xref: /DragonOS/kernel/src/time/sleep.rs (revision 81294aa2e6b257f0de5e3c28c3f3c89798330836)
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, Cpu_tsc_freq},
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: u64 = unsafe {
33             CurrentTimeArch::get_cycles() as u64
34                 + (sleep_time.tv_nsec as u64 * Cpu_tsc_freq) / 1000000000
35         };
36         while (CurrentTimeArch::get_cycles() as u64) < expired_tsc {
37             spin_loop()
38         }
39         return Ok(TimeSpec {
40             tv_sec: 0,
41             tv_nsec: 0,
42         });
43     }
44 
45     let total_sleep_time_us: u64 =
46         sleep_time.tv_sec as u64 * 1000000 + sleep_time.tv_nsec as u64 / 1000;
47     // 创建定时器
48     let handler: Box<WakeUpHelper> = WakeUpHelper::new(ProcessManager::current_pcb());
49     let timer: Arc<Timer> = Timer::new(handler, next_n_us_timer_jiffies(total_sleep_time_us));
50 
51     let irq_guard: crate::exception::IrqFlagsGuard =
52         unsafe { CurrentIrqArch::save_and_disable_irq() };
53     ProcessManager::mark_sleep(true).ok();
54 
55     let start_time = getnstimeofday();
56     timer.activate();
57 
58     drop(irq_guard);
59     sched();
60 
61     let end_time = getnstimeofday();
62     // 返回正确的剩余时间
63     let real_sleep_time = end_time - start_time;
64     let rm_time: TimeSpec = (sleep_time - real_sleep_time.into()).into();
65 
66     return Ok(rm_time);
67 }
68 
69 /// @brief 休眠指定时间(单位:微秒)
70 ///
71 ///  @param usec 微秒
72 ///
73 /// @return Ok(TimeSpec) 剩余休眠时间
74 ///
75 /// @return Err(SystemError) 错误码
76 pub fn usleep(sleep_time: TimeSpec) -> Result<TimeSpec, SystemError> {
77     match nanosleep(sleep_time) {
78         Ok(value) => return Ok(value),
79         Err(err) => return Err(err),
80     };
81 }
82 
83 //===== 以下为提供给C的接口 =====
84 
85 /// @brief 休眠指定时间(单位:微秒)(提供给C的接口)
86 ///
87 ///  @param usec 微秒
88 ///
89 /// @return Ok(i32) 0
90 ///
91 /// @return Err(SystemError) 错误码
92 #[no_mangle]
93 pub extern "C" fn rs_usleep(usec: useconds_t) -> i32 {
94     let sleep_time = TimeSpec {
95         tv_sec: (usec / 1000000) as i64,
96         tv_nsec: ((usec % 1000000) * 1000) as i64,
97     };
98     match usleep(sleep_time) {
99         Ok(_) => {
100             return 0;
101         }
102         Err(err) => {
103             return err.to_posix_errno();
104         }
105     };
106 }
107