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