servo: Merge #2500 - Workqueue cleanups (from brendanzab:workqueue); r=pcwalton

cc. @pcwalton

Source-Repo: https://github.com/servo/servo
Source-Revision: 14ae870d75187225e2072f1062850a310c3ed8d2

servo/src/components/util/workqueue.rs

@@ -18,66 +18,65 @@ use std::task::TaskOpts;
 
 /// A unit of work.
 ///
-/// The type parameter `QUD` stands for "queue user data" and represents global custom data for the
-/// entire work queue, and the type parameter `WUD` stands for "work user data" and represents
-/// custom data specific to each unit of work.
-pub struct WorkUnit<QUD,WUD> {
+/// # Type parameters
+///
+/// - `QueueData`: global custom data for the entire work queue.
+/// - `WorkData`: custom data specific to each unit of work.
+pub struct WorkUnit<QueueData, WorkData> {
     /// The function to execute.
-    pub fun: extern "Rust" fn(WUD, &mut WorkerProxy<QUD,WUD>),
+    pub fun: extern "Rust" fn(WorkData, &mut WorkerProxy<QueueData, WorkData>),
     /// Arbitrary data.
-    pub data: WUD,
+    pub data: WorkData,
 }
 
 /// Messages from the supervisor to the worker.
-enum WorkerMsg<QUD,WUD> {
+enum WorkerMsg<QueueData, WorkData> {
     /// Tells the worker to start work.
-    StartMsg(Worker<WorkUnit<QUD,WUD>>, *mut AtomicUint, *QUD),
-
+    StartMsg(Worker<WorkUnit<QueueData, WorkData>>, *mut AtomicUint, *QueueData),
     /// Tells the worker to stop. It can be restarted again with a `StartMsg`.
     StopMsg,
-
     /// Tells the worker thread to terminate.
     ExitMsg,
 }
 
 /// Messages to the supervisor.
-enum SupervisorMsg<QUD,WUD> {
+enum SupervisorMsg<QueueData, WorkData> {
     FinishedMsg,
-    ReturnDequeMsg(uint, Worker<WorkUnit<QUD,WUD>>),
+    ReturnDequeMsg(uint, Worker<WorkUnit<QueueData, WorkData>>),
 }
 
 /// Information that the supervisor thread keeps about the worker threads.
-struct WorkerInfo<QUD,WUD> {
+struct WorkerInfo<QueueData, WorkData> {
     /// The communication channel to the workers.
-    chan: Sender<WorkerMsg<QUD,WUD>>,
+    chan: Sender<WorkerMsg<QueueData, WorkData>>,
     /// The buffer pool for this deque.
-    pool: BufferPool<WorkUnit<QUD,WUD>>,
+    pool: BufferPool<WorkUnit<QueueData, WorkData>>,
     /// The worker end of the deque, if we have it.
-    deque: Option<Worker<WorkUnit<QUD,WUD>>>,
+    deque: Option<Worker<WorkUnit<QueueData, WorkData>>>,
     /// The thief end of the work-stealing deque.
-    thief: Stealer<WorkUnit<QUD,WUD>>,
+    thief: Stealer<WorkUnit<QueueData, WorkData>>,
 }
 
 /// Information specific to each worker thread that the thread keeps.
-struct WorkerThread<QUD,WUD> {
+struct WorkerThread<QueueData, WorkData> {
     /// The index of this worker.
     index: uint,
     /// The communication port from the supervisor.
-    port: Receiver<WorkerMsg<QUD,WUD>>,
+    port: Receiver<WorkerMsg<QueueData, WorkData>>,
     /// The communication channel on which messages are sent to the supervisor.
-    chan: Sender<SupervisorMsg<QUD,WUD>>,
+    chan: Sender<SupervisorMsg<QueueData, WorkData>>,
     /// The thief end of the work-stealing deque for all other workers.
-    other_deques: Vec<Stealer<WorkUnit<QUD,WUD>>>,
+    other_deques: Vec<Stealer<WorkUnit<QueueData, WorkData>>>,
     /// The random number generator for this worker.
     rng: XorShiftRng,
 }
 
 static SPIN_COUNT: uint = 1000;
 
