1 /** 2 * @file 3 * OS abstraction layer 4 */ 5 6 /* 7 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without modification, 11 * are permitted provided that the following conditions are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright notice, 14 * this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 30 * OF SUCH DAMAGE. 31 * 32 * This file is part of the lwIP TCP/IP stack. 33 * 34 * Author: Adam Dunkels <adam@sics.se> 35 */ 36 37 #ifndef LWIP_HDR_SYS_H 38 #define LWIP_HDR_SYS_H 39 40 #include "lwip/opt.h" 41 42 #ifdef __cplusplus 43 extern "C" { 44 #endif 45 46 #if NO_SYS 47 48 /* For a totally minimal and standalone system, we provide null 49 definitions of the sys_ functions. */ 50 typedef u8_t sys_sem_t; 51 typedef u8_t sys_mutex_t; 52 typedef u8_t sys_mbox_t; 53 54 #define sys_sem_new(s, c) ERR_OK 55 #define sys_sem_signal(s) 56 #define sys_sem_wait(s) 57 #define sys_arch_sem_wait(s,t) 58 #define sys_sem_free(s) 59 #define sys_sem_valid(s) 0 60 #define sys_sem_valid_val(s) 0 61 #define sys_sem_set_invalid(s) 62 #define sys_sem_set_invalid_val(s) 63 #define sys_mutex_new(mu) ERR_OK 64 #define sys_mutex_lock(mu) 65 #define sys_mutex_unlock(mu) 66 #define sys_mutex_free(mu) 67 #define sys_mutex_valid(mu) 0 68 #define sys_mutex_set_invalid(mu) 69 #define sys_mbox_new(m, s) ERR_OK 70 #define sys_mbox_fetch(m,d) 71 #define sys_mbox_tryfetch(m,d) 72 #define sys_mbox_post(m,d) 73 #define sys_mbox_trypost(m,d) 74 #define sys_mbox_free(m) 75 #define sys_mbox_valid(m) 76 #define sys_mbox_valid_val(m) 77 #define sys_mbox_set_invalid(m) 78 #define sys_mbox_set_invalid_val(m) 79 80 #define sys_thread_new(n,t,a,s,p) 81 82 #define sys_msleep(t) 83 84 #else /* NO_SYS */ 85 86 /** Return code for timeouts from sys_arch_mbox_fetch and sys_arch_sem_wait */ 87 #define SYS_ARCH_TIMEOUT 0xffffffffUL 88 89 /** sys_mbox_tryfetch() returns SYS_MBOX_EMPTY if appropriate. 90 * For now we use the same magic value, but we allow this to change in future. 91 */ 92 #define SYS_MBOX_EMPTY SYS_ARCH_TIMEOUT 93 94 #include "lwip/err.h" 95 #include "arch/sys_arch.h" 96 97 /** Function prototype for thread functions */ 98 typedef void (*lwip_thread_fn)(void *arg); 99 100 /* Function prototypes for functions to be implemented by platform ports 101 (in sys_arch.c) */ 102 103 /* Mutex functions: */ 104 105 /** Define LWIP_COMPAT_MUTEX if the port has no mutexes and binary semaphores 106 should be used instead */ 107 #ifndef LWIP_COMPAT_MUTEX 108 #define LWIP_COMPAT_MUTEX 0 109 #endif 110 111 #if LWIP_COMPAT_MUTEX 112 /* for old ports that don't have mutexes: define them to binary semaphores */ 113 #define sys_mutex_t sys_sem_t 114 #define sys_mutex_new(mutex) sys_sem_new(mutex, 1) 115 #define sys_mutex_lock(mutex) sys_sem_wait(mutex) 116 #define sys_mutex_unlock(mutex) sys_sem_signal(mutex) 117 #define sys_mutex_free(mutex) sys_sem_free(mutex) 118 #define sys_mutex_valid(mutex) sys_sem_valid(mutex) 119 #define sys_mutex_set_invalid(mutex) sys_sem_set_invalid(mutex) 120 121 #else /* LWIP_COMPAT_MUTEX */ 122 123 /** 124 * @ingroup sys_mutex 125 * Create a new mutex. 