Further step_or_park implementations [WIP]

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 All notable changes to this project will be documented in this file.
 
+## Unreleased
+
+### Added
+
+A `Worker` now has a `step_or_park(Option<Duration>)` method, which instructs the worker to take a step and gives it permission to part the worker thread for at most the supplied timeout if there is no work to perform. A value of `None` implies no timeout (unboundedly parked) whereas a value of `Some(0)` should return immediately. The communication layers are implemented to awaken workers if they receive new communications, and workers should hand out copies of their `Thread` if they want other threads to wake them for other reasons (e.g. queues from threads external to timely).
+
 ## 0.9.0
 
 ### Added

communication/src/allocator/counters.rs

@@ -91,10 +91,11 @@ impl<T, P: Push<T>> Push<T> for ArcPusher<T, P> {
         // else {
         //     self.count += 1;
         // }
+        let _ =
         self.events
-            .send((self.index, Event::Pushed(1)))
+            .send((self.index, Event::Pushed(1)));
             // TODO : Perhaps this shouldn't be a fatal error (e.g. in shutdown).
-            .expect("Failed to send message count");
+            // .expect("Failed to send message count");
 
         self.pusher.push(element)
     }

communication/src/allocator/generic.rs

@@ -94,6 +94,14 @@ impl Allocate for Generic {
     fn receive(&mut self) { self.receive(); }
     fn release(&mut self) { self.release(); }
     fn events(&self) -> &Rc<RefCell<VecDeque<(usize, Event)>>> { self.events() }
+    fn await_events(&self, _duration: Option<std::time::Duration>) {
+        match self {
+            &Generic::Thread(ref t) => t.await_events(_duration),
+            &Generic::Process(ref p) => p.await_events(_duration),
+            &Generic::ProcessBinary(ref pb) => pb.await_events(_duration),
+            &Generic::ZeroCopy(ref z) => z.await_events(_duration),
+        }
+    }
 }
 
 

communication/src/allocator/process.rs

@@ -5,11 +5,13 @@ use std::cell::RefCell;
 use std::sync::{Arc, Mutex};
 use std::any::Any;
 use std::sync::mpsc::{Sender, Receiver, channel};
+use std::time::Duration;
 use std::collections::{HashMap, VecDeque};
 
 use crate::allocator::thread::{ThreadBuilder};
 use crate::allocator::{Allocate, AllocateBuilder, Event, Thread};
 use crate::{Push, Pull, Message};
+use crate::buzzer::Buzzer;
 
 /// An allocator for inter-thread, intra-process communication
 pub struct ProcessBuilder {
@@ -19,18 +21,34 @@ pub struct ProcessBuilder {
     // below: `Box<Any+Send>` is a `Box<Vec<Option<(Vec<Sender<T>>, Receiver<T>)>>>`
     channels: Arc<Mutex<HashMap<usize, Box<Any+Send>>>>,
 
+    // Buzzers for waking other local workers.
+    buzzers_send: Vec<Sender<Buzzer>>,
+    buzzers_recv: Vec<Receiver<Buzzer>>,
+
     counters_send: Vec<Sender<(usize, Event)>>,
     counters_recv: Receiver<(usize, Event)>,
 }
 
 impl AllocateBuilder for ProcessBuilder {
     type Allocator = Process;
     fn build(self) -> Self::Allocator {
+
+        // Initialize buzzers; send first, then recv.
+        for worker in self.buzzers_send.iter() {
+            let buzzer = Buzzer::new();
+            worker.send(buzzer).expect("Failed to send buzzer");
+        }
+        let mut buzzers = Vec::new();
+        for worker in self.buzzers_recv.iter() {
+            buzzers.push(worker.recv().expect("Failed to recv buzzer"));
+        }
+
         Process {
             inner: self.inner.build(),
             index: self.index,
             peers: self.peers,
             channels: self.channels,
+            buzzers,
             counters_send: self.counters_send,
             counters_recv: self.counters_recv,
         }
@@ -44,6 +62,7 @@ pub struct Process {
     peers: usize,
     // below: `Box<Any+Send>` is a `Box<Vec<Option<(Vec<Sender<T>>, Receiver<T>)>>>`
     channels: Arc<Mutex<HashMap</* channel id */ usize, Box<Any+Send>>>>,
+    buzzers: Vec<Buzzer>,
     counters_send: Vec<Sender<(usize, Event)>>,
     counters_recv: Receiver<(usize, Event)>,
 }
@@ -64,14 +83,21 @@ impl Process {
 
         let channels = Arc::new(Mutex::new(HashMap::new()));
 
