/* * Copyright (c) 2001-2004 Swedish Institute of Computer Science. * All rights reserved.  *  * Redistribution and use in source and binary forms, with or without modification,  * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, *    this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, *    this list of conditions and the following disclaimer in the documentation *    and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products *    derived from this software without specific prior written permission.  * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY  * OF SUCH DAMAGE. * * This file is part of the lwIP TCP/IP stack. *  * Author: Adam Dunkels <adam@sics.se> * */#ifndef __LWIP_SYS_H__#define __LWIP_SYS_H__#include "lwip/opt.h"#ifdef __cplusplusextern "C" {#endif#if NO_SYS/* For a totally minimal and standalone system, we provide null   definitions of the sys_ functions. */typedef u8_t sys_sem_t;typedef u8_t sys_mbox_t;typedef u8_t sys_prot_t;struct sys_timeo {u8_t dummy;};#define sys_init()#define sys_timeout(m,h,a)#define sys_untimeout(m,a)#define sys_sem_new(c) c#define sys_sem_signal(s)#define sys_sem_wait(s)#define sys_sem_wait_timeout(s,t)#define sys_arch_sem_wait(s,t)#define sys_sem_free(s)#define sys_mbox_new(s) 0#define sys_mbox_fetch(m,d)#define sys_mbox_tryfetch(m,d)#define sys_mbox_post(m,d)#define sys_mbox_trypost(m,d)#define sys_mbox_free(m)#define sys_thread_new(n,t,a,s,p)#else /* NO_SYS *//** Return code for timeouts from sys_arch_mbox_fetch and sys_arch_sem_wait */#define SYS_ARCH_TIMEOUT 0xffffffffUL/* sys_mbox_tryfetch returns SYS_MBOX_EMPTY if appropriate. * For now we use the same magic value, but we allow this to change in future. */#define SYS_MBOX_EMPTY SYS_ARCH_TIMEOUT #include "lwip/err.h"#include "arch/sys_arch.h"typedef void (* sys_timeout_handler)(void *arg);struct sys_timeo {  struct sys_timeo *next;  u32_t time;  sys_timeout_handler h;  void *arg;};struct sys_timeouts {  struct sys_timeo *next;};/* sys_init() must be called before anthing else. */void sys_init(void);/* * sys_timeout(): * * Schedule a timeout a specified amount of milliseconds in the * future. When the timeout occurs, the specified timeout handler will * be called. The handler will be passed the "arg" argument when * called. * */void sys_timeout(u32_t msecs, sys_timeout_handler h, void *arg);void sys_untimeout(sys_timeout_handler h, void *arg);struct sys_timeouts *sys_arch_timeouts(void);/* Semaphore functions. */sys_sem_t sys_sem_new(u8_t count);void sys_sem_signal(sys_sem_t sem);u32_t sys_arch_sem_wait(sys_sem_t sem, u32_t timeout);void sys_sem_free(sys_sem_t sem);void sys_sem_wait(sys_sem_t sem);int sys_sem_wait_timeout(sys_sem_t sem, u32_t timeout);/* Time functions. */#ifndef sys_msleepvoid sys_msleep(u32_t ms); /* only has a (close to) 1 jiffy resolution. */#endif#ifndef sys_jiffiesu32_t sys_jiffies(void); /* since power up. */#endif/* Mailbox functions. */sys_mbox_t sys_mbox_new(int size);void sys_mbox_post(sys_mbox_t mbox, void *msg);err_t sys_mbox_trypost(sys_mbox_t mbox, void *msg);u32_t sys_arch_mbox_fetch(sys_mbox_t mbox, void **msg, u32_t timeout);#ifndef sys_arch_mbox_tryfetch /* Allow port to override with a macro */u32_t sys_arch_mbox_tryfetch(sys_mbox_t mbox, void **msg);#endif/* For now, we map straight to sys_arch implementation. */#define sys_mbox_tryfetch(mbox, msg) sys_arch_mbox_tryfetch(mbox, msg)void sys_mbox_free(sys_mbox_t mbox);void sys_mbox_fetch(sys_mbox_t mbox, void **msg);/* Thread functions. */sys_thread_t sys_thread_new(char *name, void (* thread)(void *arg), void *arg, int stacksize, int prio);/* The following functions are used only in Unix code, and   can be omitted when porting the stack. *//* Returns the current time in microseconds. */unsigned long sys_now(void);#endif /* NO_SYS *//* Critical Region Protection *//* These functions must be implemented in the sys_arch.c file.   