Checking this in before I pull the thread code out to its own file.

Cargo.lock

@@ -2,11 +2,23 @@
 name = "apprentice"
 version = "0.1.0"
 dependencies = [
+ "chrono 0.9.0 (git+https://gitlab.com/CyberMages/chrono.git)",
  "scribe 0.1.0 (git+https://gitlab.com/CyberMages/scribe.git)",
+ "spellbook 0.1.0 (git+https://gitlab.com/CyberMages/spellbook.git)",
 ]
 
+[[package]]
+name = "chrono"
+version = "0.9.0"
+source = "git+https://gitlab.com/CyberMages/chrono.git#10f1633ac1334cb6ada86222c68efeea89141be7"
+
 [[package]]
 name = "scribe"
 version = "0.1.0"
-source = "git+https://gitlab.com/CyberMages/scribe.git#d6a6f5107c8d03b13e081c9378486781e31daa4e"
+source = "git+https://gitlab.com/CyberMages/scribe.git#e52418d3bfc28cd1f03cc7f31af06fce2e03f844"
+
+[[package]]
+name = "spellbook"
+version = "0.1.0"
+source = "git+https://gitlab.com/CyberMages/spellbook.git#f8526d248f3b7eb4f15f672368ac45a64c4eacbd"
 

Cargo.toml

@@ -9,5 +9,11 @@ documentation = ""
 keywords = ["scheduler", "task", "thread"]
 
 
+[dependencies.chrono]
+git = "https://gitlab.com/CyberMages/chrono.git"
+
 [dependencies.scribe]
 git = "https://gitlab.com/CyberMages/scribe.git"
+
+[dependencies.spellbook]
+git = "https://gitlab.com/CyberMages/spellbook.git"

README.md

@@ -0,0 +1 @@
+# Apprentice #

examples/sample_tasks.rs

@@ -8,5 +8,11 @@ use apprentice::*;
 
 pub fn main()
 {
-   println!("Hello world");
+   let mut scheduler: Scheduler;
+
+   scheduler = Scheduler::new(None, Some(4));
+   scheduler.queue_task(Task::new("Test"));
+   scheduler.process_tasks(true);
+   scheduler.process_tasks(true);
+   //scheduler.process_tasks(true);
 }

src/lib.rs

@@ -1,14 +1,22 @@
 #[macro_use]
 extern crate scribe;
 
+#[macro_use]
+extern crate spellbook;
+
+extern crate chrono;
+
 
 
 mod scheduler;
 mod task;
+mod task_state;
 mod thread;
+mod thread_data;
+mod thread_state;
 
 
 
 pub use self::scheduler::Scheduler;
 pub use self::task::Task;
-pub use self::thread::Thread;
+pub use self::task_state::TaskState;

src/scheduler.rs

@@ -1,18 +1,70 @@
+use std::collections::binary_heap::BinaryHeap;
+use std::ops::{Deref, DerefMut};
+use std::sync::{Arc, Mutex};
+use std::sync::mpsc::{channel, Receiver, Sender, TryRecvError};
+use std::thread::JoinHandle;
+use std::time::Duration;
+use std::vec::Vec;
+
+use ::task::Task;
+use ::task_state::TaskState;
 use ::thread::Thread;
+use ::thread_data::ThreadData;
+use ::thread_state::ThreadState;
+
+use chrono::MonotonicTime;
 
 
 
 ///
 pub struct Scheduler
 {
-   ///
+   /// The minimum amount of compute threads that the
-   has_unlimited_threads: bool,
+   /// scheduler will keep alive.
+   minimum_thread_amount: u64,
 
-   ///
+   /// The maximum amount of compute threads that the
+   /// scheduler will have alive at one given time.
    maximum_thread_amount: u64,
 
-   ///
+   /// Specify the maximum amount of time that a thread
-   thread_list: Vec<Thread>
+   /// can stay idle before it is marked to be killed.
+   maximum_thread_idle_time: Duration,
+
+   /// The threads created to handle
+   /// non-blocking computation tasks.
+   compute_threads: Vec<ThreadData>,
+
+   /// The threads created to handle blocking tasks.
+   blocking_threads: Vec<ThreadData>,
+
+   /// The main task queue that threads can use to process tasks.
+   task_queue: Arc<Mutex<BinaryHeap<Task>>>
+}
+
+
+
+macro_rules! change_thread_state
+{
+   ($state: expr, $state_holder: expr, $sender: expr) =>
+   {
+      {
+         $state_holder = $state;
+         match $sender.send($state_holder)
+         {
+            Ok(_) =>
+            {
+            }
+
+            Err(error) =>
+            {
+               // We lost our connection to the
+               // state channel.
+               warn!("{}", error);
+            }
+         }
+      }
+   }
 }
 
