1 /* Copyright (C) 1994-2015 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
23 /* XXX Temporary cheezoid implementation; see __setitmr.c. */
25 /* These are defined in __setitmr.c. */
26 extern spin_lock_t _hurd_itimer_lock
;
27 extern struct itimerval _hurd_itimerval
;
28 extern struct timeval _hurd_itimer_started
;
31 subtract_timeval (struct timeval
*from
, const struct timeval
*subtract
)
33 from
->tv_usec
-= subtract
->tv_usec
;
34 from
->tv_sec
-= subtract
->tv_sec
;
35 while (from
->tv_usec
< 0)
38 from
->tv_usec
+= 1000000;
42 /* Set *VALUE to the current setting of timer WHICH.
43 Return 0 on success, -1 on errors. */
45 __getitimer (which
, value
)
46 enum __itimer_which which
;
47 struct itimerval
*value
;
50 struct timeval elapsed
;
55 return __hurd_fail (EINVAL
);
59 return __hurd_fail (ENOSYS
);
65 /* Get the time now. */
66 if (__gettimeofday (&elapsed
, NULL
) < 0)
69 /* Extract the current timer setting; and the time it was set, so we can
70 calculate the time elapsed so far. */
72 __spin_lock (&_hurd_itimer_lock
);
73 val
= _hurd_itimerval
;
74 subtract_timeval (&elapsed
, &_hurd_itimer_started
);
75 __spin_unlock (&_hurd_itimer_lock
);
78 if ((val
.it_value
.tv_sec
| val
.it_value
.tv_usec
) != 0)
80 /* There is a pending alarm set. VAL indicates the interval it was
81 set for, relative to the time recorded in _hurd_itimer_started.
82 Now compensate for the time elapsed since to get the user's
83 conception of the current value of the timer (as if the value
84 stored decreased every microsecond). */
85 if (timercmp (&val
.it_value
, &elapsed
, <))
87 /* Hmm. The timer should have just gone off, but has not been
88 reset. This is a possible timing glitch. The alarm will signal
89 soon, so fabricate a value for how soon. */
90 val
.it_value
.tv_sec
= 0;
91 val
.it_value
.tv_usec
= 10; /* Random. */
94 /* Subtract the time elapsed since the timer was set
95 from the current timer value the user sees. */
96 subtract_timeval (&val
.it_value
, &elapsed
);
103 weak_alias (__getitimer
, getitimer
)