1971462beSGnoCiYeH use alloc::{ 2971462beSGnoCiYeH collections::LinkedList, 3971462beSGnoCiYeH sync::{Arc, Weak}, 4971462beSGnoCiYeH }; 5971462beSGnoCiYeH use core::hash::{Hash, Hasher}; 6971462beSGnoCiYeH use core::{intrinsics::likely, sync::atomic::AtomicU64}; 7971462beSGnoCiYeH use hashbrown::HashMap; 891e9d4abSLoGin use system_error::SystemError; 9971462beSGnoCiYeH 10971462beSGnoCiYeH use crate::{ 11*f0c87a89SGnoCiYeH arch::{CurrentIrqArch, MMArch}, 12971462beSGnoCiYeH exception::InterruptArch, 13971462beSGnoCiYeH libs::spinlock::{SpinLock, SpinLockGuard}, 14971462beSGnoCiYeH mm::{ucontext::AddressSpace, MemoryManagementArch, VirtAddr}, 15971462beSGnoCiYeH process::{ProcessControlBlock, ProcessManager}, 16*f0c87a89SGnoCiYeH sched::{schedule, SchedMode}, 1791e9d4abSLoGin syscall::user_access::UserBufferReader, 18971462beSGnoCiYeH time::{ 19971462beSGnoCiYeH timer::{next_n_us_timer_jiffies, Timer, WakeUpHelper}, 20971462beSGnoCiYeH TimeSpec, 21971462beSGnoCiYeH }, 22971462beSGnoCiYeH }; 23971462beSGnoCiYeH 24971462beSGnoCiYeH use super::constant::*; 25971462beSGnoCiYeH 26971462beSGnoCiYeH static mut FUTEX_DATA: Option<FutexData> = None; 27971462beSGnoCiYeH 28971462beSGnoCiYeH pub struct FutexData { 29971462beSGnoCiYeH data: SpinLock<HashMap<FutexKey, FutexHashBucket>>, 30971462beSGnoCiYeH } 31971462beSGnoCiYeH 32971462beSGnoCiYeH impl FutexData { 33971462beSGnoCiYeH pub fn futex_map() -> SpinLockGuard<'static, HashMap<FutexKey, FutexHashBucket>> { 34971462beSGnoCiYeH unsafe { FUTEX_DATA.as_ref().unwrap().data.lock() } 35971462beSGnoCiYeH } 36971462beSGnoCiYeH 37971462beSGnoCiYeH pub fn try_remove(key: &FutexKey) -> Option<FutexHashBucket> { 38971462beSGnoCiYeH unsafe { 39971462beSGnoCiYeH let mut guard = FUTEX_DATA.as_ref().unwrap().data.lock(); 40971462beSGnoCiYeH if let Some(futex) = guard.get(key) { 41971462beSGnoCiYeH if futex.chain.is_empty() { 42971462beSGnoCiYeH return guard.remove(key); 43971462beSGnoCiYeH } 44971462beSGnoCiYeH } 45971462beSGnoCiYeH } 46971462beSGnoCiYeH None 47971462beSGnoCiYeH } 48971462beSGnoCiYeH } 49971462beSGnoCiYeH 50971462beSGnoCiYeH pub struct Futex; 51971462beSGnoCiYeH 52971462beSGnoCiYeH // 对于同一个futex的进程或线程将会在这个bucket等待 53971462beSGnoCiYeH pub struct FutexHashBucket { 54971462beSGnoCiYeH // 该futex维护的等待队列 55971462beSGnoCiYeH chain: LinkedList<Arc<FutexObj>>, 56971462beSGnoCiYeH } 57971462beSGnoCiYeH 58971462beSGnoCiYeH impl FutexHashBucket { 59971462beSGnoCiYeH /// ## 判断是否在bucket里 60971462beSGnoCiYeH pub fn contains(&self, futex_q: &FutexObj) -> bool { 61971462beSGnoCiYeH self.chain 62971462beSGnoCiYeH .iter() 63971462beSGnoCiYeH .filter(|x| futex_q.pcb.ptr_eq(&x.pcb) && x.key == futex_q.key) 64971462beSGnoCiYeH .count() 65971462beSGnoCiYeH != 0 66971462beSGnoCiYeH } 67971462beSGnoCiYeH 68971462beSGnoCiYeH /// 让futex_q在该bucket上挂起 69971462beSGnoCiYeH /// 70971462beSGnoCiYeH /// 进入该函数前,需要关中断 71971462beSGnoCiYeH #[inline(always)] 72971462beSGnoCiYeH pub fn sleep_no_sched(&mut self, futex_q: Arc<FutexObj>) -> Result<(), SystemError> { 73b5b571e0SLoGin assert!