X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=geekos%2Finclude%2Fuip%2Fpt.h;fp=geekos%2Finclude%2Fuip%2Fpt.h;h=a24cc169b27c67c3857425aaf9780d48a9f13d79;hp=0000000000000000000000000000000000000000;hb=ddc16b0737cf58f7aa90a69c6652cdf4090aec51;hpb=626595465a2c6987606a6bc697df65130ad8c2d3 diff --git a/geekos/include/uip/pt.h b/geekos/include/uip/pt.h new file mode 100644 index 0000000..a24cc16 --- /dev/null +++ b/geekos/include/uip/pt.h @@ -0,0 +1,323 @@ +/* + * 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: pt.h,v 1.2 2008/08/06 23:40:07 andrewlxia Exp $ + */ + +/** + * \addtogroup pt + * @{ + */ + +/** + * \file + * Protothreads implementation. + * \author + * Adam Dunkels + * + */ + +#ifndef __PT_H__ +#define __PT_H__ + +#include + +typedef struct pt { + lc_t lc; +}pt; + +#define PT_WAITING 0 +#define PT_EXITED 1 +#define PT_ENDED 2 +#define PT_YIELDED 3 + +/** + * \name Initialization + * @{ + */ + +/** + * Initialize a protothread. + * + * Initializes a protothread. Initialization must be done prior to + * starting to execute the protothread. + * + * \param pt A pointer to the protothread control structure. + * + * \sa PT_SPAWN() + * + * \hideinitializer + */ +#define PT_INIT(pt) LC_INIT((pt)->lc) + +/** @} */ + +/** + * \name Declaration and definition + * @{ + */ + +/** + * Declaration of a protothread. + * + * This macro is used to declare a protothread. All protothreads must + * be declared with this macro. + * + * \param name_args The name and arguments of the C function + * implementing the protothread. + * + * \hideinitializer + */ +#define PT_THREAD(name_args) char name_args + +/** + * Declare the start of a protothread inside the C function + * implementing the protothread. + * + * This macro is used to declare the starting point of a + * protothread. It should be placed at the start of the function in + * which the protothread runs. All C statements above the PT_BEGIN() + * invokation will be executed each time the protothread is scheduled. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_BEGIN(pt) { char PT_YIELD_FLAG = 1; LC_RESUME((pt)->lc) + +/** + * Declare the end of a protothread. + * + * This macro is used for declaring that a protothread ends. It must + * always be used together with a matching PT_BEGIN() macro. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_END(pt) LC_END((pt)->lc); PT_YIELD_FLAG = 0; \ + PT_INIT(pt); return PT_ENDED; } + +/** @} */ + +/** + * \name Blocked wait + * @{ + */ + +/** + * Block and wait until condition is true. + * + * This macro blocks the protothread until the specified condition is + * true. + * + * \param pt A pointer to the protothread control structure. + * \param condition The condition. + * + * \hideinitializer + */ +#define PT_WAIT_UNTIL(pt, condition) \ + do { \ + LC_SET((pt)->lc); \ + if(!(condition)) { \ + return PT_WAITING; \ + } \ + } while(0) + +/** + * Block and wait while condition is true. + * + * This function blocks and waits while condition is true. See + * PT_WAIT_UNTIL(). + * + * \param pt A pointer to the protothread control structure. + * \param cond The condition. + * + * \hideinitializer + */ +#define PT_WAIT_WHILE(pt, cond) PT_WAIT_UNTIL((pt), !(cond)) + +/** @} */ + +/** + * \name Hierarchical protothreads + * @{ + */ + +/** + * Block and wait until a child protothread completes. + * + * This macro schedules a child protothread. The current protothread + * will block until the child protothread completes. + * + * \note The child protothread must be manually initialized with the + * PT_INIT() function before this function is used. + * + * \param pt A pointer to the protothread control structure. + * \param thread The child protothread with arguments + * + * \sa PT_SPAWN() + * + * \hideinitializer + */ +#define PT_WAIT_THREAD(pt, thread) PT_WAIT_WHILE((pt), PT_SCHEDULE(thread)) + +/** + * Spawn a child protothread and wait until it exits. + * + * This macro spawns a child protothread and waits until it exits. The + * macro can only be used within a protothread. + * + * \param pt A pointer to the protothread control structure. + * \param child A pointer to the child protothread's control structure. + * \param thread The child protothread with arguments + * + * \hideinitializer + */ +#define PT_SPAWN(pt, child, thread) \ + do { \ + PT_INIT((child)); \ + PT_WAIT_THREAD((pt), (thread)); \ + } while(0) + +/** @} */ + +/** + * \name Exiting and restarting + * @{ + */ + +/** + * Restart the protothread. + * + * This macro will block and cause the running protothread to restart + * its execution at the place of the PT_BEGIN() call. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_RESTART(pt) \ + do { \ + PT_INIT(pt); \ + return PT_WAITING; \ + } while(0) + +/** + * Exit the protothread. + * + * This macro causes the protothread to exit. If the protothread was + * spawned by another protothread, the parent protothread will become + * unblocked and can continue to run. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_EXIT(pt) \ + do { \ + PT_INIT(pt); \ + return PT_EXITED; \ + } while(0) + +/** @} */ + +/** + * \name Calling a protothread + * @{ + */ + +/** + * Schedule a protothread. + * + * This function shedules a protothread. The return value of the + * function is non-zero if the protothread is running or zero if the + * protothread has exited. + * + * \param f The call to the C function implementing the protothread to + * be scheduled + * + * \hideinitializer + */ +#define PT_SCHEDULE(f) ((f) == PT_WAITING) + +/** @} */ + +/** + * \name Yielding from a protothread + * @{ + */ + +/** + * Yield from the current protothread. + * + * This function will yield the protothread, thereby allowing other + * processing to take place in the system. + * + * \param pt A pointer to the protothread control structure. + * + * \hideinitializer + */ +#define PT_YIELD(pt) \ + do { \ + PT_YIELD_FLAG = 0; \ + LC_SET((pt)->lc); \ + if(PT_YIELD_FLAG == 0) { \ + return PT_YIELDED; \ + } \ + } while(0) + +/** + * \brief Yield from the protothread until a condition occurs. + * \param pt A pointer to the protothread control structure. + * \param cond The condition. + * + * This function will yield the protothread, until the + * specified condition evaluates to true. + * + * + * \hideinitializer + */ +#define PT_YIELD_UNTIL(pt, cond) \ + do { \ + PT_YIELD_FLAG = 0; \ + LC_SET((pt)->lc); \ + if((PT_YIELD_FLAG == 0) || !(cond)) { \ + return PT_YIELDED; \ + } \ + } while(0) + +/** @} */ + +#endif /* __PT_H__ */ + +/** @} */