1 | /* Copyright (C) 1994-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
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. |
8 | |
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. |
13 | |
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 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <stddef.h> |
19 | #include <errno.h> |
20 | #include <sys/time.h> |
21 | #include <hurd.h> |
22 | #include <mach.h> |
23 | |
24 | /* XXX Temporary cheezoid implementation; see setitimer.c. */ |
25 | |
26 | /* These are defined in __setitmr.c. */ |
27 | extern spin_lock_t _hurd_itimer_lock; |
28 | extern struct itimerval _hurd_itimerval; |
29 | extern struct timeval _hurd_itimer_started; |
30 | |
31 | static inline void |
32 | subtract_timeval (struct timeval *from, const struct timeval *subtract) |
33 | { |
34 | from->tv_usec -= subtract->tv_usec; |
35 | from->tv_sec -= subtract->tv_sec; |
36 | while (from->tv_usec < 0) |
37 | { |
38 | --from->tv_sec; |
39 | from->tv_usec += 1000000; |
40 | } |
41 | } |
42 | |
43 | /* Set *VALUE to the current setting of timer WHICH. |
44 | Return 0 on success, -1 on errors. */ |
45 | int |
46 | __getitimer (enum __itimer_which which, struct itimerval *value) |
47 | { |
48 | struct itimerval val; |
49 | struct timeval elapsed; |
50 | |
51 | switch (which) |
52 | { |
53 | default: |
54 | return __hurd_fail (EINVAL); |
55 | |
56 | case ITIMER_VIRTUAL: |
57 | case ITIMER_PROF: |
58 | return __hurd_fail (ENOSYS); |
59 | |
60 | case ITIMER_REAL: |
61 | break; |
62 | } |
63 | |
64 | /* Get the time now. */ |
65 | { |
66 | time_value_t tv; |
67 | __host_get_time (__mach_host_self (), &tv); |
68 | elapsed.tv_sec = tv.seconds; |
69 | elapsed.tv_usec = tv.microseconds; |
70 | } |
71 | |
72 | /* Extract the current timer setting; and the time it was set, so we can |
73 | calculate the time elapsed so far. */ |
74 | HURD_CRITICAL_BEGIN; |
75 | __spin_lock (&_hurd_itimer_lock); |
76 | val = _hurd_itimerval; |
77 | subtract_timeval (from: &elapsed, subtract: &_hurd_itimer_started); |
78 | __spin_unlock (&_hurd_itimer_lock); |
79 | HURD_CRITICAL_END; |
80 | |
81 | if ((val.it_value.tv_sec | val.it_value.tv_usec) != 0) |
82 | { |
83 | /* There is a pending alarm set. VAL indicates the interval it was |
84 | set for, relative to the time recorded in _hurd_itimer_started. |
85 | Now compensate for the time elapsed since to get the user's |
86 | conception of the current value of the timer (as if the value |
87 | stored decreased every microsecond). */ |
88 | if (timercmp (&val.it_value, &elapsed, <)) |
89 | { |
90 | /* Hmm. The timer should have just gone off, but has not been |
91 | reset. This is a possible timing glitch. The alarm will signal |
92 | soon, so fabricate a value for how soon. */ |
93 | val.it_value.tv_sec = 0; |
94 | val.it_value.tv_usec = 10; /* Random. */ |
95 | } |
96 | else |
97 | /* Subtract the time elapsed since the timer was set |
98 | from the current timer value the user sees. */ |
99 | subtract_timeval (from: &val.it_value, subtract: &elapsed); |
100 | } |
101 | |
102 | *value = val; |
103 | return 0; |
104 | } |
105 | |
106 | weak_alias (__getitimer, getitimer) |
107 | |