Tasks can now be added to computer or blocking threads.

The tasks are now objects that implement Taskable.

src/blocking_thread.rs

@@ -0,0 +1,162 @@
+use std::sync::mpsc::{Receiver, Sender, TryRecvError};
+use std::time::Duration;
+
+use ::task::Task;
+use ::task_state::TaskState;
+use ::thread::Thread;
+use ::thread_state::ThreadState;
+
+
+
+///
+pub struct BlockingThread
+{
+   ///
+   state: ThreadState,
+
+   ///
+   current_task: Box<Task>,
+
+   ///
+   shutdown_receiver: Receiver<bool>,
+
+   ///
+   state_sender: Sender<ThreadState>,
+
+   ///
+   continue_running: bool
+}
+
+
+
+impl BlockingThread
+{
+   /// 
+   pub fn new(task: Box<Task>,
+              shutdown_r: Receiver<bool>,
+              state_s: Sender<ThreadState>)
+      -> BlockingThread
+   {
+      BlockingThread
+      {
+         state: ThreadState::Starting,
+         current_task: task,
+         shutdown_receiver: shutdown_r,
+         state_sender: state_s,
+         continue_running: true
+      }
+   }
+
+   ///
+   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. For a
+   /// blocking thread this needs to queue a
+   /// new blocking thread task.
+   fn queue_task(&mut self, task: Box<Task>)
+   {
+   }
+
+   /// Check for any new thread shutdown messages.
+   fn process_shutdown_messages(&mut self)
+   {
+      let mut check_messages: bool;
+
+      // Loop through all the messages in the
+      // receivers queue.
+      check_messages = true;
+      while check_messages == true
+      {
+         match self.shutdown_receiver.try_recv()
+         {
+            Ok(val) =>
+            {
+               // Found a message.
+               self.continue_running = !val;
+            }
+
+            Err(error) =>
+            {
+               // Determine the kind of error we received.
+               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.
+                     // TODO: Handle this poisoning correctly.
+                     warn!("{}", error);
+                  }
+               }
+            }
+         }
+      }
+   }
+}
+
+impl Thread for BlockingThread
+{
+   ///
+   fn process(&mut self)
+   {
+      // Run this thread until the scheduler decides
+      // to shut it down.
+      self.change_state(ThreadState::Idle);
+      self.change_state(ThreadState::Processing);
+      while self.continue_running == true
+      {
+         // Process the task this thread is
+         // currently working on.
+         self.current_task.process();
+
+         match self.current_task.get_state()
+         {
+            TaskState::Finished =>
+            {
+               self.continue_running = false;
+            }
+
+            _ =>
+            {
+            }
+         }
+
+         // 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.
+         if self.continue_running == true
+         {
+            self.process_shutdown_messages();
+         }
+      }
+
+      // This thread is finished.
+      println!("Shutting down thread.");
+      self.change_state(ThreadState::Finished);
+   }
+}