 
@@ -20,41 +72,443 @@ pub struct Scheduler
 impl Scheduler
 {
    /// 
-   pub fn new(num_threads: Option<u64>) -> Scheduler
+   pub fn new(min_threads: Option<u64>, max_threads: Option<u64>) -> Scheduler
    {
-      let thread_count: u64;
+      let min_count: u64;
-      let unlimited_threads: bool;
+      let max_count: u64;
 
-      // Check to see if the scheduler will
+      // See if there is a minimum number of threads that
-      // be using unlimited threads.
+      // the scheduler is supposed to keep around.
-      match num_threads
+      match min_threads
+      {
+         Some(count) =>
+         {
+            min_count = count;
+         }
+
+         None =>
+         {
+            min_count = 0;
+         }
+      }
+
+      // Get the maximum amount of threads that the
+      // scheduler can create. This is for compute threads
+      // since I/O threads will block.
+      match max_threads
       {
          Some(count) =>
          {
             // Set the maximum number of threads to be the desired
             // amount.
-            thread_count = count;
+            max_count = count;
-            unlimited_threads = false;
          }
 
          None =>
          {
-            // Set that there can be an unlimited amount of threads.
+            // We don't know how many threads we can create.
-            thread_count = 0;
+            // Do the ideal thing and create 1 thread per core.
-            unlimited_threads = true;
+            max_count = 1;
          }
       }
 
-      // Create the new Scheduler.
+      debug!("Creating Scheduler with {} max threads.", max_count);
+
       Scheduler
       {
-         has_unlimited_threads: unlimited_threads,
+         minimum_thread_amount: min_count,
-         maximum_thread_amount: thread_count,
+         maximum_thread_amount: max_count,
-         thread_list: Vec::new()
+         maximum_thread_idle_time: Duration::new(5, 0),
+         compute_threads: Vec::with_capacity(max_count as usize),
+         blocking_threads: Vec::with_capacity(max_count as usize),
+         task_queue: Arc::new(Mutex::new(BinaryHeap::new()))
       }
    }
 
