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 (at) 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_mutex_new(mu) ERR_OK 55 #define sys_mutex_lock(mu) 56 #define sys_mutex_unlock(mu) 57 #define sys_mutex_free(mu) 58 #define sys_mbox_new(m, s) ERR_OK 59 #define sys_mbox_fetch(m,d) 60 #define sys_mbox_tryfetch(m,d) 61 #define sys_mbox_post(m,d) 62 #define sys_mbox_trypost(m,d) 63 #define sys_mbox_free(m) 64 65 #define sys_thread_new(n,t,a,s,p) 66 67 #define sys_msleep(t) 68 69 #else /* NO_SYS */ 70 71 /** Return code for timeouts from sys_arch_mbox_fetch and sys_arch_sem_wait */ 72 #define SYS_ARCH_TIMEOUT 0xffffffffUL 73 74 /** sys_mbox_tryfetch() returns SYS_MBOX_EMPTY if appropriate. 75 * For now we use the same magic value, but we allow this to change in future. 76 */ 77 #define SYS_MBOX_EMPTY SYS_ARCH_TIMEOUT 78 79 #include "lwip/err.h" 80 #include "arch/sys_arch.h" 81 82 /** Function prototype for thread functions */ 83 typedef void (*lwip_thread_fn)(void *arg); 84 85 /* Function prototypes for functions to be implemented by platform ports 86 (in sys_arch.c) */ 87 88 /* Mutex functions: */ 89 90 /** Define LWIP_COMPAT_MUTEX if the port has no mutexes and binary semaphores 91 should be used instead */ 92 #if LWIP_COMPAT_MUTEX 93 /* for old ports that don't have mutexes: define them to binary semaphores */ 94 #define sys_mutex_t sys_sem_t 95 #define sys_mutex_new(mutex) sys_sem_new(mutex, 1) 96 #define sys_mutex_lock(mutex) sys_sem_wait(mutex) 97 #define sys_mutex_unlock(mutex) sys_sem_signal(mutex) 98 #define sys_mutex_free(mutex) sys_sem_free(mutex) 99 #define sys_mutex_valid(mutex) sys_sem_valid(mutex) 100 #define sys_mutex_set_invalid(mutex) sys_sem_set_invalid(mutex) 101 102 #else /* LWIP_COMPAT_MUTEX */ 103 104 /** Create a new mutex 105 * @param mutex pointer to the mutex to create 106 * @return a new mutex */ 107 err_t sys_mutex_new(sys_mutex_t *mutex); 108 /** Lock a mutex 109 * @param mutex the mutex to lock */ 110 void sys_mutex_lock(sys_mutex_t *mutex); 111 /** Unlock a mutex 112 * @param mutex the mutex to unlock */ 113 void sys_mutex_unlock(sys_mutex_t *mutex); 114 /** Delete a semaphore 115 * @param mutex the mutex to delete */ 116 void sys_mutex_free(sys_mutex_t *mutex); 117 #ifndef sys_mutex_valid 118 /** Check if a mutex is valid/allocated: return 1 for valid, 0 for invalid */ 119 int sys_mutex_valid(sys_mutex_t *mutex); 120 #endif 121 #ifndef sys_mutex_set_invalid 122 /** Set a mutex invalid so that sys_mutex_valid returns 0 */ 123 void sys_mutex_set_invalid(sys_mutex_t *mutex); 124 #endif 125 #endif /* LWIP_COMPAT_MUTEX */ 126 127 /* Semaphore functions: */ 128 129 /** Create a new semaphore 130 * @param sem pointer to the semaphore to create 131 * @param count initial count of the semaphore 132 * @return ERR_OK if successful, another err_t otherwise */ 133 err_t sys_sem_new(sys_sem_t *sem, u8_t count); 134 /** Signals a semaphore 135 * @param sem the semaphore to signal */ 136 void sys_sem_signal(sys_sem_t *sem); 137 /** Wait for a semaphore for the specified timeout 138 * @param sem the semaphore to wait for 139 * @param timeout timeout in milliseconds to wait (0 = wait forever) 140 * @return time (in milliseconds) waited for the semaphore 141 * or SYS_ARCH_TIMEOUT on timeout */ 142 u32_t sys_arch_sem_wait(sys_sem_t *sem, u32_t timeout); 143 /** Delete a semaphore 144 * @param sem semaphore to delete */ 145 void sys_sem_free(sys_sem_t *sem); 146 /** Wait for a semaphore - forever/no timeout */ 147 #define sys_sem_wait(sem) sys_arch_sem_wait(sem, 0) 148 #ifndef sys_sem_valid 149 /** Check if a sempahore is valid/allocated: return 