X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=geekos%2Finclude%2Fuip%2Flc-switch.h;fp=geekos%2Finclude%2Fuip%2Flc-switch.h;h=d05ca88f2fbfd0bfa7190078fd37c7de51e50941;hp=0000000000000000000000000000000000000000;hb=ddc16b0737cf58f7aa90a69c6652cdf4090aec51;hpb=626595465a2c6987606a6bc697df65130ad8c2d3 diff --git a/geekos/include/uip/lc-switch.h b/geekos/include/uip/lc-switch.h new file mode 100644 index 0000000..d05ca88 --- /dev/null +++ b/geekos/include/uip/lc-switch.h @@ -0,0 +1,76 @@ +/* + * 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 uIP TCP/IP stack + * + * Author: Adam Dunkels + * + * $Id: lc-switch.h,v 1.2 2008/08/06 23:40:07 andrewlxia Exp $ + */ + +/** + * \addtogroup lc + * @{ + */ + +/** + * \file + * Implementation of local continuations based on switch() statment + * \author Adam Dunkels + * + * 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_INIT(s) s = 0; + +#define LC_RESUME(s) switch(s) { case 0: + +#define LC_SET(s) s = __LINE__; case __LINE__: + +#define LC_END(s) } + +#endif /* __LC_SWITCH_H__ */ + +/** @} */