cosmopolitan/libc/calls/ensurefds.c
Justine Tunney 4e56d89dcd Eliminate some flakes
- Get ASAN working on Windows.

- Deleting directories and then recreating them with the same name in a
  short period of time appears to be a no-no on Windows.

- There's no reason to call FlushFileBuffers on close() for pipes, and
  it's harmful since it might block indefinitely for no good reason.
2021-02-03 06:25:27 -08:00

53 lines
2.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/bits/bits.h"
#include "libc/bits/weaken.h"
#include "libc/calls/internal.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
int __ensurefds(int fd) {
size_t n1, n2;
struct Fd *p1, *p2;
for (;;) {
p1 = g_fds.p;
n1 = g_fds.n;
if (fd < n1) return fd;
if (weaken(malloc)) {
n2 = MAX(fd + 1, n1 + (n1 << 1));
if ((p2 = weaken(malloc)(n2 * sizeof(*p1)))) {
memcpy(p2, p1, n1 * sizeof(*p1));
memset(p2 + n1, 0, (n2 - n1) * sizeof(*p1));
if (p1 != g_fds.__init_p && weaken(free)) weaken(free)(p1);
if (cmpxchg(&g_fds.p, p1, p2)) {
g_fds.n = n2;
return fd;
} else if (weaken(free)) {
weaken(free)(p2);
}
} else {
return enomem();
}
} else {
return emfile();
}
}
}