(!CurrentIrqArch::is_irq_enabled()); 74971462beSGnoCiYeH self.chain.push_back(futex_q); 75971462beSGnoCiYeH 76971462beSGnoCiYeH ProcessManager::mark_sleep(true)?; 77971462beSGnoCiYeH 78971462beSGnoCiYeH Ok(()) 79971462beSGnoCiYeH } 80971462beSGnoCiYeH 81971462beSGnoCiYeH /// ## 唤醒队列中的最多nr_wake个进程 82971462beSGnoCiYeH /// 83971462beSGnoCiYeH /// return: 唤醒的进程数 84971462beSGnoCiYeH #[inline(always)] 85971462beSGnoCiYeH pub fn wake_up( 86971462beSGnoCiYeH &mut self, 87971462beSGnoCiYeH key: FutexKey, 88971462beSGnoCiYeH bitset: Option<u32>, 89971462beSGnoCiYeH nr_wake: u32, 90971462beSGnoCiYeH ) -> Result<usize, SystemError> { 91971462beSGnoCiYeH let mut count = 0; 92971462beSGnoCiYeH let mut pop_count = 0; 93971462beSGnoCiYeH while let Some(futex_q) = self.chain.pop_front() { 94971462beSGnoCiYeH if futex_q.key == key { 95971462beSGnoCiYeH // TODO: 考虑优先级继承的机制 96971462beSGnoCiYeH 97971462beSGnoCiYeH if let Some(bitset) = bitset { 98971462beSGnoCiYeH if futex_q.bitset != bitset { 99971462beSGnoCiYeH self.chain.push_back(futex_q); 100971462beSGnoCiYeH continue; 101971462beSGnoCiYeH } 102971462beSGnoCiYeH } 103971462beSGnoCiYeH 104971462beSGnoCiYeH // 唤醒 105971462beSGnoCiYeH if futex_q.pcb.upgrade().is_some() { 106971462beSGnoCiYeH self.remove(futex_q.clone()); 107971462beSGnoCiYeH ProcessManager::wakeup(&futex_q.pcb.upgrade().unwrap())?; 108971462beSGnoCiYeH } 109971462beSGnoCiYeH 110971462beSGnoCiYeH // 判断唤醒数 111971462beSGnoCiYeH count += 1; 112971462beSGnoCiYeH if count >= nr_wake { 113971462beSGnoCiYeH break; 114971462beSGnoCiYeH } 115971462beSGnoCiYeH } else { 116971462beSGnoCiYeH self.chain.push_back(futex_q); 117971462beSGnoCiYeH } 118971462beSGnoCiYeH // 判断是否循环完队列了 119971462beSGnoCiYeH pop_count += 1; 120971462beSGnoCiYeH if pop_count >= self.chain.len() { 121971462beSGnoCiYeH break; 122971462beSGnoCiYeH } 123971462beSGnoCiYeH } 124971462beSGnoCiYeH Ok(count as usize) 125971462beSGnoCiYeH } 126971462beSGnoCiYeH 127971462beSGnoCiYeH /// 将FutexObj从bucket中删除 128971462beSGnoCiYeH pub fn remove(&mut self, futex: Arc<FutexObj>) { 1291a72a751SLoGin self.chain 1301a72a751SLoGin .extract_if(|x| Arc::ptr_eq(x, &futex)) 1311a72a751SLoGin .for_each(drop); 132971462beSGnoCiYeH } 133971462beSGnoCiYeH } 134971462beSGnoCiYeH 135971462beSGnoCiYeH #[derive(Debug)] 136971462beSGnoCiYeH pub struct FutexObj { 137971462beSGnoCiYeH pcb: Weak<ProcessControlBlock>, 138971462beSGnoCiYeH key: FutexKey, 139971462beSGnoCiYeH bitset: u32, 140971462beSGnoCiYeH // TODO: 优先级继承 141971462beSGnoCiYeH } 142971462beSGnoCiYeH 143971462beSGnoCiYeH pub enum FutexAccess { 144971462beSGnoCiYeH FutexRead, 145971462beSGnoCiYeH FutexWrite, 146971462beSGnoCiYeH } 147971462beSGnoCiYeH 148971462beSGnoCiYeH #[allow(dead_code)] 149971462beSGnoCiYeH #[derive(Hash, PartialEq, Eq, Clone, Debug)] 150971462beSGnoCiYeH /// ### 用于定位内核唯一的futex 151971462beSGnoCiYeH pub enum InnerFutexKey { 152971462beSGnoCiYeH Shared(SharedKey), 153971462beSGnoCiYeH Private(PrivateKey), 154971462beSGnoCiYeH } 155971462beSGnoCiYeH 156971462beSGnoCiYeH #[derive(Hash, PartialEq, Eq, Clone, Debug)] 157971462beSGnoCiYeH pub struct FutexKey { 158971462beSGnoCiYeH ptr: u64, 159971462beSGnoCiYeH word: u64, 160971462beSGnoCiYeH offset: u32, 161971462beSGnoCiYeH key: InnerFutexKey, 162971462beSGnoCiYeH } 163971462beSGnoCiYeH 164971462beSGnoCiYeH /// 不同进程间通过文件共享futex变量,表明该变量在文件中的位置 165971462beSGnoCiYeH #[derive(Hash, PartialEq, Eq, Clone, Debug)] 166971462beSGnoCiYeH pub struct SharedKey { 167971462beSGnoCiYeH i_seq: u64, 168971462beSGnoCiYeH