126 * Note that mutexes are expected to not be taken recursively by the lwIP code, 127 * so both implementation types (recursive or non-recursive) should work. 128 * @param mutex pointer to the mutex to create 129 * @return ERR_OK if successful, another err_t otherwise 130 */ 131 err_t sys_mutex_new(sys_mutex_t *mutex); 132 /** 133 * @ingroup sys_mutex 134 * Lock a mutex 135 * @param mutex the mutex to lock 136 */ 137 void sys_mutex_lock(sys_mutex_t *mutex); 138 /** 139 * @ingroup sys_mutex 140 * Unlock a mutex 141 * @param mutex the mutex to unlock 142 */ 143 void sys_mutex_unlock(sys_mutex_t *mutex); 144 /** 145 * @ingroup sys_mutex 146 * Delete a semaphore 147 * @param mutex the mutex to delete 148 */ 149 void sys_mutex_free(sys_mutex_t *mutex); 150 #ifndef sys_mutex_valid 151 /** 152 * @ingroup sys_mutex 153 * Check if a mutex is valid/allocated: return 1 for valid, 0 for invalid 154 */ 155 int sys_mutex_valid(sys_mutex_t *mutex); 156 #endif 157 #ifndef sys_mutex_set_invalid 158 /** 159 * @ingroup sys_mutex 160 * Set a mutex invalid so that sys_mutex_valid returns 0 161 */ 162 void sys_mutex_set_invalid(sys_mutex_t *mutex); 163 #endif 164 #endif /* LWIP_COMPAT_MUTEX */ 165 166 /* Semaphore functions: */ 167 168 /** 169 * @ingroup sys_sem 170 * Create a new semaphore 171 * @param sem pointer to the semaphore to create 172 * @param count initial count of the semaphore 173 * @return ERR_OK if successful, another err_t otherwise 174 */ 175 err_t sys_sem_new(sys_sem_t *sem, u8_t count); 176 /** 177 * @ingroup sys_sem 178 * Signals a semaphore 179 * @param sem the semaphore to signal 180 */ 181 void sys_sem_signal(sys_sem_t *sem); 182 /** 183 * @ingroup sys_sem 184 * Wait for a semaphore for the specified timeout 185 * @param sem the semaphore to wait for 186 * @param timeout timeout in milliseconds to wait (0 = wait forever) 187 * @return time (in milliseconds) waited for the semaphore 188 * or SYS_ARCH_TIMEOUT on timeout 189 */ 190 u32_t sys_arch_sem_wait(sys_sem_t *sem, u32_t timeout); 191 /** 192 * @ingroup sys_sem 193 * Delete a semaphore 194 * @param sem semaphore to delete 195 */ 196 void sys_sem_free(sys_sem_t *sem); 197 /** Wait for a semaphore - forever/no timeout */ 198 #define sys_sem_wait(sem) sys_arch_sem_wait(sem, 0) 199 #ifndef sys_sem_valid 200 /** 201 * @ingroup sys_sem 202 * Check if a semaphore is valid/allocated: return 1 for valid, 0 for invalid 203 */ 204 int sys_sem_valid(sys_sem_t *sem); 205 #endif 206 #ifndef sys_sem_set_invalid 207 /** 208 * @ingroup sys_sem 209 * Set a semaphore invalid so that sys_sem_valid returns 0 210 */ 211 void sys_sem_set_invalid(sys_sem_t *sem); 212 #endif 213 #ifndef sys_sem_valid_val 214 /** 215 * Same as sys_sem_valid() but taking a value, not a pointer 216 */ 217 #define sys_sem_valid_val(sem) sys_sem_valid(&(sem)) 218 #endif 219 #ifndef sys_sem_set_invalid_val 220 /** 221 * Same as sys_sem_set_invalid() but taking a value, not a pointer 222 */ 223 #define sys_sem_set_invalid_val(sem) sys_sem_set_invalid(&(sem)) 224 #endif 225 226 #ifndef sys_msleep 227 /** 228 * @ingroup sys_misc 229 * Sleep for specified number of ms 230 */ 231 void sys_msleep(u32_t ms); /* only has a (close to) 1 ms resolution. */ 232 #endif 233 234 /* Mailbox functions. */ 235 236 /** 237 * @ingroup sys_mbox 238 * Create a new mbox of specified size 239 * @param mbox pointer to the mbox to create 240 * @param size (minimum) number of messages in this mbox 241 * @return ERR_OK if successful, another err_t otherwise 242 */ 243 err_t sys_mbox_new(sys_mbox_t *mbox, int size); 244 /** 245 * @ingroup sys_mbox 246 * Post a message to an mbox - may not fail 247 * -> blocks if full, only used from tasks not from ISR 248 * @param mbox mbox to posts the message 249 * @param msg message to post (ATTENTION: can be NULL) 250 */ 251 void sys_mbox_post(sys_mbox_t *mbox, void *msg); 252 /** 253 * @ingroup sys_mbox 254 * Try to post a message to an mbox - may fail