
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pthread_spin_lock(&_atforks.lock);
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for (a = _atforks.list; a; a = a->p[!i]) {
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if (a->f[i]) {
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STRACE("pthread_atfork(%s, %t)", op, a->f[i]);
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a->f[i]();
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}
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_atforks.list = a;
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}
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if (i)
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pthread_spin_unlock(&_atforks.lock);
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}
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void _pthread_onfork_prepare(void) {
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_pthread_onfork(0, "prepare");
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}
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void _pthread_onfork_parent(void) {
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_pthread_onfork(1, "parent");
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}
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void _pthread_onfork_child(void) {
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_pthread_onfork(2, "child");
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}
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static struct AtFork *_pthread_atfork_alloc(void) {
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int i, n = ARRAYLEN(_atforks.pool);
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if (atomic_load_explicit(&_atforks.allocated, memory_order_relaxed) < n &&
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(i = atomic_fetch_add(&_atforks.allocated, 1)) < n) {
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return _atforks.pool + i;
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} else {
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return 0;
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}
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}
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int _pthread_atfork(atfork_f prepare, atfork_f parent, atfork_f child) {
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int rc;
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struct AtFork *a;
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if (!(a = _pthread_atfork_alloc()))
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return ENOMEM;
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a->f[0] = prepare;
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a->f[1] = parent;
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a->f[2] = child;
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pthread_spin_lock(&_atforks.lock);
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a->p[0] = 0;
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a->p[1] = _atforks.list;
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if (_atforks.list)
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_atforks.list->p[0] = a;
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_atforks.list = a;
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pthread_spin_unlock(&_atforks.lock);
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rc = 0;
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return rc;
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}
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