-   fn create_thread()
+   /// Queues a task to be processed.
+   pub fn queue_task(&mut self, task: Task)
+   {
+      // Just add the task to the queue.
+      match self.task_queue.lock()
+      {
+         Ok(ref mut guard) =>
+         {
+            guard.deref_mut().push(task);
+         }
+
+         Err(error) =>
+         {
+            error!("{}", error);
+         }
+      }
+   }
+
+   /// Processing the currently queued tasks.
+   ///
+   /// If this is not a single iteration, then it will block
+   /// the current thread until all tasks are finished processed.
+   /// This does not count immortal tasks.
+   pub fn process_tasks(&mut self, is_single_iteration: bool)
+   {
+      let mut continue_processing: bool;
+      let mut new_thread_count: u64;
+
+      // Continue to process the tasks as long as possible.
+      continue_processing = true;
+      while continue_processing == true
+      {
+         debug!("There are currently {} tasks to process.",
+                self.get_task_count());
+         debug!("Currently running {} out of {} threads.",
+                self.compute_threads.len(), self.maximum_thread_amount);
+
+         // Determine how many threads need to be created.
+         new_thread_count = self.determine_new_thread_amount();
+
+         // Create the threads that we determined that we needed
+         // to process the current tasks.
+         self.spawn_compute_threads(new_thread_count);
+
+         // Check to see if this was to be a single iteration
+         // of the task scheduler.
+         if is_single_iteration == true
+         {
+            // This was only a single iteration,
+            // so stop the processing.
+            continue_processing = false;
+         }
+//         else
+//         {
+            // Let the thread sleep before
+            // handling the next iteration.
+            ::std::thread::sleep(Duration::new(1, 0));
+//         }
+      }
+   }
+
+   /// Get the amount of tasks in the queue.
+   fn get_task_count(&mut self) -> u64
+   {
+      // Get the size of the task queue.
+      match self.task_queue.lock()
+      {
+         Ok(ref mut guard) =>
+         {
+            return guard.deref_mut().len() as u64;
+         }
+
+         Err(error) =>
+         {
+            error!("{}", error);
+         }
+      }
+
+      0u64
+   }
+
+   /// This will calculate the new amount of compute threads
+   /// that need to be created.
+   fn determine_new_thread_amount(&mut self) -> u64
+   {
+      let task_count: u64;
+      let thread_count: u64;
+      let potential_threads: u64;
+      let mut desired_threads: u64;
+      let mut available_threads: u64;
+      let mut new_thread_count: u64;
+
+      // Determine the amount of tasks that need to be processed.
+      task_count = self.get_task_count();
+      debug!("There are currently {} compute tasks to process.", task_count);
+
+      // Determine how many threads we currently have available.
+      thread_count = self.compute_threads.len() as u64;
+      debug!("Currently running {} out of {} compute threads.",
+             thread_count, self.maximum_thread_amount);
+
+      // Determine how many of these threads currently are
+      // not processing anything.
+      available_threads = 0u64;
+      for thread_data in self.compute_threads.iter()
+      {
+         match thread_data.state
+         {
+            ThreadState::Idle =>
+            {
+               available_threads += 1u64;
+            }
+
+            ThreadState::Starting =>
+            {
+               available_threads += 1u64;
+            }
+
+            _ =>
             {
             }
+         }
+      }
+
+      // Calculate how many threads we would need to
+      // process all the tasks in our queue if each
+      // task was given its own thread.
+      println!("task_count: {}\navailable_threads: {}", task_count, available_threads);
+      desired_threads = 0u64;
+      if task_count > available_threads
+      {
+         desired_threads = task_count - available_threads;
+      }
+      new_thread_count = desired_threads;
+
+      // Calculate how many potential threads can be created.
+      potential_threads = self.maximum_thread_amount - thread_count;
+
+      // We are limited by a hard ceiling of runnable threads.
+      // Make sure we have as many as we can to process
+       // the currently queued tasks.
+      if potential_threads < desired_threads
+      {
+         // Make sure we have atleast the maximum number
+         // of threads aloud.
+         new_thread_count = self.maximum_thread_amount - thread_count;
+      }
+
+      // Return the determined amount of threads to create.
+      new_thread_count
+   }
+
+   ///
+   fn spawn_compute_threads(&mut self, amount: u64)
+   {
+      let mut shutdown_channel: (Sender<bool>, Receiver<bool>);
+      let mut state_channel: (Sender<ThreadState>, Receiver<ThreadState>);
+      let mut shutdown_receiver: Receiver<bool>;
+      let mut state_sender: Sender<ThreadState>;
+      let mut join_handle: JoinHandle<()>;
+      let mut task_queue: Arc<Mutex<BinaryHeap<Task>>>;
+      let mut data: ThreadData;
+
+      // Loop through and create all the required threads.
+      debug!("Spawning {} compute threads", amount);
+      for _i in 0..amount
+      {
+         // Create the channel to shutdown the thread.
+         shutdown_channel = channel::<bool>();
+         shutdown_receiver = shutdown_channel.1;
+
+         // Create the channel to retrieve the
+         // status of the thread.
+         state_channel = channel::<ThreadState>();
+         state_sender = state_channel.0;
+
+         // Clone the task queue for the thread.
+         task_queue = self.task_queue.clone();
+
+         // Create a new Thread.
+         join_handle = ::std::thread::spawn(move ||
+            {
+               let mut check_messages: bool;
+               let mut continue_running: bool;
+               let mut current_state: ThreadState;
+               let mut current_task: Option<Task>;
+
+               println!("Starting thread.");
