1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/*
ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chpipes.c
* @brief Pipes code.
* @details Byte pipes.
* <h2>Operation mode</h2>
* A pipe is an asynchronous communication mechanism.<br>
* Operations defined for mailboxes:
* - <b>Write</b>: Writes a buffer of data in the pipe in FIFO order.
* - <b>Read</b>: A buffer of data is read from the read and removed.
* - <b>Reset</b>: The pipe is emptied and all the stored data
* is lost.
* .
* @pre In order to use the pipes APIs the @p CH_CFG_USE_PIPES
* option must be enabled in @p chconf.h.
* @note Compatible with RT and NIL.
*
* @addtogroup oslib_pipes
* @{
*/
#include "ch.h"
#if (CH_CFG_USE_PIPES == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* Module local definitions. */
/*===========================================================================*/
/*
* Defaults on the best synchronization mechanism available.
*/
#if (CH_CFG_USE_MUTEXES == TRUE) || defined(__DOXYGEN__)
#define P_LOCK(p) chMtxLock(&(p)->mtx)
#define P_UNLOCK(p) chMtxUnlock(&(p)->mtx)
#else
#define P_LOCK(p) (void) chSemWait(&(p)->sem)
#define P_UNLOCK(p) chSemSignal(&(p)->sem)
#endif
/*===========================================================================*/
/* Module exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local types. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Module exported functions. */
/*===========================================================================*/
/**
* @brief Initializes a @p mailbox_t object.
*
* @param[out] pp the pointer to the @p pipe_t structure to be
* initialized
* @param[in] buf pointer to the pipe buffer as an array of @p uint8_t
* @param[in] n number of elements in the buffer array
*
* @init
*/
void chPipeObjectInit(pipe_t *pp, uint8_t *buf, size_t n) {
chDbgCheck((pp != NULL) && (buf != NULL) && (n > (size_t)0));
pp->buffer = buf;
pp->rdptr = buf;
pp->wrptr = buf;
pp->top = &buf[n];
pp->cnt = (size_t)0;
pp->reset = false;
chThdQueueObjectInit(&pp->qw);
chThdQueueObjectInit(&pp->qr);
}
/**
* @brief Resets a @p pipe_t object.
* @details All the waiting threads are resumed with status @p MSG_RESET and
* the queued data is lost.
* @post The pipe is in reset state, all operations will fail and
* return @p MSG_RESET until the mailbox is enabled again using
* @p chPipeResumeX().
*
* @param[in] pp the pointer to an initialized @p pipe_t object
*
* @api
*/
void chPipeReset(pipe_t *pp) {
chDbgCheck(pp != NULL);
P_LOCK(pp);
chSysLock();
pipe_t->wrptr = pipe_t->buffer;
pipe_t->rdptr = pipe_t->buffer;
pipe_t->cnt = (size_t)0;
pipe_t->reset = true;
chThdDequeueAllI(&pipe_t->qw, MSG_RESET);
chThdDequeueAllI(&pipe_t->qr, MSG_RESET);
chSchRescheduleS();
chSysUnlock();
P_UNLOCK();
}
/**
* @brief Pipe write with timeout.
* @details The function writes data from a buffer to a pipe. The
* operation completes when the specified amount of data has been
* transferred or after the specified timeout or if the pipe has
* been reset.
*
* @param[in] pp the pointer to an initialized @p pipe_t object
* @param[in] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred, the
* value 0 is reserved
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The number of bytes effectively transferred.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @api
*/
size_t chPipeWriteTimeout(pipe_t *pp, const uint8_t *bp,
size_t n, sysinterval_t timeout) {
}
/**
* @brief Pipe read with timeout.
* @details The function reads data from a pipe into a buffer. The
* operation completes when the specified amount of data has been
* transferred or after the specified timeout or if the pipe has
* been reset.
*
* @param[in] pp the pointer to an initialized @p pipe_t object
* @param[out] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred, the
* value 0 is reserved
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The number of bytes effectively transferred.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @api
*/
size_t chPipeReadTimeout(pipe_t *pp, uint8_t *bp,
size_t n, sysinterval_t timeout) {
}
#endif /* CH_CFG_USE_MAILBOXES == TRUE */
/** @} */
|
