feat(sched): ✨ proper task handlers

examples/sched.rs

@@ -3,6 +3,8 @@ use lool::sched::{recur, ruleset, Scheduler};
 fn my_action() {
     let now = chrono::Local::now();
     println!("I'm running at {}", now.format("%Y-%m-%d %H:%M:%S"));
+
+    std::thread::sleep(std::time::Duration::from_secs(15));
 }
 
 fn main() {
@@ -13,18 +15,15 @@ fn main() {
     std::thread::sleep(std::time::Duration::from_secs(1));
 
     loop {
-        {
-            let task = handler.task.lock().unwrap();
+        let is_running = handler.is_running();
+        let last_run = handler.get_last_run();
+        let next_run = handler.get_next_run();
+        let name = handler.name();
 
-            let is_running = task.is_running();
-            let last_run = task.get_last_run();
-            let name = task.name();
+        println!(
+            "task {name} |--> running: {is_running}, last: {last_run:?}, next: {next_run:?}"
+        );
         
-            println!(
-                "task {} |--> is running: {}, last run: {:?}",
-                name, is_running, last_run
-            );
-        }
 
         std::thread::sleep(std::time::Duration::from_secs(2));
     }

lib/sched/scheduler.rs

@@ -1,5 +1,5 @@
 use std::sync::{
-    atomic::{AtomicBool, Ordering},
+    atomic::{AtomicBool, AtomicPtr, AtomicUsize, Ordering},
     Arc, Mutex,
 };
 
@@ -21,12 +21,14 @@ type Action = Box<dyn FnMut() + Send + Sync + 'static>;
 /// status of the task.
 pub struct ScheduledTask {
     #[allow(dead_code)]
-    index: usize,
+    index: Arc<AtomicUsize>,
     name: String,
     action: Action,
-    rules: Vec<SchedulingRule>,
-    is_running: AtomicBool,
-    last_run: Arc<Mutex<Option<DateTime<Local>>>>, // TODO: remaining limits
+    rules: Arc<Vec<SchedulingRule>>,
+    is_running: Arc<AtomicBool>,
+    is_stopped: Arc<AtomicBool>,
+    is_removed: Arc<AtomicBool>,
+    last_run: Arc<AtomicPtr<DateTime<Local>>>,
 }
 
 impl ScheduledTask {
@@ -35,17 +37,16 @@ impl ScheduledTask {
         action();
     }
 
-    pub fn get_last_run(&self) -> Option<DateTime<Local>> {
-        let last_run_lock = self.last_run.lock().unwrap();
-        last_run_lock.as_ref().cloned()
-    }
-
-    pub fn is_running(&self) -> bool {
-        self.is_running.load(Ordering::Relaxed)
-    }
-
-    pub fn name(&self) -> &str {
-        &self.name
+    fn make_handler(&self) -> TaskHandler {
+        TaskHandler {
+            index: self.index.clone(),
+            name: self.name.clone(),
+            rules: self.rules.clone(),
+            is_running: self.is_running.clone(),
+            is_stopped: self.is_stopped.clone(),
+            is_removed: self.is_removed.clone(),
+            last_run: self.last_run.clone(),
+        }
     }
 }
 
@@ -113,19 +114,26 @@ impl Scheduler {
         let index = self.tasks.len();
 
         let task = Arc::new(Mutex::new(ScheduledTask {
-            index,
+            index: Arc::new(AtomicUsize::new(index)),
             name: name.to_string(),
             action: Box::new(action),
-            rules,
-            is_running: AtomicBool::new(false),
-            last_run: Arc::new(Mutex::new(None)),
+            rules: Arc::new(rules),
+            is_running: Arc::new(AtomicBool::new(false)),
+            is_stopped: Arc::new(AtomicBool::new(false)),
+            is_removed: Arc::new(AtomicBool::new(false)),
+            last_run: Arc::new(AtomicPtr::new(std::ptr::null_mut())),
         }));
 
         self.tasks.push(task.clone());
 
         run_in_pool(task.clone(), &self.pool);
 
-        TaskHandler { task: task.clone() }
+        let handler: TaskHandler = {
+            let task = task.lock().unwrap();
+            task.make_handler()
+        };
+
+        handler
     }
 }
 
