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; 8971462beSGnoCiYeH 9971462beSGnoCiYeH use crate::{ 10971462beSGnoCiYeH arch::{sched::sched, CurrentIrqArch, MMArch}, 11971462beSGnoCiYeH exception::InterruptArch, 12971462beSGnoCiYeH libs::spinlock::{SpinLock, SpinLockGuard}, 13971462beSGnoCiYeH mm::{ucontext::AddressSpace, MemoryManagementArch, VirtAddr}, 14971462beSGnoCiYeH process::{ProcessControlBlock, ProcessManager}, 15971462beSGnoCiYeH syscall::{user_access::UserBufferReader, SystemError}, 16971462beSGnoCiYeH time::{ 17971462beSGnoCiYeH timer::{next_n_us_timer_jiffies, Timer, WakeUpHelper}, 18971462beSGnoCiYeH TimeSpec, 19971462beSGnoCiYeH }, 20971462beSGnoCiYeH }; 21971462beSGnoCiYeH 22971462beSGnoCiYeH use super::constant::*; 23971462beSGnoCiYeH 24971462beSGnoCiYeH static mut FUTEX_DATA: Option<FutexData> = None; 25971462beSGnoCiYeH 26971462beSGnoCiYeH pub struct FutexData { 27971462beSGnoCiYeH data: SpinLock<HashMap<FutexKey, FutexHashBucket>>, 28971462beSGnoCiYeH } 29971462beSGnoCiYeH 30971462beSGnoCiYeH impl FutexData { 31971462beSGnoCiYeH pub fn futex_map() -> SpinLockGuard<'static, HashMap<FutexKey, FutexHashBucket>> { 32971462beSGnoCiYeH unsafe { FUTEX_DATA.as_ref().unwrap().data.lock() } 33971462beSGnoCiYeH } 34971462beSGnoCiYeH 35971462beSGnoCiYeH pub fn try_remove(key: &FutexKey) -> Option<FutexHashBucket> { 36971462beSGnoCiYeH unsafe { 37971462beSGnoCiYeH let mut guard = FUTEX_DATA.as_ref().unwrap().data.lock(); 38971462beSGnoCiYeH if let Some(futex) = guard.get(key) { 39971462beSGnoCiYeH if futex.chain.is_empty() { 40971462beSGnoCiYeH return guard.remove(key); 41971462beSGnoCiYeH } 42971462beSGnoCiYeH } 43971462beSGnoCiYeH } 44971462beSGnoCiYeH None 45971462beSGnoCiYeH } 46971462beSGnoCiYeH } 47971462beSGnoCiYeH 48971462beSGnoCiYeH pub struct Futex; 49971462beSGnoCiYeH 50971462beSGnoCiYeH // 对于同一个futex的进程或线程将会在这个bucket等待 51971462beSGnoCiYeH pub struct FutexHashBucket { 52971462beSGnoCiYeH // 该futex维护的等待队列 53971462beSGnoCiYeH chain: LinkedList<Arc<FutexObj>>, 54971462beSGnoCiYeH } 55971462beSGnoCiYeH 56971462beSGnoCiYeH impl FutexHashBucket { 57971462beSGnoCiYeH /// ## 判断是否在bucket里 58971462beSGnoCiYeH pub fn contains(&self, futex_q: &FutexObj) -> bool { 59971462beSGnoCiYeH self.chain 60971462beSGnoCiYeH .iter() 61971462beSGnoCiYeH .filter(|x| futex_q.pcb.ptr_eq(&x.pcb) && x.key == futex_q.key) 62971462beSGnoCiYeH .count() 63971462beSGnoCiYeH != 0 64971462beSGnoCiYeH } 65971462beSGnoCiYeH 66971462beSGnoCiYeH /// 让futex_q在该bucket上挂起 67971462beSGnoCiYeH /// 68971462beSGnoCiYeH /// 进入该函数前,需要关中断 69971462beSGnoCiYeH #[inline(always)] 70971462beSGnoCiYeH pub fn sleep_no_sched(&mut self, futex_q: Arc<FutexObj>) -> Result<(), SystemError> { 71971462beSGnoCiYeH assert!