Code Review changes

Author: sooraj-srini

bench/bench_atomic_skiplist.ml

@@ -1,90 +1,59 @@
 open Lockfree
-let num_elems = 200_000
-let num_threads = 2
 
-(* A write heavy workload with threads with 50% adds and 50% removes. *)
-let write_heavy_workload () = 
-  let sl = Atomicskiplist.create () in
-  (* let elems = Array.init num_elems (fun _ -> Random.int 10000) in  *)
-  let push = (fun () -> Domain.spawn ( fun () ->
-    let start_time = Unix.gettimeofday () in 
-    for i = 0 to (num_elems - 1) do ( 
-      if (i/2) < num_elems/2 then 
-        Atomicskiplist.add sl (i) |> ignore
-    else
-        Atomicskiplist.remove sl (i - (num_elems/2)) |> ignore)
-    done;
-    start_time
-  )) in 
-  let threads = List.init num_threads (fun _ -> push ()) in 
-  let start_time_threads = List.map (fun domain -> Domain.join domain) threads in 
-  let end_time = Unix.gettimeofday () in 
-  let time_diff = end_time -. (List.nth start_time_threads 0) in 
+let max_height = 10
+
+let workload num_elems num_threads add remove =
+  let sl = Atomicskiplist.create max_height in
+  let elems = Array.init num_elems (fun _ -> Random.int 10000) in
+  let push () =
+    Domain.spawn (fun () ->
+        let start_time = Unix.gettimeofday () in
+        for i = 0 to (num_elems - 1) / num_threads do
+          Domain.cpu_relax ();
+          let prob = Random.float 1.0 in
+          if prob < add then Atomicskiplist.add sl (Random.int 10000) |> ignore
+          else if prob >= add && prob < add +. remove then
+            Atomicskiplist.remove sl (Random.int 10000) |> ignore
+          else Atomicskiplist.mem sl elems.(i) |> ignore
+        done;
+        start_time)
+  in
+  let threads = List.init num_threads (fun _ -> push ()) in
+  let start_time_threads =
+    List.map (fun domain -> Domain.join domain) threads
+  in
+  let end_time = Unix.gettimeofday () in
+  let time_diff = end_time -. List.nth start_time_threads 0 in
   time_diff
 
+(* A write heavy workload with threads with 50% adds and 50% removes. *)
+let write_heavy_workload num_elems num_threads =
+  workload num_elems num_threads 0.5 0.5
+
 (* A regular workload with 90% reads, 9% adds and 1% removes. *)
-let read_heavy_workload () = 
-  let sl = Atomicskiplist.create () in
-  let elems = Array.init num_elems (fun _ -> Random.int 10000) in 
-  let push = (fun () -> Domain.spawn ( fun () ->
-    let start_time = Unix.gettimeofday () in 
-    for i = 0 to (num_elems - 1) do ( 
-      if i mod 1000 < 90 then 
-        Atomicskiplist.add sl elems.(i) |> ignore
-      else if i mod 1000 >= 90 && i mod 1000 < 100 then 
-        Atomicskiplist.remove sl elems.(i) |> ignore
-      else 
-        Atomicskiplist.find sl elems.(i) |> ignore
-    )
-    done;
-    start_time
-  )) in 
-  let threads = List.init num_threads (fun _ -> push ()) in 
-  let start_time_threads = List.map (fun domain -> Domain.join domain) threads in 
-  let end_time = Unix.gettimeofday () in 
-  let time_diff = end_time -. (List.nth start_time_threads 0) in 
-  time_diff
-  
-  
-  let moderate_heavy_workload () = 
-    let sl = Atomicskiplist.create () in
-    let elems = Array.init num_elems (fun _ -> Random.int 10000) in 
-    let push = (fun () -> Domain.spawn ( fun () ->
-      let start_time = Unix.gettimeofday () in 
-      for i = 0 to (num_elems - 1) do ( 
-        if i mod 1000 < 200 then 
-          Atomicskiplist.add sl elems.(i) |> ignore
-        else if i mod 1000 >= 200 && i mod 1000 < 300 then 
-          Atomicskiplist.remove sl elems.(i) |> ignore
-        else 
-          Atomicskiplist.find sl elems.(i) |> ignore
-      )
-      done;
-      start_time
-    )) in 
-    let threads = List.init num_threads (fun _ -> push ()) in 
-    let start_time_threads = List.map (fun domain -> Domain.join domain) threads in 
-    let end_time = Unix.gettimeofday () in 
-    let time_diff = end_time -. (List.nth start_time_threads 0) in 
-    time_diff
-    
+let read_heavy_workload num_elems num_threads =
+  workload num_elems num_threads 0.09 0.01
+
+let moderate_heavy_workload num_elems num_threads =
+  workload num_elems num_threads 0.2 0.1
 
+let balanced_heavy_workload num_elems num_threads =
+  workload num_elems num_threads 0.3 0.2
 
-let bench ~workload_type () =
+let bench ~workload_type ~num_elems ~num_threads () =
   let workload =
-    if workload_type = "read_heavy" then 
-      read_heavy_workload
-    else if workload_type == "moderate_heavy" then 
-      moderate_heavy_workload
-    else 
-      write_heavy_workload
-    in
+    if workload_type = "read_heavy" then read_heavy_workload
+    else if workload_type = "moderate_heavy" then moderate_heavy_workload
+    else if workload_type = "balanced_heavy" then balanced_heavy_workload
+    else write_heavy_workload
+  in
   let results = ref [] in
   for i = 1 to 10 do
-    let time = workload () in
+    let time = workload num_elems num_threads in
     if i > 1 then results := time :: !results
   done;
   let results = List.sort Float.compare !results in
   let median_time = List.nth results 4 in
   let median_throughput = Float.of_int num_elems /. median_time in
-  Benchmark_result.create_generic ~median_time ~median_throughput ("atomic_skiplist_"^workload_type)
+  Benchmark_result.create_generic ~median_time ~median_throughput
+    ("atomic_skiplist_" ^ workload_type)

bench/main.ml

@@ -16,8 +16,10 @@ let benchmark_list =
     Mpmc_queue.bench ~use_cas:true ~takers:4 ~pushers:4;
     Mpmc_queue.bench ~use_cas:true ~takers:1 ~pushers:8;
     Mpmc_queue.bench ~use_cas:true ~takers:8 ~pushers:1;
-    Bench_atomic_skiplist.bench ~workload_type:"read_heavy";
-    Bench_atomic_skiplist.bench ~workload_type:"moderate_heavy";
+    Bench_atomic_skiplist.bench ~workload_type:"read_heavy" ~num_elems:2000000
+      ~num_threads:2;
+    Bench_atomic_skiplist.bench ~workload_type:"moderate_heavy"
+      ~num_elems:2000000 ~num_threads:2;
   ]
   @ backoff_benchmarks