adamdunkels | a2f3c42 | 2004-09-12 20:24:53 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2004, Swedish Institute of Computer Science. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. Neither the name of the Institute nor the names of its contributors |
| 14 | * may be used to endorse or promote products derived from this software |
| 15 | * without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | * |
| 29 | * This file is part of the Contiki operating system. |
| 30 | * |
| 31 | * Author: Adam Dunkels <adam@sics.se> |
| 32 | * |
adamdunkels | 442bdc8 | 2005-02-22 22:46:33 +0000 | [diff] [blame] | 33 | * $Id: mt.h,v 1.4 2005/02/22 22:46:33 adamdunkels Exp $ |
adamdunkels | a2f3c42 | 2004-09-12 20:24:53 +0000 | [diff] [blame] | 34 | */ |
| 35 | |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 36 | /** |
adamdunkels | 442bdc8 | 2005-02-22 22:46:33 +0000 | [diff] [blame] | 37 | * \defgroup mt Multi-threading library |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 38 | * @{ |
| 39 | * |
| 40 | * The event driven Contiki kernel does not provide multi-threading |
| 41 | * by itself - instead, preemptive multi-threading is implemented |
| 42 | * as a library that optionally can be linked with applications. This |
| 43 | * library constists of two parts: a platform independent part, which is |
| 44 | * the same for all platforms on which Contiki runs, and a platform |
| 45 | * specific part, which must be implemented specifically for the |
| 46 | * platform that the multi-threading library should run. |
| 47 | */ |
| 48 | |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 49 | /** |
| 50 | * \defgroup mtarch Architecture support for multi-threading |
| 51 | * @{ |
| 52 | * |
| 53 | * The Contiki multi-threading library requires some architecture |
| 54 | * specific support for seting up and switching stacks. This support |
| 55 | * requires three stack manipulation functions to be implemented: |
| 56 | * mtarch_start(), which sets up the stack frame for a new thread, |
| 57 | * mtarch_exec(), which switches in the stack of a thread, and |
| 58 | * mtarch_yield(), which restores the kernel stack from a thread's |
| 59 | * stack. Additionally, two functions for controlling the preemption |
| 60 | * (if any) must be implemented: mtarch_preemption_start() and |
| 61 | * mtarch_preemption_stop(). If no preemption is used, these functions |
| 62 | * can be implemented as empty functions. Finally, the function |
| 63 | * mtarch_init() is called by mt_init(), and can be used for |
| 64 | * initalization of timer interrupts, or any other mechanisms required |
| 65 | * for correct operation of the architecture specific support funcions. |
| 66 | * |
| 67 | */ |
| 68 | |
| 69 | /** |
adamdunkels | 12860b0 | 2004-08-20 21:27:42 +0000 | [diff] [blame] | 70 | * \file |
| 71 | * Header file for the preemptive multitasking library for Contiki. |
| 72 | * \author |
| 73 | * Adam Dunkels <adam@sics.se> |
| 74 | * |
| 75 | */ |
| 76 | #ifndef __MT_H__ |
| 77 | #define __MT_H__ |
| 78 | |
| 79 | #include "ek.h" |
| 80 | |
| 81 | |
| 82 | /** |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 83 | * An opaque structure that is used for holding the state of a thread. |
| 84 | * |
| 85 | * The structure should be defined in the "mtarch.h" file. This |
| 86 | * structure typically holds the entire stack for the thread. |
| 87 | */ |
| 88 | struct mtarch_thread; |
| 89 | |
| 90 | /** |
| 91 | * Initialize the architecture specific support functions for the |
| 92 | * multi-thread library. |
| 93 | * |
| 94 | * This function is implemented by the architecture specific functions |
| 95 | * for the multi-thread library and is called by the mt_init() |
| 96 | * function as part of the initialization of the library. The |
| 97 | * mtarch_init() function can be used for, e.g., starting preemtion |
| 98 | * timers or other architecture specific mechanisms required for the |
| 99 | * operation of the library. |
| 100 | */ |
| 101 | void mtarch_init(void); |
| 102 | |
| 103 | /** |
| 104 | * Uninstall library and clean up. |
| 105 | * |
| 106 | */ |
| 107 | void mtarch_remove(void); |
| 108 | |
| 109 | /** |
| 110 | * Setup the stack frame for a thread that is being started. |
| 111 | * |
| 112 | * This function is called by the mt_start() function in order to set |
| 113 | * up the architecture specific stack of the thread to be started. |
| 114 | * |
| 115 | * \param thread A pointer to a struct mtarch_thread for the thread to |
| 116 | * be started. |
| 117 | * |
