1 use core::{ 2 fmt::Debug, 3 intrinsics::unlikely, 4 sync::atomic::{compiler_fence, AtomicBool, AtomicU64, Ordering}, 5 }; 6 7 use alloc::{ 8 boxed::Box, 9 collections::LinkedList, 10 sync::{Arc, Weak}, 11 }; 12 13 use crate::{ 14 arch::{sched::sched, CurrentIrqArch}, 15 exception::{ 16 softirq::{softirq_vectors, SoftirqNumber, SoftirqVec}, 17 InterruptArch, 18 }, 19 kerror, kinfo, 20 libs::spinlock::SpinLock, 21 process::{ProcessControlBlock, ProcessManager}, 22 syscall::SystemError, 23 }; 24 25 use super::timekeeping::update_wall_time; 26 27 const MAX_TIMEOUT: i64 = i64::MAX; 28 const TIMER_RUN_CYCLE_THRESHOLD: usize = 20; 29 static TIMER_JIFFIES: AtomicU64 = AtomicU64::new(0); 30 31 lazy_static! { 32 pub static ref TIMER_LIST: SpinLock<LinkedList<Arc<Timer>>> = SpinLock::new(LinkedList::new()); 33 } 34 35 /// 定时器要执行的函数的特征 36 pub trait TimerFunction: Send + Sync + Debug { 37 fn run(&mut self) -> Result<(), SystemError>; 38 } 39 40 #[derive(Debug)] 41 /// WakeUpHelper函数对应的结构体 42 pub struct WakeUpHelper { 43 pcb: Arc<ProcessControlBlock>, 44 } 45 46 impl WakeUpHelper { 47 pub fn new(pcb: Arc<ProcessControlBlock>) -> Box<WakeUpHelper> { 48 return Box::new(WakeUpHelper { pcb }); 49 } 50 } 51 52 impl TimerFunction for WakeUpHelper { 53 fn run(&mut self) -> Result<(), SystemError> { 54 ProcessManager::wakeup(&self.pcb).ok(); 55 return Ok(()); 56 } 57 } 58 59 #[derive(Debug)] 60 pub struct Timer(SpinLock<InnerTimer>); 61 62 impl Timer { 63 /// @brief 创建一个定时器（单位：ms） 64 /// 65 /// @param timer_func 定时器需要执行的函数对应的结构体 66 /// 67 /// @param expire_jiffies 定时器结束时刻 68 /// 69 /// @return 定时器结构体 70 pub fn new(timer_func: Box<dyn TimerFunction>, expire_jiffies: u64) -> Arc<Self> { 71 let result: Arc<Timer> = Arc::new(Timer(SpinLock::new(InnerTimer { 72 expire_jiffies, 73 timer_func, 74 self_ref: Weak::default(), 75 triggered: false, 76 }))); 77 78 result.0.lock().self_ref = Arc::downgrade(&result); 79 80 return result; 81 } 82 83 /// @brief 将定时器插入到定时器链表中 84 pub fn activate(&self) { 85 let inner_guard = self.0.lock(); 86 let timer_list = &mut TIMER_LIST.lock(); 87 88 // 链表为空，则直接插入 89 if timer_list.is_empty() { 90 // FIXME push_timer 91 92 timer_list.push_back(inner_guard.self_ref.upgrade().unwrap()); 93 94 drop(inner_guard); 95 drop(timer_list); 96 compiler_fence(Ordering::SeqCst); 97 98 return; 99 } 100 let mut split_pos: usize = 0; 101 for (pos, elt) in timer_list.iter().enumerate() { 102 if elt.0.lock().expire_jiffies > inner_guard.expire_jiffies { 103 split_pos = pos; 104 break; 105 } 106 } 107 let mut temp_list: LinkedList<Arc<Timer>> = timer_list.split_off(split_pos); 108 timer_list.push_back(inner_guard.self_ref.upgrade().unwrap()); 109 timer_list.append(&mut temp_list); 110 drop(inner_guard); 111 drop(timer_list); 112 } 113 114 #[inline] 115 fn run(&self) { 116 let mut timer = self.0.lock(); 117 timer.triggered = true; 118 let r = timer.timer_func.run(); 119 if unlikely(r.is_err()) { 120 kerror!