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/*
* Copyright (c) 2008, 2009, 2010, 2011, 2013 Nicira, Inc.
*
* 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.
*
* The intended usage is for each thread'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.
*
*
* Thread-safety
* =============
*
* The poll set is per-thread, so all functions in this module are thread-safe.
*/
#ifndef POLL_LOOP_H
#define POLL_LOOP_H 1
#include <poll.h>
#include "util.h"
#ifdef __cplusplus
extern "C" {
#endif
/* 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. Each of these ways to schedule an event has
* a function and a macro wrapper. The macro version automatically supplies
* the source code location of the caller. The function version allows the
* caller to supply a location explicitly, which is useful if the caller's own
* caller would be more useful in log output. See timer_wait_at() for an
* example. */
void poll_fd_wait_at(int fd, HANDLE wevent, short int events, const char *where);
#ifndef _WIN32
#define poll_fd_wait(fd, events) poll_fd_wait_at(fd, 0, events, SOURCE_LOCATOR)
#endif
#define poll_fd_wait_event(fd, wevent, events) \
poll_fd_wait_at(fd, wevent, events, SOURCE_LOCATOR)
void poll_timer_wait_at(long long int msec, const char *where);
#define poll_timer_wait(msec) poll_timer_wait_at(msec, SOURCE_LOCATOR)
void poll_timer_wait_until_at(long long int msec, const char *where);
#define poll_timer_wait_until(msec) \
poll_timer_wait_until_at(msec, SOURCE_LOCATOR)
void poll_immediate_wake_at(const char *where);
#define poll_immediate_wake() poll_immediate_wake_at(SOURCE_LOCATOR)
/* Wait until an event occurs. */
void poll_block(void);
#ifdef __cplusplus
}
#endif
#endif /* poll-loop.h */
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