+
+               // Threads start off in the starting state.
+               current_state = ThreadState::Starting;
+
+               // This thread will start off with no
+               // tasks to process.
+               current_task = None;
+
+               // Run this thread until the scheduler decides
+               // to shut it down.
+               change_thread_state!(ThreadState::Idle, current_state,
+                                    state_sender);
+               continue_running = true;
+               while continue_running == true
+               {
+                  println!("Running thread.");
+                  process_compute_thread(&mut current_task,
+                                         &mut current_state,
+                                         &mut task_queue,
+                                         &state_sender);
+
+                  // Sleep the thread so that other threads
+                  // get a chance to run 
+                  ::std::thread::sleep(Duration::new(0, 100));
+
+                  // Check to see if this thread should be shutdown.
+                  check_messages = true;
+                  while check_messages == true
+                  {
+                     match shutdown_receiver.try_recv()
+                     {
+                        Ok(val) =>
+                        {
+                           continue_running = !val;
+                        }
+
+                        Err(error) =>
+                        {
+                           match error
+                           {
+                              TryRecvError::Empty =>
+                              {
+                                 // No messages to handle.
+                                 check_messages = false;
+                                 debug!("There were no shutdown messages.");
+                              }
+
+                              TryRecvError::Disconnected =>
+                              {
+                                 // We lost our connection to the
+                                 // shutdown channel.
+                                 warn!("{}", error);
+                              }
+                           }
+                        }
+                     }
+                  }
+               }
+
+               // This thread is finished.
+               println!("Shutting down thread.");
+               change_thread_state!(ThreadState::Idle, current_state,
+                                    state_sender);
+            }
+         );
+
+         // Create a new set of data for the
+         // thread we want to create.
+         data = ThreadData::new(join_handle, shutdown_channel.0,
+                                state_channel.1);
+
+         // Add the new ThreadData to the set
+         // of compute threads.
+         self.compute_threads.push(data);
+      }
+   }
+}
+
+impl Drop for Scheduler
+{
+   fn drop(&mut self)
+   {
+      debug!("Destroying scheduler.");
+
+      // Stop any threads that are running.
+      debug!("Stopping threads.");
+      for thread_data in self.compute_threads.iter_mut()
+      {
+         // Stop the thread.
+         thread_data.shutdown_sender.send(true);
+      }
+
+      // Wait about 5 seconds to make sure all
+      // the threads have been stopped.
+      debug!("Giving threads a chance to end.");
+      ::std::thread::sleep(Duration::new(5, 0));
+   }
+}
+
+
+
+///
+fn process_compute_thread(current_task: &mut Option<Task>,
+                          current_state: &mut ThreadState,
+                          task_queue: &mut Arc<Mutex<BinaryHeap<Task>>>,
+                          state_sender: &Sender<ThreadState>)
+{
+   let mut task_completed: bool;
+
+   // No task was recently completed.
+   task_completed = false;
+
+   // Make sure that this thread has a Task
+   // to currently work on.
+   match *current_task
+   {
+      Some(ref mut task) =>
+      {
+         // Process the task this thread is
+         // currently working on.
+         task.process();
+
+         match task.state
+         {
+            TaskState::Finished =>
+            {
+               task_completed = true;
+            }
+
+            _ =>
+            {
+            }
+         }
+      }
+
+      None =>
+      {
+         // This thread does not have a current task.
+         // Get another task to work on from the Queue.
+         match task_queue.lock()
+         {
+            Ok(ref mut guard) =>
+            {
+               *current_task = guard.deref_mut().pop();
+
+               match *current_task
+               {
+                  Some(_) =>
+                  {
+                     debug!("Received a task.");
+                     change_thread_state!(ThreadState::Processing,
+                                          *current_state, state_sender);
+                  }
+
+                  None =>
+                  {
+                     debug!("No new task to process.");
+                  }
+               }
+            }
+
+            Err(error) =>
+            {
+               error!("{}", error);
+            }
+         }
+
+         // If we don't have a task to process,
+         // then we may need to switch over to
+         // an idle state.
+         if current_task.is_none()
+         {
+            match *current_state
+            {
+               ThreadState::Idle =>
+               {
+                  // The thread is already sitting idle.
+               }
+
+               _ =>
+               {
+                  // There is nothing for this thread
+                  // to process, so mark the thread as idle.
+                  change_thread_state!(ThreadState::Idle, *current_state,
+                                       state_sender);
+               }
+            }
+         }
+      }
+   }
+
+   if task_completed == true
+   {
+      println!("Task completed.");
+      *current_task = None;
+      change_thread_state!(ThreadState::Idle, *current_state,
+                           state_sender);
+   }
 }

