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
|
/* Definitions for POSIX timer implementation on top of NPTL.
Copyright (C) 2000-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Kaz Kylheku <kaz@ashi.footprints.net>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <limits.h>
#include <signal.h>
#include <list.h>
/* Forward declaration. */
struct timer_node;
/* Definitions for an internal thread of the POSIX timer implementation. */
struct thread_node
{
struct list_head links;
pthread_attr_t attr;
pthread_t id;
unsigned int exists;
struct list_head timer_queue;
pthread_cond_t cond;
struct timer_node *current_timer;
pthread_t captured;
clockid_t clock_id;
};
/* Internal representation of a timer. */
struct timer_node
{
struct list_head links;
struct sigevent event;
clockid_t clock;
struct itimerspec value;
struct timespec expirytime;
pthread_attr_t attr;
unsigned int abstime;
unsigned int armed;
enum {
TIMER_FREE, TIMER_INUSE, TIMER_DELETED
} inuse;
struct thread_node *thread;
pid_t creator_pid;
int refcount;
int overrun_count;
};
/* The limit is not published if we are compiled with kernel timer support.
But we still compiled in this implementation with its limit unless built
to require the kernel support. */
#ifndef TIMER_MAX
# define TIMER_MAX 256
#endif
/* Static array with the structures for all the timers. */
extern struct timer_node __timer_array[TIMER_MAX];
/* Global lock to protect operation on the lists. */
extern pthread_mutex_t __timer_mutex;
/* Variable to protext initialization. */
extern pthread_once_t __timer_init_once_control;
/* Nonzero if initialization of timer implementation failed. */
extern int __timer_init_failed;
/* Node for the thread used to deliver signals. */
extern struct thread_node __timer_signal_thread_rclk;
/* Return pointer to timer structure corresponding to ID. */
#define timer_id2ptr(timerid) ((struct timer_node *) timerid)
#define timer_ptr2id(timerid) ((void *) timerid)
/* Check whether timer is valid; global mutex must be held. */
static inline int
timer_valid (struct timer_node *timer)
{
return timer && timer->inuse == TIMER_INUSE;
}
/* Timer refcount functions; need global mutex. */
extern void __timer_dealloc (struct timer_node *timer);
static inline void
timer_addref (struct timer_node *timer)
{
timer->refcount++;
}
static inline void
timer_delref (struct timer_node *timer)
{
if (--timer->refcount == 0)
__timer_dealloc (timer);
}
/* Timespec helper routines. */
static inline int
__attribute ((always_inline))
timespec_compare (const struct timespec *left, const struct timespec *right)
{
if (left->tv_sec < right->tv_sec)
return -1;
if (left->tv_sec > right->tv_sec)
return 1;
if (left->tv_nsec < right->tv_nsec)
return -1;
if (left->tv_nsec > right->tv_nsec)
return 1;
return 0;
}
static inline void
timespec_add (struct timespec *sum, const struct timespec *left,
const struct timespec *right)
{
sum->tv_sec = left->tv_sec + right->tv_sec;
sum->tv_nsec = left->tv_nsec + right->tv_nsec;
if (sum->tv_nsec >= 1000000000)
{
++sum->tv_sec;
sum->tv_nsec -= 1000000000;
}
}
static inline void
timespec_sub (struct timespec *diff, const struct timespec *left,
const struct timespec *right)
{
diff->tv_sec = left->tv_sec - right->tv_sec;
diff->tv_nsec = left->tv_nsec - right->tv_nsec;
if (diff->tv_nsec < 0)
{
--diff->tv_sec;
diff->tv_nsec += 1000000000;
}
}
/* We need one of the list functions in the other modules. */
static inline void
list_unlink_ip (struct list_head *list)
{
struct list_head *lnext = list->next, *lprev = list->prev;
lnext->prev = lprev;
lprev->next = lnext;
/* The suffix ip means idempotent; list_unlink_ip can be called
* two or more times on the same node.
*/
list->next = list;
list->prev = list;
}
/* Functions in the helper file. */
extern void __timer_mutex_cancel_handler (void *arg);
extern void __timer_init_once (void);
extern struct timer_node *__timer_alloc (void);
extern int __timer_thread_start (struct thread_node *thread);
extern struct thread_node *__timer_thread_find_matching (const pthread_attr_t *desired_attr, clockid_t);
extern struct thread_node *__timer_thread_alloc (const pthread_attr_t *desired_attr, clockid_t);
extern void __timer_thread_dealloc (struct thread_node *thread);
extern int __timer_thread_queue_timer (struct thread_node *thread,
struct timer_node *insert);
extern void __timer_thread_wakeup (struct thread_node *thread);
|
GitWeb