xref: /DragonOS/kernel/src/time/sleep.rs (revision da152319797436368304cbc3f85a3b9ec049134b)
1 use core::hint::spin_loop;
2 
3 use alloc::{boxed::Box, sync::Arc};
4 use system_error::SystemError;
5 
6 use crate::{
7     arch::{sched::sched, CurrentIrqArch, CurrentTimeArch},
8     exception::InterruptArch,
9     include::bindings::bindings::useconds_t,
10     process::ProcessManager,
11     time::timekeeping::getnstimeofday,
12 };
13 
14 use super::{
15     timer::{next_n_us_timer_jiffies, Timer, WakeUpHelper},
16     TimeArch, TimeSpec,
17 };
18 
19 /// @brief 休眠指定时间(单位:纳秒)
20 ///
21 /// @param sleep_time 指定休眠的时间
22 ///
23 /// @return Ok(TimeSpec) 剩余休眠时间
24 ///
25 /// @return Err(SystemError) 错误码
26 pub fn nanosleep(sleep_time: TimeSpec) -> Result<TimeSpec, SystemError> {
27     if sleep_time.tv_nsec < 0 || sleep_time.tv_nsec >= 1000000000 {
28         return Err(SystemError::EINVAL);
29     }
30     // 对于小于500us的时间,使用spin/rdtsc来进行定时
31     if sleep_time.tv_nsec < 500000 && sleep_time.tv_sec == 0 {
32         let expired_tsc: usize = CurrentTimeArch::cal_expire_cycles(sleep_time.tv_nsec as usize);
33         while CurrentTimeArch::get_cycles() < expired_tsc {
34             spin_loop()
35         }
36         return Ok(TimeSpec {
37             tv_sec: 0,
38             tv_nsec: 0,
39         });
40     }
41 
42     let total_sleep_time_us: u64 =
43         sleep_time.tv_sec as u64 * 1000000 + sleep_time.tv_nsec as u64 / 1000;
44     // 创建定时器
45     let handler: Box<WakeUpHelper> = WakeUpHelper::new(ProcessManager::current_pcb());
46     let timer: Arc<Timer> = Timer::new(handler, next_n_us_timer_jiffies(total_sleep_time_us));
47 
48     let irq_guard: crate::exception::IrqFlagsGuard =
49         unsafe { CurrentIrqArch::save_and_disable_irq() };
50     ProcessManager::mark_sleep(true).ok();
51 
52     let start_time = getnstimeofday();
53     timer.activate();
54 
55     drop(irq_guard);
56     sched();
57 
58     let end_time = getnstimeofday();
59     // 返回正确的剩余时间
60     let real_sleep_time = end_time - start_time;
61     let rm_time: TimeSpec = (sleep_time - real_sleep_time.into()).into();
62 
63     return Ok(rm_time);
64 }
65 
66 /// @brief 休眠指定时间(单位:微秒)
67 ///
68 ///  @param usec 微秒
69 ///
70 /// @return Ok(TimeSpec) 剩余休眠时间
71 ///
72 /// @return Err(SystemError) 错误码
73 pub fn usleep(sleep_time: TimeSpec) -> Result<TimeSpec, SystemError> {
74     match nanosleep(sleep_time) {
75         Ok(value) => return Ok(value),
76         Err(err) => return Err(err),
77     };
78 }
79 
80 //===== 以下为提供给C的接口 =====
81 
82 /// @brief 休眠指定时间(单位:微秒)(提供给C的接口)
83 ///
84 ///  @param usec 微秒
85 ///
86 /// @return Ok(i32) 0
87 ///
88 /// @return Err(SystemError) 错误码
89 #[no_mangle]
90 pub extern "C" fn rs_usleep(usec: useconds_t) -> i32 {
91     let sleep_time = TimeSpec {
92         tv_sec: (usec / 1000000) as i64,
93         tv_nsec: ((usec % 1000000) * 1000) as i64,
94     };
95     match usleep(sleep_time) {
96         Ok(_) => {
97             return 0;
98         }
99         Err(err) => {
100             return err.to_posix_errno();
101         }
102     };
103 }
104