src/compute_thread.rs

@@ -0,0 +1,274 @@
+use std::collections::binary_heap::BinaryHeap;
+use std::ops::DerefMut;
+use std::sync::{Arc, Mutex};
+use std::sync::mpsc::{Receiver, Sender, TryRecvError};
+use std::time::Duration;
+
+use ::task::Task;
+use ::task_state::TaskState;
+use ::thread::Thread;
+use ::thread_state::ThreadState;
+
+
+
+///
+pub struct ComputeThread
+{
+   ///
+   state: ThreadState,
+
+   ///
+   current_task: Option<Box<Task>>,
+
+   ///
+   task_queue: Arc<Mutex<BinaryHeap<Box<Task>>>>,
+
+   ///
+   shutdown_receiver: Receiver<bool>,
+
+   ///
+   state_sender: Sender<ThreadState>,
+
+   ///
+   continue_running: bool,
+}
+
+
+
+impl ComputeThread
+{
+   /// 
+   pub fn new(queue: Arc<Mutex<BinaryHeap<Box<Task>>>>,
+              shutdown_r: Receiver<bool>,
+              state_s: Sender<ThreadState>)
+      -> ComputeThread
+   {
+      ComputeThread
+      {
+         state: ThreadState::Starting,
+         current_task: None,
+         task_queue: queue,
+         shutdown_receiver: shutdown_r,
+         state_sender: state_s,
+         continue_running: true
+      }
+   }
+
+   ///
+   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);
+         }
+      }
+   }
+
+   ///
+   fn retrieve_task(&mut self)
+   {
+      // There is nothing to do if this thread already
+      // has a task to work on.
+      if self.current_task.is_some() == true
+      {
+         return;
+      }
+
+      // 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);
+         }
+      }
+   }
+
+   /// Queues a task to be processed.
+   fn queue_task(&mut self, task: Box<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);
+         }
+      }
+   }
+
+   /// Check for any new thread shutdown messages.
+   fn process_shutdown_messages(&mut self)
+   {
+      let mut check_messages: bool;
+
+      // Loop through all the messages in the
+      // receivers queue.
+      check_messages = true;
+      while check_messages == true
+      {
+         match self.shutdown_receiver.try_recv()
+         {
+            Ok(val) =>
+            {
+               // Found a message.
+               self.continue_running = !val;
+            }
+
+            Err(error) =>
+            {
+               // Determine the kind of error we received.
+               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.
+                     // TODO: Handle this poisoning correctly.
+                     warn!("{}", error);
+                  }
+               }
+            }
+         }
+      }
+   }
+}
+
+impl Thread for ComputeThread
+{
+   ///
+   fn process(&mut self)
+   {
+      let mut check_messages: bool;
+      let mut task_completed: bool;
+
+      // Run this thread until the scheduler decides
+      // to shut it down.
+      self.change_state(ThreadState::Idle);
+      while self.continue_running == true
+      {
+         // 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.get_state()
+               {
+                  TaskState::Finished =>
+                  {
+                     task_completed = true;
+                  }
+
+                  _ =>
+                  {
+                  }
+               }
+            }
+
+            None =>
+            {
+               // Try to get a task to work on.
+               self.retrieve_task();
+               match self.current_task
+               {
+                  Some(_) =>
+                  {
+                     // We have a task to work on, so switch to
+                     // a Processing state.
+                     self.change_state(ThreadState::Processing);
+                  }
+
+                  None =>
+                  {
+                     // If we don't have a task to process,
+                     // then we may need to switch over to
+                     // an idle state.
+                     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);
+                        }
+                     }
+                  }
+               }
+            }
+         }
+
+         // Check to see if the task this thread
+         // was processing was completed.
+         if task_completed == true
+         {
+            println!("Task completed.");
+            self.current_task = None;
+            self.change_state(ThreadState::Idle);
+         }
+
+         // 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.
+         self.process_shutdown_messages();
+      }
+
+      // This thread is finished.
+      println!("Shutting down thread.");
+      self.change_state(ThreadState::Finished);
+   }
+}

src/lib.rs

@@ -10,7 +10,11 @@ extern crate chrono;
 
 mod scheduler;
 mod task;
+mod taskable;
+mod task_container;
 mod task_state;
+mod blocking_thread;
+mod compute_thread;
 mod thread;
 mod thread_data;
 mod thread_state;
@@ -18,5 +22,4 @@ mod thread_state;
 
 
 pub use self::scheduler::Scheduler;
-pub use self::task::Task;
-pub use self::task_state::TaskState;
+pub use self::taskable::Taskable;

src/scheduler.rs

@@ -6,7 +6,13 @@ use std::thread::JoinHandle;
 use std::time::Duration;
 use std::vec::Vec;
 
+use chrono::MonotonicTime;
+
 use ::task::Task;
+use ::taskable::Taskable;
+use ::task_container::TaskContainer;
+use ::blocking_thread::BlockingThread;
+use ::compute_thread::ComputeThread;
 use ::thread::Thread;
 use ::thread_data::ThreadData;
 use ::thread_state::ThreadState;
@@ -36,7 +42,7 @@ pub struct Scheduler
    blocking_threads: Vec<ThreadData>,
 
