mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
128 lines
4.1 KiB
C
128 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 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/bits/weaken.h"
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#include "libc/calls/calls.h"
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#include "libc/calls/internal.h"
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#include "libc/calls/strace.internal.h"
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#include "libc/intrin/kprintf.h"
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#include "libc/intrin/spinlock.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/runtime/runtime.h"
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#include "libc/str/str.h"
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#include "libc/sysv/errfuns.h"
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/**
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* Grows file descriptor array memory if needed.
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*/
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int __ensurefds_unlocked(int fd) {
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size_t n1, n2;
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struct Fd *p1, *p2;
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n1 = g_fds.n;
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if (fd >= n1) {
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STRACE("__ensurefds(%d) extending", fd);
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if (weaken(malloc)) {
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// TODO(jart): we need a semaphore for this
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p1 = g_fds.p;
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n2 = fd + (fd >> 1);
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if ((p2 = weaken(malloc)(n2 * sizeof(*p1)))) {
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memcpy(p2, p1, n1 * sizeof(*p1));
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g_fds.p = p2;
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g_fds.n = n2;
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if (p1 != g_fds.__init_p) {
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__cxa_atexit(free, p1, 0);
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}
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} else {
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fd = enomem();
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}
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} else {
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fd = emfile();
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}
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}
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return fd;
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}
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/**
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* Grows file descriptor array memory if needed.
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*/
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int __ensurefds(int fd) {
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_spinlock(&__fds_lock);
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fd = __ensurefds_unlocked(fd);
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_spunlock(&__fds_lock);
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return fd;
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}
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/**
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* Finds open file descriptor slot.
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*/
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int __reservefd_unlocked(int start) {
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int fd;
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for (fd = g_fds.f; fd < g_fds.n; ++fd) {
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if (!g_fds.p[fd].kind) {
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break;
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}
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}
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fd = __ensurefds_unlocked(fd);
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bzero(g_fds.p + fd, sizeof(*g_fds.p));
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g_fds.p[fd].kind = kFdReserved;
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return fd;
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}
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/**
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* Finds open file descriptor slot.
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*/
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int __reservefd(int start) {
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int fd;
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_spinlock(&__fds_lock);
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fd = __reservefd_unlocked(start);
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_spunlock(&__fds_lock);
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return fd;
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}
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/**
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* Closes non-stdio file descriptors to free dynamic memory.
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*/
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static void FreeFds(void) {
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int i;
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NTTRACE("FreeFds()");
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_spinlock(&__fds_lock);
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for (i = 3; i < g_fds.n; ++i) {
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if (g_fds.p[i].kind) {
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_spunlock(&__fds_lock);
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close(i);
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_spinlock(&__fds_lock);
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}
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}
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if (g_fds.p != g_fds.__init_p) {
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memcpy(g_fds.__init_p, g_fds.p, sizeof(*g_fds.p) * 3);
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weaken(free)(g_fds.p);
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g_fds.p = g_fds.__init_p;
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g_fds.n = ARRAYLEN(g_fds.__init_p);
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}
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_spunlock(&__fds_lock);
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}
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static textstartup void FreeFdsInit(void) {
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atexit(FreeFds);
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}
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const void *const FreeFdsCtor[] initarray = {
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FreeFdsInit,
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};
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