00001 /* 00002 * Copyright (c) 2004-2005, Swedish Institute of Computer Science. 00003 * All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without 00006 * modification, are permitted provided that the following conditions 00007 * are met: 00008 * 1. Redistributions of source code must retain the above copyright 00009 * notice, this list of conditions and the following disclaimer. 00010 * 2. Redistributions in binary form must reproduce the above copyright 00011 * notice, this list of conditions and the following disclaimer in the 00012 * documentation and/or other materials provided with the distribution. 00013 * 3. Neither the name of the Institute nor the names of its contributors 00014 * may be used to endorse or promote products derived from this software 00015 * without specific prior written permission. 00016 * 00017 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 00018 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00019 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00020 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 00021 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00022 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 00023 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 00024 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00025 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 00026 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00027 * SUCH DAMAGE. 00028 * 00029 * This file is part of the protothreads library. 00030 * 00031 * Author: Adam Dunkels <adam@sics.se> 00032 * 00033 * $Id: lc-switch.h,v 1.2 2005/02/24 10:36:59 adam Exp $ 00034 */ 00035 00036 /** 00037 * \addtogroup lc 00038 * @{ 00039 */ 00040 00041 /** 00042 * \file 00043 * Implementation of local continuations based on switch() statment 00044 * \author Adam Dunkels <adam@sics.se> 00045 * 00046 * This implementation of local continuations uses the C switch() 00047 * statement to resume execution of a function somewhere inside the 00048 * function's body. The implementation is based on the fact that 00049 * switch() statements are able to jump directly into the bodies of 00050 * control structures such as if() or while() statmenets. 00051 * 00052 * This implementation borrows heavily from Simon Tatham's coroutines 00053 * implementation in C: 00054 * 00055 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html 00056 */ 00057 00058 #ifndef __LC_SWITCH_H__ 00059 #define __LC_SWTICH_H__ 00060 00061 /* WARNING! lc implementation using switch() does not work if an 00062 LC_SET() is done within another switch() statement! */ 00063 00064 /** \hideinitializer */ 00065 typedef unsigned short lc_t; 00066 00067 #define LC_SET(s) case __LINE__: s = __LINE__ 00068 00069 #define LC_RESUME(s) switch(s) { case 0: 00070 00071 #define LC_END(s) } 00072 00073 #define LC_INIT(s) s = 0; 00074 00075 #endif /* __LC_SWITCH_H__ */ 00076 00077 /** @} */