1 | /**
|
---|
2 | * @file
|
---|
3 | * lwIP Operating System abstraction
|
---|
4 | *
|
---|
5 | */
|
---|
6 |
|
---|
7 | /*
|
---|
8 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
|
---|
9 | * All rights reserved.
|
---|
10 | *
|
---|
11 | * Redistribution and use in source and binary forms, with or without modification,
|
---|
12 | * are permitted provided that the following conditions are met:
|
---|
13 | *
|
---|
14 | * 1. Redistributions of source code must retain the above copyright notice,
|
---|
15 | * this list of conditions and the following disclaimer.
|
---|
16 | * 2. Redistributions in binary form must reproduce the above copyright notice,
|
---|
17 | * this list of conditions and the following disclaimer in the documentation
|
---|
18 | * and/or other materials provided with the distribution.
|
---|
19 | * 3. The name of the author may not be used to endorse or promote products
|
---|
20 | * derived from this software without specific prior written permission.
|
---|
21 | *
|
---|
22 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
---|
23 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
---|
24 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
|
---|
25 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
---|
26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
---|
27 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
---|
28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
---|
29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
---|
30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
|
---|
31 | * OF SUCH DAMAGE.
|
---|
32 | *
|
---|
33 | * This file is part of the lwIP TCP/IP stack.
|
---|
34 | *
|
---|
35 | * Author: Adam Dunkels <adam@sics.se>
|
---|
36 | *
|
---|
37 | */
|
---|
38 |
|
---|
39 | /**
|
---|
40 | * @defgroup sys_layer Porting (system abstraction layer)
|
---|
41 | * @ingroup lwip
|
---|
42 | *
|
---|
43 | * @defgroup sys_os OS abstraction layer
|
---|
44 | * @ingroup sys_layer
|
---|
45 | * No need to implement functions in this section in NO_SYS mode.
|
---|
46 | * The OS-specific code should be implemented in arch/sys_arch.h
|
---|
47 | * and sys_arch.c of your port.
|
---|
48 | *
|
---|
49 | * The operating system emulation layer provides a common interface
|
---|
50 | * between the lwIP code and the underlying operating system kernel. The
|
---|
51 | * general idea is that porting lwIP to new architectures requires only
|
---|
52 | * small changes to a few header files and a new sys_arch
|
---|
53 | * implementation. It is also possible to do a sys_arch implementation
|
---|
54 | * that does not rely on any underlying operating system.
|
---|
55 | *
|
---|
56 | * The sys_arch provides semaphores, mailboxes and mutexes to lwIP. For the full
|
---|
57 | * lwIP functionality, multiple threads support can be implemented in the
|
---|
58 | * sys_arch, but this is not required for the basic lwIP
|
---|
59 | * functionality. Timer scheduling is implemented in lwIP, but can be implemented
|
---|
60 | * by the sys_arch port (LWIP_TIMERS_CUSTOM==1).
|
---|
61 | *
|
---|
62 | * In addition to the source file providing the functionality of sys_arch,
|
---|
63 | * the OS emulation layer must provide several header files defining
|
---|
64 | * macros used throughout lwip. The files required and the macros they
|
---|
65 | * must define are listed below the sys_arch description.
|
---|
66 | *
|
---|
67 | * Since lwIP 1.4.0, semaphore, mutexes and mailbox functions are prototyped in a way that
|
---|
68 | * allows both using pointers or actual OS structures to be used. This way, memory
|
---|
69 | * required for such types can be either allocated in place (globally or on the
|
---|
70 | * stack) or on the heap (allocated internally in the "*_new()" functions).
|
---|
71 | *
|
---|
72 | * Note:
|
---|
73 | * -----
|
---|
74 | * Be careful with using mem_malloc() in sys_arch. When malloc() refers to
|
---|
75 | * mem_malloc() you can run into a circular function call problem. In mem.c
|
---|
76 | * mem_init() tries to allocate a semaphore using mem_malloc, which of course
|
---|
77 | * can't be performed when sys_arch uses mem_malloc.
