线程调度
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小牛编辑
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2023-12-01
调度器
调度器的算法有许多种,我们将它提取出一个 trait 作为接口
os/src/algorithm/src/scheduler/mod.rs
/// 线程调度器
///
/// 这里 `ThreadType` 就是 `Arc<Thread>`
pub trait Scheduler<ThreadType: Clone + Eq>: Default {
/// 优先级的类型
type Priority;
/// 向线程池中添加一个线程
fn add_thread(&mut self, thread: ThreadType);
/// 获取下一个时间段应当执行的线程
fn get_next(&mut self) -> Option<ThreadType>;
/// 移除一个线程
fn remove_thread(&mut self, thread: &ThreadType);
/// 设置线程的优先级
fn set_priority(&mut self, thread: ThreadType, priority: Self::Priority);
}
具体的算法就不在此展开了,我们可以参照目录 os/src/algorithm/src/scheduler
下的一些样例。
运行!
修改 main.rs
,我们就可以跑起来多线程了。
os/src/main.rs
pub extern "C" fn rust_main() -> ! {
memory::init();
interrupt::init();
{
let mut processor = PROCESSOR.lock();
// 创建一个内核进程
let kernel_process = Process::new_kernel().unwrap();
// 为这个进程创建多个线程,并设置入口均为 sample_process,而参数不同
for i in 1..9usize {
processor.add_thread(create_kernel_thread(
kernel_process.clone(),
sample_process as usize,
Some(&[i]),
));
}
}
extern "C" {
fn __restore(context: usize);
}
// 获取第一个线程的 Context
let context = PROCESSOR.lock().prepare_next_thread();
// 启动第一个线程
unsafe { __restore(context as usize) };
unreachable!()
}
fn sample_process(message: usize) {
println!("hello from kernel thread {}", id);
}
运行一下,我们会得到类似的输出:
运行输出
hello from kernel thread 7
thread 7 exit
hello from kernel thread 6
thread 6 exit
hello from kernel thread 5
thread 5 exit
hello from kernel thread 4
thread 4 exit
hello from kernel thread 3
thread 3 exit
hello from kernel thread 2
thread 2 exit
hello from kernel thread 1
thread 1 exit
hello from kernel thread 8
thread 8 exit
src/process/processor.rs:87: 'all threads terminated, shutting down'