NetBSD/dist/hostapd/eloop.h

155 lines
5.5 KiB
C

/*
* Event loop
* Copyright (c) 2002-2005, Jouni Malinen <jkmaline@cc.hut.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*
* This file defines an event loop interface that supports processing events
* from registered timeouts (i.e., do something after N seconds), sockets
* (e.g., a new packet available for reading), and signals. eloop.c is an
* implementation of this interface using select() and sockets. This is
* suitable for most UNIX/POSIX systems. When porting to other operating
* systems, it may be necessary to replace that implementation with OS specific
* mechanisms.
*/
#ifndef ELOOP_H
#define ELOOP_H
/**
* ELOOP_ALL_CTX - eloop_cancel_timeout() magic number to match all timeouts
*/
#define ELOOP_ALL_CTX (void *) -1
/**
* eloop_init() - Initialize global event loop data
* @user_data: Pointer to global data passed as eloop_ctx to signal handlers
*
* This function must be called before any other eloop_* function. user_data
* can be used to configure a global (to the process) pointer that will be
* passed as eloop_ctx parameter to signal handlers.
*/
void eloop_init(void *user_data);
/**
* eloop_register_read_sock - Register handler for read events
* @sock: File descriptor number for the socket
* @handler: Callback function to be called when data is available for reading
* @eloop_data: Callback context data (eloop_ctx)
* @user_data: Callback context data (sock_ctx)
* Returns: 0 on success, -1 on failure
*
* Register a read socket notifier for the given file descriptor. The handler
* function will be called whenever data is available for reading from the
* socket.
*/
int eloop_register_read_sock(int sock,
void (*handler)(int sock, void *eloop_ctx,
void *sock_ctx),
void *eloop_data, void *user_data);
/**
* eloop_unregister_read_sock - Unregister handler for read events
* @sock: File descriptor number for the socket
*
* Unregister a read socket notifier that was previously registered with
* eloop_register_read_sock().
*/
void eloop_unregister_read_sock(int sock);
/**
* eloop_register_timeout - Register timeout
* @secs: Number of seconds to the timeout
* @usecs: Number of microseconds to the timeout
* @handler: Callback function to be called when timeout occurs
* @eloop_data: Callback context data (eloop_ctx)
* @user_data: Callback context data (sock_ctx)
* Returns: 0 on success, -1 on failure
*
* Register a timeout that will cause the handler function to be called after
* given time.
*/
int eloop_register_timeout(unsigned int secs, unsigned int usecs,
void (*handler)(void *eloop_ctx, void *timeout_ctx),
void *eloop_data, void *user_data);
/**
* eloop_cancel_timeout - Cancel timeouts
* @handler: Matching callback function
* @eloop_data: Matching eloop_data or %ELOOP_ALL_CTX to match all
* @user_data: Matching user_data or %ELOOP_ALL_CTX to match all
* Returns: Number of cancelled timeouts
*
* Cancel matching <handler,eloop_data,user_data> timeouts registered with
* eloop_register_timeout(). ELOOP_ALL_CTX can be used as a wildcard for
* cancelling all timeouts regardless of eloop_data/user_data.
*/
int eloop_cancel_timeout(void (*handler)(void *eloop_ctx, void *sock_ctx),
void *eloop_data, void *user_data);
/**
* eloop_register_signal - Register handler for signals
* @sig: Signal number (e.g., SIGHUP)
* @handler: Callback function to be called when the signal is received
* @user_data: Callback context data (signal_ctx)
* Returns: 0 on success, -1 on failure
*
* Register a callback function that will be called when a signal is received.
* The calback function is actually called only after the system signal handler
* has returned. This means that the normal limits for sighandlers (i.e., only
* "safe functions" allowed) do not apply for the registered callback.
*
* Signals are 'global' events and there is no local eloop_data pointer like
* with other handlers. The global user_data pointer registered with
* eloop_init() will be used as eloop_ctx for signal handlers.
*/
int eloop_register_signal(int sig,
void (*handler)(int sig, void *eloop_ctx,
void *signal_ctx),
void *user_data);
/**
* eloop_run - Start the event loop
*
* Start the event loop and continue running as long as there are any
* registered event handlers. This function is run after event loop has been
* initialized with event_init() and one or more events have been registered.
*/
void eloop_run(void);
/**
* eloop_terminate - Terminate event loop
*
* Terminate event loop even if there are registered events. This can be used
* to request the program to be terminated cleanly.
*/
void eloop_terminate(void);
/**
* eloop_destroy - Free any resources allocated for the event loop
*
* After calling eloop_destroy(), other eloop_* functions must not be called
* before re-running eloop_init().
*/
void eloop_destroy(void);
/**
* eloop_terminated - Check whether event loop has been terminated
* Returns: 1 = event loop terminate, 0 = event loop still running
*
* This function can be used to check whether eloop_terminate() has been called
* to request termination of the event loop. This is normally used to abort
* operations that may still be queued to be run when eloop_terminate() was
* called.
*/
int eloop_terminated(void);
#endif /* ELOOP_H */