(CurrentIrqArch::is_irq_enabled() == false); 72971462beSGnoCiYeH self.chain.push_back(futex_q); 73971462beSGnoCiYeH 74971462beSGnoCiYeH ProcessManager::mark_sleep(true)?; 75971462beSGnoCiYeH 76971462beSGnoCiYeH Ok(()) 77971462beSGnoCiYeH } 78971462beSGnoCiYeH 79971462beSGnoCiYeH /// ## 唤醒队列中的最多nr_wake个进程 80971462beSGnoCiYeH /// 81971462beSGnoCiYeH /// return: 唤醒的进程数 82971462beSGnoCiYeH #[inline(always)] 83971462beSGnoCiYeH pub fn wake_up( 84971462beSGnoCiYeH &mut self, 85971462beSGnoCiYeH key: FutexKey, 86971462beSGnoCiYeH bitset: Option<u32>, 87971462beSGnoCiYeH nr_wake: u32, 88971462beSGnoCiYeH ) -> Result<usize, SystemError> { 89971462beSGnoCiYeH let mut count = 0; 90971462beSGnoCiYeH let mut pop_count = 0; 91971462beSGnoCiYeH while let Some(futex_q) = self.chain.pop_front() { 92971462beSGnoCiYeH if futex_q.key == key { 93971462beSGnoCiYeH // TODO: 考虑优先级继承的机制 94971462beSGnoCiYeH 95971462beSGnoCiYeH if let Some(bitset) = bitset { 96971462beSGnoCiYeH if futex_q.bitset != bitset { 97971462beSGnoCiYeH self.chain.push_back(futex_q); 98971462beSGnoCiYeH continue; 99971462beSGnoCiYeH } 100971462beSGnoCiYeH } 101971462beSGnoCiYeH 102971462beSGnoCiYeH // 唤醒 103971462beSGnoCiYeH if futex_q.pcb.upgrade().is_some() { 104971462beSGnoCiYeH self.remove(futex_q.clone()); 105971462beSGnoCiYeH ProcessManager::wakeup(&futex_q.pcb.upgrade().unwrap())?; 106971462beSGnoCiYeH } 107971462beSGnoCiYeH 108971462beSGnoCiYeH // 判断唤醒数 109971462beSGnoCiYeH count += 1; 110971462beSGnoCiYeH if count >= nr_wake { 111971462beSGnoCiYeH break; 112971462beSGnoCiYeH } 113971462beSGnoCiYeH } else { 114971462beSGnoCiYeH self.chain.push_back(futex_q); 115971462beSGnoCiYeH } 116971462beSGnoCiYeH // 判断是否循环完队列了 117971462beSGnoCiYeH pop_count += 1; 118971462beSGnoCiYeH if pop_count >= self.chain.len() { 119971462beSGnoCiYeH break; 120971462beSGnoCiYeH } 121971462beSGnoCiYeH } 122971462beSGnoCiYeH Ok(count as usize) 123971462beSGnoCiYeH } 124971462beSGnoCiYeH 125971462beSGnoCiYeH /// 将FutexObj从bucket中删除 126971462beSGnoCiYeH pub fn remove(&mut self, futex: Arc<FutexObj>) { 127*1a72a751SLoGin self.chain 128*1a72a751SLoGin .extract_if(|x| Arc::ptr_eq(x, &futex)) 129*1a72a751SLoGin .for_each(drop); 130971462beSGnoCiYeH } 131971462beSGnoCiYeH } 132971462beSGnoCiYeH 133971462beSGnoCiYeH #[derive(Debug)] 134971462beSGnoCiYeH pub struct FutexObj { 135971462beSGnoCiYeH pcb: Weak<ProcessControlBlock>, 136971462beSGnoCiYeH key: FutexKey, 137971462beSGnoCiYeH bitset: u32, 138971462beSGnoCiYeH // TODO: 优先级继承 139971462beSGnoCiYeH } 140971462beSGnoCiYeH 141971462beSGnoCiYeH pub enum FutexAccess { 142971462beSGnoCiYeH FutexRead, 143971462beSGnoCiYeH FutexWrite, 144971462beSGnoCiYeH } 145971462beSGnoCiYeH 146971462beSGnoCiYeH #[allow(dead_code)] 147971462beSGnoCiYeH #[derive(Hash, PartialEq, Eq, Clone, Debug)] 148971462beSGnoCiYeH /// ### 用于定位内核唯一的futex 149971462beSGnoCiYeH pub enum InnerFutexKey { 150971462beSGnoCiYeH Shared(SharedKey), 151971462beSGnoCiYeH Private(PrivateKey), 152971462beSGnoCiYeH } 153971462beSGnoCiYeH 154971462beSGnoCiYeH #[derive(Hash, PartialEq, Eq, Clone, Debug)] 155971462beSGnoCiYeH pub struct FutexKey { 156971462beSGnoCiYeH ptr: u64, 157971462beSGnoCiYeH word: u64, 158971462beSGnoCiYeH offset: u32, 159971462beSGnoCiYeH key: InnerFutexKey, 160971462beSGnoCiYeH } 161971462beSGnoCiYeH 162971462beSGnoCiYeH /// 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 163971462beSGnoCiYeH #[derive(Hash, PartialEq, Eq, Clone, Debug)] 164971462beSGnoCiYeH