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post-12 async/await

master
Timothy Warren 2 months ago
parent
commit
1517c956a5
6 changed files with 113 additions and 5 deletions
  1. +1
    -1
      src/allocator.rs
  2. +1
    -0
      src/lib.rs
  3. +2
    -2
      src/main.rs
  4. +1
    -0
      src/task.rs
  5. +108
    -0
      src/task/executor.rs
  6. +0
    -2
      src/vga_buffer.rs

+ 1
- 1
src/allocator.rs View File

@@ -53,7 +53,7 @@ pub fn init_heap(
.ok_or(MapToError::FrameAllocationFailed)?;

let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
unsafe { mapper.map_to(page, frame, flags, frame_allocator)?.flush() };
mapper.map_to(page, frame, flags, frame_allocator)?.flush();
}

unsafe {


+ 1
- 0
src/lib.rs View File

@@ -6,6 +6,7 @@
#![feature(const_fn)]
#![feature(const_in_array_repeat_expressions)]
#![feature(custom_test_frameworks)]
#![feature(wake_trait)]
#![test_runner(crate::test_runner)]
#![reexport_test_harness_main = "test_main"]



+ 2
- 2
src/main.rs View File

@@ -10,7 +10,7 @@ use alloc::{boxed::Box, rc::Rc, vec, vec::Vec};
use core::panic::PanicInfo;

use blog_os::println;
use blog_os::task::{keyboard, Task, simple_executor::SimpleExecutor};
use blog_os::task::{keyboard, Task, executor::Executor};
use bootloader::{entry_point, BootInfo};

/// This function is called on panic.
@@ -66,7 +66,7 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
Rc::strong_count(&cloned_reference)
);

let mut executor = SimpleExecutor::new();
let mut executor = Executor::new();
executor.spawn(Task::new(example_task()));
executor.spawn(Task::new(keyboard::print_keypresses()));
executor.run();


+ 1
- 0
src/task.rs View File

@@ -3,6 +3,7 @@ use core::sync::atomic::{AtomicU64, Ordering};
use core::task::{Context, Poll};
use alloc::boxed::Box;

pub mod executor;
pub mod keyboard;
pub mod simple_executor;



+ 108
- 0
src/task/executor.rs View File

@@ -0,0 +1,108 @@
use super::{Task, TaskId};
use alloc::{collections::{BTreeMap, VecDeque}, sync::Arc};
use alloc::task::Wake;
use core::task::{Waker, Poll, Context};
use crossbeam_queue::ArrayQueue;

pub struct Executor {
task_queue: VecDeque<Task>,
waiting_tasks: BTreeMap<TaskId, Task>,
wake_queue: Arc<ArrayQueue<TaskId>>,
waker_cache: BTreeMap<TaskId, Waker>,
}

impl Executor {
pub fn new() -> Self {
Executor {
task_queue: VecDeque::new(),
waiting_tasks: BTreeMap::new(),
wake_queue: Arc::new(ArrayQueue::new(100)),
waker_cache: BTreeMap::new(),
}
}

pub fn spawn(&mut self, task: Task) {
self.task_queue.push_back(task)
}

fn run_ready_tasks(&mut self) {
while let Some(mut task) = self.task_queue.pop_front() {
let task_id = task.id;
if !self.waker_cache.contains_key(&task_id) {
self.waker_cache.insert(task_id, self.create_waker(task_id));
}
let waker = self.waker_cache.get(&task_id).expect("should exist");
let mut context = Context::from_waker(waker);
match task.poll(&mut context) {
Poll::Ready(()) => {
// task done -> remove cached waker
self.waker_cache.remove(&task_id);
}
Poll::Pending => {
if self.waiting_tasks.insert(task_id, task).is_some() {
panic!("task with same ID already in waiting_tasks");
}
}
}
}
}

fn create_waker(&self, task_id: TaskId) -> Waker {
Waker::from(Arc::new(TaskWaker {
task_id,
wake_queue: self.wake_queue.clone(),
}))
}

fn wake_tasks(&mut self) {
while let Ok(task_id) = self.wake_queue.pop() {
if let Some(task) = self.waiting_tasks.remove(&task_id) {
self.task_queue.push_back(task);
}
}
}

pub fn run(&mut self) -> ! {
loop {
self.wake_tasks();
self.run_ready_tasks();
self.sleep_if_idle();
}
}

fn sleep_if_idle(&self) {
use x86_64::instructions::interrupts::{self, enable_interrupts_and_hlt};

if !self.wake_queue.is_empty() {
return;
}

interrupts::disable();
if self.wake_queue.is_empty() {
enable_interrupts_and_hlt();
} else {
interrupts::enable();
}
}
}

struct TaskWaker {
task_id: TaskId,
wake_queue: Arc<ArrayQueue<TaskId>>,
}

impl TaskWaker {
fn wake_task(&self) {
self.wake_queue.push(self.task_id).expect("wake_queue full");
}
}

impl Wake for TaskWaker {
fn wake(self: Arc<Self>) {
self.wake_task();
}

fn wake_by_ref(self: &Arc<Self>) {
self.wake_task();
}
}

+ 0
- 2
src/vga_buffer.rs View File

@@ -6,8 +6,6 @@ use volatile::Volatile;
#[cfg(test)]
use crate::{serial_print, serial_println};

use crate::println;

#[allow(dead_code)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u8)]


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