1 | /* Copyright (C) 2000-2022 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 License as |
6 | published by the Free Software Foundation; either version 2.1 of the |
7 | 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; see the file COPYING.LIB. If |
16 | not, see <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <pthread.h> |
20 | #include <time.h> |
21 | |
22 | #include "posix-timer.h" |
23 | |
24 | |
25 | /* Set timer TIMERID to VALUE, returning old value in OVLAUE. */ |
26 | int |
27 | timer_settime (timer_t timerid, int flags, const struct itimerspec *value, |
28 | struct itimerspec *ovalue) |
29 | { |
30 | struct timer_node *timer; |
31 | struct thread_node *thread = NULL; |
32 | struct timespec now; |
33 | int have_now = 0, need_wakeup = 0; |
34 | int retval = -1; |
35 | |
36 | timer = timer_id2ptr (timerid); |
37 | if (timer == NULL) |
38 | { |
39 | __set_errno (EINVAL); |
40 | goto bail; |
41 | } |
42 | |
43 | if (! valid_nanoseconds (ns: value->it_interval.tv_nsec) |
44 | || ! valid_nanoseconds (ns: value->it_value.tv_nsec)) |
45 | { |
46 | __set_errno (EINVAL); |
47 | goto bail; |
48 | } |
49 | |
50 | /* Will need to know current time since this is a relative timer; |
51 | might as well make the system call outside of the lock now! */ |
52 | |
53 | if ((flags & TIMER_ABSTIME) == 0) |
54 | { |
55 | __clock_gettime (timer->clock, &now); |
56 | have_now = 1; |
57 | } |
58 | |
59 | pthread_mutex_lock (mutex: &__timer_mutex); |
60 | timer_addref (timer); |
61 | |
62 | /* One final check of timer validity; this one is possible only |
63 | until we have the mutex, because it accesses the inuse flag. */ |
64 | |
65 | if (! timer_valid(timer)) |
66 | { |
67 | __set_errno (EINVAL); |
68 | goto unlock_bail; |
69 | } |
70 | |
71 | if (ovalue != NULL) |
72 | { |
73 | ovalue->it_interval = timer->value.it_interval; |
74 | |
75 | if (timer->armed) |
76 | { |
77 | if (! have_now) |
78 | { |
79 | pthread_mutex_unlock (mutex: &__timer_mutex); |
80 | __clock_gettime (timer->clock, &now); |
81 | have_now = 1; |
82 | pthread_mutex_lock (mutex: &__timer_mutex); |
83 | timer_addref (timer); |
84 | } |
85 | |
86 | timespec_sub (diff: &ovalue->it_value, left: &timer->expirytime, right: &now); |
87 | } |
88 | else |
89 | { |
90 | ovalue->it_value.tv_sec = 0; |
91 | ovalue->it_value.tv_nsec = 0; |
92 | } |
93 | } |
94 | |
95 | timer->value = *value; |
96 | |
97 | list_unlink_ip (list: &timer->links); |
98 | timer->armed = 0; |
99 | |
100 | thread = timer->thread; |
101 | |
102 | /* A value of { 0, 0 } causes the timer to be stopped. */ |
103 | if (value->it_value.tv_sec != 0 |
104 | || __builtin_expect (value->it_value.tv_nsec != 0, 1)) |
105 | { |
106 | if ((flags & TIMER_ABSTIME) != 0) |
107 | /* The user specified the expiration time. */ |
108 | timer->expirytime = value->it_value; |
109 | else |
110 | timespec_add (sum: &timer->expirytime, left: &now, right: &value->it_value); |
111 | |
112 | /* Only need to wake up the thread if timer is inserted |
113 | at the head of the queue. */ |
114 | if (thread != NULL) |
115 | need_wakeup = __timer_thread_queue_timer (thread, insert: timer); |
116 | timer->armed = 1; |
117 | } |
118 | |
119 | retval = 0; |
120 | |
121 | unlock_bail: |
122 | timer_delref (timer); |
123 | pthread_mutex_unlock (mutex: &__timer_mutex); |
124 | |
125 | bail: |
126 | if (thread != NULL && need_wakeup) |
127 | __timer_thread_wakeup (thread); |
128 | |
129 | return retval; |
130 | } |
131 | |