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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <errno.h>
#include <stdio.h>
#include <sys/poll.h>
#include <sys/select.h>
#include <sys/time.h>
#include <syscall.h>
#include <AK/Vector.h>
extern "C" {
// https://pubs.opengroup.org/onlinepubs/9699919799/functions/select.html
int select(int nfds, fd_set* readfds, fd_set* writefds, fd_set* exceptfds, timeval* timeout_tv)
{
timespec* timeout_ts = nullptr;
timespec timeout;
if (timeout_tv) {
timeout_ts = &timeout;
TIMEVAL_TO_TIMESPEC(timeout_tv, timeout_ts);
}
return pselect(nfds, readfds, writefds, exceptfds, timeout_ts, nullptr);
}
// https://pubs.opengroup.org/onlinepubs/9699919799/functions/pselect.html
int pselect(int nfds, fd_set* readfds, fd_set* writefds, fd_set* exceptfds, const timespec* timeout, const sigset_t* sigmask)
{
Vector<pollfd, FD_SETSIZE> fds;
if (nfds < 0 || static_cast<size_t>(nfds) >= fds.capacity())
return EINVAL;
for (int fd = 0; fd < nfds; fd++) {
short events = 0;
if (readfds && FD_ISSET(fd, readfds))
events |= POLLIN;
if (writefds && FD_ISSET(fd, writefds))
events |= POLLOUT;
if (exceptfds && FD_ISSET(fd, exceptfds))
events |= POLLPRI;
if (!events)
continue;
fds.unchecked_append({ fd, events, 0 });
}
if (ppoll(fds.data(), fds.size(), timeout, sigmask) < 0)
return -1;
if (readfds)
FD_ZERO(readfds);
if (writefds)
FD_ZERO(writefds);
if (exceptfds)
FD_ZERO(exceptfds);
int marked_fd_count = 0;
for (auto& fd_entry : fds) {
if (fd_entry.revents == 0)
continue;
if (readfds && (fd_entry.revents & POLLIN)) {
FD_SET(fd_entry.fd, readfds);
marked_fd_count++;
}
if (writefds && (fd_entry.revents & POLLOUT)) {
FD_SET(fd_entry.fd, writefds);
marked_fd_count++;
}
if (exceptfds && (fd_entry.revents & (POLLPRI | POLLERR | POLLHUP))) {
FD_SET(fd_entry.fd, exceptfds);
marked_fd_count++;
}
}
return marked_fd_count;
}
}
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