burritos/src/kernel/synch.rs

use crate::utility::list::List;
use crate::kernel::thread::Thread;
use std::rc::Rc;
use crate::simulator::interrupt::InterruptStatus::InterruptOff;
use crate::simulator::machine::Machine;

pub struct Semaphore{

    counter:i32,
    waiting_queue:List<Rc<Thread>>

}

impl Semaphore{

    pub fn p(&mut self, current_thread:Rc<Thread>, machine: &mut Machine){
        let old_status = machine.interrupt.set_status(InterruptOff);
        self.counter-=1;
        if self.counter < 0 {
            self.waiting_queue.push(Rc::clone(&current_thread));
            current_thread.sleep();
        }
        machine.interrupt.set_status(old_status);
    }

    pub fn v(&mut self, current_thread:Rc<Thread>, machine: &mut Machine){
        let old_status = machine.interrupt.set_status(InterruptOff);
        self.counter-=1;
        if self.waiting_queue.peek() == None {
            self.waiting_queue.push(Rc::clone(&current_thread));
            current_thread.sleep();
        }
        machine.interrupt.set_status(old_status);
    }
}

pub struct Lock{

}

pub struct Condition{

}