@@ -134,14 +142,77 @@ impl Scheduler {
 /// returned by the `Scheduler::schedule` method,
 /// this struct can be used to check and control
 /// the status of the task.
+#[derive(Clone)]
 pub struct TaskHandler {
-    // HACK: holding the task in the TaskHandler is a temporal hack
-    //       TaskHandler should hold Atomic references to the important parts of the task
-    //       instead. e.g. is_running, last_run, etc.
-    //       the problem is with last_run, as its a DateTime, and not a primitive type
-    //       we could get around this by instead of holding the DateTime, holding the i64
-    //       value (unix timestamp) and then converting it to a DateTime when needed.
-    pub task: Arc<Mutex<ScheduledTask>>,
+    name: String,
+    index: Arc<AtomicUsize>,
+    rules: Arc<Vec<SchedulingRule>>,
+    is_running: Arc<AtomicBool>,
+    is_stopped: Arc<AtomicBool>,
+    is_removed: Arc<AtomicBool>,
+    last_run: Arc<AtomicPtr<DateTime<Local>>>,
+}
+
+impl TaskHandler {
+    /// 🧉 » last run date
+    ///
+    /// returns a `DateTime<Local>` representing the last time the task was run or None if the task
+    /// has never been run before.
+    pub fn get_last_run(&self) -> Option<DateTime<Local>> {
+        let last_run = self.last_run.load(Ordering::Relaxed);
+        if last_run.is_null() {
+            None
+        } else {
+            Some(unsafe { *last_run })
+        }
+    }
+
+    /// 🧉 » next run date
+    ///
+    /// returns a `DateTime<Local>` representing the next time the task is scheduled to run
+    pub fn get_next_run(&self) -> Option<DateTime<Local>> {
+        get_next_run_time(&self.rules, None)
+    }
+
+    /// 🧉 » is running?
+    ///
+    /// returns a `bool` indicating if the task is currently running in this moment
+    pub fn is_running(&self) -> bool {
+        self.is_running.load(Ordering::Relaxed)
+    }
+
+    /// 🧉 » name
+    ///
+    /// returns the name of the task
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+
+    /// 🧉 » is active?
+    ///
+    /// returns a `bool` indicating if the task is active
+    pub fn is_active(&self) -> bool {
+        !self.is_stopped.load(Ordering::Relaxed) && !self.is_removed.load(Ordering::Relaxed)
+    }
+
+    /// 🧉 » is stopped?
+    ///
+    /// returns a `bool` indicating if the task has been stopped
+    ///
+    /// a task being stopped means that it has been paused, but not removed from the scheduler.
+    /// So, although it's not running, it's still in the scheduler and can be resumed.
+    pub fn is_stopped(&self) -> bool {
+        self.is_stopped.load(Ordering::Relaxed)
+    }
+
+    /// 🧉 » is removed?
+    ///
+    /// returns a `bool` indicating if the task has been removed
+    ///
+    /// once a task is removed, it's no longer in the scheduler and can't be resumed.
+    pub fn is_removed(&self) -> bool {
+        self.is_removed.load(Ordering::Relaxed)
+    }
 }
 
 /// **main function to run the task in the thread pool**
@@ -176,11 +247,16 @@ fn run_in_pool(task_mutex: Arc<Mutex<ScheduledTask>>, pool: &ThreadPool) {
 
             let mut task = task_mutex.lock().unwrap();
 
-            task.last_run = Arc::new(Mutex::new(Some(run_date)));
+            let run_date_box = Box::new(run_date);
+            let run_date_raw = Box::into_raw(run_date_box);
+            task.last_run.store(run_date_raw, Ordering::Relaxed);
+
             task.is_running.store(true, Ordering::SeqCst);
             task.run();
             task.is_running.store(false, Ordering::SeqCst);
-            maybe_next_run = get_next_run_time(&task.rules, Some(run_date));
+
+            let run_date_box = unsafe { Box::from_raw(task.last_run.load(Ordering::Relaxed)) };
+            maybe_next_run = get_next_run_time(&task.rules, Some(*run_date_box));
         }
     });
 }