In some implementations they can provide a more light-weight protection   mechanism than using semaphores. Otherwise semaphores can be used for   implementation */#ifndef SYS_ARCH_PROTECT/** SYS_LIGHTWEIGHT_PROT * define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection * for certain critical regions during buffer allocation, deallocation and memory * allocation and deallocation. */#if SYS_LIGHTWEIGHT_PROT/** SYS_ARCH_DECL_PROTECT * declare a protection variable. This macro will default to defining a variable of * type sys_prot_t. If a particular port needs a different implementation, then * this macro may be defined in sys_arch.h. */#define SYS_ARCH_DECL_PROTECT(lev) sys_prot_t lev/** SYS_ARCH_PROTECT * Perform a "fast" protect. This could be implemented by * disabling interrupts for an embedded system or by using a semaphore or * mutex. The implementation should allow calling SYS_ARCH_PROTECT when * already protected. The old protection level is returned in the variable * "lev". This macro will default to calling the sys_arch_protect() function * which should be implemented in sys_arch.c. If a particular port needs a * different implementation, then this macro may be defined in sys_arch.h */#define SYS_ARCH_PROTECT(lev) lev = sys_arch_protect()/** SYS_ARCH_UNPROTECT * Perform a "fast" set of the protection level to "lev". This could be * implemented by setting the interrupt level to "lev" within the MACRO or by * using a semaphore or mutex.  This macro will default to calling the * sys_arch_unprotect() function which should be implemented in * sys_arch.c. If a particular port needs a different implementation, then * this macro may be defined in sys_arch.h */#define SYS_ARCH_UNPROTECT(lev) sys_arch_unprotect(lev)sys_prot_t sys_arch_protect(void);void sys_arch_unprotect(sys_prot_t pval);#else#define SYS_ARCH_DECL_PROTECT(lev)#define SYS_ARCH_PROTECT(lev)#define SYS_ARCH_UNPROTECT(lev)#endif /* SYS_LIGHTWEIGHT_PROT */#endif /* SYS_ARCH_PROTECT *//* * Macros to set/get and increase/decrease variables in a thread-safe way. * Use these for accessing variable that are used from more than one thread. */#ifndef SYS_ARCH_INC#define SYS_ARCH_INC(var, val) do { \                                SYS_ARCH_DECL_PROTECT(old_level); \                                SYS_ARCH_PROTECT(old_level); \                                var += val; \                                SYS_ARCH_UNPROTECT(old_level); \                              } while(0)#endif /* SYS_ARCH_INC */#ifndef SYS_ARCH_DEC#define SYS_ARCH_DEC(var, val) do { \                                SYS_ARCH_DECL_PROTECT(old_level); \                                SYS_ARCH_PROTECT(old_level); \                                var -= val; \                                SYS_ARCH_UNPROTECT(old_level); \                              } while(0)#endif /* SYS_ARCH_DEC */#ifndef SYS_ARCH_GET#define SYS_ARCH_GET(var, ret) do { \                                SYS_ARCH_DECL_PROTECT(old_level); \                                SYS_ARCH_PROTECT(old_level); \                                ret = var; \                                SYS_ARCH_UNPROTECT(old_level); \                              } while(0)#endif /* SYS_ARCH_GET */#ifndef SYS_ARCH_SET#define SYS_ARCH_SET(var, val) do { \                                SYS_ARCH_DECL_PROTECT(old_level); \                                SYS_ARCH_PROTECT(old_level); \                                var = val; \                                SYS_ARCH_UNPROTECT(old_level); \                              } while(0)#endif /* SYS_ARCH_SET */#ifdef __cplusplus}#endif#endif /* __LWIP_SYS_H__ */