cosmopolitan/libc/calls/growfds.c

47 lines
2.5 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 │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/bits/weaken.h"
#include "libc/calls/internal.h"
#include "libc/mem/mem.h"
#include "libc/sysv/errfuns.h"
int __ensurefds(int fd) {
size_t i, n;
struct Fd *p;
if (fd < g_fds.n) return fd;
if (weaken(realloc)) {
if ((p = weaken(realloc)(
g_fds.p != g_fds.__init_p ? g_fds.p : NULL,
(n = MAX(fd + 1, (i = g_fds.n) << 1)) * sizeof(*p)))) {
do {
p[i++].kind = kFdEmpty;
} while (i < n);
g_fds.p = p;
g_fds.n = n;
return fd;
} else {
return enomem();
}
} else {
return emfile();
}
}