pub struct SharedKey { 165971462beSGnoCiYeH i_seq: u64, 166971462beSGnoCiYeH page_offset: u64, 167971462beSGnoCiYeH } 168971462beSGnoCiYeH 169971462beSGnoCiYeH /// 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 170971462beSGnoCiYeH #[derive(Clone, Debug)] 171971462beSGnoCiYeH pub struct PrivateKey { 172971462beSGnoCiYeH // 所在的地址空间 173971462beSGnoCiYeH address_space: Option<Weak<AddressSpace>>, 174971462beSGnoCiYeH // 表示所在页面的初始地址 175971462beSGnoCiYeH address: u64, 176971462beSGnoCiYeH } 177971462beSGnoCiYeH 178971462beSGnoCiYeH impl Hash for PrivateKey { 179*1a72a751SLoGin fn hash<H: Hasher>(&self, state: &mut H) { 180971462beSGnoCiYeH self.address.hash(state); 181971462beSGnoCiYeH } 182971462beSGnoCiYeH } 183971462beSGnoCiYeH 184971462beSGnoCiYeH impl Eq for PrivateKey {} 185971462beSGnoCiYeH 186971462beSGnoCiYeH impl PartialEq for PrivateKey { 187971462beSGnoCiYeH fn eq(&self, other: &Self) -> bool { 188971462beSGnoCiYeH if self.address_space.is_none() && other.address_space.is_none() { 189971462beSGnoCiYeH return self.address == other.address; 190971462beSGnoCiYeH } else { 191971462beSGnoCiYeH return self 192971462beSGnoCiYeH .address_space 193971462beSGnoCiYeH .as_ref() 194971462beSGnoCiYeH .unwrap_or(&Weak::default()) 195971462beSGnoCiYeH .ptr_eq(&other.address_space.as_ref().unwrap_or(&Weak::default())) 196971462beSGnoCiYeH && self.address == other.address; 197971462beSGnoCiYeH } 198971462beSGnoCiYeH } 199971462beSGnoCiYeH } 200971462beSGnoCiYeH 201971462beSGnoCiYeH impl Futex { 202971462beSGnoCiYeH /// ### 初始化FUTEX_DATA 203971462beSGnoCiYeH pub fn init() { 204971462beSGnoCiYeH unsafe { 205971462beSGnoCiYeH FUTEX_DATA = Some(FutexData { 206971462beSGnoCiYeH data: SpinLock::new(HashMap::new()), 207971462beSGnoCiYeH }) 208971462beSGnoCiYeH }; 209971462beSGnoCiYeH } 210971462beSGnoCiYeH 211971462beSGnoCiYeH /// ### 让当前进程在指定futex上等待直到futex_wake显式唤醒 212971462beSGnoCiYeH pub fn futex_wait( 213971462beSGnoCiYeH uaddr: VirtAddr, 214971462beSGnoCiYeH flags: FutexFlag, 215971462beSGnoCiYeH val: u32, 216971462beSGnoCiYeH abs_time: Option<TimeSpec>, 217971462beSGnoCiYeH bitset: u32, 218971462beSGnoCiYeH ) -> Result<usize, SystemError> { 219971462beSGnoCiYeH if bitset == 0 { 220971462beSGnoCiYeH return Err(SystemError::EINVAL); 221971462beSGnoCiYeH } 222971462beSGnoCiYeH 223971462beSGnoCiYeH // 获取全局hash表的key值 224971462beSGnoCiYeH let key = Self::get_futex_key( 225971462beSGnoCiYeH uaddr, 226971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 227971462beSGnoCiYeH FutexAccess::FutexRead, 228971462beSGnoCiYeH )?; 229971462beSGnoCiYeH 230971462beSGnoCiYeH let mut futex_map_guard = FutexData::futex_map(); 231971462beSGnoCiYeH let bucket = futex_map_guard.get_mut(&key); 232971462beSGnoCiYeH let bucket_mut = match bucket { 233971462beSGnoCiYeH Some(bucket) => bucket, 234971462beSGnoCiYeH None => { 235971462beSGnoCiYeH let bucket = FutexHashBucket { 236971462beSGnoCiYeH chain: LinkedList::new(), 237971462beSGnoCiYeH }; 238971462beSGnoCiYeH futex_map_guard.insert(key.clone(), bucket); 239971462beSGnoCiYeH futex_map_guard.get_mut(&key).unwrap() 