    /// The main task queue that threads can use to process tasks.
-   task_queue: Arc<Mutex<BinaryHeap<Task>>>
+   task_queue: Arc<Mutex<BinaryHeap<Box<Task>>>>
 }
 
 
@@ -86,6 +92,7 @@ impl Scheduler
 
       debug!("Creating Scheduler with {} max threads.", max_count);
 
+      // Create the new scheduler.
       Scheduler
       {
          minimum_thread_amount: min_count,
@@ -98,14 +105,19 @@ impl Scheduler
    }
 
    /// Queues a task to be processed.
-   pub fn queue_task(&mut self, task: Task)
+   pub fn queue_task<T>(&mut self, task: T) where T: Taskable + 'static
    {
+      let container: TaskContainer<T>;
+
+      // Create the container to hold the task.
+      container = TaskContainer::new(task);
+
       // Just add the task to the queue.
       match self.task_queue.lock()
       {
          Ok(ref mut guard) =>
          {
-            guard.deref_mut().push(task);
+            guard.deref_mut().push(Box::new(container));
          }
 
          Err(error) =>
@@ -115,6 +127,25 @@ impl Scheduler
       }
    }
 
+   /// Queues a task, that is known to block, to be processed.
+   pub fn queue_blocking_task<T>(&mut self, task: T) where T: Taskable+ 'static
+   {
+      let data: ThreadData;
+      let container: TaskContainer<T>;
+
+      // Create the container to hold the task.
+      container = TaskContainer::new(task);
+
+      // Spawn a new blocking thread
+      // and process this task on it.
+      debug!("Spawning blocking thread.");
+
+      // Add the new ThreadData to the set
+      // of compute threads.
+      data = self.spawn_blocking_thread(Box::new(container));
+      self.blocking_threads.push(data);
+   }
+
    /// Processing the currently queued tasks.
    ///
    /// If this is not a single iteration, then it will block
@@ -141,6 +172,10 @@ impl Scheduler
          // to process the current tasks.
          self.spawn_compute_threads(new_thread_count);
 
+         // Check to see if there are any compute threads
+         // that need to be destroyed.
+         self.trim_compute_threads();
+
          // Check to see if this was to be a single iteration
          // of the task scheduler.
          if is_single_iteration == true
@@ -149,12 +184,10 @@ impl Scheduler
             // so stop the processing.
             continue_processing = false;
          }
-//         else
-//         {
-            // Let the thread sleep before
-            // handling the next iteration.
-            ::std::thread::sleep(Duration::new(0, 100));
-//         }
+
+         // Let the thread sleep before
+         // handling the next iteration.
+         ::std::thread::sleep(Duration::new(0, 100));
       }
    }
 
@@ -247,45 +280,83 @@ impl Scheduler
       new_thread_count
    }
 
+   ///
+   fn trim_compute_threads(&mut self)
+   {
+      
+   }
+
    ///
    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 join_handle: JoinHandle<()>;
       let mut data: ThreadData;
-      let mut new_thread: Thread;
 