src/status.rs

@@ -0,0 +1,9 @@
+///
+pub enum Status
+{
+   ///
+   Waiting,
+
+   ///
+   Finished
+}

src/task.rs

@@ -1,8 +1,16 @@
+use std::cmp::Ordering;
+
+use ::task_state::TaskState;
+
+
 ///
 pub struct Task
 {
    ///
-   name: String
+   pub name: String,
+
+   ///
+   pub state: TaskState
 }
 
 
@@ -14,7 +22,50 @@ impl Task
    {
       Task
       {
-         name: String::from(task_name)
+         name: String::from(task_name),
+         state: TaskState::Starting
       }
    }
+
+   ///
+   pub fn set_processing_func(&self) -> i8
+   {
+      0
+   }
+
+   ///
+   pub fn process(&mut self)
+   {
+      self.state = TaskState::Processing;
+      println!("Processing task.");
+      self.state = TaskState::Finished;
+   }
+}
+
+impl PartialEq for Task
+{
+   fn eq(&self, other: &Self) -> bool
+   {
+       self.name.eq(&other.name)
+   }
+}
+
+impl Eq for Task
+{
+}
+
+impl PartialOrd for Task
+{
+   fn partial_cmp(&self, other: &Self) -> Option<Ordering>
+   {
+      Some(self.cmp(other))
+   }
+}
+
+impl Ord for Task
+{
+   fn cmp(&self, other: &Self) -> Ordering
+   {
+      self.name.cmp(&other.name)
+   }
 }

src/task_state.rs

@@ -0,0 +1,40 @@
+/// The different states a Task can go through during its lifetime.
+pub enum TaskState
+{
+   /// The state that every Task starts in.
+   ///
+   /// The STARTING state can only lead to the processing state.
+   Starting,
+
+   /// The state that each Task is in while it is actually
+   /// being process and running on a thread.
+   ///
+   /// The PROCESSING state can only lead to WAITING,
+   /// FINISHED, or UNKNOWN states.
+   Processing,
+
+   /// The state a Task is in while it is waiting for child
+   /// tasks to switch to the FINISHED state.
+   ///
+   /// The WAITING state can only lead to the DONE_WAITING
+   /// and UNKNOWN states.
+   Waiting,
+
+   /// The state a Task is in once it is done processing
+   /// child tasks, but prior to going back to the PROCESSING state.
+   ///
+   /// The DONE_WAITING state can only lead to the PROCESSING
+   /// and UNKNOWN states.
+   DoneWaiting,
+
+   /// The state a Task will be in when it is FINISHED processing
+   /// and ready to be destroyed.
+   ///
+   /// The FINISHED state cannot lead to any states and shows that the
+   /// task is completed.
+   Finished,
+
+   /// The state a Task will be placed in if it is detected to be
+   /// in an inproper state during its lifetime.
+   Unknown
+}

src/task_type.rs

@@ -0,0 +1,10 @@
+///
+pub enum TaskType
+{
+   /// A task ment to get its own thread so that
+   /// it can run as long as it needs to.
+   Immortal,
+
+   ///
+   Mortal
+}

src/thread.rs

@@ -1,8 +1,37 @@
+use std::collections::binary_heap::BinaryHeap;
+use std::ops::{Deref, DerefMut};
+use std::sync::{Arc, Mutex};
+use std::sync::mpsc::{channel, Receiver, Sender, TryRecvError};
+use std::thread::JoinHandle;
+use std::time::Duration;
+use std::vec::Vec;
+
+use ::task::Task;
+use ::task_state::TaskState;
+use ::thread_data::ThreadData;
+use ::thread_state::ThreadState;
+
+use chrono::MonotonicTime;
+
+
+
 ///
 pub struct Thread
 {
    ///
-   empty: i8
+   state: ThreadState,
+
+   ///
+   current_task: Option<Task>,
+
+   ///
+   task_queue: Arc<Mutex<BinaryHeap<Task>>>,
+
+   ///
+   shutdown_receiver: Receiver<bool>,
+
+   ///
+   state_sender: Sender<ThreadState>
 }
 
