From 9acb9eb162ab31ca7d23350c508b207a775da79f Mon Sep 17 00:00:00 2001 From: Seonah Moon Date: Thu, 7 Apr 2016 14:01:07 +0900 Subject: Update to 2.74 Change-Id: Ic7e94612466be7786c3d2b0724d745c7720e01c9 Signed-off-by: Seonah Moon --- src/poll.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 src/poll.c (limited to 'src/poll.c') diff --git a/src/poll.c b/src/poll.c new file mode 100644 index 0000000..d71b1b9 --- /dev/null +++ b/src/poll.c @@ -0,0 +1,125 @@ +/* dnsmasq is Copyright (c) 2000-2015 Simon Kelley + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 dated June, 1991, or + (at your option) version 3 dated 29 June, 2007. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +*/ + +#include "dnsmasq.h" + +/* Wrapper for poll(). Allocates and extends array of struct pollfds, + keeps them in fd order so that we can set and test conditions on + fd using a simple but efficient binary chop. */ + +/* poll_reset() + poll_listen(fd, event) + . + . + poll_listen(fd, event); + + hits = do_poll(timeout); + + if (poll_check(fd, event) + . + . + + if (poll_check(fd, event) + . + . + + event is OR of POLLIN, POLLOUT, POLLERR, etc +*/ + +static struct pollfd *pollfds = NULL; +static nfds_t nfds, arrsize = 0; + +/* Binary search. Returns either the pollfd with fd, or + if the fd doesn't match, or return equals nfds, the entry + to the left of which a new record should be inserted. */ +static nfds_t fd_search(int fd) +{ + nfds_t left, right, mid; + + if ((right = nfds) == 0) + return 0; + + left = 0; + + while (1) + { + if (right == left + 1) + return (pollfds[left].fd >= fd) ? left : right; + + mid = (left + right)/2; + + if (pollfds[mid].fd > fd) + right = mid; + else + left = mid; + } +} + +void poll_reset(void) +{ + nfds = 0; +} + +int do_poll(int timeout) +{ + return poll(pollfds, nfds, timeout); +} + +int poll_check(int fd, short event) +{ + nfds_t i = fd_search(fd); + + if (i < nfds && pollfds[i].fd == fd) + return pollfds[i].revents & event; + + return 0; +} + +void poll_listen(int fd, short event) +{ + nfds_t i = fd_search(fd); + + if (i < nfds && pollfds[i].fd == fd) + pollfds[i].events |= event; + else + { + if (arrsize != nfds) + memmove(&pollfds[i+1], &pollfds[i], (nfds - i) * sizeof(struct pollfd)); + else + { + /* Array too small, extend. */ + struct pollfd *new; + + arrsize = (arrsize == 0) ? 64 : arrsize * 2; + + if (!(new = whine_malloc(arrsize * sizeof(struct pollfd)))) + return; + + if (pollfds) + { + memcpy(new, pollfds, i * sizeof(struct pollfd)); + memcpy(&new[i+1], &pollfds[i], (nfds - i) * sizeof(struct pollfd)); + free(pollfds); + } + + pollfds = new; + } + + pollfds[i].fd = fd; + pollfds[i].events = event; + nfds++; + } +} -- cgit v1.2.3