hirun 0.1.18

A concurrent framework for asynchronous programming based on event-driven, non-blocking I/O mechanism
Documentation
use super::{Attr, Config, GroupSender, Task, TaskQueue, TaskRef, Worker};
use crate::channel::mpsc;
use crate::thread::{self, JoinHandle, Mutex};
use crate::{Error, Result};
use core::cell::UnsafeCell;
use core::future::Future;
use core::result;
use core::sync::atomic::{AtomicBool, Ordering};
use hipool::{Arc, Boxed, BoxedMemPool, MemPool, NullAlloc, PoolAlloc};

pub(crate) type MpscSender = mpsc::Sender<'static, Signo, MemPool>;
pub(crate) type MpscReceiver = mpsc::Receiver<'static, Signo, MemPool>;

#[allow(non_camel_case_types)]
pub enum Signo {
    SIG_STOP,
    SIG_NAME(&'static str),
}

static GROUPS: GroupArray = GroupArray::new();
const NON_GROUP: Option<BoxedGroup> = None;

struct GroupArray {
    groups: UnsafeCell<[Option<BoxedGroup>; 256]>,
    lock: Mutex<()>,
}

unsafe impl Sync for GroupArray {}

impl GroupArray {
    const fn new() -> Self {
        Self {
            groups: UnsafeCell::new([NON_GROUP; 256]),
            lock: Mutex::new(()),
        }
    }

    fn get(&self, id: u8) -> Option<&Group> {
        let groups = unsafe { &*self.groups.get() };
        groups[id as usize].as_deref()
    }

    fn active(&self, grp: BoxedGroup) -> Result<()> {
        let id = grp.id() as usize;
        let _ = self.lock.lock();
        let groups = unsafe { &mut *self.groups.get() };
        if groups[id].is_some() {
            return Err(Error::new(libc::EEXIST));
        }
        groups[id].replace(grp);
        Ok(())
    }

    unsafe fn reactive(&self, grp: BoxedGroup) -> Result<()> {
        if let Some(worker) = Worker::current() {
            if worker.group_id() == grp.id() {
                return Err(Error::new(libc::EPERM));
            }
        }

        let id = grp.id() as usize;
        let _ = self.lock.lock();
        let groups = unsafe { &mut *self.groups.get() };
        if let Some(ref mut old_grp) = groups[id] {
            old_grp.stop();
        }
        groups[id].replace(grp);
        Ok(())
    }
}

#[repr(C)]
pub(crate) struct WorkerProxy {
    id: usize,
    mpscs: ArcMpsc,
    stopped: AtomicBool,
    thread: Option<JoinHandle<()>>,
}

unsafe impl Sync for WorkerProxy {}

type BoxedWorkers = Boxed<'static, [Option<WorkerProxy>], MemPool>;

impl WorkerProxy {
    fn stop(&mut self) {
        if !self.stopped.swap(true, Ordering::Relaxed) {
            if let Some(handle) = self.thread.take() {
                self.signal(Signo::SIG_STOP);
                let _ = handle.join();
            }
        }
    }
    fn signal(&self, sig: Signo) {
        self.mpscs[self.id].send(sig);
    }
    fn try_signal(&self, sig: Signo) -> result::Result<(), Signo> {
        self.mpscs[self.id].try_send(sig)
    }
}

impl Drop for WorkerProxy {
    fn drop(&mut self) {
        self.stop();
    }
}

type ArcQueue = Arc<'static, [TaskQueue], MemPool>;
type ArcMpsc = Arc<'static, [MpscSender], MemPool>;

#[allow(dead_code)]
#[repr(C)]
pub struct Group {
    sender: GroupSender,
    queues: ArcQueue,
    mpscs: ArcMpsc,
    workers: BoxedWorkers,
    conf: Config,
    pool: BoxedMemPool<PoolAlloc>,
}

unsafe impl Sync for Group {}

type BoxedGroup = Boxed<'static, Group, NullAlloc>;
type GroupRef = &'static Group;

impl Group {
    pub(crate) fn new(conf: &Config) -> Result<BoxedGroup> {
        let conf = Self::conf(conf);
        // 都在堆上申请,保证'static
        let pool = MemPool::new_boxed(0)?.leak().0;
        let boxed_pool = unsafe { MemPool::from_raw(pool) };
        let nth = conf.nth;

