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
38extern "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 {
48        u8_t dummy;
49    };
50
51#define sys_init()
52#define sys_timeout(m,h,a)
53#define sys_untimeout(m,a)
54#define sys_sem_new(c) c
55#define sys_sem_signal(s)
56#define sys_sem_wait(s)
57#define sys_sem_wait_timeout(s,t)
58#define sys_arch_sem_wait(s,t)
59#define sys_sem_free(s)
60#define sys_mbox_new(s) 0
61#define sys_mbox_fetch(m,d)
62#define sys_mbox_tryfetch(m,d)
63#define sys_mbox_post(m,d)
64#define sys_mbox_trypost(m,d)
65#define sys_mbox_free(m)
66
67#define sys_thread_new(n,t,a,s,p)
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    typedef void (*sys_timeout_handler) (void *arg);
83
84    struct sys_timeo {
85        struct sys_timeo *next;
86        u32_t time;
87        sys_timeout_handler h;
88        void *arg;
89    };
90
91    struct sys_timeouts {
92        struct sys_timeo *next;
93    };
94
95/* sys_init() must be called before anthing else. */
96    void sys_init(void);
97
98/*
99 * sys_timeout():
100 *
101 * Schedule a timeout a specified amount of milliseconds in the
102 * future. When the timeout occurs, the specified timeout handler will
103 * be called. The handler will be passed the "arg" argument when
104 * called.
105 *
106 */
107    void sys_timeout(u32_t msecs, sys_timeout_handler h, void *arg);
108    void sys_untimeout(sys_timeout_handler h, void *arg);
109    struct sys_timeouts *sys_arch_timeouts(void);
110
111/* Semaphore functions. */
112    sys_sem_t sys_sem_new(u8_t count);
113    void sys_sem_signal(sys_sem_t sem);
114    u32_t sys_arch_sem_wait(sys_sem_t sem, u32_t timeout);
115    void sys_sem_free(sys_sem_t sem);
116    void sys_sem_wait(sys_sem_t sem);
117    int sys_sem_wait_timeout(sys_sem_t sem, u32_t timeout);
118
119/* Time functions. */
120#ifndef sys_msleep
121    void sys_msleep(u32_t ms);  /* only has a (close to) 1 jiffy resolution. */
122#endif
123#ifndef sys_jiffies
124    u32_t sys_jiffies(void);    /* since power up. */
125#endif
126
127/* Mailbox functions. */
128    sys_mbox_t sys_mbox_new(int size);
129    void sys_mbox_post(sys_mbox_t mbox, void *msg);
130    err_t sys_mbox_trypost(sys_mbox_t mbox, void *msg);
131    u32_t sys_arch_mbox_fetch(sys_mbox_t mbox, void **msg, u32_t timeout);
132#ifndef sys_arch_mbox_tryfetch  /* Allow port to override with a macro */
133    u32_t sys_arch_mbox_tryfetch(sys_mbox_t mbox, void **msg);
134#endif
135/* For now, we map straight to sys_arch implementation. */
136#define sys_mbox_tryfetch(mbox, msg) sys_arch_mbox_tryfetch(mbox, msg)
137    void sys_mbox_free(sys_mbox_t mbox);
138    void sys_mbox_fetch(sys_mbox_t mbox, void **msg);
139
140/* Thread functions. */
141    sys_thread_t sys_thread_new(char *name, void (*thread) (void *arg),
142                                void *arg, int stacksize, int prio);
143
144#endif                          /* NO_SYS */
145
146/** Returns the current time in milliseconds. */
147    u32_t sys_now(void);
148
149/* Critical Region Protection */
150/* These functions must be implemented in the sys_arch.c file.
151   In some implementations they can provide a more light-weight protection
152   mechanism than using semaphores. Otherwise semaphores can be used for
153   implementation */
154#ifndef SYS_ARCH_PROTECT
155/** SYS_LIGHTWEIGHT_PROT
156 * define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection
157 * for certain critical regions during buffer allocation, deallocation and memory
158 * allocation and deallocation.
