Module queue 

Queue management module (FR-011, FR-017)

This module provides bounded queue functionality with configurable overflow policies for CAN message handling.

Overview

The queue module provides a bounded message queue that prevents unbounded memory growth when messages arrive faster than they can be processed.

Components

• BoundedQueue: A fixed-capacity queue for CAN messages
• QueueOverflowPolicy: Strategy for handling queue overflow
• QueueStats: Statistics about queue operations
• QueueConfig: Configuration loaded from TOML files

Overflow Policies

When the queue is full, one of these policies is applied:

• QueueOverflowPolicy::DropOldest: Remove the oldest message (default)
• QueueOverflowPolicy::DropNewest: Reject the new message
• QueueOverflowPolicy::Block: Block until space is available (with timeout)

Example

use canlink_hal::queue::{BoundedQueue, QueueOverflowPolicy};
use canlink_hal::CanMessage;

// Create a queue with capacity 100 and DropOldest policy
let mut queue = BoundedQueue::with_policy(100, QueueOverflowPolicy::DropOldest);

// Push messages
let msg = CanMessage::new_standard(0x123, &[1, 2, 3]).unwrap();
queue.push(msg).unwrap();

// Pop messages
if let Some(msg) = queue.pop() {
    println!("Received: {:?}", msg);
}

// Check statistics
let stats = queue.stats();
println!("Enqueued: {}, Dequeued: {}, Dropped: {}",
         stats.enqueued, stats.dequeued, stats.dropped);

Thread Safety

BoundedQueue is not thread-safe by itself. For multi-threaded access, wrap it in appropriate synchronization primitives (e.g., Mutex, RwLock).

Structs

BoundedQueue

Bounded message queue

QueueConfig

Queue configuration from TOML

QueueStats

Queue statistics

Enums

QueueOverflowPolicy

Queue overflow handling policy