 
@@ -10,11 +39,155 @@ pub struct Thread
 impl Thread
 {
    /// 
-   pub fn new() -> Thread
+   pub fn new(queue: Arc<Mutex<BinaryHeap<Task>>>,
+              shutdown_r: Receiver<bool>,
+              state_s: Sender<ThreadState>)
+      -> Thread
    {
       Thread
       {
-         empty: 0
+         state: ThreadState::Starting,
+         current_task: None,
+         task_queue: queue,
+         shutdown_receiver: shutdown_r,
+         state_sender: state_s
+      }
+   }
+
+   ///
+   pub fn process(&mut self)
+   {
+      let mut task_completed: bool;
+
+      // No task was recently completed.
+      task_completed = false;
+
+      // Make sure that this thread has a Task
+      // to currently work on.
+      match self.current_task
+      {
+         Some(ref mut task) =>
+         {
+            // Process the task this thread is
+            // currently working on.
+            task.process();
+
+            match task.state
+            {
+               TaskState::Finished =>
+               {
+                  task_completed = true;
+               }
+
+               _ =>
+               {
+               }
+            }
+         }
+
+         None =>
+         {
+            // This thread does not have a current task.
+            // Get another task to work on from the Queue.
+            match self.task_queue.lock()
+            {
+               Ok(ref mut guard) =>
+               {
+                  self.current_task = guard.deref_mut().pop();
+
+                  match self.current_task
+                  {
+                     Some(_) =>
+                     {
+                        debug!("Received a task.");
+                     }
+
+                     None =>
+                     {
+                        debug!("No new task to process.");
+                     }
+                  }
+               }
+
+               Err(error) =>
+               {
+                  error!("{}", error);
+               }
+            }
+
+            // If we don't have a task to process,
+            // then we may need to switch over to
+            // an idle state.
+            match self.current_task
+            {
+               Some(_) =>
+               {
+                  self.change_state(ThreadState::Processing);
+               }
+
+               None =>
+               {
+                  match self.state
+                  {
+                     ThreadState::Idle =>
+                     {
+                        // The thread is already sitting idle.
+                     }
+
+                     _ =>
+                     {
+                        // There is nothing for this thread
+                        // to process, so mark the thread as idle.
+                        self.change_state(ThreadState::Idle);
+                     }
+                  }
+               }
+            }
+         }
+      }
+
+      if task_completed == true
+      {
+         println!("Task completed.");
+         self.current_task = None;
+         self.change_state(ThreadState::Idle);
+      }
+   }
+
+   ///
+   fn change_state(&mut self, new_state: ThreadState)
+   {
+      self.state = new_state;
+      match self.state_sender.send(self.state)
+      {
+         Ok(_) =>
+         {
+         }
+
+         Err(error) =>
+         {
+            // We lost our connection to the
+            // state channel.
+            warn!("{}", error);
+         }
+      }
+   }
+
+   /// Queues a task to be processed.
+   fn queue_task(&mut self, task: Task)
+   {
+      // Just add the task to the queue.
+      match self.task_queue.lock()
+      {
+         Ok(ref mut guard) =>
+         {
+            guard.deref_mut().push(task);
+         }
+
+         Err(error) =>
+         {
+            error!("{}", error);
+         }
       }
    }
 }

src/thread_data.rs

@@ -0,0 +1,45 @@
+use std::sync::mpsc::{Sender, Receiver};
+use std::thread::JoinHandle;
+
+use ::thread_state::ThreadState;
+
+use chrono::MonotonicTime;
+
+
+
+///
+pub struct ThreadData
+{
+   ///
+   pub state: ThreadState,
+
+   ///
+   pub handle: JoinHandle<()>,
+
+   ///
+   pub idle_time: MonotonicTime,
+
+   ///
+   pub shutdown_sender: Sender<bool>,
+
+   ///
+   pub state_receiver: Receiver<ThreadState>,
+}
+
+
+
+impl ThreadData
+{
+   pub fn new(join_handle: JoinHandle<()>, shutdown_s: Sender<bool>,
+              state_r: Receiver<ThreadState>) -> ThreadData
+   {
+      ThreadData
+      {
+         state: ThreadState::Starting,
+         handle: join_handle,
+         idle_time: MonotonicTime::current(),
+         shutdown_sender: shutdown_s,
+         state_receiver: state_r
+      }
+   }
+}

src/thread_state.rs

@@ -0,0 +1,16 @@
+///
+#[derive(Clone, Copy)]
+pub enum ThreadState
+{
+   ///
+   Starting,
+
+   ///
+   Idle,
+
+   ///
+   Processing,
+
+   ///
+   Finished
+}