rcore-tutorial/os/src/task/mod.rs

127 lines
No EOL
3.3 KiB
Rust

mod context;
mod switch;
mod task;
use crate::config::MAX_APP_NUM;
use crate::loader::{get_num_app, init_app_cx};
use core::cell::RefCell;
use lazy_static::*;
use switch::__switch;
use task::{TaskControlBlock, TaskStatus};
pub use context::TaskContext;
pub struct TaskManager {
num_app: usize,
inner: RefCell<TaskManagerInner>,
}
struct TaskManagerInner {
tasks: [TaskControlBlock; MAX_APP_NUM],
current_task: usize,
}
unsafe impl Sync for TaskManager {}
lazy_static! {
pub static ref TASK_MANAGER: TaskManager = {
let num_app = get_num_app();
let mut tasks = [
TaskControlBlock { task_cx_ptr: 0, task_status: TaskStatus::UnInit };
MAX_APP_NUM
];
for i in 0..num_app {
tasks[i].task_cx_ptr = init_app_cx(i) as * const _ as usize;
tasks[i].task_status = TaskStatus::Ready;
}
TaskManager {
num_app,
inner: RefCell::new(TaskManagerInner {
tasks,
current_task: 0,
}),
}
};
}
impl TaskManager {
fn run_first_task(&self) {
self.inner.borrow_mut().tasks[0].task_status = TaskStatus::Running;
let next_task_cx_ptr2 = self.inner.borrow().tasks[0].get_task_cx_ptr2();
let _unused: usize = 0;
unsafe {
__switch(
&_unused as *const _,
next_task_cx_ptr2,
);
}
}
fn mark_current_suspended(&self) {
let mut inner = self.inner.borrow_mut();
let current = inner.current_task;
inner.tasks[current].task_status = TaskStatus::Ready;
}
fn mark_current_exited(&self) {
let mut inner = self.inner.borrow_mut();
let current = inner.current_task;
inner.tasks[current].task_status = TaskStatus::Exited;
}
fn find_next_task(&self) -> Option<usize> {
let inner = self.inner.borrow();
let current = inner.current_task;
(current + 1..current + self.num_app + 1)
.map(|id| id % self.num_app)
.find(|id| {
inner.tasks[*id].task_status == TaskStatus::Ready
})
}
fn run_next_task(&self) {
if let Some(next) = self.find_next_task() {
let mut inner = self.inner.borrow_mut();
let current = inner.current_task;
inner.tasks[next].task_status = TaskStatus::Running;
inner.current_task = next;
let current_task_cx_ptr2 = inner.tasks[current].get_task_cx_ptr2();
let next_task_cx_ptr2 = inner.tasks[next].get_task_cx_ptr2();
core::mem::drop(inner);
unsafe {
__switch(
current_task_cx_ptr2,
next_task_cx_ptr2,
);
}
} else {
panic!("All applications completed!");
}
}
}
pub fn run_first_task() {
TASK_MANAGER.run_first_task();
}
fn run_next_task() {
TASK_MANAGER.run_next_task();
}
fn mark_current_suspended() {
TASK_MANAGER.mark_current_suspended();
}
fn mark_current_exited() {
TASK_MANAGER.mark_current_exited();
}
pub fn suspend_current_and_run_next() {
mark_current_suspended();
run_next_task();
}
pub fn exit_current_and_run_next() {
mark_current_exited();
run_next_task();
}