+        // Allocate matrix of buzzer send and recv endpoints.
+        let (buzzers_send, buzzers_recv) = crate::promise_futures(peers, peers);
+
         counters_recv
             .into_iter()
+            .zip(buzzers_send.into_iter())
+            .zip(buzzers_recv.into_iter())
             .enumerate()
-            .map(|(index, recv)| {
+            .map(|(index, ((recv, bsend), brecv))| {
                 ProcessBuilder {
                     inner: ThreadBuilder,
                     index,
                     peers,
+                    buzzers_send: bsend,
+                    buzzers_recv: brecv,
                     channels: channels.clone(),
                     counters_send: counters_send.clone(),
                     counters_recv: recv,
@@ -99,10 +125,10 @@ impl Allocate for Process {
 
                 let mut pushers = Vec::new();
                 let mut pullers = Vec::new();
-                for _ in 0..self.peers {
+                for index in 0 .. self.peers {
 
                     let (s, r): (Sender<Message<T>>, Receiver<Message<T>>) = channel();
-                    pushers.push(Pusher { target: s });
+                    pushers.push(Pusher { target: s, buzzer: self.buzzers[index].clone() });
                     pullers.push(Puller { source: r, current: None });
                 }
 
@@ -152,6 +178,10 @@ impl Allocate for Process {
         self.inner.events()
     }
 
+    fn await_events(&self, duration: Option<Duration>) {
+        self.inner.await_events(duration);
+    }
+
     fn receive(&mut self) {
         let mut events = self.inner.events().borrow_mut();
         while let Ok((index, event)) = self.counters_recv.try_recv() {
@@ -163,18 +193,23 @@ impl Allocate for Process {
 /// The push half of an intra-process channel.
 struct Pusher<T> {
     target: Sender<T>,
+    buzzer: Buzzer,
 }
 
 impl<T> Clone for Pusher<T> {
     fn clone(&self) -> Self {
-        Pusher { target: self.target.clone() }
+        Self {
+            target: self.target.clone(),
+            buzzer: self.buzzer.clone()
+        }
     }
 }
 
 impl<T> Push<T> for Pusher<T> {
     #[inline] fn push(&mut self, element: &mut Option<T>) {
         if let Some(element) = element.take() {
             self.target.send(element).unwrap();
+            self.buzzer.buzz();
         }
     }
 }

communication/src/allocator/zero_copy/allocator.rs

@@ -2,19 +2,18 @@
 use std::rc::Rc;
 use std::cell::RefCell;
 use std::collections::{VecDeque, HashMap};
-// use std::sync::mpsc::{channel, Sender, Receiver};
+use std::sync::mpsc::{Sender, Receiver};
 
 use bytes::arc::Bytes;
 
 use crate::networking::MessageHeader;
 
 use crate::{Allocate, Message, Data, Push, Pull};
 use crate::allocator::AllocateBuilder;
-use crate::allocator::{Event, Process};
-use crate::allocator::process::ProcessBuilder;
+use crate::allocator::Event;
 use crate::allocator::canary::Canary;
 
-use super::bytes_exchange::{BytesPull, SendEndpoint, MergeQueue, Signal};
+use super::bytes_exchange::{BytesPull, SendEndpoint, MergeQueue};
 use super::push_pull::{Pusher, PullerInner};
 
 /// Builds an instance of a TcpAllocator.
@@ -24,12 +23,11 @@ use super::push_pull::{Pusher, PullerInner};
 /// shared between threads here, and then provide a method that will instantiate the non-movable
 /// members once in the destination thread.
 pub struct TcpBuilder<A: AllocateBuilder> {
-    inner:      A,
-    index:      usize,              // number out of peers
-    peers:      usize,              // number of peer allocators.
-    sends:      Vec<MergeQueue>,    // for pushing bytes at remote processes.
-    recvs:      Vec<MergeQueue>,    // for pulling bytes from remote processes.
-    signal:     Signal,
+    inner:  A,
+    index:  usize,                      // number out of peers
+    peers:  usize,                      // number of peer allocators.
+    futures:   Vec<Receiver<MergeQueue>>,  // to receive queues to each network thread.
+    promises:   Vec<Sender<MergeQueue>>,    // to send queues from each network thread.
 }
 
 /// Creates a vector of builders, sharing appropriate state.
@@ -44,77 +42,72 @@ pub struct TcpBuilder<A: AllocateBuilder> {
 ///   info to spawn ingress comm thresds,
 /// )
 /// ```
-pub fn new_vector(
+pub fn new_vector<A: AllocateBuilder>(
+    allocators: Vec<A>,
     my_process: usize,
-    threads: usize,
     processes: usize)
--> (Vec<TcpBuilder<ProcessBuilder>>,
-    Vec<(Vec<MergeQueue>, Signal)>,
-    Vec<Vec<MergeQueue>>) {
+-> (Vec<TcpBuilder<A>>,
+    Vec<Vec<Sender<MergeQueue>>>,
+    Vec<Vec<Receiver<MergeQueue>>>)
+{
+    let threads = allocators.len();
 
