| /* |
| * 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 Contiki operating system. |
| * |
| * Author: Adam Dunkels <adam@sics.se> |
| * |
| */ |
| |
| /** |
| * \addtogroup pt |
| * @{ |
| */ |
| |
| /** |
| * \file |
| * Protothreads implementation. |
| * \author |
| * Adam Dunkels <adam@sics.se> |
| * |
| */ |
| |
| #ifndef PT_H_ |
| #define PT_H_ |
| |
| #include "sys/lc.h" |
| |
| struct pt { |
| lc_t lc; |
| }; |
| |
| #define PT_WAITING 0 |
| #define PT_YIELDED 1 |
| #define PT_EXITED 2 |
| #define PT_ENDED 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; if (PT_YIELD_FLAG) {;} 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 schedules 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_EXITED) |
| |
| /** @} */ |
| |
| /** |
| * \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_ */ |
| |
| /** @} */ |