page_offset: u64, 169971462beSGnoCiYeH } 170971462beSGnoCiYeH 171971462beSGnoCiYeH /// 同一进程的不同线程共享futex变量,表明该变量在进程地址空间中的位置 172971462beSGnoCiYeH #[derive(Clone, Debug)] 173971462beSGnoCiYeH pub struct PrivateKey { 174971462beSGnoCiYeH // 所在的地址空间 175971462beSGnoCiYeH address_space: Option<Weak<AddressSpace>>, 176971462beSGnoCiYeH // 表示所在页面的初始地址 177971462beSGnoCiYeH address: u64, 178971462beSGnoCiYeH } 179971462beSGnoCiYeH 180971462beSGnoCiYeH impl Hash for PrivateKey { 1811a72a751SLoGin fn hash<H: Hasher>(&self, state: &mut H) { 182971462beSGnoCiYeH self.address.hash(state); 183971462beSGnoCiYeH } 184971462beSGnoCiYeH } 185971462beSGnoCiYeH 186971462beSGnoCiYeH impl Eq for PrivateKey {} 187971462beSGnoCiYeH 188971462beSGnoCiYeH impl PartialEq for PrivateKey { 189971462beSGnoCiYeH fn eq(&self, other: &Self) -> bool { 190971462beSGnoCiYeH if self.address_space.is_none() && other.address_space.is_none() { 191971462beSGnoCiYeH return self.address == other.address; 192971462beSGnoCiYeH } else { 193971462beSGnoCiYeH return self 194971462beSGnoCiYeH .address_space 195971462beSGnoCiYeH .as_ref() 196971462beSGnoCiYeH .unwrap_or(&Weak::default()) 197b5b571e0SLoGin .ptr_eq(other.address_space.as_ref().unwrap_or(&Weak::default())) 198971462beSGnoCiYeH && self.address == other.address; 199971462beSGnoCiYeH } 200971462beSGnoCiYeH } 201971462beSGnoCiYeH } 202971462beSGnoCiYeH 203971462beSGnoCiYeH impl Futex { 204971462beSGnoCiYeH /// ### 初始化FUTEX_DATA 205971462beSGnoCiYeH pub fn init() { 206971462beSGnoCiYeH unsafe { 207971462beSGnoCiYeH FUTEX_DATA = Some(FutexData { 208971462beSGnoCiYeH data: SpinLock::new(HashMap::new()), 209971462beSGnoCiYeH }) 210971462beSGnoCiYeH }; 211971462beSGnoCiYeH } 212971462beSGnoCiYeH 213971462beSGnoCiYeH /// ### 让当前进程在指定futex上等待直到futex_wake显式唤醒 214971462beSGnoCiYeH pub fn futex_wait( 215971462beSGnoCiYeH uaddr: VirtAddr, 216971462beSGnoCiYeH flags: FutexFlag, 217971462beSGnoCiYeH val: u32, 218971462beSGnoCiYeH abs_time: Option<TimeSpec>, 219971462beSGnoCiYeH bitset: u32, 220971462beSGnoCiYeH ) -> Result<usize, SystemError> { 221971462beSGnoCiYeH if bitset == 0 { 222971462beSGnoCiYeH return Err(SystemError::EINVAL); 223971462beSGnoCiYeH } 224971462beSGnoCiYeH 225971462beSGnoCiYeH // 获取全局hash表的key值 226971462beSGnoCiYeH let key = Self::get_futex_key( 227971462beSGnoCiYeH uaddr, 228971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 229971462beSGnoCiYeH FutexAccess::FutexRead, 230971462beSGnoCiYeH )?; 231971462beSGnoCiYeH 232971462beSGnoCiYeH let mut futex_map_guard = FutexData::futex_map(); 233971462beSGnoCiYeH let bucket = futex_map_guard.get_mut(&key); 234971462beSGnoCiYeH let bucket_mut = match bucket { 235971462beSGnoCiYeH Some(bucket) => bucket, 236971462beSGnoCiYeH None => { 237971462beSGnoCiYeH let bucket = FutexHashBucket { 238971462beSGnoCiYeH chain: LinkedList::new(), 239971462beSGnoCiYeH }; 240971462beSGnoCiYeH futex_map_guard.insert(key.clone(), bucket); 241971462beSGnoCiYeH futex_map_guard.get_mut(&key).unwrap() 242971462beSGnoCiYeH } 243971462beSGnoCiYeH }; 244971462beSGnoCiYeH 245971462beSGnoCiYeH // 使用UserBuffer读取futex 246971462beSGnoCiYeH let user_reader = 247971462beSGnoCiYeH UserBufferReader::new(uaddr.as_ptr::<u32>(), core::mem::size_of::<u32>(), true)?; 248971462beSGnoCiYeH 249971462beSGnoCiYeH // 从用户空间读取到futex的val 250971462beSGnoCiYeH let mut uval = 0; 251971462beSGnoCiYeH 252971462beSGnoCiYeH // 读取 253971462beSGnoCiYeH // 这里只尝试一种方式去读取用户空间,与linux不太一致 254971462beSGnoCiYeH // 对于linux,如果bucket被锁住时读取失败,将会将bucket解锁后重新读取 255971462beSGnoCiYeH user_reader.copy_one_from_user::<u32>(&mut uval, 0)?; 256971462beSGnoCiYeH 257971462beSGnoCiYeH // 不满足wait条件,返回错误 258971462beSGnoCiYeH if uval != val { 259971462beSGnoCiYeH return Err(SystemError::EAGAIN_OR_EWOULDBLOCK); 260971462beSGnoCiYeH } 261971462beSGnoCiYeH 262971462beSGnoCiYeH let pcb = ProcessManager::current_pcb(); 263971462beSGnoCiYeH // 创建超时计时器任务 264971462beSGnoCiYeH let mut timer = None; 265b5b571e0SLoGin if let Some(time) = abs_time { 266971462beSGnoCiYeH let wakeup_helper = WakeUpHelper::new(pcb.clone()); 267971462beSGnoCiYeH 268971462beSGnoCiYeH let sec = time.tv_sec; 269971462beSGnoCiYeH let nsec = time.tv_nsec; 270971462beSGnoCiYeH let jiffies = next_n_us_timer_jiffies((nsec / 1000 + sec * 1_000_000) as u64); 271971462beSGnoCiYeH 272971462beSGnoCiYeH let wake_up = Timer::new(wakeup_helper, jiffies); 273971462beSGnoCiYeH 274971462beSGnoCiYeH wake_up.activate(); 275971462beSGnoCiYeH timer = Some(wake_up); 276971462beSGnoCiYeH } 277971462beSGnoCiYeH 278971462beSGnoCiYeH let futex_q = Arc::new(FutexObj { 279971462beSGnoCiYeH pcb: Arc::downgrade(&pcb), 280971462beSGnoCiYeH key: key.clone(), 281971462beSGnoCiYeH bitset, 282971462beSGnoCiYeH }); 283971462beSGnoCiYeH let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() }; 284971462beSGnoCiYeH // 满足条件则将当前进程在该bucket上挂起 285971462beSGnoCiYeH bucket_mut.sleep_no_sched(futex_q.clone()).map_err(|e| { 286971462beSGnoCiYeH kwarn!("error:{e:?}"); 287971462beSGnoCiYeH e 288971462beSGnoCiYeH })?; 289971462beSGnoCiYeH drop(futex_map_guard); 290971462beSGnoCiYeH drop(irq_guard); 291*f0c87a89SGnoCiYeH schedule(SchedMode::SM_NONE); 292971462beSGnoCiYeH 293971462beSGnoCiYeH // 被唤醒后的检查 294971462beSGnoCiYeH let mut futex_map_guard = FutexData::futex_map(); 295971462beSGnoCiYeH let bucket = futex_map_guard.get_mut(&key); 296971462beSGnoCiYeH let bucket_mut = match bucket { 297971462beSGnoCiYeH // 如果该pcb不在链表里面了或者该链表已经被释放,就证明是正常的Wake操作 298971462beSGnoCiYeH Some(bucket_mut) => { 299971462beSGnoCiYeH if !bucket_mut.contains(&futex_q) { 300971462beSGnoCiYeH // 取消定时器任务 301b5b571e0SLoGin if let Some(timer) = timer { 302b5b571e0SLoGin timer.cancel(); 303971462beSGnoCiYeH } 304971462beSGnoCiYeH return Ok(0); 305971462beSGnoCiYeH } 306971462beSGnoCiYeH // 非正常唤醒,返回交给下层 307971462beSGnoCiYeH bucket_mut 308971462beSGnoCiYeH } 309971462beSGnoCiYeH None => { 310971462beSGnoCiYeH // 取消定时器任务 311b5b571e0SLoGin if let Some(timer) = timer { 312b5b571e0SLoGin timer.cancel(); 313971462beSGnoCiYeH } 314971462beSGnoCiYeH return Ok(0); 315971462beSGnoCiYeH } 316971462beSGnoCiYeH }; 317971462beSGnoCiYeH 318971462beSGnoCiYeH // 如果是超时唤醒,则返回错误 319b5b571e0SLoGin if timer.is_some() && timer.clone().unwrap().timeout() { 320971462beSGnoCiYeH bucket_mut.remove(futex_q); 321971462beSGnoCiYeH 322971462beSGnoCiYeH return Err(SystemError::ETIMEDOUT); 323971462beSGnoCiYeH } 324971462beSGnoCiYeH 325971462beSGnoCiYeH // TODO: 如果没有挂起的信号,则重新判断是否满足wait要求,重新进入wait 326971462beSGnoCiYeH 327971462beSGnoCiYeH // 经过前面的几个判断,到这里之后, 328971462beSGnoCiYeH // 当前进程被唤醒大概率是其他进程更改了uval,需要重新去判断当前进程是否满足wait 