Struct MultiStackQueue

pub struct MultiStackQueue<T, const N: usize, const M: usize> { /* private fields */ }

An abstract structure containin multiple stack-allocated bounded queues.

Each queue is stored as an [Option<T>; N] and the multiqueue stores

Usage

The generic definition is the following :

MultiStackQueue<T, const N: usize, const M: usize>

With :

• T - type contained in the queues
• N - length of each queue
• M - number of queues

Example usecases

• When writing a simple micro-kernel, the scheduler may need some sort of multiple Round-Robins. Having it allocated on the stack removes the need for a heap allocator, which can be useful when working on this kind of ressource-limited target.

Examples

use multi_stack_queue::MultiStackQueue;

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
struct TestStruct {
    a: usize,
    b: bool,   
}

let mut msq: MultiStackQueue<TestStruct, 16, 8> = MultiStackQueue::new();
let value = TestStruct { a: 42, b: false };

msq.push(7, value).unwrap();

assert_eq!(msq.pop(7).unwrap(), value);

Implementations

impl<T, const N: usize, const M: usize> MultiStackQueue<T, N, M>

pub fn new() -> Self

Returns a new empty multiqueue.

Examples

use multi_stack_queue::MultiStackQueue;
// Returns a fresh empty multiqueue containing 8 queues of `usize` with size 16
let a: MultiStackQueue<usize, 16, 8> = MultiStackQueue::new();

#[derive(Clone, Copy)]
struct TestStruct {
    a: usize,
    b: bool    
}

let random_data = TestStruct { a: 42, b: false };

let msq: MultiStackQueue<TestStruct, 4, 2> = MultiStackQueue::new();

pub fn push(&mut self, id: usize, value: T) -> Result<(), MSQError>

Appends a value to the multiqueue.

Examples

use multi_stack_queue::MultiStackQueue;

#[derive(Clone, Copy)]
struct TestStruct {
    a: usize,
    b: bool    
}

let random_data = TestStruct { a: 42, b: false };

let mut msq: MultiStackQueue<TestStruct, 4, 2> = MultiStackQueue::new();

msq.push(0, random_data).unwrap();

pub fn pop(&mut self, id: usize) -> Result<T, MSQError>

Pops a value from the multiqueue.

Examples

use multi_stack_queue::MultiStackQueue;

#[derive(Clone, Copy)]
struct TestStruct {
    a: usize,
    b: bool    
}

let random_data = TestStruct { a: 42, b: false };

let mut msq: MultiStackQueue<TestStruct, 4, 2> = MultiStackQueue::new();

msq.push(0, random_data).unwrap();
msq.pop(0).unwrap();

pub fn is_full(&self, id: usize) -> bool

Returns whether a particular queue is full

Examples

use multi_stack_queue::MultiStackQueue;

let mut msq: MultiStackQueue<usize, 4, 2> = MultiStackQueue::new();

assert!(!msq.is_full(0));
for _ in 0..4 {
    msq.push(0, 0);
}
assert!(msq.is_full(0));

pub fn is_empty(&self, id: usize) -> bool

Returns whether a particular queue is empty

Examples

use multi_stack_queue::MultiStackQueue;

let mut msq: MultiStackQueue<usize, 4, 2> = MultiStackQueue::new();

assert!(msq.is_empty(0));
msq.push(0, 0);
assert!(!msq.is_empty(0));