lib/drivers/lwip/src/include/lwip/sys.h

   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_mbox_t;
  47 struct sys_timeo {u8_t dummy;};
  48
  49 #define sys_init()
  50 #define sys_timeout(m,h,a)
  51 #define sys_untimeout(m,a)
  52 #define sys_sem_new(c) c
  53 #define sys_sem_signal(s)
  54 #define sys_sem_wait(s)
  55 #define sys_sem_wait_timeout(s,t)
  56 #define sys_arch_sem_wait(s,t)
  57 #define sys_sem_free(s)
  58 #define sys_mbox_new(s) 0
  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 #else /* NO_SYS */
  68
  69 /** Return code for timeouts from sys_arch_mbox_fetch and sys_arch_sem_wait */
  70 #define SYS_ARCH_TIMEOUT 0xffffffffUL
  71
  72 /* sys_mbox_tryfetch returns SYS_MBOX_EMPTY if appropriate.
  73  * For now we use the same magic value, but we allow this to change in future.
  74  */
  75 #define SYS_MBOX_EMPTY SYS_ARCH_TIMEOUT
  76
  77 #include "lwip/err.h"
  78 #include "arch/sys_arch.h"
  79
  80 typedef void (* sys_timeout_handler)(void *arg);
  81
  82 struct sys_timeo {
  83   struct sys_timeo *next;
  84   u32_t time;
  85   sys_timeout_handler h;
  86   void *arg;
  87 };
  88
  89 struct sys_timeouts {
  90   struct sys_timeo *next;
  91 };
  92
  93 /* sys_init() must be called before anthing else. */
  94 void sys_init(void);
  95
  96 /*
  97  * sys_timeout():
  98  *
  99  * Schedule a timeout a specified amount of milliseconds in the
 100  * future. When the timeout occurs, the specified timeout handler will
 101  * be called. The handler will be passed the "arg" argument when
 102  * called.
 103  *
 104  */
 105 void sys_timeout(u32_t msecs, sys_timeout_handler h, void *arg);
 106 void sys_untimeout(sys_timeout_handler h, void *arg);
 107 struct sys_timeouts *sys_arch_timeouts(void);
 108
 109 /* Semaphore functions. */
 110 sys_sem_t sys_sem_new(u8_t count);
 111 void sys_sem_signal(sys_sem_t sem);
 112 u32_t sys_arch_sem_wait(sys_sem_t sem, u32_t timeout);
 113 void sys_sem_free(sys_sem_t sem);
 114 void sys_sem_wait(sys_sem_t sem);
 115 int sys_sem_wait_timeout(sys_sem_t sem, u32_t timeout);
 116
 117 /* Time functions. */
 118 #ifndef sys_msleep
 119 void sys_msleep(u32_t ms); /* only has a (close to) 1 jiffy resolution. */
 120 #endif
 121 #ifndef sys_jiffies
 122 u32_t sys_jiffies(void); /* since power up. */
 123 #endif
 124
 125 /* Mailbox functions. */
 126 sys_mbox_t sys_mbox_new(int size);
 127 void sys_mbox_post(sys_mbox_t mbox, void *msg);
 128 err_t sys_mbox_trypost(sys_mbox_t mbox, void *msg);
 129 u32_t sys_arch_mbox_fetch(sys_mbox_t mbox, void **msg, u32_t timeout);
 130 #ifndef sys_arch_mbox_tryfetch /* Allow port to override with a macro */
 131 u32_t sys_arch_mbox_tryfetch(sys_mbox_t mbox, void **msg);
 132 #endif
 133 /* For now, we map straight to sys_arch implementation. */
 134 #define sys_mbox_tryfetch(mbox, msg) sys_arch_mbox_tryfetch(mbox, msg)
 135 void sys_mbox_free(sys_mbox_t mbox);
 136 void sys_mbox_fetch(sys_mbox_t mbox, void **msg);
 137
 138 /* Thread functions. */
 139 sys_thread_t sys_thread_new(char *name, void (* thread)(void *arg), void *arg, int stacksize, int prio);
 140
 141 #endif /* NO_SYS */
 142
 143 /** Returns the current time in milliseconds. */
 144 u32_t sys_now(void);
 145
 146 /* Critical Region Protection */
 147 /* These functions must be implemented in the sys_arch.c file.