329971462beSGnoCiYeH 330971462beSGnoCiYeH // 到这里之后,前面的唤醒条件都不满足,则是被信号唤醒 331971462beSGnoCiYeH // 需要处理信号然后重启futex系统调用 332971462beSGnoCiYeH 333971462beSGnoCiYeH // 取消定时器任务 334b5b571e0SLoGin if let Some(timer) = timer { 335971462beSGnoCiYeH if !timer.timeout() { 336971462beSGnoCiYeH timer.cancel(); 337971462beSGnoCiYeH } 338971462beSGnoCiYeH } 339b5b571e0SLoGin 340971462beSGnoCiYeH Ok(0) 341971462beSGnoCiYeH } 342971462beSGnoCiYeH 343971462beSGnoCiYeH // ### 唤醒指定futex上挂起的最多nr_wake个进程 344971462beSGnoCiYeH pub fn futex_wake( 345971462beSGnoCiYeH uaddr: VirtAddr, 346971462beSGnoCiYeH flags: FutexFlag, 347971462beSGnoCiYeH nr_wake: u32, 348971462beSGnoCiYeH bitset: u32, 349971462beSGnoCiYeH ) -> Result<usize, SystemError> { 350971462beSGnoCiYeH if bitset == 0 { 351971462beSGnoCiYeH return Err(SystemError::EINVAL); 352971462beSGnoCiYeH } 353971462beSGnoCiYeH 354971462beSGnoCiYeH // 获取futex_key,并且判断地址空间合法性 355971462beSGnoCiYeH let key = Self::get_futex_key( 356971462beSGnoCiYeH uaddr, 357971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 358971462beSGnoCiYeH FutexAccess::FutexRead, 359971462beSGnoCiYeH )?; 360971462beSGnoCiYeH let mut binding = FutexData::futex_map(); 361971462beSGnoCiYeH let bucket_mut = binding.get_mut(&key).ok_or(SystemError::EINVAL)?; 362971462beSGnoCiYeH 363971462beSGnoCiYeH // 确保后面的唤醒操作是有意义的 364971462beSGnoCiYeH if bucket_mut.chain.is_empty() { 365971462beSGnoCiYeH return Ok(0); 366971462beSGnoCiYeH } 367971462beSGnoCiYeH // 从队列中唤醒 368971462beSGnoCiYeH let count = bucket_mut.wake_up(key.clone(), Some(bitset), nr_wake)?; 369971462beSGnoCiYeH 370971462beSGnoCiYeH drop(binding); 371971462beSGnoCiYeH 372971462beSGnoCiYeH FutexData::try_remove(&key); 373971462beSGnoCiYeH 374971462beSGnoCiYeH Ok(count) 375971462beSGnoCiYeH } 376971462beSGnoCiYeH 377971462beSGnoCiYeH /// ### 唤醒制定uaddr1上的最多nr_wake个进程,然后将uaddr1最多nr_requeue个进程移动到uaddr2绑定的futex上 378971462beSGnoCiYeH pub fn futex_requeue( 379971462beSGnoCiYeH uaddr1: VirtAddr, 380971462beSGnoCiYeH flags: FutexFlag, 381971462beSGnoCiYeH uaddr2: VirtAddr, 382971462beSGnoCiYeH nr_wake: i32, 383971462beSGnoCiYeH nr_requeue: i32, 384971462beSGnoCiYeH cmpval: Option<u32>, 385971462beSGnoCiYeH requeue_pi: bool, 386971462beSGnoCiYeH ) -> Result<usize, SystemError> { 387971462beSGnoCiYeH if nr_requeue < 0 || nr_wake < 0 { 388971462beSGnoCiYeH return Err(SystemError::EINVAL); 389971462beSGnoCiYeH } 390971462beSGnoCiYeH 391971462beSGnoCiYeH // 暂时不支持优先级继承 392971462beSGnoCiYeH if requeue_pi { 393971462beSGnoCiYeH return Err(SystemError::ENOSYS); 394971462beSGnoCiYeH } 395971462beSGnoCiYeH 396971462beSGnoCiYeH let key1 = Self::get_futex_key( 397971462beSGnoCiYeH uaddr1, 398971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 399971462beSGnoCiYeH FutexAccess::FutexRead, 400971462beSGnoCiYeH )?; 401971462beSGnoCiYeH let key2 = Self::get_futex_key(uaddr2, flags.contains(FutexFlag::FLAGS_SHARED), { 402971462beSGnoCiYeH match requeue_pi { 403971462beSGnoCiYeH true => FutexAccess::FutexWrite, 404971462beSGnoCiYeH false => FutexAccess::FutexRead, 405971462beSGnoCiYeH } 406971462beSGnoCiYeH })?; 407971462beSGnoCiYeH 408971462beSGnoCiYeH if requeue_pi && key1 == key2 { 409971462beSGnoCiYeH return Err(SystemError::EINVAL); 410971462beSGnoCiYeH } 411971462beSGnoCiYeH 