|
---|
78 | *
|
---|
79 | * @defgroup sys_sem Semaphores
|
---|
80 | * @ingroup sys_os
|
---|
81 | * Semaphores can be either counting or binary - lwIP works with both
|
---|
82 | * kinds.
|
---|
83 | * Semaphores are represented by the type "sys_sem_t" which is typedef'd
|
---|
84 | * in the sys_arch.h file. Mailboxes are equivalently represented by the
|
---|
85 | * type "sys_mbox_t". Mutexes are represented by the type "sys_mutex_t".
|
---|
86 | * lwIP does not place any restrictions on how these types are represented
|
---|
87 | * internally.
|
---|
88 | *
|
---|
89 | * @defgroup sys_mutex Mutexes
|
---|
90 | * @ingroup sys_os
|
---|
91 | * Mutexes are recommended to correctly handle priority inversion,
|
---|
92 | * especially if you use LWIP_CORE_LOCKING .
|
---|
93 | *
|
---|
94 | * @defgroup sys_mbox Mailboxes
|
---|
95 | * @ingroup sys_os
|
---|
96 | * Mailboxes should be implemented as a queue which allows multiple messages
|
---|
97 | * to be posted (implementing as a rendez-vous point where only one message can be
|
---|
98 | * posted at a time can have a highly negative impact on performance). A message
|
---|
99 | * in a mailbox is just a pointer, nothing more.
|
---|
100 | *
|
---|
101 | * @defgroup sys_time Time
|
---|
102 | * @ingroup sys_layer
|
---|
103 | *
|
---|
104 | * @defgroup sys_prot Critical sections
|
---|
105 | * @ingroup sys_layer
|
---|
106 | * Used to protect short regions of code against concurrent access.
|
---|
107 | * - Your system is a bare-metal system (probably with an RTOS)
|
---|
108 | * and interrupts are under your control:
|
---|
109 | * Implement this as LockInterrupts() / UnlockInterrupts()
|
---|
110 | * - Your system uses an RTOS with deferred interrupt handling from a
|
---|
111 | * worker thread: Implement as a global mutex or lock/unlock scheduler
|
---|
112 | * - Your system uses a high-level OS with e.g. POSIX signals:
|
---|
113 | * Implement as a global mutex
|
---|
114 | *
|
---|
115 | * @defgroup sys_misc Misc
|
---|
116 | * @ingroup sys_os
|
---|
117 | */
|
---|
118 |
|
---|
119 | #include "lwip/opt.h"
|
---|
120 |
|
---|
121 | #include "lwip/sys.h"
|
---|
122 |
|
---|
123 | /* Most of the functions defined in sys.h must be implemented in the
|
---|
124 | * architecture-dependent file sys_arch.c */
|
---|
125 |
|
---|
126 | #if !NO_SYS
|
---|
127 |
|
---|
128 | #ifndef sys_msleep
|
---|
129 | /**
|
---|
130 | * Sleep for some ms. Timeouts are NOT processed while sleeping.
|
---|
131 | *
|
---|
132 | * @param ms number of milliseconds to sleep
|
---|
133 | */
|
---|
134 | void
|
---|
135 | sys_msleep(u32_t ms)
|
---|
136 | {
|
---|
137 | if (ms > 0) {
|
---|
138 | sys_sem_t delaysem;
|
---|
139 | err_t err = sys_sem_new(&delaysem, 0);
|
---|
140 | if (err == ERR_OK) {
|
---|
141 | sys_arch_sem_wait(&delaysem, ms);
|
---|
142 | sys_sem_free(&delaysem);
|
---|
143 | }
|
---|
144 | }
|
---|
145 | }
|
---|
146 | #endif /* sys_msleep */
|
---|
147 |
|
---|
148 | #endif /* !NO_SYS */
|
---|