-impl<QUD:Send,WUD:Send> WorkerThread<QUD,WUD> {
+impl<QueueData: Send, WorkData: Send> WorkerThread<QueueData, WorkData> {
     /// The main logic. This function starts up the worker and listens for
     /// messages.
-    pub fn start(&mut self) {
+    fn start(&mut self) {
         loop {
             // Wait for a start message.
             let (mut deque, ref_count, queue_data) = match self.port.recv() {
@@ -160,16 +159,16 @@ impl<QUD:Send,WUD:Send> WorkerThread<QUD,WUD> {
 }
 
 /// A handle to the work queue that individual work units have.
-pub struct WorkerProxy<'a,QUD,WUD> {
-    pub worker: &'a mut Worker<WorkUnit<QUD,WUD>>,
-    pub ref_count: *mut AtomicUint,
-    pub queue_data: *QUD,
+pub struct WorkerProxy<'a, QueueData, WorkData> {
+    worker: &'a mut Worker<WorkUnit<QueueData, WorkData>>,
+    ref_count: *mut AtomicUint,
+    queue_data: *QueueData,
 }
 
-impl<'a,QUD,WUD:Send> WorkerProxy<'a,QUD,WUD> {
+impl<'a, QueueData, WorkData: Send> WorkerProxy<'a, QueueData, WorkData> {
     /// Enqueues a block into the work queue.
     #[inline]
-    pub fn push(&mut self, work_unit: WorkUnit<QUD,WUD>) {
+    pub fn push(&mut self, work_unit: WorkUnit<QueueData, WorkData>) {
         unsafe {
             drop((*self.ref_count).fetch_add(1, SeqCst));
         }
@@ -178,7 +177,7 @@ impl<'a,QUD,WUD:Send> WorkerProxy<'a,QUD,WUD> {
 
     /// Retrieves the queue user data.
     #[inline]
-    pub fn user_data<'a>(&'a self) -> &'a QUD {
+    pub fn user_data<'a>(&'a self) -> &'a QueueData {
         unsafe {
             cast::transmute(self.queue_data)
         }
@@ -186,21 +185,21 @@ impl<'a,QUD,WUD:Send> WorkerProxy<'a,QUD,WUD> {
 }
 
 /// A work queue on which units of work can be submitted.
-pub struct WorkQueue<QUD,WUD> {
+pub struct WorkQueue<QueueData, WorkData> {
     /// Information about each of the workers.
-    workers: Vec<WorkerInfo<QUD,WUD>>,
+    workers: Vec<WorkerInfo<QueueData, WorkData>>,
     /// A port on which deques can be received from the workers.
-    port: Receiver<SupervisorMsg<QUD,WUD>>,
+    port: Receiver<SupervisorMsg<QueueData, WorkData>>,
     /// The amount of work that has been enqueued.
-    pub work_count: uint,
+    work_count: uint,
     /// Arbitrary user data.
-    pub data: QUD,
+    pub data: QueueData,
 }
 
-impl<QUD:Send,WUD:Send> WorkQueue<QUD,WUD> {
+impl<QueueData: Send, WorkData: Send> WorkQueue<QueueData, WorkData> {
     /// Creates a new work queue and spawns all the threads associated with
     /// it.
-    pub fn new(task_name: &'static str, thread_count: uint, user_data: QUD) -> WorkQueue<QUD,WUD> {
+    pub fn new(task_name: &'static str, thread_count: uint, user_data: QueueData) -> WorkQueue<QueueData, WorkData> {
         // Set up data structures.
         let (supervisor_chan, supervisor_port) = channel();
         let (mut infos, mut threads) = (vec!(), vec!());
@@ -253,7 +252,7 @@ impl<QUD:Send,WUD:Send> WorkQueue<QUD,WUD> {
 
     /// Enqueues a block into the work queue.
     #[inline]
-    pub fn push(&mut self, work_unit: WorkUnit<QUD,WUD>) {
+    pub fn push(&mut self, work_unit: WorkUnit<QueueData, WorkData>) {
         match self.workers.get_mut(0).deque {
             None => {
                 fail!("tried to push a block but we don't have the deque?!")