| 118 | * \param function A pointer to the function that the thread will |
| 119 | * start executing the first time it is scheduled to run. |
| 120 | * |
| 121 | * \param data A pointer to the argument that the function should be |
| 122 | * passed. |
| 123 | */ |
| 124 | void mtarch_start(struct mtarch_thread *thread, |
| 125 | void (* function)(void *data), |
| 126 | void *data); |
| 127 | |
| 128 | /** |
| 129 | * Yield the processor. |
| 130 | * |
| 131 | * This function is called by the mt_yield() function, which is called |
| 132 | * from the running thread in order to give up the processor. |
| 133 | * |
| 134 | */ |
| 135 | void mtarch_yield(void); |
| 136 | |
| 137 | /** |
| 138 | * Start executing a thread. |
| 139 | * |
| 140 | * This function is called from mt_exec() and the purpose of the |
| 141 | * function is to start execution of the thread. The function should |
| 142 | * switch in the stack of the thread, and does not return until the |
| 143 | * thread has explicitly yielded (using mt_yield()) or until it is |
| 144 | * preempted. |
| 145 | * |
| 146 | */ |
| 147 | void mtarch_exec(struct mtarch_thread *thread); |
| 148 | |
| 149 | |
| 150 | void mtarch_pstart(void); |
| 151 | void mtarch_pstop(void); |
| 152 | |
| 153 | /** @} */ |
| 154 | |
| 155 | |
| 156 | #include "mtarch.h" |
| 157 | #include "ek.h" |
| 158 | |
| 159 | struct mt_thread { |
| 160 | int state; |
| 161 | ek_event_t *evptr; |
| 162 | ek_data_t *dataptr; |
| 163 | struct mtarch_thread thread; |
| 164 | }; |
| 165 | |
| 166 | /** |
| 167 | * No error. |
| 168 | * |
| 169 | * \hideinitializer |
| 170 | */ |
| 171 | #define MT_OK 1 |
| 172 | |
| 173 | /** |
| 174 | * Initializes the multithreading library. |
| 175 | * |
| 176 | */ |
| 177 | void mt_init(void); |
| 178 | |
| 179 | /** |
| 180 | * Uninstalls library and cleans up. |
| 181 | * |
| 182 | */ |
| 183 | void mt_remove(void); |
| 184 | |
| 185 | |
| 186 | /** |
| 187 | * Starts a multithreading thread. |
| 188 | * |
| 189 | * \param thread Pointer to an mt_thread struct that must have been |
| 190 | * previously allocated by the caller. |
| 191 | * |
| 192 | * \param function A pointer to the entry function of the thread that is |
| 193 | * to be set up. |
| 194 | * |
| 195 | * \param data A pointer that will be passed to the entry function. |
| 196 | * |
| 197 | */ |
| 198 | void mt_start(struct mt_thread *thread, void (* function)(void *), void *data); |
| 199 | |
| 200 | /** |
| 201 | * Start executing a thread. |
| 202 | * |
| 203 | * This function is called by a Contiki process and starts running a |
| 204 | * thread. The function does not return until the thread has yielded, |
| 205 | * or is preempted. |
| 206 | * |
| 207 | * \note The thread must first be initialized with the mt_init() function. |
| 208 | * |
| 209 | * \param thread A pointer to a struct mt_thread block that must be |
| 210 | * allocated by the caller. |
| 211 | * |
| 212 | */ |
| 213 | void mt_exec(struct mt_thread *thread); |
| 214 | |
| 215 | /** |
| 216 | * Post an event to a thread. |
| 217 | * |
| 218 | * This function posts an event to a thread. The thread will be |
| 219 | * scheduled if the thread currently is waiting for the posted event |
| 220 | * number. If the thread is not waiting for the event, this function |
| 221 | * does nothing. |
| 222 | * |
| 223 | * \note The thread must first be initialized with the mt_init() function. |
| 224 | * |
| 225 | * \param thread A pointer to a struct mt_thread block that must be |
| 226 | * allocated by the caller. |
| 227 | * |
| 228 | * \param s The event that is posted to the thread. |
adamdunkels | 442bdc8 | 2005-02-22 22:46:33 +0000 | [diff] [blame] | 229 | * |
| 230 | * \param data An opaque pointer to a user specified structure |
| 231 | * containing additonal information, or NULL if no additional |
| 232 | * information is needed. |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 233 | */ |
| 234 | void mt_exec_event(struct mt_thread *thread, ek_event_t s, ek_data_t data); |
| 235 | |
| 236 | /** |
| 237 | * Voluntarily give up the processor. |
| 238 | * |
| 239 | * This function is called by a running thread in order to give up |
| 240 | * control of the CPU. |
| 241 | * |
| 242 | */ |
| 243 | void mt_yield(void); |
| 244 | |
| 245 | /** |
| 246 | * Emit a signal to another process. |
| 247 | * |
| 248 | * This function is called by a running thread and will emit a signal |
| 249 | * to another Contiki process. This will cause the currently executing |
| 250 | * thread to yield. |
| 251 | * |