( 121 "Failed to run timer function: {self:?} {:?}", 122 r.err().unwrap() 123 ); 124 } 125 } 126 127 /// ## 判断定时器是否已经触发 128 pub fn timeout(&self) -> bool { 129 self.0.lock().triggered 130 } 131 132 /// ## 取消定时器任务 133 pub fn cancel(&self) -> bool { 134 TIMER_LIST 135 .lock() 136 .drain_filter(|x| Arc::<Timer>::as_ptr(&x) == self as *const Timer); 137 true 138 } 139 } 140 141 /// 定时器类型 142 #[derive(Debug)] 143 pub struct InnerTimer { 144 /// 定时器结束时刻 145 pub expire_jiffies: u64, 146 /// 定时器需要执行的函数结构体 147 pub timer_func: Box<dyn TimerFunction>, 148 /// self_ref 149 self_ref: Weak<Timer>, 150 /// 判断该计时器是否触发 151 triggered: bool, 152 } 153 154 #[derive(Debug)] 155 pub struct DoTimerSoftirq { 156 running: AtomicBool, 157 } 158 159 impl DoTimerSoftirq { 160 pub fn new() -> Self { 161 return DoTimerSoftirq { 162 running: AtomicBool::new(false), 163 }; 164 } 165 166 fn set_run(&self) -> bool { 167 let x = self 168 .running 169 .compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed); 170 if x.is_ok() { 171 return true; 172 } else { 173 return false; 174 } 175 } 176 177 fn clear_run(&self) { 178 self.running.store(false, Ordering::Release); 179 } 180 } 181 impl SoftirqVec for DoTimerSoftirq { 182 fn run(&self) { 183 if self.set_run() == false { 184 return; 185 } 186 // 最多只处理TIMER_RUN_CYCLE_THRESHOLD个计时器 187 for _ in 0..TIMER_RUN_CYCLE_THRESHOLD { 188 // kdebug!("DoTimerSoftirq run"); 189 let timer_list = TIMER_LIST.try_lock(); 190 if timer_list.is_err() { 191 continue; 192 } 193 let mut timer_list = timer_list.unwrap(); 194 195 if timer_list.is_empty() { 196 break; 197 } 198 199 let timer_list_front = timer_list.pop_front().unwrap(); 200 // kdebug!("to lock timer_list_front"); 201 let mut timer_list_front_guard = None; 202 for _ in 0..10 { 203 let x = timer_list_front.0.try_lock(); 204 if x.is_err() { 205 continue; 206 } 207 timer_list_front_guard = Some(x.unwrap()); 208 } 209 if timer_list_front_guard.is_none() { 210 continue; 211 } 212 let timer_list_front_guard = timer_list_front_guard.unwrap(); 213 if timer_list_front_guard.expire_jiffies > TIMER_JIFFIES.load(Ordering::SeqCst) { 214 drop(timer_list_front_guard); 215 timer_list.push_front(timer_list_front); 216 break; 217 } 218 drop(timer_list_front_guard); 219 drop(timer_list); 220 timer_list_front.run(); 221 } 222 223 self.clear_run(); 224 } 225 } 226 227 /// @brief 初始化timer模块 228 pub fn timer_init() { 229 // FIXME 调用register_trap 230 let do_timer_softirq = Arc::new(DoTimerSoftirq::new()); 231 softirq_vectors() 232 .register_softirq(SoftirqNumber::TIMER, do_timer_softirq) 233 .expect("Failed to register timer softirq"); 234 kinfo!