Task Scheduler RS

A flexible, async task scheduler for Rust that supports both one-time and recurring tasks using tokio, with thread-safe implementation.

Features

• Async Task Scheduling: Built on tokio for efficient asynchronous execution
• Thread-safe: Uses Arc and Mutex for safe concurrent access
• Task Types:
  • One-time tasks with delay
  • Recurring tasks with customizable intervals
• Task Management:
  • Add and remove tasks dynamically
  • List active tasks
  • Automatic cleanup of completed tasks

Installation

Add this to your Cargo.toml:

[dependencies]
task-scheduler-rs = "0.4.0"
tokio = { version = "1.0", features = ["full"] }

Basic Example

use std::sync::Arc;
use tokio::sync::Mutex;
use tokio::time::Duration;
use task_scheduler_rs::{Scheduler, Task};
use task_scheduler_rs::scheduler::task::RecurrenceType;

#[tokio::main]
async fn main() {
    // Create a thread-safe scheduler
    let scheduler = Arc::new(Mutex::new(Scheduler::new()));
    
    // Add tasks with lock
    {
        let mut scheduler = scheduler.lock().await;
        
        // Add a one-time task
        scheduler.add_task(
            "one_time_task".to_string(),
            |task| println!("Executing task: {}", task.name),
            Duration::from_secs(5)  // Runs after 5 seconds
        );
        
        // Add a recurring task
        scheduler.add_recurring_task(
            "recurring_task".to_string(),
            |task| println!("Running recurring task: {}", task.name),
            Duration::from_secs(0),  // No initial delay
            RecurrenceType::Fixed(Duration::from_secs(2))  // Repeats every 2 seconds
        );
    }

    // Run scheduler in separate task
    let scheduler_clone = Arc::clone(&scheduler);
    tokio::spawn(async move {
        let mut scheduler = scheduler_clone.lock().await;
        scheduler.execute().await;
    });
}

Task Management Example

// Remove a task
let scheduler_clone = Arc::clone(&scheduler);
tokio::spawn(async move {
    tokio::time::sleep(Duration::from_secs(5)).await;
    let mut scheduler = scheduler_clone.lock().await;
    scheduler.remove_task_by_name("one_time_task");
    println!("Current tasks: {:?}", scheduler.list_tasks());
});

Scheduler Methods

• new(): Create a new scheduler instance
• add_task(name: String, callback: impl FnMut(&Task) + Send + 'static, delay: Duration): Add a one-time task
• add_recurring_task(name: String, callback: impl FnMut(&Task) + Send + 'static, delay: Duration, recurrence: RecurrenceType): Add a recurring task
• execute(): Start executing scheduled tasks
• remove_task_by_name(name: &str): Remove a task by its name
• list_tasks(): Get a list of all task names
• stop(): Stop all running tasks

Task Types

pub enum RecurrenceType {
    None,               // One-time task
    Fixed(Duration),    // Recurring task with fixed interval
}

Thread Safety

The scheduler is designed to be thread-safe using Arc<Mutex<Scheduler>>. This allows:

• Concurrent access from multiple tasks
• Safe task management across different threads
• Dynamic task addition/removal while the scheduler is running

Best Practices

1. Always use proper locking with .lock().await
2. Keep lock durations as short as possible
3. Clone the Arc for different tasks that need scheduler access
4. Handle potential task panics in callbacks

Requirements

• Rust edition 2021 or later
• tokio with full features enabled

Important Note

This is a learning project as I'm still getting familiar with Rust. The current implementation focuses on basic functionality and might not include advanced features or optimizations. If you're looking for a production-ready task scheduler with more advanced features, please consider using other established crates like:

• tokio-cron-scheduler
• delay-timer
• scheduled-thread-pool

Others example

#[tokio::main]
async fn main() {
    let scheduler = Arc::new(Mutex::new(Scheduler::new()));
    {
        let mut scheduler = scheduler.lock().await; // Lock for adding tasks
        scheduler.add_task(
            "daily_backup".to_string(),
            Box::new(|task: &Task| println!("Backing up... {}", task.name)),
            Duration::from_secs(1),
        );
        scheduler.add_task(
            "hourly_check".to_string(),
            Box::new(|task: &Task| println!("Checking... {}", task.name)),
            Duration::from_secs(2),
        );
        scheduler.add_recurring_task(
            "recurring_task".to_string(),
            |task| println!("Running task: {}", task.name),
            Duration::from_secs(0),  // initial delay
            RecurrenceType::Fixed(Duration::from_secs(5))  // repeat every 5 seconds
        );
    };


    let scheduler_clone = Arc::clone(&scheduler);
    // Task 1: Execute the scheduler
    tokio::spawn(async move {
        let mut scheduler = scheduler_clone.lock().await;
        scheduler.execute().await;
    });


    let scheduler_clone = Arc::clone(&scheduler);
    // Task 2: Remove 'daily_backup' after 5 seconds
    tokio::spawn(async move {
        sleep(Duration::from_secs(5)).await; // Wait 5 seconds
        let mut scheduler = scheduler_clone.lock().await;
        scheduler.remove_task_by_name("daily_backup");
        println!("Removed 'daily_backup'");
        println!("Current tasks: {:?}", scheduler.list_tasks());
    });


    // Main thread keeps running
    loop {
        sleep(Duration::from_secs(1)).await;
        println!("Main thread is still running...");
    }
}