1 for valid, 0 for invalid */ 150 int sys_sem_valid(sys_sem_t *sem); 151 #endif 152 #ifndef sys_sem_set_invalid 153 /** Set a semaphore invalid so that sys_sem_valid returns 0 */ 154 void sys_sem_set_invalid(sys_sem_t *sem); 155 #endif 156 157 /* Time functions. */ 158 #ifndef sys_msleep 159 void sys_msleep(u32_t ms); /* only has a (close to) 1 jiffy resolution. */ 160 #endif 161 162 /* Mailbox functions. */ 163 164 /** Create a new mbox of specified size 165 * @param mbox pointer to the mbox to create 166 * @param size (miminum) number of messages in this mbox 167 * @return ERR_OK if successful, another err_t otherwise */ 168 err_t sys_mbox_new(sys_mbox_t *mbox, int size); 169 /** Post a message to an mbox - may not fail 170 * -> blocks if full, only used from tasks not from ISR 171 * @param mbox mbox to posts the message 172 * @param msg message to post (ATTENTION: can be NULL) */ 173 void sys_mbox_post(sys_mbox_t *mbox, void *msg); 174 /** Try to post a message to an mbox - may fail if full or ISR 175 * @param mbox mbox to posts the message 176 * @param msg message to post (ATTENTION: can be NULL) */ 177 err_t sys_mbox_trypost(sys_mbox_t *mbox, void *msg); 178 /** Wait for a new message to arrive in the mbox 179 * @param mbox mbox to get a message from 180 * @param msg pointer where the message is stored 181 * @param timeout maximum time (in milliseconds) to wait for a message 182 * @return time (in milliseconds) waited for a message, may be 0 if not waited 183 or SYS_ARCH_TIMEOUT on timeout 184 * The returned time has to be accurate to prevent timer jitter! */ 185 u32_t sys_arch_mbox_fetch(sys_mbox_t *mbox, void **msg, u32_t timeout); 186 /* Allow port to override with a macro, e.g. special timout for sys_arch_mbox_fetch() */ 187 #ifndef sys_arch_mbox_tryfetch 188 /** Wait for a new message to arrive in the mbox 189 * @param mbox mbox to get a message from 190 * @param msg pointer where the message is stored 191 * @param timeout maximum time (in milliseconds) to wait for a message 192 * @return 0 (milliseconds) if a message has been received 193 * or SYS_MBOX_EMPTY if the mailbox is empty */ 194 u32_t sys_arch_mbox_tryfetch(sys_mbox_t *mbox, void **msg); 195 #endif 196 /** For now, we map straight to sys_arch implementation. */ 197 #define sys_mbox_tryfetch(mbox, msg) sys_arch_mbox_tryfetch(mbox, msg) 198 /** Delete an mbox 199 * @param mbox mbox to delete */ 200 void sys_mbox_free(sys_mbox_t *mbox); 201 #define sys_mbox_fetch(mbox, msg) sys_arch_mbox_fetch(mbox, msg, 0) 202 #ifndef sys_mbox_valid 203 /** Check if an mbox is valid/allocated: return 1 for valid, 0 for invalid */ 204 int sys_mbox_valid(sys_mbox_t *mbox); 205 #endif 206 #ifndef sys_mbox_set_invalid 207 /** Set an mbox invalid so that sys_mbox_valid returns 0 */ 208 void sys_mbox_set_invalid(sys_mbox_t *mbox); 209 #endif 210 211 /** The only thread function: 212 * Creates a new thread 213 * @param name human-readable name for the thread (used for debugging purposes) 214 * @param thread thread-function 215 * @param arg parameter passed to 'thread' 216 * @param stacksize stack size in bytes for the new thread (may be ignored by ports) 217 * @param prio priority of the new thread (may be ignored by ports) */ 218 sys_thread_t sys_thread_new(const char *name, lwip_thread_fn thread, void *arg, int stacksize, int prio); 219 220 #endif /* NO_SYS */ 221 222 /* sys_init() must be called before anthing else. */ 223 void sys_init(void); 224 225 #ifndef sys_jiffies 226 /** Ticks/jiffies since power up. */ 227 u32_t sys_jiffies(void); 228 #endif 229 230 /** Returns the current time in milliseconds, 231 * may