cosmopolitan/libc/calls/select.c
2024-10-07 15:29:53 -07:00

53 lines
3.1 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et 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/sock/select.h"
#include "libc/calls/struct/timeval.h"
/**
* Checks status on multiple file descriptors at once.
*
* @param readfds may be used to be notified when you can call read() on
* a file descriptor without it blocking; this includes when data is
* is available to be read as well as eof and error conditions
* @param writefds may be used to be notified when write() may be called
* on a file descriptor without it blocking
* @param exceptfds may be used to be notified of exceptional conditions
* such as out-of-band data on a socket; it is equivalent to POLLPRI
* in the revents of poll()
* @param timeout may be null which means to block indefinitely; cosmo's
* implementation of select() never modifies this parameter
* @raise E2BIG if we exceeded the 64 socket limit on Windows
* @raise ECANCELED if thread was cancelled in masked mode
* @raise EINTR if signal was delivered
* @cancelationpoint
* @asyncsignalsafe
* @norestart
*/
int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
struct timeval *timeout) {
struct timespec ts;
struct timespec *tsp;
if (timeout) {
ts = timeval_totimespec(*timeout);
tsp = &ts;
} else {
tsp = 0;
}
return pselect(nfds, readfds, writefds, exceptfds, tsp, 0);
}