if full or ISR 255 * @param mbox mbox to posts the message 256 * @param msg message to post (ATTENTION: can be NULL) 257 */ 258 err_t sys_mbox_trypost(sys_mbox_t *mbox, void *msg); 259 /** 260 * @ingroup sys_mbox 261 * Wait for a new message to arrive in the mbox 262 * @param mbox mbox to get a message from 263 * @param msg pointer where the message is stored 264 * @param timeout maximum time (in milliseconds) to wait for a message (0 = wait forever) 265 * @return time (in milliseconds) waited for a message, may be 0 if not waited 266 or SYS_ARCH_TIMEOUT on timeout 267 * The returned time has to be accurate to prevent timer jitter! 268 */ 269 u32_t sys_arch_mbox_fetch(sys_mbox_t *mbox, void **msg, u32_t timeout); 270 /* Allow port to override with a macro, e.g. special timeout for sys_arch_mbox_fetch() */ 271 #ifndef sys_arch_mbox_tryfetch 272 /** 273 * @ingroup sys_mbox 274 * Wait for a new message to arrive in the mbox 275 * @param mbox mbox to get a message from 276 * @param msg pointer where the message is stored 277 * @return 0 (milliseconds) if a message has been received 278 * or SYS_MBOX_EMPTY if the mailbox is empty 279 */ 280 u32_t sys_arch_mbox_tryfetch(sys_mbox_t *mbox, void **msg); 281 #endif 282 /** 283 * For now, we map straight to sys_arch implementation. 284 */ 285 #define sys_mbox_tryfetch(mbox, msg) sys_arch_mbox_tryfetch(mbox, msg) 286 /** 287 * @ingroup sys_mbox 288 * Delete an mbox 289 * @param mbox mbox to delete 290 */ 291 void sys_mbox_free(sys_mbox_t *mbox); 292 #define sys_mbox_fetch(mbox, msg) sys_arch_mbox_fetch(mbox, msg, 0) 293 #ifndef sys_mbox_valid 294 /** 295 * @ingroup sys_mbox 296 * Check if an mbox is valid/allocated: return 1 for valid, 0 for invalid 297 */ 298 int sys_mbox_valid(sys_mbox_t *mbox); 299 #endif 300 #ifndef sys_mbox_set_invalid 301 /** 302 * @ingroup sys_mbox 303 * Set an mbox invalid so that sys_mbox_valid returns 0 304 */ 305 void sys_mbox_set_invalid(sys_mbox_t *mbox); 306 #endif 307 #ifndef sys_mbox_valid_val 308 /** 309 * Same as sys_mbox_valid() but taking a value, not a pointer 310 */ 311 #define sys_mbox_valid_val(mbox) sys_mbox_valid(&(mbox)) 312 #endif 313 #ifndef sys_mbox_set_invalid_val 314 /** 315 * Same as sys_mbox_set_invalid() but taking a value, not a pointer 316 */ 317 #define sys_mbox_set_invalid_val(mbox) sys_mbox_set_invalid(&(mbox)) 318 #endif 319 320 321 /** 322 * @ingroup sys_misc 323 * The only thread function: 324 * Creates a new thread 325 * ATTENTION: although this function returns a value, it MUST NOT FAIL (ports have to assert this!) 326 * @param name human-readable name for the thread (used for debugging purposes) 327 * @param thread thread-function 328 * @param arg parameter passed to 'thread' 329 * @param stacksize stack size in bytes for the new thread (may be ignored by ports) 330 * @param prio priority of the new thread (may be ignored by ports) */ 331 sys_thread_t sys_thread_new(const char *name, lwip_thread_fn thread, void *arg, int stacksize, int prio); 332 333 #endif /* NO_SYS */ 334 335 /* sys_init() must be called before anything else. */ 336 void sys_init(void); 337 338 #ifndef sys_jiffies 339 /** 340 * Ticks/jiffies since power up. 341 */ 342 u32_t sys_jiffies(void); 343 #endif 344 345 /** 346 * @ingroup sys_time 347 * Returns the current time in milliseconds, 348 * may be the same as sys_jiffies or at least based on it. 349 */ 350 u32_t sys_now(void); 351 352 /* Critical Region Protection */ 353 /* These functions must be implemented in the sys_arch.c file. 354 In some implementations they can provide a more light-weight protection 355 mechanism than using semaphores. Otherwise semaphores can be used for 356 implementation */ 357 #ifndef SYS_ARCH_PROTECT 358 /** SYS_LIGHTWEIGHT_PROT 359 * define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection 360 * for certain critical regions during buffer allocation, deallocation and memory 361 * allocation and deallocation. 