From 3e0eb5e49e673ba3d00a890ae51d36d67cbb389d Mon Sep 17 00:00:00 2001
From: Frank McSherry <fmcsherry@me.com>
Date: Sun, 19 May 2019 11:06:34 -0400
Subject: [PATCH 1/2] simplify park

---
 timely/src/logging.rs | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/timely/src/logging.rs b/timely/src/logging.rs
index adb8ed620..00e648b85 100644
--- a/timely/src/logging.rs
+++ b/timely/src/logging.rs
@@ -198,29 +198,22 @@ pub struct InputEvent {
     pub start_stop: StartStop,
 }
 
-#[derive(Serialize, Deserialize, Abomonation, Debug, Clone, Hash, Eq, PartialEq, Ord, PartialOrd)]
-/// Input logic start/stop
-pub struct ParkEvent {
-    /// True when activity begins, false when it stops
-    pub event: ParkUnpark
-}
-
-impl ParkEvent {
-    /// Creates a new park event from the supplied duration.
-    pub fn park(duration: Option<Duration>) -> Self { ParkEvent { event: ParkUnpark::Park(duration) } }
-    /// Creates a new unpark event.
-    pub fn unpark() -> Self { ParkEvent { event: ParkUnpark::Unpark } }
-}
-
 /// Records the starting and stopping of an operator.
 #[derive(Serialize, Deserialize, Abomonation, Debug, Clone, Hash, PartialEq, Eq, Ord, PartialOrd)]
-pub enum ParkUnpark {
+pub enum ParkEvent {
     /// Worker parks.
     Park(Option<Duration>),
     /// Worker unparks.
     Unpark,
 }
 
+impl ParkEvent {
+    /// Creates a new park event from the supplied duration.
+    pub fn park(duration: Option<Duration>) -> Self { ParkEvent::Park(duration) }
+    /// Creates a new unpark event.
+    pub fn unpark() -> Self { ParkEvent::Unpark }
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, Abomonation, Hash, Eq, PartialEq, Ord, PartialOrd)]
 /// An event in a timely worker
 pub enum TimelyEvent {

From 37474012e1906b901ae333a3d78537448138acf8 Mon Sep 17 00:00:00 2001
From: Frank McSherry <fmcsherry@me.com>
Date: Sun, 26 May 2019 19:33:19 -0400
Subject: [PATCH 2/2] Mutable Exchange

---
 timely/src/dataflow/channels/pact.rs             | 8 ++++----
 timely/src/dataflow/channels/pushers/exchange.rs | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/timely/src/dataflow/channels/pact.rs b/timely/src/dataflow/channels/pact.rs
index 0f0146d90..6a99d31d3 100644
--- a/timely/src/dataflow/channels/pact.rs
+++ b/timely/src/dataflow/channels/pact.rs
@@ -43,8 +43,8 @@ impl<T: 'static, D: 'static> ParallelizationContract<T, D> for Pipeline {
 }
 
 /// An exchange between multiple observers by data
-pub struct Exchange<D, F: Fn(&D)->u64+'static> { hash_func: F, phantom: PhantomData<D>, }
-impl<D, F: Fn(&D)->u64> Exchange<D, F> {
+pub struct Exchange<D, F: FnMut(&D)->u64+'static> { hash_func: F, phantom: PhantomData<D>, }
+impl<D, F: FnMut(&D)->u64> Exchange<D, F> {
     /// Allocates a new `Exchange` pact from a distribution function.
     pub fn new(func: F) -> Exchange<D, F> {
         Exchange {
@@ -55,12 +55,12 @@ impl<D, F: Fn(&D)->u64> Exchange<D, F> {
 }
 
 // Exchange uses a `Box<Pushable>` because it cannot know what type of pushable will return from the allocator.
-impl<T: Eq+Data+Clone, D: Data+Clone, F: Fn(&D)->u64+'static> ParallelizationContract<T, D> for Exchange<D, F> {
+impl<T: Eq+Data+Clone, D: Data+Clone, F: FnMut(&D)->u64+'static> ParallelizationContract<T, D> for Exchange<D, F> {
     // TODO: The closure in the type prevents us from naming it.
     //       Could specialize `ExchangePusher` to a time-free version.
     type Pusher = Box<Push<Bundle<T, D>>>;
     type Puller = Box<Pull<Bundle<T, D>>>;
-    fn connect<A: AsWorker>(self, allocator: &mut A, identifier: usize, address: &[usize], logging: Option<Logger>) -> (Self::Pusher, Self::Puller) {
+    fn connect<A: AsWorker>(mut self, allocator: &mut A, identifier: usize, address: &[usize], logging: Option<Logger>) -> (Self::Pusher, Self::Puller) {
         let (senders, receiver) = allocator.allocate::<Message<T, D>>(identifier, address);
         let senders = senders.into_iter().enumerate().map(|(i,x)| LogPusher::new(x, allocator.index(), i, identifier, logging.clone())).collect::<Vec<_>>();
         (Box::new(ExchangePusher::new(senders, move |_, d| (self.hash_func)(d))), Box::new(LogPuller::new(receiver, allocator.index(), identifier, logging.clone())))
diff --git a/timely/src/dataflow/channels/pushers/exchange.rs b/timely/src/dataflow/channels/pushers/exchange.rs
index d0477858d..5b37a8438 100644
--- a/timely/src/dataflow/channels/pushers/exchange.rs
+++ b/timely/src/dataflow/channels/pushers/exchange.rs
@@ -6,14 +6,14 @@ use crate::dataflow::channels::{Bundle, Message};
 
 // TODO : Software write combining
 /// Distributes records among target pushees according to a distribution function.
-pub struct Exchange<T, D, P: Push<Bundle<T, D>>, H: Fn(&T, &D) -> u64> {
+pub struct Exchange<T, D, P: Push<Bundle<T, D>>, H: FnMut(&T, &D) -> u64> {
     pushers: Vec<P>,
     buffers: Vec<Vec<D>>,
     current: Option<T>,
     hash_func: H,
 }
 
-impl<T: Clone, D, P: Push<Bundle<T, D>>, H: Fn(&T, &D)->u64>  Exchange<T, D, P, H> {
+impl<T: Clone, D, P: Push<Bundle<T, D>>, H: FnMut(&T, &D)->u64>  Exchange<T, D, P, H> {
     /// Allocates a new `Exchange` from a supplied set of pushers and a distribution function.
     pub fn new(pushers: Vec<P>, key: H) -> Exchange<T, D, P, H> {
         let mut buffers = vec![];
@@ -37,7 +37,7 @@ impl<T: Clone, D, P: Push<Bundle<T, D>>, H: Fn(&T, &D)->u64>  Exchange<T, D, P,
     }
 }
 
-impl<T: Eq+Data, D: Data, P: Push<Bundle<T, D>>, H: Fn(&T, &D)->u64> Push<Bundle<T, D>> for Exchange<T, D, P, H> {
+impl<T: Eq+Data, D: Data, P: Push<Bundle<T, D>>, H: FnMut(&T, &D)->u64> Push<Bundle<T, D>> for Exchange<T, D, P, H> {
     #[inline(never)]
     fn push(&mut self, message: &mut Option<Bundle<T, D>>) {
         // if only one pusher, no exchange