cosmopolitan/libc/sock/select.c
Justine Tunney f0701d2a24 Make improvements
- Polyfill pselect() on Windows
- Add -O NOFILE flag to pledge.com
- Polyfill ppoll() on NetBSD, XNU, and Windows
- Support negative numbers and errno in sizetol()
- Add .RSS, .NOFILE, and .MAXCORE to Landlock Make
- Fix issue with .PLEDGE preventing touching of output files
- Add __watch() function (like ftrace) for logging memory changes
2022-08-15 15:20:36 -07:00

56 lines
3.2 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/calls/strace.internal.h"
#include "libc/calls/struct/timeval.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/sock/internal.h"
#include "libc/sock/select.h"
#include "libc/sysv/errfuns.h"
/**
* Does what poll() does except with bitset API.
*
* This system call is supported on all platforms. However, on Windows,
* this is polyfilled to translate into poll(). So it's recommended that
* poll() be used instead.
*/
int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
struct timeval *timeout) {
int rc;
POLLTRACE("select(%d, %p, %p, %p, %s) → ...", nfds, readfds, writefds,
exceptfds, DescribeTimeval(0, timeout));
if (nfds < 0) {
rc = einval();
} else if (IsAsan() &&
((readfds && !__asan_is_valid(readfds, FD_SIZE(nfds))) ||
(writefds && !__asan_is_valid(writefds, FD_SIZE(nfds))) ||
(exceptfds && !__asan_is_valid(exceptfds, FD_SIZE(nfds))) ||
(timeout && !__asan_is_valid(timeout, sizeof(*timeout))))) {
rc = efault();
} else if (!IsWindows()) {
rc = sys_select(nfds, readfds, writefds, exceptfds, timeout);
} else {
rc = sys_select_nt(nfds, readfds, writefds, exceptfds, timeout, 0);
}
POLLTRACE("select(%d, %p, %p, %p, [%s]) → %d% m", nfds, readfds, writefds,
exceptfds, DescribeTimeval(rc, timeout), rc);
return rc;
}