1 /* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
4 * We are making the OpenFlow specification and associated documentation
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14 * permit persons to whom the Software is furnished to do so, subject to
15 * the following conditions:
17 * The above copyright notice and this permission notice shall be
18 * included in all copies or substantial portions of the Software.
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22 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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34 #include "poll-loop.h"
41 #define THIS_MODULE VLM_poll_loop
48 struct pollfd *pollfd;
52 poll_fd_func *function;
56 static struct list waiters = LIST_INITIALIZER(&waiters);
57 static size_t n_waiters;
58 static int timeout = -1;
61 static struct poll_waiter *running_cb;
64 static struct poll_waiter *
65 new_waiter(int fd, short int events)
67 struct poll_waiter *waiter = xcalloc(1, sizeof *waiter);
70 waiter->events = events;
71 list_push_back(&waiters, &waiter->node);
77 poll_fd_callback(int fd, short int events, poll_fd_func *function, void *aux)
79 struct poll_waiter *pw = new_waiter(fd, events);
80 pw->function = function;
86 poll_fd_wait(int fd, short int events, short int *revents)
88 struct poll_waiter *pw = new_waiter(fd, events);
89 pw->revents = revents;
97 poll_cancel(struct poll_waiter *pw)
100 assert(pw != running_cb);
101 list_remove(&pw->node);
107 poll_immediate_wake(void)
113 poll_timer_wait(int msec)
115 if (timeout < 0 || msec < timeout) {
116 timeout = MAX(0, msec);
123 static struct pollfd *pollfds;
124 static size_t max_pollfds;
126 struct poll_waiter *pw;
132 if (max_pollfds < n_waiters) {
133 max_pollfds = n_waiters;
134 pollfds = xrealloc(pollfds, max_pollfds * sizeof *pollfds);
138 LIST_FOR_EACH (pw, struct poll_waiter, node, &waiters) {
139 pw->pollfd = &pollfds[n_pollfds];
140 pollfds[n_pollfds].fd = pw->fd;
141 pollfds[n_pollfds].events = pw->events;
142 pollfds[n_pollfds].revents = 0;
147 retval = poll(pollfds, n_pollfds, timeout);
148 } while (retval < 0 && errno == EINTR);
150 VLOG_ERR("poll: %s", strerror(errno));
153 for (node = waiters.next; node != &waiters; ) {
154 pw = CONTAINER_OF(node, struct poll_waiter, node);
155 if (!pw->pollfd || !pw->pollfd->revents) {
165 pw->function(pw->fd, pw->pollfd->revents, pw->aux);
169 } else if (pw->revents) {
170 *pw->revents = pw->pollfd->revents;
173 node = list_remove(node);