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#ifndef foowatchhfoo
#define foowatchhfoo
/***
This file is part of avahi.
avahi 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.
avahi 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 avahi; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
/** \file watch.h Simplistic main loop abstraction */
#include <sys/poll.h>
#include <sys/time.h>
#include <avahi-common/cdecl.h>
AVAHI_C_DECL_BEGIN
/** An I/O watch object */
typedef struct AvahiWatch AvahiWatch;
/** A timeout watch object */
typedef struct AvahiTimeout AvahiTimeout;
/** An event polling abstraction object */
typedef struct AvahiPoll AvahiPoll;
/** Type of watch events */
typedef enum {
AVAHI_WATCH_IN = POLLIN, /**< Input event */
AVAHI_WATCH_OUT = POLLOUT, /**< Output event */
AVAHI_WATCH_ERR = POLLERR, /**< Error event */
AVAHI_WATCH_HUP = POLLHUP /**< Hangup event */
} AvahiWatchEvent;
/** Called whenever an I/O event happens on an I/O watch */
typedef void (*AvahiWatchCallback)(AvahiWatch *w, int fd, AvahiWatchEvent event, void *userdata);
/** Called when the timeout is reached */
typedef void (*AvahiTimeoutCallback)(AvahiTimeout *t, void *userdata);
/** Defines an abstracted event polling API. This may be used to
connect Avahi to other main loops. This is loosely based on Unix
poll(2). A consumer will call watch_new() for all file descriptors it
wants to listen for events on. In addition he can call timeout_new()
to define time based events .*/
struct AvahiPoll {
/** Some abstract user data usable by the provider of the API */
void* userdata;
/** Create a new watch for the specified file descriptor and for
* the specified events. The API will call the callback function
* whenever any of the events happens. */
AvahiWatch* (*watch_new)(const AvahiPoll *api, int fd, AvahiWatchEvent event, AvahiWatchCallback callback, void *userdata);
/** Update the events to wait for. It is safe to call this function from an AvahiWatchCallback */
void (*watch_update)(AvahiWatch *w, AvahiWatchEvent event);
/** Return the events that happened. It is safe to call this function from an AvahiWatchCallback */
AvahiWatchEvent (*watch_get_events)(AvahiWatch *w);
/** Free a watch. It is safe to call this function from an AvahiWatchCallback */
void (*watch_free)(AvahiWatch *w);
/** Set a wakeup time for the polling loop. The API will call the
callback function when the absolute time *tv is reached. If tv is
NULL, the timeout is disabled. After the timeout expired the
callback function will be called and the timeout is disabled. You
can reenable it by calling timeout_update() */
AvahiTimeout* (*timeout_new)(const AvahiPoll *api, const struct timeval *tv, AvahiTimeoutCallback callback, void *userdata);
/** Update the absolute expiration time for a timeout, If tv is
* NULL, the timeout is disabled. It is safe to call this function from an AvahiTimeoutCallback */
void (*timeout_update)(AvahiTimeout *, const struct timeval *tv);
/** Free a timeout. It is safe to call this function from an AvahiTimeoutCallback */
void (*timeout_free)(AvahiTimeout *t);
};
AVAHI_C_DECL_END
#endif
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