be the same as sys_jiffies or at least based on it. */ 232 u32_t sys_now(void); 233 234 /* Critical Region Protection */ 235 /* These functions must be implemented in the sys_arch.c file. 236 In some implementations they can provide a more light-weight protection 237 mechanism than using semaphores. Otherwise semaphores can be used for 238 implementation */ 239 #ifndef SYS_ARCH_PROTECT 240 /** SYS_LIGHTWEIGHT_PROT 241 * define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection 242 * for certain critical regions during buffer allocation, deallocation and memory 243 * allocation and deallocation. 244 */ 245 #if SYS_LIGHTWEIGHT_PROT 246 247 /** SYS_ARCH_DECL_PROTECT 248 * declare a protection variable. This macro will default to defining a variable of 249 * type sys_prot_t. If a particular port needs a different implementation, then 250 * this macro may be defined in sys_arch.h. 251 */ 252 #define SYS_ARCH_DECL_PROTECT(lev) sys_prot_t lev 253 /** SYS_ARCH_PROTECT 254 * Perform a "fast" protect. This could be implemented by 255 * disabling interrupts for an embedded system or by using a semaphore or 256 * mutex. The implementation should allow calling SYS_ARCH_PROTECT when 257 * already protected. The old protection level is returned in the variable 258 * "lev". This macro will default to calling the sys_arch_protect() function 259 * which should be implemented in sys_arch.c. If a particular port needs a 260 * different implementation, then this macro may be defined in sys_arch.h 261 */ 262 #define SYS_ARCH_PROTECT(lev) lev = sys_arch_protect() 263 /** SYS_ARCH_UNPROTECT 264 * Perform a "fast" set of the protection level to "lev". This could be 265 * implemented by setting the interrupt level to "lev" within the MACRO or by 266 * using a semaphore or mutex. This macro will default to calling the 267 * sys_arch_unprotect() function which should be implemented in 268 * sys_arch.c. If a particular port needs a different implementation, then 269 * this macro may be defined in sys_arch.h 270 */ 271 #define SYS_ARCH_UNPROTECT(lev) sys_arch_unprotect(lev) 272 sys_prot_t sys_arch_protect(void); 273 void sys_arch_unprotect(sys_prot_t pval); 274 275 #else 276 277 #define SYS_ARCH_DECL_PROTECT(lev) 278 #define SYS_ARCH_PROTECT(lev) 279 #define SYS_ARCH_UNPROTECT(lev) 280 281 #endif /* SYS_LIGHTWEIGHT_PROT */ 282 283 #endif /* SYS_ARCH_PROTECT */ 284 285 /* 286 * Macros to set/get and increase/decrease variables in a thread-safe way. 287 * Use these for accessing variable that are used from more than one thread. 288 */ 289 290 #ifndef SYS_ARCH_INC 291 #define SYS_ARCH_INC(var, val) do { \ 292 SYS_ARCH_DECL_PROTECT(old_level); \ 293 SYS_ARCH_PROTECT(old_level); \ 294 var += val; \ 295 SYS_ARCH_UNPROTECT(old_level); \ 296 } while(0) 297 #endif /* SYS_ARCH_INC */ 298 299 #ifndef SYS_ARCH_DEC 300 #define SYS_ARCH_DEC(var, val) do { \ 301 SYS_ARCH_DECL_PROTECT(old_level); \ 302 SYS_ARCH_PROTECT(old_level); \ 303 var -= val; \ 304 SYS_ARCH_UNPROTECT(old_level); \ 305 } while(0) 306 #endif /* SYS_ARCH_DEC */ 307 308 #ifndef SYS_ARCH_GET 309 #define SYS_ARCH_GET(var, ret) do { \ 310 SYS_ARCH_DECL_PROTECT(old_level); \ 311 SYS_ARCH_PROTECT(old_level); \ 312 ret = var; \ 313 SYS_ARCH_UNPROTECT(old_level); \ 314 } while(0) 315 #endif /* SYS_ARCH_GET */ 316 317 #ifndef SYS_ARCH_SET 318 #define SYS_ARCH_SET(var, val) do { \ 319 SYS_ARCH_DECL_PROTECT(old_level); \ 320 SYS_ARCH_PROTECT(old_level); \ 321 var = val; \ 322 SYS_ARCH_UNPROTECT(old_level); \ 323 } while(0) 324 #endif /* SYS_ARCH_SET */ 325 326 327 #ifdef __cplusplus 328 } 329 #endif 330 331 #endif /* __LWIP_SYS_H__ */ 332