240971462beSGnoCiYeH } 241971462beSGnoCiYeH }; 242971462beSGnoCiYeH 243971462beSGnoCiYeH // 使用UserBuffer读取futex 244971462beSGnoCiYeH let user_reader = 245971462beSGnoCiYeH UserBufferReader::new(uaddr.as_ptr::<u32>(), core::mem::size_of::<u32>(), true)?; 246971462beSGnoCiYeH 247971462beSGnoCiYeH // 从用户空间读取到futex的val 248971462beSGnoCiYeH let mut uval = 0; 249971462beSGnoCiYeH 250971462beSGnoCiYeH // 读取 251971462beSGnoCiYeH // 这里只尝试一种方式去读取用户空间,与linux不太一致 252971462beSGnoCiYeH // 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 253971462beSGnoCiYeH user_reader.copy_one_from_user::<u32>(&mut uval, 0)?; 254971462beSGnoCiYeH 255971462beSGnoCiYeH // 不满足wait条件,返回错误 256971462beSGnoCiYeH if uval != val { 257971462beSGnoCiYeH return Err(SystemError::EAGAIN_OR_EWOULDBLOCK); 258971462beSGnoCiYeH } 259971462beSGnoCiYeH 260971462beSGnoCiYeH let pcb = ProcessManager::current_pcb(); 261971462beSGnoCiYeH // 创建超时计时器任务 262971462beSGnoCiYeH let mut timer = None; 263971462beSGnoCiYeH if !abs_time.is_none() { 264971462beSGnoCiYeH let time = abs_time.unwrap(); 265971462beSGnoCiYeH 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); 291971462beSGnoCiYeH sched(); 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 301971462beSGnoCiYeH if timer.is_some() { 302971462beSGnoCiYeH timer.unwrap().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 311971462beSGnoCiYeH if timer.is_some() { 312971462beSGnoCiYeH timer.unwrap().cancel(); 313971462beSGnoCiYeH } 314971462beSGnoCiYeH return Ok(0); 315971462beSGnoCiYeH } 316971462beSGnoCiYeH }; 317971462beSGnoCiYeH 318971462beSGnoCiYeH // 如果是超时唤醒,则返回错误 319971462beSGnoCiYeH if timer.is_some() { 320971462beSGnoCiYeH if timer.clone().unwrap().timeout() { 321971462beSGnoCiYeH bucket_mut.remove(futex_q); 322971462beSGnoCiYeH 323971462beSGnoCiYeH return Err(SystemError::ETIMEDOUT); 324971462beSGnoCiYeH } 325971462beSGnoCiYeH } 326971462beSGnoCiYeH 327971462beSGnoCiYeH // 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 328971462beSGnoCiYeH 329971462beSGnoCiYeH // 经过前面的几个判断,到这里之后, 330971462beSGnoCiYeH // 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 331971462beSGnoCiYeH 332971462beSGnoCiYeH // 到这里之后,前面的唤醒条件都不满足,则是被信号唤醒 333971462beSGnoCiYeH // 需要处理信号然后重启futex系统调用 334971462beSGnoCiYeH 335971462beSGnoCiYeH // 取消定时器任务 336971462beSGnoCiYeH if timer.is_some() { 337971462beSGnoCiYeH let timer = timer.unwrap(); 338971462beSGnoCiYeH if !timer.timeout() { 339971462beSGnoCiYeH timer.cancel(); 340971462beSGnoCiYeH } 341971462beSGnoCiYeH } 342971462beSGnoCiYeH Ok(0) 343971462beSGnoCiYeH } 344971462beSGnoCiYeH 345971462beSGnoCiYeH // ### 唤醒指定futex上挂起的最多nr_wake个进程 346971462beSGnoCiYeH pub fn futex_wake( 347971462beSGnoCiYeH uaddr: VirtAddr, 348971462beSGnoCiYeH flags: FutexFlag, 349971462beSGnoCiYeH nr_wake: u32, 350971462beSGnoCiYeH bitset: u32, 351971462beSGnoCiYeH ) -> Result<usize, SystemError> { 352971462beSGnoCiYeH if bitset == 0 { 353971462beSGnoCiYeH return Err(SystemError::EINVAL); 354971462beSGnoCiYeH } 355971462beSGnoCiYeH 356971462beSGnoCiYeH // 获取futex_key,并且判断地址空间合法性 357971462beSGnoCiYeH let key = Self::get_futex_key( 