412b5b571e0SLoGin if likely(cmpval.is_some()) { 413971462beSGnoCiYeH let uval_reader = 414971462beSGnoCiYeH UserBufferReader::new(uaddr1.as_ptr::<u32>(), core::mem::size_of::<u32>(), true)?; 415971462beSGnoCiYeH let curval = uval_reader.read_one_from_user::<u32>(0)?; 416971462beSGnoCiYeH 417971462beSGnoCiYeH // 判断是否满足条件 418971462beSGnoCiYeH if *curval != cmpval.unwrap() { 419971462beSGnoCiYeH return Err(SystemError::EAGAIN_OR_EWOULDBLOCK); 420971462beSGnoCiYeH } 421971462beSGnoCiYeH } 422971462beSGnoCiYeH 423971462beSGnoCiYeH let mut futex_data_guard = FutexData::futex_map(); 424971462beSGnoCiYeH if !requeue_pi { 425971462beSGnoCiYeH // 唤醒nr_wake个进程 426971462beSGnoCiYeH let bucket_1_mut = futex_data_guard.get_mut(&key1).ok_or(SystemError::EINVAL)?; 427971462beSGnoCiYeH let ret = bucket_1_mut.wake_up(key1.clone(), None, nr_wake as u32)?; 428971462beSGnoCiYeH // 将bucket1中最多nr_requeue个任务转移到bucket2 429971462beSGnoCiYeH for _ in 0..nr_requeue { 430971462beSGnoCiYeH let bucket_1_mut = futex_data_guard.get_mut(&key1).ok_or(SystemError::EINVAL)?; 431971462beSGnoCiYeH let futex_q = bucket_1_mut.chain.pop_front(); 432971462beSGnoCiYeH match futex_q { 433971462beSGnoCiYeH Some(futex_q) => { 434971462beSGnoCiYeH let bucket_2_mut = 435971462beSGnoCiYeH futex_data_guard.get_mut(&key2).ok_or(SystemError::EINVAL)?; 436971462beSGnoCiYeH bucket_2_mut.chain.push_back(futex_q); 437971462beSGnoCiYeH } 438971462beSGnoCiYeH None => { 439971462beSGnoCiYeH break; 440971462beSGnoCiYeH } 441971462beSGnoCiYeH } 442971462beSGnoCiYeH } 443971462beSGnoCiYeH 444971462beSGnoCiYeH return Ok(ret); 445971462beSGnoCiYeH } else { 446971462beSGnoCiYeH // 暂时不支持优先级继承 447971462beSGnoCiYeH todo!() 448971462beSGnoCiYeH } 449971462beSGnoCiYeH } 450971462beSGnoCiYeH 451971462beSGnoCiYeH /// ### 唤醒futex上的进程的同时进行一些操作 452971462beSGnoCiYeH pub fn futex_wake_op( 453971462beSGnoCiYeH uaddr1: VirtAddr, 454971462beSGnoCiYeH flags: FutexFlag, 455971462beSGnoCiYeH uaddr2: VirtAddr, 456971462beSGnoCiYeH nr_wake: i32, 457971462beSGnoCiYeH nr_wake2: i32, 458971462beSGnoCiYeH op: i32, 459971462beSGnoCiYeH ) -> Result<usize, SystemError> { 460971462beSGnoCiYeH let key1 = Futex::get_futex_key( 461971462beSGnoCiYeH uaddr1, 462971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 463971462beSGnoCiYeH FutexAccess::FutexRead, 464971462beSGnoCiYeH )?; 465971462beSGnoCiYeH let key2 = Futex::get_futex_key( 466971462beSGnoCiYeH uaddr2, 467971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 468971462beSGnoCiYeH FutexAccess::FutexWrite, 469971462beSGnoCiYeH )?; 470971462beSGnoCiYeH 471971462beSGnoCiYeH let mut futex_data_guard = FutexData::futex_map(); 472971462beSGnoCiYeH let bucket1 = futex_data_guard.get_mut(&key1).ok_or(SystemError::EINVAL)?; 473971462beSGnoCiYeH let mut wake_count = 0; 474971462beSGnoCiYeH 475971462beSGnoCiYeH // 唤醒uaddr1中的进程 476971462beSGnoCiYeH wake_count += bucket1.wake_up(key1, None, nr_wake as u32)?; 477971462beSGnoCiYeH 478971462beSGnoCiYeH match Self::futex_atomic_op_inuser(op as u32, uaddr2) { 479971462beSGnoCiYeH Ok(ret) => { 480971462beSGnoCiYeH // 操作成功则唤醒uaddr2中的进程 481971462beSGnoCiYeH if ret { 482971462beSGnoCiYeH let bucket2 = futex_data_guard.get_mut(&key2).ok_or(SystemError::EINVAL)?; 483971462beSGnoCiYeH wake_count += bucket2.wake_up(key2, None, nr_wake2 as u32)?; 484971462beSGnoCiYeH } 485971462beSGnoCiYeH } 486971462beSGnoCiYeH Err(e) => { 487971462beSGnoCiYeH // TODO:retry? 