       // 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>();
-
-         // Create the channel to retrieve the
-         // status of the thread.
-         state_channel = channel::<ThreadState>();
-
-         // Create a new Thread.
-         new_thread = Thread::new(self.task_queue.clone(),
-                                  shutdown_channel.1, state_channel.0);
-         join_handle = ::std::thread::spawn(move ||
-            {
-               new_thread.process();
-            }
-         );
-
-         // 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.
+         data = self.spawn_compute_thread();
          self.compute_threads.push(data);
       }
    }
+
+   fn spawn_compute_thread(&self) -> ThreadData
+   {
+      let shutdown_channel: (Sender<bool>, Receiver<bool>);
+      let state_channel: (Sender<ThreadState>, Receiver<ThreadState>);
+      let join_handle: JoinHandle<()>;
+      let mut new_thread: ComputeThread;
+
+      // Create the channel to shutdown the thread.
+      shutdown_channel = channel::<bool>();
+
+      // Create the channel to retrieve the
+      // status of the thread.
+      state_channel = channel::<ThreadState>();
+
+      // Create a new Thread.
+      new_thread = ComputeThread::new(self.task_queue.clone(),
+                                      shutdown_channel.1, state_channel.0);
+      join_handle = ::std::thread::spawn(move ||
+         {
+            new_thread.process();
+         }
+      );
+
+      // Create a new set of data for the
+      // thread we want to create.
+      ThreadData::new(join_handle, shutdown_channel.0, state_channel.1)
+   }
+
+   fn spawn_blocking_thread(&self, task: Box<Task>) -> ThreadData
+   {
+      let shutdown_channel: (Sender<bool>, Receiver<bool>);
+      let state_channel: (Sender<ThreadState>, Receiver<ThreadState>);
+      let join_handle: JoinHandle<()>;
+      let mut new_thread: BlockingThread;
+
+      // Create the channel to shutdown the thread.
+      shutdown_channel = channel::<bool>();
+
+      // Create the channel to retrieve the
+      // status of the thread.
+      state_channel = channel::<ThreadState>();
+
+      // Create a new Thread.
+      new_thread = BlockingThread::new(task, shutdown_channel.1,
+                                       state_channel.0);
+      join_handle = ::std::thread::spawn(move ||
+         {
+            new_thread.process();
+         }
+      );
+
+      // Create a new set of data for the
+      // thread we want to create.
+      ThreadData::new(join_handle, shutdown_channel.0, state_channel.1)
+   }
 }
 
 impl Drop for Scheduler
@@ -295,7 +366,24 @@ impl Drop for Scheduler
       debug!("Destroying scheduler.");
 
       // Stop any threads that are running.
-      debug!("Stopping threads.");
+      debug!("Stopping blocking threads.");
+      for thread_data in self.blocking_threads.iter_mut()
+      {
+         // Stop the thread.
+         match thread_data.shutdown_sender.send(true)
+         {
+            Ok(_) =>
+            {
+            }
+
+            Err(error) =>
+            {
+               warn!("{}", error);
+            }
+         }
+      }
+
+      debug!("Stopping compute threads.");
       for thread_data in self.compute_threads.iter_mut()
       {
          // Stop the thread.

src/task.rs

@@ -3,50 +3,22 @@ use std::cmp::Ordering;
 use ::task_state::TaskState;
 
 
-///
-pub struct Task
-{
-   ///
-   pub name: String,
 
-   ///
-   pub state: TaskState
+pub trait Task: Send + Sync
+{
+   fn get_name(&self) -> &str;
+   fn get_state(&self) -> TaskState;
+
+   fn process(&mut self);
 }
 
 
 
-impl Task
-{
-   ///
-   pub fn new(task_name: &str) -> Task
-   {
-      Task
-      {
-         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)
+      self.get_name().to_string().eq(&other.get_name().to_string())
    }
 }
 
@@ -66,6 +38,6 @@ impl Ord for Task
 {
    fn cmp(&self, other: &Self) -> Ordering
    {
-      self.name.cmp(&other.name)
+      self.get_name().to_string().cmp(&other.get_name().to_string())
    }
 }

src/task_container.rs

@@ -0,0 +1,53 @@
+use ::task::Task;
+use ::taskable::Taskable;
+use ::task_state::TaskState;
+
+
+
+///
+pub struct TaskContainer<T>
+{
+   ///
+   pub state: TaskState,
+
+   ///
+   pub task: T
+}
+
+
+
+impl<T> TaskContainer<T> where T: Taskable
+{
+   ///
+   pub fn new(task: T) -> TaskContainer<T>
+   {
+      TaskContainer
+      {
+         state: TaskState::Starting,
+         task: task
+      }
+   }
+}
+
+impl<T> Task for TaskContainer<T> where T: Taskable
+{
+   ///
+   fn get_name(&self) -> &str
+   {
+      self.task.get_name()
+   }
+
+   ///
+   fn get_state(&self) -> TaskState
+   {
+      self.state
+   }
+
+   ///
+   fn process(&mut self)
+   {
+      self.state = TaskState::Processing;
+      println!("Processing task.");
+      self.state = TaskState::Finished;
+   }
+}

src/task_state.rs

@@ -1,4 +1,5 @@
 /// The different states a Task can go through during its lifetime.
+#[derive(Clone, Copy)]
 pub enum TaskState
 {
    /// The state that every Task starts in.

