/*

 * Amanda, The Advanced Maryland Automatic Network Disk Archiver

 * Copyright (c) 1999 University of Maryland at College Park

 * Copyright (c) 2007-2012 Zmanda, Inc.  All Rights Reserved.

 * Copyright (c) 2013-2016 Carbonite, Inc.  All Rights Reserved.

 * All Rights Reserved.

 *

 * Permission to use, copy, modify, distribute, and sell this software and its

 * documentation for any purpose is hereby granted without fee, provided that

 * the above copyright notice appear in all copies and that both that

 * copyright notice and this permission notice appear in supporting

 * documentation, and that the name of U.M. not be used in advertising or

 * publicity pertaining to distribution of the software without specific,

 * written prior permission.  U.M. makes no representations about the

 * suitability of this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 *

 * U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.

 * BE LIABLE FOR ANY SPECIAL, 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.

 *

 * Authors: the Amanda Development Team.  Its members are listed in a

 * file named AUTHORS, in the root directory of this distribution.

 */

/*

 * $Id: event.h,v 1.9 2006/06/16 10:55:05 martinea Exp $

 */

#ifndef EVENT_H

#define EVENT_H

/*

 * These functions define a generic event interface.  One can register a

 * function vector and the type of events to act on, and the event handler

 * will dispatch as necessary.

 */

/*

 * An opaque handle returned by the registry functions that can be

 * used to unregister an event in the future.

 */

struct event_handle;

typedef struct event_handle event_handle_t;

/*

 * The 'id' of the event.  The meaning of this depends on the type of

 * event we are registering -- see event_register.  The name 'id' is

 * historical: it is quite possible to have many outstanding events with

 * the same ID (same timeout or same file descriptor).

 *

 * Event id's are supplied by the caller, and in some cases are cast from

 * pointers, so this value must be wide enough to hold a pointer without

 * truncation.

 */

typedef	intmax_t event_id_t;

/*

 * The types of events we can register.

 */

typedef enum {

    EV_READFD,			/* file descriptor is ready for reading */

    EV_WRITEFD,			/* file descriptor is ready for writing */

    EV_TIME,			/* n seconds have elapsed */

    EV_WAIT,			/* event_wakeup() was called with this id */

} event_type_t;

/*

 * The function signature for functions that get called when an event

 * fires.

 */

typedef void (*event_fn_t)(void *);

/*

 * Register an event handler.

 *

 * For readfd and writefd events, the first arg is the file descriptor.

 * There can be multiple callers firing on the same file descriptor.

 *

 * For signal events, the first arg is the signal number as defined in

 * <signal.h>.  There can only be one signal handler. (do we need more?)

 *

 * For time events, the first arg is the interval in seconds between

 * pulses.  There can be multiple time events, of course.  Don't

 * count on the time events being too accurate.  They depend on the

 * caller calling event_loop() often enough.

 */

//event_handle_t *event_register(event_id_t, event_type_t, event_fn_t, void *);

event_handle_t *event_create(event_id_t, event_type_t, event_fn_t, void *);

void event_activate(event_handle_t *);

/*

 * Release an event handler.

 */

void event_release(event_handle_t *);

/*

 * Wake up all EV_WAIT events waiting on a specific id.  This happens immediately,

 * not in the next iteration of the event loop.  If callbacks made during the wakeup

 * register a new event with the same ID, that new event will *not* be awakened.

 */

int event_wakeup(event_id_t);

/*

 * Call event_loop, returning when one of the following conditions is

 * true:

 *  evt is EV_WAIT, and it is released; or

 *  evt is EV_READFD, EV_WRITEFD, or EV_TIME, and it is fired.

 */

void event_wait(event_handle_t *evt);

/*

 * Process events.  If the argument is nonzero, then the loop does

 * not block.

 */

void event_loop(int nonblock);

/*

 * Process events, not even stopping when there are no more event API events

 * left (there may be other GMainLoop events pending); similar to

 * g_main_loop_run, but compatible with the event API.

 */

void event_loop_run(void);

/*

 * Stop an event_loop_run invocation; similar to g_main_loop_quit, but

 * compatible with the event API

 */

void event_loop_quit(void);

/*

 * Get the default GMainLoop object.  Applications which use the Glib

 * main loop directly should use this object for calls to e.g.,

 * g_main_loop_run(loop).

 */

GMainLoop *default_main_loop(void);

/*

 * Utility GSources

 */

/* Create a GSource that will callback when the given file descriptor is in

 * any of the given conditions.  The callback is a simple GSourceFunc.

 *

 * @param fd: the file descriptr

 * @param events: the conditions (GIOCondition flags)

 * @return: GSource object

 */

GSource * new_fdsource(gint fd, GIOCondition events);

/* Create a GSource that will callback when the given child dies.  The callback

 * should match ChildWatchFunc.  Once the callback is made, it will not be called

 * again by this source.

 *

 * Note: This is provided by glib in later versions, but not in version 2.2.0.

 * This function and callback is modeled on g_child_watch_source_new.

 *

 * @param pid: the process ID @return: GSource object

 */

typedef void (*ChildWatchFunc)(pid_t pid, gint status, gpointer data); 

GSource * new_child_watch_source(pid_t pid);

#endif	/* EVENT_H */