-    // The results are a vector of builders, as well as the necessary shared state to build each
-    // of the send and receive communication threads, respectively.
-
-    // One signal per local destination worker thread
-    let worker_signals: Vec<Signal> = (0 .. threads).map(|_| Signal::new()).collect();
-
-    // One signal per destination egress communication thread
-    let network_signals: Vec<Signal> = (0 .. processes-1).map(|_| Signal::new()).collect();
-
-    let worker_to_network: Vec<Vec<_>> = (0 .. threads).map(|_| (0 .. processes-1).map(|p| MergeQueue::new(network_signals[p].clone())).collect()).collect();
-    let network_to_worker: Vec<Vec<_>> = (0 .. processes-1).map(|_| (0 .. threads).map(|t| MergeQueue::new(worker_signals[t].clone())).collect()).collect();
-
-    let worker_from_network: Vec<Vec<_>> = (0 .. threads).map(|t| (0 .. processes-1).map(|p| network_to_worker[p][t].clone()).collect()).collect();
-    let network_from_worker: Vec<Vec<_>> = (0 .. processes-1).map(|p| (0 .. threads).map(|t| worker_to_network[t][p].clone()).collect()).collect();
+    // For queues from worker threads to network threads, and vice versa.
+    let (network_promises, worker_futures) = crate::promise_futures(processes-1, threads);
+    let (worker_promises, network_futures) = crate::promise_futures(threads, processes-1);
 
     let builders =
-    Process::new_vector(threads) // Vec<Process> (Process is Allocate)
+    allocators
         .into_iter()
-        .zip(worker_signals)
-        .zip(worker_to_network)
-        .zip(worker_from_network)
+        .zip(worker_promises)
+        .zip(worker_futures)
         .enumerate()
-        .map(|(index, (((inner, signal), sends), recvs))| {
-            // sends are handles to MergeQueues to remote processes
-            // (one per remote process)
-            // recvs are handles to MergeQueues from remote processes
-            // (one per remote process)
+        .map(|(index, ((inner, promises), futures))| {
             TcpBuilder {
                 inner,
                 index: my_process * threads + index,
                 peers: threads * processes,
-                sends,
-                recvs,
-                signal,
+                promises,
+                futures,
             }})
         .collect();
 
-    // for each egress communicaton thread, construct the tuple (MergeQueues from local
-    // threads, corresponding signal)
-    let sends = network_from_worker.into_iter().zip(network_signals).collect();
-
-    (/* AllocateBuilder for local threads */  builders,
-     /* info to spawn egress comm threads */  sends,
-     /* info to spawn ingress comm thresds */ network_to_worker)
+    (builders, network_promises, network_futures)
 }
 
 impl<A: AllocateBuilder> TcpBuilder<A> {
 
     /// Builds a `TcpAllocator`, instantiating `Rc<RefCell<_>>` elements.
     pub fn build(self) -> TcpAllocator<A::Allocator> {
 
-        let sends: Vec<_> = self.sends.into_iter().map(
-            |send| Rc::new(RefCell::new(SendEndpoint::new(send)))).collect();
+        // Fulfill puller obligations.
+        let mut recvs = Vec::with_capacity(self.peers);
+        for promise in self.promises.into_iter() {
+            let buzzer = crate::buzzer::Buzzer::new();
+            let queue = MergeQueue::new(buzzer);
+            promise.send(queue.clone()).expect("Failed to send MergeQueue");
+            recvs.push(queue.clone());
+        }
+
+        // Extract pusher commitments.
+        let mut sends = Vec::with_capacity(self.peers);
+        for pusher in self.futures.into_iter() {
+            let queue = pusher.recv().expect("Failed to receive push queue");
+            let sendpoint = SendEndpoint::new(queue);
+            sends.push(Rc::new(RefCell::new(sendpoint)));
+        }
+
+        // let sends: Vec<_> = self.sends.into_iter().map(
+        //     |send| Rc::new(RefCell::new(SendEndpoint::new(send)))).collect();
 
         TcpAllocator {
             inner: self.inner.build(),
             index: self.index,
             peers: self.peers,
-            _signal: self.signal,
             canaries: Rc::new(RefCell::new(Vec::new())),
             staged: Vec::new(),
             sends,
-            recvs: self.recvs,
+            recvs,
             to_local: HashMap::new(),
         }
     }
@@ -128,8 +121,6 @@ pub struct TcpAllocator<A: Allocate> {
     index:      usize,                              // number out of peers
     peers:      usize,                              // number of peer allocators (for typed channel allocation).
 
-    _signal:     Signal,
-
     staged:     Vec<Bytes>,                         // staging area for incoming Bytes
     canaries:   Rc<RefCell<Vec<usize>>>,
 
@@ -260,4 +251,7 @@ impl<A: Allocate> Allocate for TcpAllocator<A> {
     fn events(&self) -> &Rc<RefCell<VecDeque<(usize, Event)>>> {
         self.inner.events()
     }
+    fn await_events(&self, duration: Option<std::time::Duration>) {
+        self.inner.await_events(duration);
+    }
 }