2 * Copyright (c) 2008 Nicira Networks.
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 /* High-level wrapper around the "poll" system call.
19 * Intended usage is for the program's main loop to go about its business
20 * servicing whatever events it needs to. Then, when it runs out of immediate
21 * tasks, it calls each subordinate module's "wait" function, which in turn
22 * calls one (or more) of the functions poll_fd_wait(), poll_immediate_wake(),
23 * and poll_timer_wait() to register to be awakened when the appropriate event
24 * occurs. Then the main loop calls poll_block(), which blocks until one of
25 * the registered events happens.
27 * There is also some support for autonomous subroutines that are executed by
28 * poll_block() when a file descriptor becomes ready. To prevent these
29 * routines from starving if events are continuously ready, the application
30 * should bound the amount of work it does between poll_block() calls. */
39 /* Schedule events to wake up the following poll_block(). */
40 struct poll_waiter *poll_fd_wait(int fd, short int events);
41 void poll_timer_wait(int msec);
42 void poll_immediate_wake(void);
44 /* Wait until an event occurs. */
45 void poll_block(void);
47 /* Autonomous function callbacks. */
48 typedef void poll_fd_func(int fd, short int revents, void *aux);
49 struct poll_waiter *poll_fd_callback(int fd, short int events,
50 poll_fd_func *, void *aux);
52 /* Cancel a file descriptor callback or event. */
53 void poll_cancel(struct poll_waiter *);
55 #endif /* poll-loop.h */