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
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
/********************************************************************************
* sched/timer/timer_create.c
*
* Copyright (C) 2007-2009, 2011, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <stdint.h>
#include <unistd.h>
#include <time.h>
#include <string.h>
#include <errno.h>
#include <nuttx/wdog.h>
#include <nuttx/kmalloc.h>
#include "timer/timer.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/********************************************************************************
* Definitions
********************************************************************************/
/********************************************************************************
* Private Data
********************************************************************************/
/********************************************************************************
* Public Data
********************************************************************************/
/********************************************************************************
* Private Functions
********************************************************************************/
/********************************************************************************
* Name: timer_allocate
*
* Description:
* Allocate one POSIX timer and place it into the allocated timer list.
*
********************************************************************************/
static struct posix_timer_s *timer_allocate(void)
{
struct posix_timer_s *ret;
irqstate_t flags;
uint8_t pt_flags;
/* Try to get a preallocated timer from the free list */
#if CONFIG_PREALLOC_TIMERS > 0
flags = irqsave();
ret = (struct posix_timer_s*)sq_remfirst((sq_queue_t*)&g_freetimers);
irqrestore(flags);
/* Did we get one? */
if (ret)
{
pt_flags = PT_FLAGS_PREALLOCATED;
}
else
#endif
{
/* Allocate a new timer from the heap */
ret = (struct posix_timer_s*)kmalloc(sizeof(struct posix_timer_s));
pt_flags = 0;
}
/* If we have a timer, then put it into the allocated timer list */
if (ret)
{
/* Initialize the timer structure */
memset(ret, 0, sizeof(struct posix_timer_s));
ret->pt_flags = pt_flags;
/* And add it to the end of the list of allocated timers */
flags = irqsave();
sq_addlast((sq_entry_t*)ret, (sq_queue_t*)&g_alloctimers);
irqrestore(flags);
}
return ret;
}
/********************************************************************************
* Public Functions
********************************************************************************/
/********************************************************************************
* Name: timer_create
*
* Description:
* The timer_create() function creates per-thread timer using the specified
* clock, clock_id, as the timing base. The timer_create() function returns, in
* the location referenced by timerid, a timer ID of type timer_t used to identify
* the timer in timer requests. This timer ID is unique until the timer is
* deleted. The particular clock, clock_id, is defined in <time.h>. The timer
* whose ID is returned will be in a disarmed state upon return from
* timer_create().
*
* The evp argument, if non-NULL, points to a sigevent structure. This structure
* is allocated by the called and defines the asynchronous notification to occur.
* If the evp argument is NULL, the effect is as if the evp argument pointed to
* a sigevent structure with the sigev_notify member having the value SIGEV_SIGNAL,
* the sigev_signo having a default signal number, and the sigev_value member
* having the value of the timer ID.
*
* Each implementation defines a set of clocks that can be used as timing bases
* for per-thread timers. All implementations shall support a clock_id of
* CLOCK_REALTIME.
*
* Parameters:
* clockid - Specifies the clock to use as the timing base.
* evp - Refers to a user allocated sigevent structure that defines the
* asynchronous notification. evp may be NULL (see above).
* timerid - The pre-thread timer created by the call to timer_create().
*
* Return Value:
* If the call succeeds, timer_create() will return 0 (OK) and update the
* location referenced by timerid to a timer_t, which can be passed to the
* other per-thread timer calls. If an error occurs, the function will return
* a value of -1 (ERROR) and set errno to indicate the error.
*
* EAGAIN - The system lacks sufficient signal queuing resources to honor the
* request.
* EAGAIN - The calling process has already created all of the timers it is
* allowed by this implementation.
* EINVAL - The specified clock ID is not defined.
* ENOTSUP - The implementation does not support the creation of a timer attached
* to the CPU-time clock that is specified by clock_id and associated with a
* thread different thread invoking timer_create().
*
* Assumptions:
*
********************************************************************************/
int timer_create(clockid_t clockid, FAR struct sigevent *evp, FAR timer_t *timerid)
{
struct posix_timer_s *ret;
WDOG_ID wdog;
/* Sanity checks. Also, we support only CLOCK_REALTIME */
if (!timerid || clockid != CLOCK_REALTIME)
{
errno = EINVAL;
return ERROR;
}
/* Allocate a watchdog to provide the underling CLOCK_REALTIME timer */
wdog = wd_create();
if (!wdog)
{
errno = EAGAIN;
return ERROR;
}
/* Allocate a timer instance to contain the watchdog */
ret = timer_allocate();
if (!ret)
{
errno = EAGAIN;
return ERROR;
}
/* Initialize the timer instance */
ret->pt_crefs = 1;
ret->pt_owner = getpid();
ret->pt_delay = 0;
ret->pt_wdog = wdog;
if (evp)
{
ret->pt_signo = evp->sigev_signo;
#ifdef CONFIG_CAN_PASS_STRUCTS
ret->pt_value = evp->sigev_value;
#else
ret->pt_value.sival_ptr = evp->sigev_value.sival_ptr;
#endif
}
else
{
ret->pt_signo = SIGALRM;
ret->pt_value.sival_ptr = ret;
}
/* Return the timer */
*timerid = ret;
return OK;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */
|
