summaryrefslogtreecommitdiff
path: root/nptl/sysdeps/pthread/timer_settime.c
blob: da0908b0bcad6da77ef41495d3e7755ae51a04e7 (plain)
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
/* Copyright (C) 2000, 2001 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 <errno.h>
#include <pthread.h>
#include <time.h>

#include "posix-timer.h"


/* Set timer TIMERID to VALUE, returning old value in OVLAUE.  */
int
timer_settime (timerid, flags, value, ovalue)
     timer_t timerid;
     int flags;
     const struct itimerspec *value;
     struct itimerspec *ovalue;
{
  struct timer_node *timer;
  struct thread_node *thread = NULL;
  struct timespec now;
  int have_now = 0, need_wakeup = 0;
  int retval = -1;

  timer = timer_id2ptr (timerid);
  if (timer == NULL)
    {
      __set_errno (EINVAL);
      goto bail;
    }

  if (value->it_interval.tv_nsec < 0
      || value->it_interval.tv_nsec >= 1000000000
      || value->it_value.tv_nsec < 0
      || value->it_value.tv_nsec >= 1000000000)
    {
      __set_errno (EINVAL);
      goto bail;
    }

  /* Will need to know current time since this is a relative timer;
     might as well make the system call outside of the lock now! */

  if ((flags & TIMER_ABSTIME) == 0)
    {
      clock_gettime (timer->clock, &now);
      have_now = 1;
    }

  pthread_mutex_lock (&__timer_mutex);
  timer_addref (timer);

  /* One final check of timer validity; this one is possible only
     until we have the mutex, because it accesses the inuse flag. */

  if (! timer_valid(timer))
    {
      __set_errno (EINVAL);
      goto unlock_bail;
    }

  if (ovalue != NULL)
    {
      ovalue->it_interval = timer->value.it_interval;

      if (timer->armed)
	{
	  if (! have_now)
	    {
	      pthread_mutex_unlock (&__timer_mutex);
	      clock_gettime (timer->clock, &now);
	      have_now = 1;
	      pthread_mutex_lock (&__timer_mutex);
	      timer_addref (timer);
	    }

	  timespec_sub (&ovalue->it_value, &timer->expirytime, &now);
	}
      else
	{
	  ovalue->it_value.tv_sec = 0;
	  ovalue->it_value.tv_nsec = 0;
	}
    }

  timer->value = *value;

  list_unlink_ip (&timer->links);
  timer->armed = 0;

  thread = timer->thread;

  /* A value of { 0, 0 } causes the timer to be stopped. */
  if (value->it_value.tv_sec != 0
      || __builtin_expect (value->it_value.tv_nsec != 0, 1))
    {
      if ((flags & TIMER_ABSTIME) != 0)
	/* The user specified the expiration time.  */
	timer->expirytime = value->it_value;
      else
	timespec_add (&timer->expirytime, &now, &value->it_value);

      /* Only need to wake up the thread if timer is inserted
	 at the head of the queue. */
      if (thread != NULL)
	need_wakeup = __timer_thread_queue_timer (thread, timer);
      timer->armed = 1;
    }

  retval = 0;

unlock_bail:
  timer_delref (timer);
  pthread_mutex_unlock (&__timer_mutex);

bail:
  if (thread != NULL && need_wakeup)
    __timer_thread_wakeup (thread);

  return retval;
}