358971462beSGnoCiYeH uaddr, 359971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 360971462beSGnoCiYeH FutexAccess::FutexRead, 361971462beSGnoCiYeH )?; 362971462beSGnoCiYeH let mut binding = FutexData::futex_map(); 363971462beSGnoCiYeH let bucket_mut = binding.get_mut(&key).ok_or(SystemError::EINVAL)?; 364971462beSGnoCiYeH 365971462beSGnoCiYeH // 确保后面的唤醒操作是有意义的 366971462beSGnoCiYeH if bucket_mut.chain.is_empty() { 367971462beSGnoCiYeH return Ok(0); 368971462beSGnoCiYeH } 369971462beSGnoCiYeH // 从队列中唤醒 370971462beSGnoCiYeH let count = bucket_mut.wake_up(key.clone(), Some(bitset), nr_wake)?; 371971462beSGnoCiYeH 372971462beSGnoCiYeH drop(binding); 373971462beSGnoCiYeH 374971462beSGnoCiYeH FutexData::try_remove(&key); 375971462beSGnoCiYeH 376971462beSGnoCiYeH Ok(count) 377971462beSGnoCiYeH } 378971462beSGnoCiYeH 379971462beSGnoCiYeH /// ### 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 380971462beSGnoCiYeH pub fn futex_requeue( 381971462beSGnoCiYeH uaddr1: VirtAddr, 382971462beSGnoCiYeH flags: FutexFlag, 383971462beSGnoCiYeH uaddr2: VirtAddr, 384971462beSGnoCiYeH nr_wake: i32, 385971462beSGnoCiYeH nr_requeue: i32, 386971462beSGnoCiYeH cmpval: Option<u32>, 387971462beSGnoCiYeH requeue_pi: bool, 388971462beSGnoCiYeH ) -> Result<usize, SystemError> { 389971462beSGnoCiYeH if nr_requeue < 0 || nr_wake < 0 { 390971462beSGnoCiYeH return Err(SystemError::EINVAL); 391971462beSGnoCiYeH } 392971462beSGnoCiYeH 393971462beSGnoCiYeH // 暂时不支持优先级继承 394971462beSGnoCiYeH if requeue_pi { 395971462beSGnoCiYeH return Err(SystemError::ENOSYS); 396971462beSGnoCiYeH } 397971462beSGnoCiYeH 398971462beSGnoCiYeH let key1 = Self::get_futex_key( 399971462beSGnoCiYeH uaddr1, 400971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 401971462beSGnoCiYeH FutexAccess::FutexRead, 402971462beSGnoCiYeH )?; 403971462beSGnoCiYeH let key2 = Self::get_futex_key(uaddr2, flags.contains(FutexFlag::FLAGS_SHARED), { 404971462beSGnoCiYeH match requeue_pi { 405971462beSGnoCiYeH true => FutexAccess::FutexWrite, 406971462beSGnoCiYeH false => FutexAccess::FutexRead, 407971462beSGnoCiYeH } 408971462beSGnoCiYeH })?; 409971462beSGnoCiYeH 410971462beSGnoCiYeH if requeue_pi && key1 == key2 { 411971462beSGnoCiYeH return Err(SystemError::EINVAL); 412971462beSGnoCiYeH } 413971462beSGnoCiYeH 414971462beSGnoCiYeH if likely(!cmpval.is_none()) { 415971462beSGnoCiYeH let uval_reader = 416971462beSGnoCiYeH UserBufferReader::new(uaddr1.as_ptr::<u32>(), core::mem::size_of::<u32>(), true)?; 417971462beSGnoCiYeH let curval = uval_reader.read_one_from_user::<u32>(0)?; 418971462beSGnoCiYeH 419971462beSGnoCiYeH // 判断是否满足条件 420971462beSGnoCiYeH if *curval != cmpval.unwrap() { 421971462beSGnoCiYeH return Err(SystemError::EAGAIN_OR_EWOULDBLOCK); 422971462beSGnoCiYeH } 423971462beSGnoCiYeH } 424971462beSGnoCiYeH 425971462beSGnoCiYeH let mut futex_data_guard = FutexData::futex_map(); 426971462beSGnoCiYeH if !requeue_pi { 427971462beSGnoCiYeH // 唤醒nr_wake个进程 428971462beSGnoCiYeH let bucket_1_mut = futex_data_guard.get_mut(&key1).ok_or(SystemError::EINVAL)?; 429971462beSGnoCiYeH let ret = bucket_1_mut.wake_up(key1.clone(), None, nr_wake as u32)?; 430971462beSGnoCiYeH // 将bucket1中最多nr_requeue个任务转移到bucket2 431971462beSGnoCiYeH for _ in 0..nr_requeue { 432971462beSGnoCiYeH let bucket_1_mut = futex_data_guard.get_mut(&key1).ok_or(SystemError::EINVAL)?; 433971462beSGnoCiYeH let futex_q = bucket_1_mut.chain.pop_front(); 434971462beSGnoCiYeH match futex_q { 435971462beSGnoCiYeH Some(futex_q) => { 436971462beSGnoCiYeH let bucket_2_mut = 437971462beSGnoCiYeH futex_data_guard.get_mut(&key2).ok_or(SystemError::EINVAL)?; 438971462beSGnoCiYeH bucket_2_mut.chain.push_back(futex_q); 439971462beSGnoCiYeH } 440971462beSGnoCiYeH None => { 441971462beSGnoCiYeH break; 442971462beSGnoCiYeH } 443971462beSGnoCiYeH } 444971462beSGnoCiYeH } 445971462beSGnoCiYeH 446971462beSGnoCiYeH return Ok(ret); 447971462beSGnoCiYeH } else { 448971462beSGnoCiYeH // 暂时不支持优先级继承 449971462beSGnoCiYeH todo!() 450971462beSGnoCiYeH } 451971462beSGnoCiYeH } 452971462beSGnoCiYeH 453971462beSGnoCiYeH /// ### 唤醒futex上的进程的同时进行一些操作 454971462beSGnoCiYeH pub fn futex_wake_op( 455971462beSGnoCiYeH uaddr1: VirtAddr, 456971462beSGnoCiYeH flags: FutexFlag, 457971462beSGnoCiYeH uaddr2: VirtAddr, 458971462beSGnoCiYeH nr_wake: i32, 459971462beSGnoCiYeH nr_wake2: i32, 460971462beSGnoCiYeH op: i32, 461971462beSGnoCiYeH ) -> Result<usize, SystemError> { 462971462beSGnoCiYeH let key1 = Futex::get_futex_key( 463971462beSGnoCiYeH uaddr1, 464971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 465971462beSGnoCiYeH FutexAccess::FutexRead, 466971462beSGnoCiYeH )?; 467971462beSGnoCiYeH let key2 = Futex::get_futex_key( 468971462beSGnoCiYeH uaddr2, 469971462beSGnoCiYeH flags.contains(FutexFlag::FLAGS_SHARED), 470971462beSGnoCiYeH FutexAccess::FutexWrite, 471971462beSGnoCiYeH )?; 472971462beSGnoCiYeH 473971462beSGnoCiYeH let mut futex_data_guard = FutexData::futex_map(); 474971462beSGnoCiYeH let bucket1 = futex_data_guard.get_mut(&key1).ok_or(SystemError::EINVAL)?; 475971462beSGnoCiYeH let mut wake_count = 0; 476971462beSGnoCiYeH 477971462beSGnoCiYeH // 唤醒uaddr1中的进程 478971462beSGnoCiYeH wake_count += bucket1.wake_up(key1, None, nr_wake as u32)?; 479971462beSGnoCiYeH 480971462beSGnoCiYeH match Self::futex_atomic_op_inuser(op as u32, uaddr2) { 481971462beSGnoCiYeH Ok(ret) => { 482971462beSGnoCiYeH // 操作成功则唤醒uaddr2中的进程 483971462beSGnoCiYeH if ret { 484971462beSGnoCiYeH let bucket2 = futex_data_guard.get_mut(&key2).ok_or(SystemError::EINVAL)?; 485971462beSGnoCiYeH wake_count += bucket2.wake_up(key2, None, nr_wake2 as u32)?; 486971462beSGnoCiYeH } 487971462beSGnoCiYeH } 488971462beSGnoCiYeH Err(e) => { 489971462beSGnoCiYeH // TODO:retry? 490971462beSGnoCiYeH return Err(e); 491971462beSGnoCiYeH } 492971462beSGnoCiYeH } 493971462beSGnoCiYeH 494971462beSGnoCiYeH Ok(wake_count) 495971462beSGnoCiYeH } 496971462beSGnoCiYeH 497971462beSGnoCiYeH fn get_futex_key( 498971462beSGnoCiYeH uaddr: VirtAddr, 499971462beSGnoCiYeH fshared: bool, 500971462beSGnoCiYeH _access: FutexAccess, 501971462beSGnoCiYeH ) -> Result<FutexKey, SystemError> { 502971462beSGnoCiYeH let mut address = uaddr.data(); 503971462beSGnoCiYeH 504971462beSGnoCiYeH // 计算相对页的偏移量 505971462beSGnoCiYeH let offset = address & (MMArch::PAGE_SIZE - 1); 506971462beSGnoCiYeH // 判断内存对齐 507971462beSGnoCiYeH if !