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
|
/************************************************************
* uip-wait.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
************************************************************/
/************************************************************
* Included Files
************************************************************/
#include <nuttx/config.h>
#include <semaphore.h>
#include <arch/irq.h>
#include <net/uip/uip.h>
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Data
************************************************************/
/* Threads and tasks can both wait a semaphore. This
* initializer uses internal, non-portable knowledge of the\
* structure of sem_t to initialize it to the value 0.
*/
static sem_t uip_waitsem = { 0 }; /* Semaphore to wait on */
static uint16 uip_waitflags = 0; /* UIP flags to wait for */
/************************************************************
* Private Functions
************************************************************/
/************************************************************
* Global Functions
************************************************************/
/* This function is called user code to set up the wait */
int uip_event_wait(uint16 waitflags)
{
/* Prevent conflicts with the interrupt level operation of
* uip_event_signal().
*/
irqstate_t save = irqsave();
/* At present, we support only a single waiter. If uip_waitflags
* is non-zero on entry, then there is a problem.
*/
if ( uip_waitflags == 0)
{
/* If the requested event bits are not set in the uip_flags,
* then wait. We will be awakened as soon as an interrupt is
* received that sets these bits.
*/
goto errout_with_irqdisabled;
}
/* Loop until the requested bits are set in the flags */
while ((waitflags & uip_flags) != 0)
{
/* Set the event flags that the caller is waiting on */
uip_waitflags = waitflags;
/* Wait for the event to occur */
if (sem_wait(&uip_waitsem) != 0)
{
goto errout_with_irqdisabled;
}
}
irqrestore(save);
return OK;
errout_with_irqdisabled:
irqrestore(save);
return ERROR;
}
/* This function is called from uip_interrupt() to wake up any
* waiting threads/tasks.
*/
void uip_event_signal(void)
{
/* If any bits in uip_waitflags match bits set in uip_flags, then
* there must be a thread/task waiting for this event to occur.
*/
if ((uip_waitflags & uip_flags) != 0)
{
sem_post(&uip_waitsem); /* Post the event */
uip_waitflags = 0; /* Prohibit posting the event multiple times */
}
}
|
