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/*
* Copyright (c) 2008 Nicira Networks.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* High-level wrapper around the "poll" system call.
*
* Intended usage is for the program's main loop to go about its business
* servicing whatever events it needs to. Then, when it runs out of immediate
* tasks, it calls each subordinate module's "wait" function, which in turn
* calls one (or more) of the functions poll_fd_wait(), poll_immediate_wake(),
* and poll_timer_wait() to register to be awakened when the appropriate event
* occurs. Then the main loop calls poll_block(), which blocks until one of
* the registered events happens.
*
* There is also some support for autonomous subroutines that are executed by
* poll_block() when a file descriptor becomes ready. To prevent these
* routines from starving if events are continuously ready, the application
* should bound the amount of work it does between poll_block() calls. */
#ifndef POLL_LOOP_H
#define POLL_LOOP_H 1
#include <poll.h>
struct poll_waiter;
/* Schedule events to wake up the following poll_block(). */
struct poll_waiter *poll_fd_wait(int fd, short int events);
void poll_timer_wait(int msec);
void poll_immediate_wake(void);
/* Wait until an event occurs. */
void poll_block(void);
/* Autonomous function callbacks. */
typedef void poll_fd_func(int fd, short int revents, void *aux);
struct poll_waiter *poll_fd_callback(int fd, short int events,
poll_fd_func *, void *aux);
/* Cancel a file descriptor callback or event. */
void poll_cancel(struct poll_waiter *);
#endif /* poll-loop.h */
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