dd7ca772d8
This PR extends `Std.Channel` to provide a full sync and async API, as well as unbounded, zero sized and bounded channels. A few notes on the implementation: - the bounded channel is inspired by [Go channels on steroids](https://docs.google.com/document/d/1yIAYmbvL3JxOKOjuCyon7JhW4cSv1wy5hC0ApeGMV9s/pub) though currently doesn't do any of the lock-free optimizations - @mhuisi convinced me that having a non-closable channel may be a good idea as this alleviates the need for error handling which is very annoying when working with `Task`. This does complicate the API a little bit and I'm not quite sure whether this is a choice we want users to give. An alternative to this would be to just write `send!` that panics on sending to a closed channel (receiving from a closed channel is not an error), this is for example the behavior that golang goes with.
117 lines
3.4 KiB
Text
117 lines
3.4 KiB
Text
import Std.Sync.Channel
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/-
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Inspired by:
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https://github.com/crossbeam-rs/crossbeam/tree/bd87a61ce3858ca772c42525d5f0c9aa12cc80ac/crossbeam-channel/benchmarks.
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We conduct for:
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- capacity 0 channels
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- capacity 1 channels
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- capacity `N` channels
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- unbounded channels
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the following tests:
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- `seq`: A single thread sends `N` messages. Then it receives `N` messages.
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- `spsc`: One thread sends `N` messages. Another thread receives `N` messages.
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- `mpsc`: `T` threads send `N / T` messages each. One thread receives `N` messages.
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- `mpmc`: `T` threads send `N / T` messages each. `T` other threads receive `N / T` messages each.
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Note that we will stick exclusively to the sync interface for this as there is no benefit to be
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reaped from async in this benchmark so we might as well just block.
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-/
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def MESSAGES : Nat := 1_000_000
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def THREADS : Nat := 4
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def seq (ch : Std.CloseableChannel.Sync Nat) (amount : Nat) : IO Unit := do
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for i in [:amount] do
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ch.send i
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for _ in [:amount] do
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discard <| ch.recv
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def spsc (ch : Std.CloseableChannel.Sync Nat) (amount : Nat) : IO Unit := do
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let t1 ← IO.asTask (prio := .dedicated) do
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for i in [:amount] do
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ch.send i
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let t2 ← BaseIO.asTask (prio := .dedicated) do
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for _ in [:amount] do
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discard <| ch.recv
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IO.ofExcept (← IO.wait t1)
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IO.wait t2
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def mpsc (ch : Std.CloseableChannel.Sync Nat) (amount : Nat) : IO Unit := do
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let mut producers := Array.emptyWithCapacity THREADS
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for _ in [:THREADS] do
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let t ← IO.asTask (prio := .dedicated) do
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for i in [:(amount/THREADS)] do
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ch.send i
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producers := producers.push t
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let consumer ← BaseIO.asTask (prio := .dedicated) do
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for _ in [:amount] do
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discard <| ch.recv
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IO.wait consumer
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for producer in producers do
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(IO.ofExcept (← IO.wait producer))
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def mpmc (ch : Std.CloseableChannel.Sync Nat) (amount : Nat) : IO Unit := do
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let mut producers := Array.emptyWithCapacity THREADS
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for _ in [:THREADS] do
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let t ← IO.asTask (prio := .dedicated) do
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for i in [:(amount/THREADS)] do
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ch.send i
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producers := producers.push t
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let mut consumers := Array.emptyWithCapacity THREADS
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for _ in [:THREADS] do
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let t ← IO.asTask (prio := .dedicated) do
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while true do
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if let some _ ← ch.recv then
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continue
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else
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break
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consumers := consumers.push t
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for producer in producers do
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(IO.ofExcept (← IO.wait producer))
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ch.close
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for consumer in consumers do
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(IO.ofExcept (← IO.wait consumer))
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return ()
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def run (name : String) (cap : Option Nat) (bench : Std.CloseableChannel.Sync Nat → Nat → IO Unit) :
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IO Unit := do
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let ch ← Std.CloseableChannel.new cap
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let t1 ← IO.monoMsNow
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bench ch.sync MESSAGES
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let t2 ← IO.monoMsNow
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let time : Float := (t2 - t1).toFloat / 1000.0
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IO.println s!"{name}: {time}"
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def main : IO Unit := do
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run "bounded0_spsc" (some 0) spsc
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run "bounded0_mpsc" (some 0) mpsc
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run "bounded0_mpmc" (some 0) mpmc
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run "bounded1_spsc" (some 1) spsc
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run "bounded1_mpsc" (some 1) mpsc
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run "bounded1_mpmc" (some 1) mpmc
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run "boundedn_spsc" (some MESSAGES) spsc
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run "boundedn_mpsc" (some MESSAGES) mpsc
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run "boundedn_mpmc" (some MESSAGES) mpmc
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run "boundedn_seq" (some MESSAGES) seq
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run "unbounded_spsc" none spsc
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run "unbounded_mpsc" none mpsc
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run "unbounded_mpmc" none mpmc
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run "unbounded_seq" none seq
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