| 252 | * \param s The signal to be emitted. |
| 253 | * \param data A pointer to a message that is to be delivered together with the signal. |
| 254 | * \param id The process ID of the receiver of the signal, or EK_ID_ALL for a broadcast signal. |
| 255 | */ |
| 256 | void mt_post(ek_id_t id, ek_event_t s, ek_data_t data); |
| 257 | |
| 258 | /** |
| 259 | * Block and wait for an event to occur. |
| 260 | * |
| 261 | * This function can be called by a running thread in order to block |
| 262 | * and wait for an event. The function returns when an event has |
| 263 | * occured. The event number and the associated data are placed in the |
| 264 | * variables pointed to by the function arguments. |
| 265 | * |
| 266 | */ |
| 267 | void mt_wait(ek_event_t *s, ek_data_t *data); |
| 268 | |
| 269 | /** |
| 270 | * Exit a thread. |
| 271 | * |
| 272 | * This function is called from within an executing thread in order to |
| 273 | * exit the thread. The function never returns. |
| 274 | * |
| 275 | */ |
| 276 | void mt_exit(void); |
| 277 | |
| 278 | /** |
| 279 | * \defgroup mtp Multi-threading library convenience functions |
| 280 | * @{ |
| 281 | * |
| 282 | * The Contiki multi-threading library has an interface that might be |
| 283 | * hard to use. Therefore, the mtp module provides a simpler |
| 284 | * interface. |
| 285 | * |
| 286 | * Example: |
| 287 | \code |
| 288 | static void |
| 289 | example_thread_code(void *data) |
| 290 | { |
| 291 | while(1) { |
| 292 | printf("Test\n"); |
| 293 | mt_yield(); |
| 294 | } |
| 295 | } |
| 296 | MTP(example_thread, "Example thread", p1, t1, t1_idle); |
| 297 | |
| 298 | int |
| 299 | main(int argc, char *argv[]) |
| 300 | { |
| 301 | mtp_start(&example_thread, example_thread_code, NULL); |
| 302 | } |
| 303 | \endcode |
| 304 | * |
| 305 | */ |
| 306 | |
| 307 | #include "mt.h" |
| 308 | |
| 309 | /** |
| 310 | * Declare a thread. |
| 311 | * |
| 312 | * This macro is used to covneniently declare a thread, and the |
| 313 | * process in which the thread should execute. The names of the |
| 314 | * variables provided to the macro should be chosen to be unique |
| 315 | * within the file that the thread is used. |
| 316 | * |
| 317 | * Example: |
| 318 | \code |
adamdunkels | 442bdc8 | 2005-02-22 22:46:33 +0000 | [diff] [blame] | 319 | MTP(example_thread, example_proc, "Example thread"); |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 320 | \endcode |
| 321 | * |
adamdunkels | 442bdc8 | 2005-02-22 22:46:33 +0000 | [diff] [blame] | 322 | * \param thread The variable name of the thread. |
| 323 | * |
| 324 | * \param proc The variable name of the process containing the thread. |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 325 | * |
| 326 | * \param name A string that specifies the user-visible name of the |
| 327 | * process in which the thread will run. |
| 328 | * |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 329 | * \hideinitializer |
| 330 | */ |
| 331 | #define MTP(thread, proc, name) \ |
| 332 | extern struct mtp_thread thread; \ |
| 333 | EK_PROCESS(proc, name, EK_PRIO_NORMAL, mtp_eventhandler, \ |
| 334 | NULL, (void *)&thread); \ |
| 335 | static struct mtp_thread thread = {&proc} |
| 336 | |
| 337 | struct mtp_thread { |
| 338 | struct ek_proc *p; |
| 339 | struct mt_thread t; |
| 340 | }; |
| 341 | |
| 342 | /** |
| 343 | * Start a thread. |
| 344 | * |
| 345 | * This function starts the process in which the thread is to run, and |
| 346 | * also sets up the thread to run within the process. The function |
| 347 | * should be passed variable names declared with the MTP() macro. |
| 348 | * |
| 349 | * Example: |
| 350 | \code |
| 351 | mtp_start(&t, example_thread_code, NULL); |
| 352 | \endcode |
| 353 | * \param t A pointer to a thread structure previously declared with MTP(). |
| 354 | * |
| 355 | * \param function A pointer to the function that the thread should |
| 356 | * start executing. |
| 357 | * |
| 358 | * \param data A pointer that the function should be passed when first |
| 359 | * invocated. |
| 360 | */ |
| 361 | void mtp_start(struct mtp_thread *t, |
| 362 | void (* function)(void *), void *data); |
| 363 | |
| 364 | void mtp_exit(void); |
| 365 | |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 366 | |
| 367 | void mtp_eventhandler(ek_event_t ev, ek_data_t data); |
| 368 | |
adamdunkels | 12860b0 | 2004-08-20 21:27:42 +0000 | [diff] [blame] | 369 | /** @} */ |
adamdunkels | 50b3feb | 2004-07-04 15:04:56 +0000 | [diff] [blame] | 370 | /** @} */ |
| 371 | #endif /* __MT_H__ */ |
| 372 | |