 148    In some implementations they can provide a more light-weight protection
 149    mechanism than using semaphores. Otherwise semaphores can be used for
 150    implementation */
 151 #ifndef SYS_ARCH_PROTECT
 152 /** SYS_LIGHTWEIGHT_PROT
 153  * define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection
 154  * for certain critical regions during buffer allocation, deallocation and memory
 155  * allocation and deallocation.
 156  */
 157 #if SYS_LIGHTWEIGHT_PROT
 158
 159 /** SYS_ARCH_DECL_PROTECT
 160  * declare a protection variable. This macro will default to defining a variable of
 161  * type sys_prot_t. If a particular port needs a different implementation, then
 162  * this macro may be defined in sys_arch.h.
 163  */
 164 #define SYS_ARCH_DECL_PROTECT(lev) sys_prot_t lev
 165 /** SYS_ARCH_PROTECT
 166  * Perform a "fast" protect. This could be implemented by
 167  * disabling interrupts for an embedded system or by using a semaphore or
 168  * mutex. The implementation should allow calling SYS_ARCH_PROTECT when
 169  * already protected. The old protection level is returned in the variable
 170  * "lev". This macro will default to calling the sys_arch_protect() function
 171  * which should be implemented in sys_arch.c. If a particular port needs a
 172  * different implementation, then this macro may be defined in sys_arch.h
 173  */
 174 #define SYS_ARCH_PROTECT(lev) lev = sys_arch_protect()
 175 /** SYS_ARCH_UNPROTECT
 176  * Perform a "fast" set of the protection level to "lev". This could be
 177  * implemented by setting the interrupt level to "lev" within the MACRO or by
 178  * using a semaphore or mutex.  This macro will default to calling the
 179  * sys_arch_unprotect() function which should be implemented in
 180  * sys_arch.c. If a particular port needs a different implementation, then
 181  * this macro may be defined in sys_arch.h
 182  */
 183 #define SYS_ARCH_UNPROTECT(lev) sys_arch_unprotect(lev)
 184 sys_prot_t sys_arch_protect(void);
 185 void sys_arch_unprotect(sys_prot_t pval);
 186
 187 #else
 188
 189 #define SYS_ARCH_DECL_PROTECT(lev)
 190 #define SYS_ARCH_PROTECT(lev)
 191 #define SYS_ARCH_UNPROTECT(lev)
 192
 193 #endif /* SYS_LIGHTWEIGHT_PROT */
 194
 195 #endif /* SYS_ARCH_PROTECT */
 196
 197 /*
 198  * Macros to set/get and increase/decrease variables in a thread-safe way.
 199  * Use these for accessing variable that are used from more than one thread.
 200  */
 201
 202 #ifndef SYS_ARCH_INC
 203 #define SYS_ARCH_INC(var, val) do { \
 204                                 SYS_ARCH_DECL_PROTECT(old_level); \
 205                                 SYS_ARCH_PROTECT(old_level); \
 206                                 var += val; \
 207                                 SYS_ARCH_UNPROTECT(old_level); \
 208                               } while(0)
 209 #endif /* SYS_ARCH_INC */
 210
 211 #ifndef SYS_ARCH_DEC
 212 #define SYS_ARCH_DEC(var, val) do { \
 213                                 SYS_ARCH_DECL_PROTECT(old_level); \
 214                                 SYS_ARCH_PROTECT(old_level); \
 215                                 var -= val; \
 216                                 SYS_ARCH_UNPROTECT(old_level); \
 217                               } while(0)
 218 #endif /* SYS_ARCH_DEC */
 219
 220 #ifndef SYS_ARCH_GET
 221 #define SYS_ARCH_GET(var, ret) do { \
 222                                 SYS_ARCH_DECL_PROTECT(old_level); \
 223                                 SYS_ARCH_PROTECT(old_level); \
 224                                 ret = var; \
 225                                 SYS_ARCH_UNPROTECT(old_level); \
 226                               } while(0)
 227 #endif /* SYS_ARCH_GET */
 228
 229 #ifndef SYS_ARCH_SET
 230 #define SYS_ARCH_SET(var, val) do { \
 231                                 SYS_ARCH_DECL_PROTECT(old_level); \
 232                                 SYS_ARCH_PROTECT(old_level); \
 233                                 var = val; \
 234                                 SYS_ARCH_UNPROTECT(old_level); \
 235                               } while(0)
 236 #endif /* SYS_ARCH_SET */
 237
 238
 239 #ifdef __cplusplus
 240 }
 241 #endif
 242
 243 #endif /* __LWIP_SYS_H__ */