362 */ 363 #if SYS_LIGHTWEIGHT_PROT 364 365 /** 366 * @ingroup sys_prot 367 * SYS_ARCH_DECL_PROTECT 368 * declare a protection variable. This macro will default to defining a variable of 369 * type sys_prot_t. If a particular port needs a different implementation, then 370 * this macro may be defined in sys_arch.h. 371 */ 372 #define SYS_ARCH_DECL_PROTECT(lev) sys_prot_t lev 373 /** 374 * @ingroup sys_prot 375 * SYS_ARCH_PROTECT 376 * Perform a "fast" protect. This could be implemented by 377 * disabling interrupts for an embedded system or by using a semaphore or 378 * mutex. The implementation should allow calling SYS_ARCH_PROTECT when 379 * already protected. The old protection level is returned in the variable 380 * "lev". This macro will default to calling the sys_arch_protect() function 381 * which should be implemented in sys_arch.c. If a particular port needs a 382 * different implementation, then this macro may be defined in sys_arch.h 383 */ 384 #define SYS_ARCH_PROTECT(lev) lev = sys_arch_protect() 385 /** 386 * @ingroup sys_prot 387 * SYS_ARCH_UNPROTECT 388 * Perform a "fast" set of the protection level to "lev". This could be 389 * implemented by setting the interrupt level to "lev" within the MACRO or by 390 * using a semaphore or mutex. This macro will default to calling the 391 * sys_arch_unprotect() function which should be implemented in 392 * sys_arch.c. If a particular port needs a different implementation, then 393 * this macro may be defined in sys_arch.h 394 */ 395 #define SYS_ARCH_UNPROTECT(lev) sys_arch_unprotect(lev) 396 sys_prot_t sys_arch_protect(void); 397 void sys_arch_unprotect(sys_prot_t pval); 398 399 #else 400 401 #define SYS_ARCH_DECL_PROTECT(lev) 402 #define SYS_ARCH_PROTECT(lev) 403 #define SYS_ARCH_UNPROTECT(lev) 404 405 #endif /* SYS_LIGHTWEIGHT_PROT */ 406 407 #endif /* SYS_ARCH_PROTECT */ 408 409 /* 410 * Macros to set/get and increase/decrease variables in a thread-safe way. 411 * Use these for accessing variable that are used from more than one thread. 412 */ 413 414 #ifndef SYS_ARCH_INC 415 #define SYS_ARCH_INC(var, val) do { \ 416 SYS_ARCH_DECL_PROTECT(old_level); \ 417 SYS_ARCH_PROTECT(old_level); \ 418 var += val; \ 419 SYS_ARCH_UNPROTECT(old_level); \ 420 } while(0) 421 #endif /* SYS_ARCH_INC */ 422 423 #ifndef SYS_ARCH_DEC 424 #define SYS_ARCH_DEC(var, val) do { \ 425 SYS_ARCH_DECL_PROTECT(old_level); \ 426 SYS_ARCH_PROTECT(old_level); \ 427 var -= val; \ 428 SYS_ARCH_UNPROTECT(old_level); \ 429 } while(0) 430 #endif /* SYS_ARCH_DEC */ 431 432 #ifndef SYS_ARCH_GET 433 #define SYS_ARCH_GET(var, ret) do { \ 434 SYS_ARCH_DECL_PROTECT(old_level); \ 435 SYS_ARCH_PROTECT(old_level); \ 436 ret = var; \ 437 SYS_ARCH_UNPROTECT(old_level); \ 438 } while(0) 439 #endif /* SYS_ARCH_GET */ 440 441 #ifndef SYS_ARCH_SET 442 #define SYS_ARCH_SET(var, val) do { \ 443 SYS_ARCH_DECL_PROTECT(old_level); \ 444 SYS_ARCH_PROTECT(old_level); \ 445 var = val; \ 446 SYS_ARCH_UNPROTECT(old_level); \ 447 } while(0) 448 #endif /* SYS_ARCH_SET */ 449 450 451 #ifdef __cplusplus 452 } 453 #endif 454 455 #endif /* LWIP_HDR_SYS_H */ 456