lc-switch.h

来自「Protothreads are extremely lightweight s」· C头文件 代码 · 共 78 行

/*
 * Copyright (c) 2004-2005, Swedish Institute of Computer Science.
 * All rights reserved. 
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 * 3. Neither the name of the Institute nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE. 
 *
 * This file is part of the protothreads library.
 * 
 * Author: Adam Dunkels <[e-mail]>
 *
 * $Id: lc-switch.h,v 1.2 2005/02/24 10:36:59 adam Exp $
 */

/**
 * \addtogroup lc
 * @{
 */

/**
 * \file
 * Implementation of local continuations based on switch() statment
 * \author Adam Dunkels <[e-mail]>
 *
 * This implementation of local continuations uses the C switch()
 * statement to resume execution of a function somewhere inside the
 * function's body. The implementation is based on the fact that
 * switch() statements are able to jump directly into the bodies of
 * control structures such as if() or while() statmenets.
 *
 * This implementation borrows heavily from Simon Tatham's coroutines
 * implementation in C:
 *
 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
 */

#ifndef __LC_SWITCH_H__
#define __LC_SWTICH_H__

/* WARNING! lc implementation using switch() does not work if an
   LC_SET() is done within another switch() statement! */

/** \hideinitializer */
typedef unsigned short lc_t;

#define LC_SET(s) case __LINE__: s = __LINE__

#define LC_RESUME(s) switch(s) { case 0:

#define LC_END(s) }

#define LC_INIT(s) s = 0;

#endif /* __LC_SWITCH_H__ */

/** @} */