82 lines
2.3 KiB
C
82 lines
2.3 KiB
C
/* Copyright (C) 1994, 1996, 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <sys/poll.h>
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#include <sys/types.h>
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#include <errno.h>
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#include <string.h>
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#include <sys/time.h>
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/* Poll the file descriptors described by the NFDS structures starting at
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FDS. If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
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an event to occur; if TIMEOUT is -1, block until an event occurs.
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Returns the number of file descriptors with events, zero if timed out,
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or -1 for errors. */
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int
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poll (fds, nfds, timeout)
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struct pollfd *fds;
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unsigned long int nfds;
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int timeout;
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{
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struct timeval tv;
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fd_set rset, wset, xset;
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struct pollfd *f;
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int ready;
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int maxfd = 0;
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FD_ZERO (&rset);
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FD_ZERO (&wset);
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FD_ZERO (&xset);
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for (f = fds; f < &fds[nfds]; ++f)
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if (f->fd >= 0)
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{
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if (f->events & POLLIN)
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FD_SET (f->fd, &rset);
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if (f->events & POLLOUT)
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FD_SET (f->fd, &wset);
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if (f->events & POLLPRI)
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FD_SET (f->fd, &xset);
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if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI)))
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maxfd = f->fd;
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}
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tv.tv_sec = timeout / 1000;
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tv.tv_usec = (timeout % 1000) * 1000;
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ready = __select (maxfd + 1, &rset, &wset, &xset,
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timeout == -1 ? NULL : &tv);
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if (ready > 0)
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for (f = fds; f < &fds[nfds]; ++f)
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{
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f->revents = 0;
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if (f->fd >= 0)
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{
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if (FD_ISSET (f->fd, &rset))
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f->revents |= POLLIN;
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if (FD_ISSET (f->fd, &wset))
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f->revents |= POLLOUT;
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if (FD_ISSET (f->fd, &xset))
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f->revents |= POLLPRI;
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}
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}
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return ready;
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}
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