159 */
160#if SYS_LIGHTWEIGHT_PROT
161
162/** SYS_ARCH_DECL_PROTECT
163 * declare a protection variable. This macro will default to defining a variable of
164 * type sys_prot_t. If a particular port needs a different implementation, then
165 * this macro may be defined in sys_arch.h.
166 */
167#define SYS_ARCH_DECL_PROTECT(lev) sys_prot_t lev
168/** SYS_ARCH_PROTECT
169 * Perform a "fast" protect. This could be implemented by
170 * disabling interrupts for an embedded system or by using a semaphore or
171 * mutex. The implementation should allow calling SYS_ARCH_PROTECT when
172 * already protected. The old protection level is returned in the variable
173 * "lev". This macro will default to calling the sys_arch_protect() function
174 * which should be implemented in sys_arch.c. If a particular port needs a
175 * different implementation, then this macro may be defined in sys_arch.h
176 */
177#define SYS_ARCH_PROTECT(lev) lev = sys_arch_protect()
178/** SYS_ARCH_UNPROTECT
179 * Perform a "fast" set of the protection level to "lev". This could be
180 * implemented by setting the interrupt level to "lev" within the MACRO or by
181 * using a semaphore or mutex.  This macro will default to calling the
182 * sys_arch_unprotect() function which should be implemented in
183 * sys_arch.c. If a particular port needs a different implementation, then
184 * this macro may be defined in sys_arch.h
185 */
186#define SYS_ARCH_UNPROTECT(lev) sys_arch_unprotect(lev)
187    sys_prot_t sys_arch_protect(void);
188    void sys_arch_unprotect(sys_prot_t pval);
189
190#else
191
192#define SYS_ARCH_DECL_PROTECT(lev)
193#define SYS_ARCH_PROTECT(lev)
194#define SYS_ARCH_UNPROTECT(lev)
195
196#endif                          /* SYS_LIGHTWEIGHT_PROT */
197
198#endif                          /* SYS_ARCH_PROTECT */
199
200/*
201 * Macros to set/get and increase/decrease variables in a thread-safe way.
202 * Use these for accessing variable that are used from more than one thread.
203 */
204
205#ifndef SYS_ARCH_INC
206#define SYS_ARCH_INC(var, val) do { \
207                                SYS_ARCH_DECL_PROTECT(old_level); \
208                                SYS_ARCH_PROTECT(old_level); \
209                                var += val; \
210                                SYS_ARCH_UNPROTECT(old_level); \
211                              } while(0)
212#endif                          /* SYS_ARCH_INC */
213
214#ifndef SYS_ARCH_DEC
215#define SYS_ARCH_DEC(var, val) do { \
216                                SYS_ARCH_DECL_PROTECT(old_level); \
217                                SYS_ARCH_PROTECT(old_level); \
218                                var -= val; \
219                                SYS_ARCH_UNPROTECT(old_level); \
220                              } while(0)
221#endif                          /* SYS_ARCH_DEC */
222
223#ifndef SYS_ARCH_GET
224#define SYS_ARCH_GET(var, ret) do { \
225                                SYS_ARCH_DECL_PROTECT(old_level); \
226                                SYS_ARCH_PROTECT(old_level); \
227                                ret = var; \
228                                SYS_ARCH_UNPROTECT(old_level); \
229                              } while(0)
230#endif                          /* SYS_ARCH_GET */
231
232#ifndef SYS_ARCH_SET
233#define SYS_ARCH_SET(var, val) do { \
234                                SYS_ARCH_DECL_PROTECT(old_level); \
235                                SYS_ARCH_PROTECT(old_level); \
236                                var = val; \
237                                SYS_ARCH_UNPROTECT(old_level); \
238                              } while(0)
239#endif                          /* SYS_ARCH_SET */
240
241
242#ifdef __cplusplus
243}
244#endif
245extern struct thread_mutex *lwip_mutex;
246
247void lwip_mutex_lock(void);
248void lwip_mutex_unlock(void);
249
250#endif                          /* __LWIP_SYS_H__ */
251