(uaddr.data() & (core::mem::size_of::<u32>() - 1) == 0) { 508971462beSGnoCiYeH return Err(SystemError::EINVAL); 509971462beSGnoCiYeH } 510971462beSGnoCiYeH 511971462beSGnoCiYeH // 目前address指向所在页面的起始地址 512971462beSGnoCiYeH address -= offset; 513971462beSGnoCiYeH 514971462beSGnoCiYeH // 若不是进程间共享的futex,则返回Private 515971462beSGnoCiYeH if !fshared { 516971462beSGnoCiYeH return Ok(FutexKey { 517971462beSGnoCiYeH ptr: 0, 518971462beSGnoCiYeH word: 0, 519971462beSGnoCiYeH offset: offset as u32, 520971462beSGnoCiYeH key: InnerFutexKey::Private(PrivateKey { 521971462beSGnoCiYeH address: address as u64, 522971462beSGnoCiYeH address_space: None, 523971462beSGnoCiYeH }), 524971462beSGnoCiYeH }); 525971462beSGnoCiYeH } 526971462beSGnoCiYeH 527971462beSGnoCiYeH // 获取到地址所在地址空间 528971462beSGnoCiYeH let address_space = AddressSpace::current()?; 529971462beSGnoCiYeH // TODO: 判断是否为匿名映射,是匿名映射才返回PrivateKey 530971462beSGnoCiYeH return Ok(FutexKey { 531971462beSGnoCiYeH ptr: 0, 532971462beSGnoCiYeH word: 0, 533971462beSGnoCiYeH offset: offset as u32, 534971462beSGnoCiYeH key: InnerFutexKey::Private(PrivateKey { 535971462beSGnoCiYeH address: address as u64, 536971462beSGnoCiYeH address_space: Some(Arc::downgrade(&address_space)), 537971462beSGnoCiYeH }), 538971462beSGnoCiYeH }); 539971462beSGnoCiYeH 540971462beSGnoCiYeH // 未实现共享内存机制,贡献内存部分应该通过inode构建SharedKey 541971462beSGnoCiYeH // todo!("Shared memory not implemented"); 542971462beSGnoCiYeH } 543971462beSGnoCiYeH 544971462beSGnoCiYeH pub fn futex_atomic_op_inuser(encoded_op: u32, uaddr: VirtAddr) -> Result<bool, SystemError> { 545971462beSGnoCiYeH let op = FutexOP::from_bits((encoded_op & 0x70000000) >> 28).ok_or(SystemError::ENOSYS)?; 546971462beSGnoCiYeH let cmp = 547971462beSGnoCiYeH FutexOpCMP::from_bits((encoded_op & 0x0f000000) >> 24).ok_or(SystemError::ENOSYS)?; 548971462beSGnoCiYeH 549971462beSGnoCiYeH let sign_extend32 = |value: u32, index: i32| { 550971462beSGnoCiYeH let shift = (31 - index) as u8; 551971462beSGnoCiYeH return (value << shift) >> shift; 552971462beSGnoCiYeH }; 553971462beSGnoCiYeH 554971462beSGnoCiYeH let mut oparg = sign_extend32((encoded_op & 0x00fff000) >> 12, 11); 555971462beSGnoCiYeH let cmparg = sign_extend32(encoded_op & 0x00000fff, 11); 556971462beSGnoCiYeH 557971462beSGnoCiYeH if encoded_op & (FutexOP::FUTEX_OP_OPARG_SHIFT.bits() << 28) != 0 { 558971462beSGnoCiYeH if oparg > 31 { 559971462beSGnoCiYeH kwarn!( 560971462beSGnoCiYeH "futex_wake_op: pid:{} tries to shift op by {}; fix this program", 561971462beSGnoCiYeH ProcessManager::current_pcb().pid().data(), 562971462beSGnoCiYeH oparg 563971462beSGnoCiYeH ); 564971462beSGnoCiYeH 565971462beSGnoCiYeH oparg &= 31; 566971462beSGnoCiYeH } 567971462beSGnoCiYeH } 568971462beSGnoCiYeH 569971462beSGnoCiYeH // TODO: 这个汇编似乎是有问题的,目前不好测试 570971462beSGnoCiYeH let old_val = Self::arch_futex_atomic_op_inuser(op, oparg, uaddr)?; 571971462beSGnoCiYeH 572971462beSGnoCiYeH match cmp { 