488971462beSGnoCiYeH return Err(e); 489971462beSGnoCiYeH } 490971462beSGnoCiYeH } 491971462beSGnoCiYeH 492971462beSGnoCiYeH Ok(wake_count) 493971462beSGnoCiYeH } 494971462beSGnoCiYeH 495971462beSGnoCiYeH fn get_futex_key( 496971462beSGnoCiYeH uaddr: VirtAddr, 497971462beSGnoCiYeH fshared: bool, 498971462beSGnoCiYeH _access: FutexAccess, 499971462beSGnoCiYeH ) -> Result<FutexKey, SystemError> { 500971462beSGnoCiYeH let mut address = uaddr.data(); 501971462beSGnoCiYeH 502971462beSGnoCiYeH // 计算相对页的偏移量 503971462beSGnoCiYeH let offset = address & (MMArch::PAGE_SIZE - 1); 504971462beSGnoCiYeH // 判断内存对齐 505b5b571e0SLoGin if uaddr.data() & (core::mem::size_of::<u32>() - 1) != 0 { 506971462beSGnoCiYeH return Err(SystemError::EINVAL); 507971462beSGnoCiYeH } 508971462beSGnoCiYeH 509971462beSGnoCiYeH // 目前address指向所在页面的起始地址 510971462beSGnoCiYeH address -= offset; 511971462beSGnoCiYeH 512971462beSGnoCiYeH // 若不是进程间共享的futex,则返回Private 513971462beSGnoCiYeH if !fshared { 514971462beSGnoCiYeH return Ok(FutexKey { 515971462beSGnoCiYeH ptr: 0, 516971462beSGnoCiYeH word: 0, 517971462beSGnoCiYeH offset: offset as u32, 518971462beSGnoCiYeH key: InnerFutexKey::Private(PrivateKey { 519971462beSGnoCiYeH address: address as u64, 520971462beSGnoCiYeH address_space: None, 521971462beSGnoCiYeH }), 522971462beSGnoCiYeH }); 523971462beSGnoCiYeH } 524971462beSGnoCiYeH 525971462beSGnoCiYeH // 获取到地址所在地址空间 526971462beSGnoCiYeH let address_space = AddressSpace::current()?; 527971462beSGnoCiYeH // TODO: 判断是否为匿名映射,是匿名映射才返回PrivateKey 528971462beSGnoCiYeH return Ok(FutexKey { 529971462beSGnoCiYeH ptr: 0, 530971462beSGnoCiYeH word: 0, 531971462beSGnoCiYeH offset: offset as u32, 532971462beSGnoCiYeH key: InnerFutexKey::Private(PrivateKey { 533971462beSGnoCiYeH address: address as u64, 534971462beSGnoCiYeH address_space: Some(Arc::downgrade(&address_space)), 535971462beSGnoCiYeH }), 536971462beSGnoCiYeH }); 537971462beSGnoCiYeH 538971462beSGnoCiYeH // 未实现共享内存机制,贡献内存部分应该通过inode构建SharedKey 539971462beSGnoCiYeH // todo!("Shared memory not implemented"); 540971462beSGnoCiYeH } 541971462beSGnoCiYeH 542971462beSGnoCiYeH pub fn futex_atomic_op_inuser(encoded_op: u32, uaddr: VirtAddr) -> Result<bool, SystemError> { 543971462beSGnoCiYeH let op = FutexOP::from_bits((encoded_op & 0x70000000) >> 28).ok_or(SystemError::ENOSYS)?; 544971462beSGnoCiYeH let cmp = 545971462beSGnoCiYeH FutexOpCMP::from_bits((encoded_op & 0x0f000000) >> 24).ok_or(SystemError::ENOSYS)?; 546971462beSGnoCiYeH 547971462beSGnoCiYeH let sign_extend32 = |value: u32, index: i32| { 548971462beSGnoCiYeH let shift = (31 - index) as u8; 549971462beSGnoCiYeH return (value << shift) >> shift; 550971462beSGnoCiYeH }; 551971462beSGnoCiYeH 552971462beSGnoCiYeH let mut oparg = sign_extend32((encoded_op & 0x00fff000) >> 12, 11); 553971462beSGnoCiYeH let cmparg = sign_extend32(encoded_op & 0x00000fff, 11); 554971462beSGnoCiYeH 555b5b571e0SLoGin if (encoded_op & (FutexOP::FUTEX_OP_OPARG_SHIFT.bits() << 28) != 0) && oparg > 31 { 556971462beSGnoCiYeH kwarn!