libvirt/src/util/vireventpoll.h
Jonathon Jongsma 2ad45811e2 util: misc: use #pragma once in headers
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2019-06-19 17:12:33 +02:00

127 lines
3.7 KiB
C

/*
* vireventpoll.h: Poll based event loop for monitoring file handles
*
* Copyright (C) 2007 Daniel P. Berrange
* Copyright (C) 2007 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "internal.h"
/**
* virEventPollAddHandle: register a callback for monitoring file handle events
*
* @fd: file handle to monitor for events
* @events: bitset of events to watch from POLLnnn constants
* @cb: callback to invoke when an event occurs
* @opaque: user data to pass to callback
*
* returns -1 if the file handle cannot be registered, 0 upon success
*/
int virEventPollAddHandle(int fd, int events,
virEventHandleCallback cb,
void *opaque,
virFreeCallback ff);
/**
* virEventPollUpdateHandle: change event set for a monitored file handle
*
* @watch: watch whose handle to update
* @events: bitset of events to watch from POLLnnn constants
*
* Will not fail if fd exists
*/
void virEventPollUpdateHandle(int watch, int events);
/**
* virEventPollRemoveHandle: unregister a callback from a file handle
*
* @watch: watch whose handle to remove
*
* returns -1 if the file handle was not registered, 0 upon success
*/
int virEventPollRemoveHandle(int watch);
/**
* virEventPollAddTimeout: register a callback for a timer event
*
* @frequency: time between events in milliseconds
* @cb: callback to invoke when an event occurs
* @opaque: user data to pass to callback
*
* Setting frequency to -1 will disable the timer. Setting the frequency
* to zero will cause it to fire on every event loop iteration.
*
* returns -1 if the file handle cannot be registered, a positive
* integer timer id upon success
*/
int virEventPollAddTimeout(int frequency,
virEventTimeoutCallback cb,
void *opaque,
virFreeCallback ff);
/**
* virEventPollUpdateTimeout: change frequency for a timer
*
* @timer: timer id to change
* @frequency: time between events in milliseconds
*
* Setting frequency to -1 will disable the timer. Setting the frequency
* to zero will cause it to fire on every event loop iteration.
*
* Will not fail if timer exists
*/
void virEventPollUpdateTimeout(int timer, int frequency);
/**
* virEventPollRemoveTimeout: unregister a callback for a timer
*
* @timer: the timer id to remove
*
* returns -1 if the timer was not registered, 0 upon success
*/
int virEventPollRemoveTimeout(int timer);
/**
* virEventPollInit: Initialize the event loop
*
* returns -1 if initialization failed
*/
int virEventPollInit(void);
/**
* virEventPollRunOnce: run a single iteration of the event loop.
*
* Blocks the caller until at least one file handle has an
* event or the first timer expires.
*
* returns -1 if the event monitoring failed
*/
int virEventPollRunOnce(void);
int virEventPollFromNativeEvents(int events);
int virEventPollToNativeEvents(int events);
/**
* virEventPollInterrupt: wakeup any thread waiting in poll()
*
* return -1 if wakeup failed
*/
int virEventPollInterrupt(void);