573971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_EQ => { 574971462beSGnoCiYeH return Ok(cmparg == old_val); 575971462beSGnoCiYeH } 576971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_NE => { 577971462beSGnoCiYeH return Ok(cmparg != old_val); 578971462beSGnoCiYeH } 579971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_LT => { 580971462beSGnoCiYeH return Ok(cmparg < old_val); 581971462beSGnoCiYeH } 582971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_LE => { 583971462beSGnoCiYeH return Ok(cmparg <= old_val); 584971462beSGnoCiYeH } 585971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_GE => { 586971462beSGnoCiYeH return Ok(cmparg >= old_val); 587971462beSGnoCiYeH } 588971462beSGnoCiYeH FutexOpCMP::FUTEX_OP_CMP_GT => { 589971462beSGnoCiYeH return Ok(cmparg > old_val); 590971462beSGnoCiYeH } 591971462beSGnoCiYeH _ => { 592971462beSGnoCiYeH return Err(SystemError::ENOSYS); 593971462beSGnoCiYeH } 594971462beSGnoCiYeH } 595971462beSGnoCiYeH } 596971462beSGnoCiYeH 597971462beSGnoCiYeH /// ### 对futex进行操作 598971462beSGnoCiYeH /// 599971462beSGnoCiYeH /// 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 600971462beSGnoCiYeH /// 601971462beSGnoCiYeH /// ### return uaddr原来的值 602971462beSGnoCiYeH #[allow(unused_assignments)] 603971462beSGnoCiYeH pub fn arch_futex_atomic_op_inuser( 604971462beSGnoCiYeH op: FutexOP, 605971462beSGnoCiYeH oparg: u32, 606971462beSGnoCiYeH uaddr: VirtAddr, 607971462beSGnoCiYeH ) -> Result<u32, SystemError> { 608971462beSGnoCiYeH let guard = unsafe { CurrentIrqArch::save_and_disable_irq() }; 609971462beSGnoCiYeH 610971462beSGnoCiYeH let reader = 611971462beSGnoCiYeH UserBufferReader::new(uaddr.as_ptr::<u32>(), core::mem::size_of::<u32>(), true)?; 612971462beSGnoCiYeH 613971462beSGnoCiYeH let oldval = reader.read_one_from_user::<u32>(0)?; 614971462beSGnoCiYeH 615971462beSGnoCiYeH let atomic_addr = AtomicU64::new(uaddr.data() as u64); 616971462beSGnoCiYeH // 这个指针是指向指针的指针 617*1a72a751SLoGin let ptr = atomic_addr.as_ptr(); 618971462beSGnoCiYeH match op { 619971462beSGnoCiYeH FutexOP::FUTEX_OP_SET => unsafe { 620971462beSGnoCiYeH *((*ptr) as *mut u32) = oparg; 621971462beSGnoCiYeH }, 622971462beSGnoCiYeH FutexOP::FUTEX_OP_ADD => unsafe { 623971462beSGnoCiYeH *((*ptr) as *mut u32) += oparg; 624971462beSGnoCiYeH }, 625971462beSGnoCiYeH FutexOP::FUTEX_OP_OR => unsafe { 626971462beSGnoCiYeH *((*ptr) as *mut u32) |= oparg; 627971462beSGnoCiYeH }, 628971462beSGnoCiYeH FutexOP::FUTEX_OP_ANDN => unsafe { 629971462beSGnoCiYeH *((*ptr) as *mut u32) &= oparg; 630971462beSGnoCiYeH }, 631971462beSGnoCiYeH FutexOP::FUTEX_OP_XOR => unsafe { 632971462beSGnoCiYeH *((*ptr) as *mut u32) ^= oparg; 633971462beSGnoCiYeH }, 634971462beSGnoCiYeH _ => return Err(SystemError::ENOSYS), 635971462beSGnoCiYeH } 636971462beSGnoCiYeH 637971462beSGnoCiYeH drop(guard); 638971462beSGnoCiYeH 639971462beSGnoCiYeH Ok(*oldval) 640971462beSGnoCiYeH } 641971462beSGnoCiYeH } 642971462beSGnoCiYeH 643971462beSGnoCiYeH #[no_mangle] 644971462beSGnoCiYeH unsafe extern "C" fn rs_futex_init() { 645971462beSGnoCiYeH Futex::init(); 646971462beSGnoCiYeH } 647