benchmark for a concurrent, channel-based, Erathostene prime sieve

benchs/dune

@@ -1,5 +1,5 @@
 (executables
- (names fib_rec pi)
+ (names fib_rec pi primes)
  (preprocess
   (action
    (run %{project_root}/src/cpp/cpp.exe %{input-file})))

benchs/primes.ml

@@ -0,0 +1,32 @@
+let ( let@ ) = ( @@ )
+
+let generate' chan =
+  for i = 2 to Int.max_int do
+    Moonpool.Chan.push chan i;
+    Thread.yield ()
+  done
+
+let filter' in_chan out_chan prime =
+  let rec loop () =
+    let n = Moonpool.Chan.pop_await in_chan in
+    if n mod prime <> 0 then Moonpool.Chan.push out_chan n;
+    loop ()
+  in
+  loop ()
+
+let () =
+  let@ runner = Moonpool.Ws_pool.with_ () in
+  let@ () = Moonpool.Ws_pool.run_wait_block runner in
+  let primes = ref @@ Moonpool.Chan.create () in
+  Moonpool.run_async runner
+    (let chan = !primes in
+     fun () -> generate' chan);
+  for _i = 1 to 10 do
+    let prime = Moonpool.Chan.pop_await !primes in
+    Format.printf "%d\n@?" prime;
+    let filtered_chan = Moonpool.Chan.create () in
+    Moonpool.run_async runner
+      (let in_chan = !primes in
+       fun () -> filter' in_chan filtered_chan prime);
+    primes := filtered_chan
+  done