src/taskable.rs

@@ -0,0 +1,9 @@
+///
+pub trait Taskable: Send + Sync
+{
+   ///
+   fn get_name(&self) -> &str;
+
+   ///
+   fn process(&mut self);
+}

src/thread.rs

@@ -1,270 +1,6 @@
-use std::collections::binary_heap::BinaryHeap;
-use std::ops::DerefMut;
-use std::sync::{Arc, Mutex};
-use std::sync::mpsc::{Receiver, Sender, TryRecvError};
-use std::time::Duration;
-
-use ::task::Task;
-use ::task_state::TaskState;
-use ::thread_state::ThreadState;
-
-
-
 ///
-pub struct Thread
+pub trait Thread: Send
 {
    ///
-   state: ThreadState,
-
-   ///
-   current_task: Option<Task>,
-
-   ///
-   task_queue: Arc<Mutex<BinaryHeap<Task>>>,
-
-   ///
-   shutdown_receiver: Receiver<bool>,
-
-   ///
-   state_sender: Sender<ThreadState>,
-
-   ///
-   continue_running: bool,
-}
-
-
-
-impl Thread
-{
-   /// 
-   pub fn new(queue: Arc<Mutex<BinaryHeap<Task>>>,
-              shutdown_r: Receiver<bool>,
-              state_s: Sender<ThreadState>)
-      -> Thread
-   {
-      Thread
-      {
-         state: ThreadState::Starting,
-         current_task: None,
-         task_queue: queue,
-         shutdown_receiver: shutdown_r,
-         state_sender: state_s,
-         continue_running: true
-      }
-   }
-
-   ///
-   pub fn process(&mut self)
-   {
-      let mut check_messages: bool;
-      let mut task_completed: bool;
-
-      // Run this thread until the scheduler decides
-      // to shut it down.
-      self.change_state(ThreadState::Idle);
-      while self.continue_running == true
-      {
-         // 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 =>
-            {
-               // Try to get a task to work on.
-               self.retrieve_task();
-               match self.current_task
-               {
-                  Some(_) =>
-                  {
-                     // We have a task to work on, so switch to
-                     // a Processing state.
-                     self.change_state(ThreadState::Processing);
-                  }
-
-                  None =>
-                  {
-                     // If we don't have a task to process,
-                     // then we may need to switch over to
-                     // an idle state.
-                     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);
-                        }
-                     }
-                  }
-               }
-            }
-         }
-
-         // Check to see if the task this thread
-         // was processing was completed.
-         if task_completed == true
-         {
-            println!("Task completed.");
-            self.current_task = None;
-            self.change_state(ThreadState::Idle);
-         }
-
-         // 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.
-         self.process_shutdown_messages();
-      }
-
-      // This thread is finished.
-      println!("Shutting down thread.");
-      self.change_state(ThreadState::Finished);
-   }
-
-   ///
-   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);
-         }
-      }
-   }
-
-   ///
-   fn retrieve_task(&mut self)
-   {
-      // There is nothing to do if this thread already
-      // has a task to work on.
-      if self.current_task.is_some() == true
-      {
-         return;
-      }
-
-      // 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);
-         }
-      }
-   }
-
-   /// 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);
-         }
-      }
-   }
-
-   /// Check for any new thread shutdown messages.
-   fn process_shutdown_messages(&mut self)
-   {
-      let mut check_messages: bool;
-
-      // Loop through all the messages in the
-      // receivers queue.
-      check_messages = true;
-      while check_messages == true
-      {
-         match self.shutdown_receiver.try_recv()
-         {
-            Ok(val) =>
-            {
-               // Found a message.
-               self.continue_running = !val;
-            }
-
-            Err(error) =>
-            {
-               // Determine the kind of error we received.
-               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.
-                     // TODO: Handle this poisoning correctly.
-                     warn!("{}", error);
-                  }
-               }
-            }
-         }
-      }
-   }
+   fn process(&mut self);
 }