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/*
* poll.c
*
* Copyright (c) 1997-8 Graham Barr <gbarr@pobox.com>. All rights reserved.
* This program is free software; you can redistribute it and/or
* modify it under the same terms as Perl itself.
*
* For systems that do not have the poll() system call (for example Linux
* kernels < v2.1.23) try to emulate it as closely as possible using select()
*
*/
#include "EXTERN.h"
#include "perl.h"
#include "poll.h"
#ifdef I_SYS_TIME
# include <sys/time.h>
#endif
#ifdef I_TIME
# include <time.h>
#endif
#include <sys/types.h>
#if defined(HAS_SOCKET) && !defined(VMS) /* VMS handles sockets via vmsish.h */
# include <sys/socket.h>
#endif
#include <sys/stat.h>
#include <errno.h>
#ifdef HAS_SELECT
#ifdef I_SYS_SELECT
#include <sys/select.h>
#endif
#endif
#ifdef EMULATE_POLL_WITH_SELECT
# define POLL_CAN_READ (POLLIN | POLLRDNORM )
# define POLL_CAN_WRITE (POLLOUT | POLLWRNORM | POLLWRBAND )
# define POLL_HAS_EXCP (POLLRDBAND | POLLPRI )
# define POLL_EVENTS_MASK (POLL_CAN_READ | POLL_CAN_WRITE | POLL_HAS_EXCP)
int
poll(struct pollfd *fds, unsigned long nfds, int timeout)
{
int i,err;
fd_set rfd,wfd,efd,ifd;
struct timeval timebuf;
struct timeval *tbuf = (struct timeval *)0;
int n = 0;
int count;
FD_ZERO(&ifd);
again:
FD_ZERO(&rfd);
FD_ZERO(&wfd);
FD_ZERO(&efd);
for(i = 0 ; i < nfds ; i++) {
int events = fds[i].events;
int fd = fds[i].fd;
fds[i].revents = 0;
if(fd < 0 || FD_ISSET(fd, &ifd))
continue;
if(fd > n)
n = fd;
if(events & POLL_CAN_READ)
FD_SET(fd, &rfd);
if(events & POLL_CAN_WRITE)
FD_SET(fd, &wfd);
if(events & POLL_HAS_EXCP)
FD_SET(fd, &efd);
}
if(timeout >= 0) {
timebuf.tv_sec = timeout / 1000;
timebuf.tv_usec = (timeout % 1000) * 1000;
tbuf = &timebuf;
}
err = select(n+1,&rfd,&wfd,&efd,tbuf);
if(err < 0) {
#ifdef HAS_FSTAT
if(errno == EBADF) {
for(i = 0 ; i < nfds ; i++) {
struct stat buf;
if((fstat(fds[i].fd,&buf) < 0) && (errno == EBADF)) {
FD_SET(fds[i].fd, &ifd);
goto again;
}
}
}
#endif /* HAS_FSTAT */
return err;
}
count = 0;
for(i = 0 ; i < nfds ; i++) {
int revents = (fds[i].events & POLL_EVENTS_MASK);
int fd = fds[i].fd;
if(fd < 0)
continue;
if(FD_ISSET(fd, &ifd))
revents = POLLNVAL;
else {
if(!FD_ISSET(fd, &rfd))
revents &= ~POLL_CAN_READ;
if(!FD_ISSET(fd, &wfd))
revents &= ~POLL_CAN_WRITE;
if(!FD_ISSET(fd, &efd))
revents &= ~POLL_HAS_EXCP;
}
if((fds[i].revents = revents) != 0)
count++;
}
return count;
}
#endif /* EMULATE_POLL_WITH_SELECT */
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