        let queues = Arc::new_slice_then_in(pool, nth, |_| Ok(TaskQueue::new()))?;
        let mut channels = Channels::new(pool, nth, conf.qlen)?;
        let mpscs = Arc::new_slice_then_in(pool, nth, |n| Ok(channels.mpsc_send(n)))?;
        let mut workers = Boxed::new_slice_then_in::<Option<WorkerProxy>, _>(pool, nth, |_| Ok(None))?;

        for n in 0..nth {
            let id = conf.id;
            let channel = channels.mpsc_recv(n);
            let queue = queues.clone();
            let thread = Worker::active(id, n as u16, channel, queue)?;
            let proxy = WorkerProxy {
                id: n,
                mpscs: mpscs.clone(),
                thread: Some(thread),
                stopped: AtomicBool::new(false),
            };
            let _ = proxy.try_signal(Signo::SIG_NAME(conf.name));
            workers[n].replace(proxy);
        }

        let group = Boxed::new_in(
            pool,
            Self {
                sender: GroupSender::new(),
                queues,
                mpscs,
                workers,
                conf,
                pool: boxed_pool,
            },
        )
        .map(|boxed| boxed.leak_boxed())?;

        Ok(group)
    }

    pub(crate) fn active(grp: BoxedGroup) -> Result<()> {
        GROUPS.active(grp)
    }

    pub(crate) unsafe fn reactive(grp: BoxedGroup) -> Result<()> {
        GROUPS.reactive(grp)
    }
}

impl Group {
    /// 基于id获取运行时,如果运行时未启动,则会panic
    pub fn get(id: u8) -> GroupRef {
        return GROUPS.get(id).expect("Runtime {id} don't be inited");
    }

    pub(crate) fn spawn<T: Future>(&self, future: T, attr: &Attr) -> Result<TaskRef> {
        let mut task = Task::new(future, attr)?;
        let queue = self.queues.as_ref();
        if attr.hash == 0 {
            self.sender.send(queue, task.clone());
        } else {
            let id = attr.hash % queue.len();
            task.status.set_local(id as u16);
            queue[id].push(task.clone());
        }
        Ok(task)
    }

    pub(crate) fn sched(&self, task: TaskRef, local: Option<u16>) {
        let queue = self.queues.as_ref();
        // 调用很频繁,rust无分支预测的语言特性
        #[allow(clippy::unnecessary_unwrap)]
        if local.is_none() {
            self.sender.send(queue, task);
        } else {
            queue[local.unwrap() as usize].push(task);
        }
    }

    pub(crate) fn id(&self) -> u8 {
        self.conf.id
    }
}

impl Group {
    fn stop(&mut self) {
        for worker in &mut *self.workers {
            if let Some(worker) = worker.as_mut() {
                worker.stop();
            }
        }
    }

    fn conf(conf: &Config) -> Config {
        Config {
            qlen: Self::get_qlen(conf.qlen),
            nth: Self::get_nth(conf.nth),
            ..conf.clone()
        }
    }

    fn get_qlen(qlen: usize) -> usize {
        if qlen > 0 {
            qlen
        } else {
            8
        }
    }

    fn get_nth(nth: usize) -> usize {
        if nth == 0 {
            thread::get_cpu_count()
        } else if nth >= ((u16::MAX as usize) >> 1) {
            u16::MAX as usize >> 1
        } else {
            nth
        }
    }
}

struct Channels {
    mpsc_send: Boxed<'static, [Option<MpscSender>], PoolAlloc>,
    mpsc_recv: Boxed<'static, [Option<MpscReceiver>], PoolAlloc>,
}

impl Channels {
    fn new(pool: &'static MemPool, nth: usize, qlen: usize) -> Result<Self> {
        let mut mpsc_send =
            Boxed::new_slice_then_in::<Option<MpscSender>, _>(&PoolAlloc, nth, |_| Ok(None))?;
        let mut mpsc_recv =
            Boxed::new_slice_then_in::<Option<MpscReceiver>, _>(&PoolAlloc, nth, |_| Ok(None))?;
        for (send, recv) in mpsc_send.iter_mut().zip(mpsc_recv.iter_mut()) {
            let (mpsc_send, mpsc_recv) = mpsc::channel_in(pool, qlen)?;
            send.replace(mpsc_send);
            recv.replace(mpsc_recv);
        }
        Ok(Self {
            mpsc_send,
            mpsc_recv,
        })
    }

    fn mpsc_recv(&mut self, n: usize) -> MpscReceiver {
        self.mpsc_recv[n].take().unwrap()
    }

    fn mpsc_send(&mut self, n: usize) -> MpscSender {
        self.mpsc_send[n].as_ref().unwrap().clone()
    }
}