("timer initialized successfully"); 235 } 236 237 /// 计算接下来n毫秒对应的定时器时间片 238 pub fn next_n_ms_timer_jiffies(expire_ms: u64) -> u64 { 239 return TIMER_JIFFIES.load(Ordering::SeqCst) + 1000 * (expire_ms); 240 } 241 /// 计算接下来n微秒对应的定时器时间片 242 pub fn next_n_us_timer_jiffies(expire_us: u64) -> u64 { 243 return TIMER_JIFFIES.load(Ordering::SeqCst) + (expire_us); 244 } 245 246 /// @brief 让pcb休眠timeout个jiffies 247 /// 248 /// @param timeout 需要休眠的时间(单位：jiffies) 249 /// 250 /// @return Ok(i64) 剩余需要休眠的时间(单位：jiffies) 251 /// 252 /// @return Err(SystemError) 错误码 253 pub fn schedule_timeout(mut timeout: i64) -> Result<i64, SystemError> { 254 // kdebug!("schedule_timeout"); 255 if timeout == MAX_TIMEOUT { 256 ProcessManager::mark_sleep(true).ok(); 257 sched(); 258 return Ok(MAX_TIMEOUT); 259 } else if timeout < 0 { 260 kerror!("timeout can't less than 0"); 261 return Err(SystemError::EINVAL); 262 } else { 263 // 禁用中断，防止在这段期间发生调度，造成死锁 264 let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() }; 265 266 timeout += TIMER_JIFFIES.load(Ordering::SeqCst) as i64; 267 let timer = Timer::new( 268 WakeUpHelper::new(ProcessManager::current_pcb()), 269 timeout as u64, 270 ); 271 ProcessManager::mark_sleep(true).ok(); 272 timer.activate(); 273 274 drop(irq_guard); 275 276 sched(); 277 let time_remaining: i64 = timeout - TIMER_JIFFIES.load(Ordering::SeqCst) as i64; 278 if time_remaining >= 0 { 279 // 被提前唤醒，返回剩余时间 280 return Ok(time_remaining); 281 } else { 282 return Ok(0); 283 } 284 } 285 } 286 287 pub fn timer_get_first_expire() -> Result<u64, SystemError> { 288 // FIXME 289 // kdebug!("rs_timer_get_first_expire,timer_jif = {:?}", TIMER_JIFFIES); 290 for _ in 0..10 { 291 match TIMER_LIST.try_lock_irqsave() { 292 Ok(timer_list) => { 293 // kdebug!("rs_timer_get_first_expire TIMER_LIST lock successfully"); 294 if timer_list.is_empty() { 295 // kdebug!("timer_list is empty"); 296 return Ok(0); 297 } else { 298 // kdebug!("timer_list not empty"); 299 return Ok(timer_list.front().unwrap().0.lock().expire_jiffies); 300 } 301 } 302 // 加锁失败返回啥？？ 303 Err(_) => continue, 304 } 305 } 306 return Err(SystemError::EAGAIN_OR_EWOULDBLOCK); 307 } 308 309 /// 更新系统时间片 310 /// 311 /// todo: 这里的实现有问题，貌似把HPET的500us当成了500个jiffies，然后update_wall_time()里面也硬编码了这个500us 312 pub fn update_timer_jiffies(add_jiffies: u64) -> u64 { 313 let prev = TIMER_JIFFIES.fetch_add(add_jiffies, Ordering::SeqCst); 314 compiler_fence(Ordering::SeqCst); 315 update_wall_time(); 316 317 compiler_fence(Ordering::SeqCst); 318 return prev + add_jiffies; 319 } 320 321 pub fn clock() -> u64 { 322 return TIMER_JIFFIES.load(Ordering::SeqCst); 323 } 324 325 // ====== 以下为给C提供的接口 ====== 326 327 #[no_mangle] 328 pub extern "C" fn rs_timer_init() { 329 timer_init(); 330 } 331