BurritOS/src/utility/objaddr.rs

//! Burritos stores a data structure associating object ids with
//! their references. The ObjAddr struct
//! allows to maintain this data structure.

use std::collections::HashMap;

use crate::kernel::synch::{ Semaphore, Lock };

/// Brief Definition of object identifiers:
/// 
/// The struct stores the list of created objects (Semaphore, Lock, ...) and for each of them
/// associates an object identifier than can be passed to subsequent
/// system calls on the object.
/// 
/// A method allows to detect of an object corresponding to a given
/// identifier exists; this is used to check the parameters of system
/// calls.
pub struct ObjAddr {
    last_id: i32,
    semaphores: HashMap<i32, Semaphore>,
    locks: HashMap<i32, Lock>
}

impl ObjAddr {
    
    /// Initializes and returns a ObjAddr struct
    pub fn init() -> Self {
        Self {
            last_id: 3,
            semaphores: HashMap::<i32, Semaphore>::new(),
            locks: HashMap::<i32, Lock>::new()
        }
    }

    /// Adds the **obj** Semaphore to self
    pub fn add_semaphore(&mut self, obj: Semaphore) -> i32 {
        self.last_id = self.last_id + 1;
        self.semaphores.insert(self.last_id, obj);
        self.last_id
    }

    /// Adds the **obj** Lock to self
    pub fn add_lock(&mut self, obj: Lock) -> i32 {
        self.last_id = self.last_id + 1;
        self.locks.insert(self.last_id, obj);
        self.last_id
    }

    /// Searches for a semaphore of id **id** in self
    pub fn search_semaphore(&self, id: i32) -> Option<&mut Semaphore> {
        self.semaphores.get(&id)
    }

    /// Searches for a lock of id **id** in self
    pub fn search_lock(&self, id:i32) -> Option<&mut Lock> {
        self.locks.get(&id)
    }

    /// Removes the object of id **id** from self if it exists
    pub fn remove_semaphore(&mut self, id: i32) {
        self.semaphores.remove(&id)
    }

    pub fn remove_semaphore(&mut self, id:i32) {
        self.locks.remove(&id)
    }


}