( 557971462beSGnoCiYeH "futex_wake_op: pid:{} tries to shift op by {}; fix this program", 558971462beSGnoCiYeH ProcessManager::current_pcb().pid().data(), 559971462beSGnoCiYeH oparg 560971462beSGnoCiYeH ); 561971462beSGnoCiYeH 562971462beSGnoCiYeH oparg &= 31; 563971462beSGnoCiYeH } 564971462beSGnoCiYeH 565971462beSGnoCiYeH // TODO: 这个汇编似乎是有问题的,目前不好测试 566971462beSGnoCiYeH let old_val = Self::arch_futex_atomic_op_inuser(op, oparg, uaddr)?; 567971462beSGnoCiYeH 568971462beSGnoCiYeH match cmp { 569971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_EQ => { 570971462beSGnoCiYeH return Ok(cmparg == old_val); 571971462beSGnoCiYeH } 572971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_NE => { 573971462beSGnoCiYeH return Ok(cmparg != old_val); 574971462beSGnoCiYeH } 575971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_LT => { 576971462beSGnoCiYeH return Ok(cmparg < old_val); 577971462beSGnoCiYeH } 578971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_LE => { 579971462beSGnoCiYeH return Ok(cmparg <= old_val); 580971462beSGnoCiYeH } 581971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_GE => { 582971462beSGnoCiYeH return Ok(cmparg >= old_val); 583971462beSGnoCiYeH } 584971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_GT => { 585971462beSGnoCiYeH return Ok(cmparg > old_val); 586971462beSGnoCiYeH } 587971462beSGnoCiYeH _ => { 588971462beSGnoCiYeH return Err(SystemError::ENOSYS); 589971462beSGnoCiYeH } 590971462beSGnoCiYeH } 591971462beSGnoCiYeH } 592971462beSGnoCiYeH 593971462beSGnoCiYeH /// ### 对futex进行操作 594971462beSGnoCiYeH /// 595971462beSGnoCiYeH /// 进入该方法会关闭中断保证修改的原子性,所以进入该方法前应确保中断锁已释放 596971462beSGnoCiYeH /// 597971462beSGnoCiYeH /// ### return uaddr原来的值 598971462beSGnoCiYeH #[allow(unused_assignments)] 599971462beSGnoCiYeH pub fn arch_futex_atomic_op_inuser( 600971462beSGnoCiYeH op: FutexOP, 601971462beSGnoCiYeH oparg: u32, 602971462beSGnoCiYeH uaddr: VirtAddr, 603971462beSGnoCiYeH ) -> Result<u32, SystemError> { 604971462beSGnoCiYeH let guard = unsafe { CurrentIrqArch::save_and_disable_irq() }; 605971462beSGnoCiYeH 606971462beSGnoCiYeH let reader = 607971462beSGnoCiYeH UserBufferReader::new(uaddr.as_ptr::<u32>(), core::mem::size_of::<u32>(), true)?; 608971462beSGnoCiYeH 609971462beSGnoCiYeH let oldval = reader.read_one_from_user::<u32>(0)?; 610971462beSGnoCiYeH 611971462beSGnoCiYeH let atomic_addr = AtomicU64::new(uaddr.data() as u64); 612971462beSGnoCiYeH // 这个指针是指向指针的指针 6131a72a751SLoGin let ptr = atomic_addr.as_ptr(); 614971462beSGnoCiYeH match op { 615971462beSGnoCiYeH FutexOP::FUTEX_OP_SET => unsafe { 616971462beSGnoCiYeH *((*ptr) as *mut u32) = oparg; 617971462beSGnoCiYeH }, 618971462beSGnoCiYeH FutexOP::FUTEX_OP_ADD => unsafe { 619971462beSGnoCiYeH *((*ptr) as *mut u32) += oparg; 620971462beSGnoCiYeH }, 621971462beSGnoCiYeH FutexOP::FUTEX_OP_OR => unsafe { 622971462beSGnoCiYeH *((*ptr) as *mut u32) |= oparg; 623971462beSGnoCiYeH }, 624971462beSGnoCiYeH FutexOP::FUTEX_OP_ANDN => unsafe { 625971462beSGnoCiYeH *((*ptr) as *mut u32) &= oparg; 626971462beSGnoCiYeH }, 627971462beSGnoCiYeH FutexOP::FUTEX_OP_XOR => unsafe { 628971462beSGnoCiYeH *((*ptr) as *mut u32) ^= oparg; 629971462beSGnoCiYeH }, 630971462beSGnoCiYeH _ => return Err(SystemError::ENOSYS), 631971462beSGnoCiYeH } 632971462beSGnoCiYeH 633971462beSGnoCiYeH drop(guard); 634971462beSGnoCiYeH 635971462beSGnoCiYeH Ok(*oldval) 636971462beSGnoCiYeH } 637971462beSGnoCiYeH } 638