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/*
* Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* 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. */
#ifndef POLL_LOOP_H
#define POLL_LOOP_H 1
#include <poll.h>
#include "util.h"
#ifdef __cplusplus
extern "C" {
#endif
struct poll_waiter;
/* Schedule events to wake up the following poll_block().
*
* The poll_loop logs the 'where' argument to each function at "debug" level
* when an event causes a wakeup. Ordinarily, it is automatically filled in
* with the location in the source of the call, and caller should therefore
* omit it. But, if the function you are implementing is very generic, so that
* its location in the source would not be very helpful for debugging, you can
* avoid the macro expansion and pass a different argument, e.g.:
* (poll_fd_wait)(fd, events, where);
* See timer_wait() for an example.
*/
struct poll_waiter *poll_fd_wait(int fd, short int events, const char *where);
#define poll_fd_wait(fd, events) poll_fd_wait(fd, events, SOURCE_LOCATOR)
void poll_timer_wait(long long int msec, const char *where);
#define poll_timer_wait(msec) poll_timer_wait(msec, SOURCE_LOCATOR)
void poll_timer_wait_until(long long int msec, const char *where);
#define poll_timer_wait_until(msec) poll_timer_wait_until(msec, SOURCE_LOCATOR)
void poll_immediate_wake(const char *where);
#define poll_immediate_wake() poll_immediate_wake(SOURCE_LOCATOR)
/* Wait until an event occurs. */
void poll_block(void);
/* Cancel a file descriptor callback or event. */
void poll_cancel(struct poll_waiter *);
#ifdef __cplusplus
}
#endif
#endif /* poll-loop.h */
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