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
|
/* Copyright (C) 2000-2021 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 <https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <signal.h>
#include <pthread.h>
#include <time.h>
#include <unistd.h>
#include "posix-timer.h"
/* Create new per-process timer using CLOCK. */
int
timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
{
int retval = -1;
struct timer_node *newtimer = NULL;
struct thread_node *thread = NULL;
if (0
#if defined _POSIX_CPUTIME && _POSIX_CPUTIME >= 0
|| clock_id == CLOCK_PROCESS_CPUTIME_ID
#endif
#if defined _POSIX_THREAD_CPUTIME && _POSIX_THREAD_CPUTIME >= 0
|| clock_id == CLOCK_THREAD_CPUTIME_ID
#endif
)
{
/* We don't allow timers for CPU clocks. At least not in the
moment. */
__set_errno (ENOTSUP);
return -1;
}
if (clock_id != CLOCK_REALTIME)
{
__set_errno (EINVAL);
return -1;
}
pthread_once (&__timer_init_once_control, __timer_init_once);
if (__timer_init_failed)
{
__set_errno (ENOMEM);
return -1;
}
pthread_mutex_lock (&__timer_mutex);
newtimer = __timer_alloc ();
if (__glibc_unlikely (newtimer == NULL))
{
__set_errno (EAGAIN);
goto unlock_bail;
}
if (evp != NULL)
newtimer->event = *evp;
else
{
newtimer->event.sigev_notify = SIGEV_SIGNAL;
newtimer->event.sigev_signo = SIGALRM;
newtimer->event.sigev_value.sival_ptr = newtimer;
newtimer->event.sigev_notify_function = 0;
}
newtimer->event.sigev_notify_attributes = &newtimer->attr;
newtimer->creator_pid = getpid ();
switch (__builtin_expect (newtimer->event.sigev_notify, SIGEV_SIGNAL))
{
case SIGEV_NONE:
case SIGEV_SIGNAL:
/* We have a global thread for delivering timed signals.
If it is not running, try to start it up. */
thread = &__timer_signal_thread_rclk;
if (! thread->exists)
{
if (__builtin_expect (__timer_thread_start (thread),
1) < 0)
{
__set_errno (EAGAIN);
goto unlock_bail;
}
}
break;
case SIGEV_THREAD:
/* Copy over thread attributes or set up default ones. */
if (evp->sigev_notify_attributes)
newtimer->attr = *(pthread_attr_t *) evp->sigev_notify_attributes;
else
pthread_attr_init (&newtimer->attr);
/* Ensure thread attributes call for deatched thread. */
pthread_attr_setdetachstate (&newtimer->attr, PTHREAD_CREATE_DETACHED);
/* Try to find existing thread having the right attributes. */
thread = __timer_thread_find_matching (&newtimer->attr, clock_id);
/* If no existing thread has these attributes, try to allocate one. */
if (thread == NULL)
thread = __timer_thread_alloc (&newtimer->attr, clock_id);
/* Out of luck; no threads are available. */
if (__glibc_unlikely (thread == NULL))
{
__set_errno (EAGAIN);
goto unlock_bail;
}
/* If the thread is not running already, try to start it. */
if (! thread->exists
&& __builtin_expect (! __timer_thread_start (thread), 0))
{
__set_errno (EAGAIN);
goto unlock_bail;
}
break;
default:
__set_errno (EINVAL);
goto unlock_bail;
}
newtimer->clock = clock_id;
newtimer->abstime = 0;
newtimer->armed = 0;
newtimer->thread = thread;
*timerid = timer_ptr2id (newtimer);
retval = 0;
if (__builtin_expect (retval, 0) == -1)
{
unlock_bail:
if (thread != NULL)
__timer_thread_dealloc (thread);
if (newtimer != NULL)
{
timer_delref (newtimer);
__timer_dealloc (newtimer);
}
}
pthread_mutex_unlock (&__timer_mutex);
return retval;
}
|
