sys.h

Go to the documentation of this file.

/*
 * 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_HDR_SYS_H
#define LWIP_HDR_SYS_H

#include "lwip/opt.h"

#ifdef __cplusplus
extern "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_mutex_t;
typedef u8_t sys_mbox_t;

#define sys_sem_new(s, c) ERR_OK
#define sys_sem_signal(s)
#define sys_sem_wait(s)
#define sys_arch_sem_wait(s,t)
#define sys_sem_free(s)
#define sys_sem_valid(s) 0
#define sys_sem_valid_val(s) 0
#define sys_sem_set_invalid(s)
#define sys_sem_set_invalid_val(s)
#define sys_mutex_new(mu) ERR_OK
#define sys_mutex_lock(mu)
#define sys_mutex_unlock(mu)
#define sys_mutex_free(mu)
#define sys_mutex_valid(mu) 0
#define sys_mutex_set_invalid(mu)
#define sys_mbox_new(m, s) ERR_OK
#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_mbox_valid(m)
#define sys_mbox_valid_val(m)
#define sys_mbox_set_invalid(m)
#define sys_mbox_set_invalid_val(m)

#define sys_thread_new(n,t,a,s,p)

#define sys_msleep(t)

#else /* NO_SYS */

#define SYS_ARCH_TIMEOUT 0xffffffffUL

#define SYS_MBOX_EMPTY SYS_ARCH_TIMEOUT

#include "lwip/err.h"
#include "arch/sys_arch.h"

typedef void (*lwip_thread_fn)(void *arg);

/* Function prototypes for functions to be implemented by platform ports
   (in sys_arch.c) */

/* Mutex functions: */

#if LWIP_COMPAT_MUTEX
/* for old ports that don't have mutexes: define them to binary semaphores */
#define sys_mutex_t                   sys_sem_t
#define sys_mutex_new(mutex)          sys_sem_new(mutex, 1)
#define sys_mutex_lock(mutex)         sys_sem_wait(mutex)
#define sys_mutex_unlock(mutex)       sys_sem_signal(mutex)
#define sys_mutex_free(mutex)         sys_sem_free(mutex)
#define sys_mutex_valid(mutex)        sys_sem_valid(mutex)
#define sys_mutex_set_invalid(mutex)  sys_sem_set_invalid(mutex)

#else /* LWIP_COMPAT_MUTEX */

err_t sys_mutex_new(sys_mutex_t *mutex);
void sys_mutex_lock(sys_mutex_t *mutex);
void sys_mutex_unlock(sys_mutex_t *mutex);
void sys_mutex_free(sys_mutex_t *mutex);
#ifndef sys_mutex_valid

int sys_mutex_valid(sys_mutex_t *mutex);
#endif
#ifndef sys_mutex_set_invalid

void sys_mutex_set_invalid(sys_mutex_t *mutex);
#endif
#endif /* LWIP_COMPAT_MUTEX */

/* Semaphore functions: */

err_t sys_sem_new(sys_sem_t *sem, 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);
#define sys_sem_wait(sem)                  sys_arch_sem_wait(sem, 0)
#ifndef sys_sem_valid

int sys_sem_valid(sys_sem_t *sem);
#endif
#ifndef sys_sem_set_invalid

void sys_sem_set_invalid(sys_sem_t *sem);
#endif
#ifndef sys_sem_valid_val

#define sys_sem_valid_val(sem)       sys_sem_valid(&(sem))
#endif
#ifndef sys_sem_set_invalid_val

#define sys_sem_set_invalid_val(sem) sys_sem_set_invalid(&(sem))
#endif

/* Time functions. */
#ifndef sys_msleep
void sys_msleep(u32_t ms); /* only has a (close to) 1 ms resolution. */
#endif

/* Mailbox functions. */

err_t sys_mbox_new(sys_mbox_t *mbox, 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);
/* Allow port to override with a macro, e.g. special timeout for sys_arch_mbox_fetch() */
#ifndef sys_arch_mbox_tryfetch

u32_t sys_arch_mbox_tryfetch(sys_mbox_t *mbox, void **msg);
#endif

#define sys_mbox_tryfetch(mbox, msg) sys_arch_mbox_tryfetch(mbox, msg)

void sys_mbox_free(sys_mbox_t *mbox);
#define sys_mbox_fetch(mbox, msg) sys_arch_mbox_fetch(mbox, msg, 0)
#ifndef sys_mbox_valid

int sys_mbox_valid(sys_mbox_t *mbox);
#endif
#ifndef sys_mbox_set_invalid

void sys_mbox_set_invalid(sys_mbox_t *mbox);
#endif
#ifndef sys_mbox_valid_val

#define sys_mbox_valid_val(mbox)       sys_mbox_valid(&(mbox))
#endif
#ifndef sys_mbox_set_invalid_val

#define sys_mbox_set_invalid_val(mbox) sys_mbox_set_invalid(&(mbox))
#endif


sys_thread_t sys_thread_new(const char *name, lwip_thread_fn thread, void *arg, int stacksize, int prio);

#endif /* NO_SYS */

/* sys_init() must be called before anything else. */
void sys_init(void);

#ifndef sys_jiffies

u32_t sys_jiffies(void);
#endif

u32_t sys_now(void);

/* 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

#if SYS_LIGHTWEIGHT_PROT

#define SYS_ARCH_DECL_PROTECT(lev) sys_prot_t lev

#define SYS_ARCH_PROTECT(lev) lev = sys_arch_protect()

#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_HDR_SYS_H */