From e6069f3ef7e72038b63075c6244f696332e1d607 Mon Sep 17 00:00:00 2001
From: Fernando Gasperi Jabalera <fgasperi@fb.com>
Date: Tue, 14 Jan 2020 02:47:58 -0800
Subject: [PATCH] Create RestartScheduler

Summary:
These changes introduce the RestartScheduler which for now is a copy of the FileScheduler:

- added it as a possible argument to the recently added `--scheduler` option.
- made the necessary changes in `InferAnalyze` to call it if it was chosen.

Reviewed By: ngorogiannis

Differential Revision: D19373505

fbshipit-source-id: 98f065057
---
 infer/man/man1/infer-full.txt          |  2 +-
 infer/src/backend/FileScheduler.ml     |  1 +
 infer/src/backend/InferAnalyze.ml      |  6 ++++--
 infer/src/backend/RestartScheduler.ml  | 22 ++++++++++++++++++++++
 infer/src/backend/RestartScheduler.mli |  9 +++++++++
 infer/src/base/Config.ml               |  4 ++--
 infer/src/base/Config.mli              |  2 +-
 7 files changed, 40 insertions(+), 6 deletions(-)
 create mode 100644 infer/src/backend/RestartScheduler.ml
 create mode 100644 infer/src/backend/RestartScheduler.mli

diff --git a/infer/man/man1/infer-full.txt b/infer/man/man1/infer-full.txt
index ccec92908..7f2003fea 100644
--- a/infer/man/man1/infer-full.txt
+++ b/infer/man/man1/infer-full.txt
@@ -1690,7 +1690,7 @@ INTERNAL OPTIONS
            Reset the list of folders containing linters definitions to be
            empty (see linters-def-folder).
 
-       --scheduler { File | SyntacticCallGraph }
+       --scheduler { file | restart | callgraph }
            Specify the scheduler used for the analysis phase
 
        --scuba-logging
diff --git a/infer/src/backend/FileScheduler.ml b/infer/src/backend/FileScheduler.ml
index 845448cad..705902159 100644
--- a/infer/src/backend/FileScheduler.ml
+++ b/infer/src/backend/FileScheduler.ml
@@ -15,6 +15,7 @@ let make sources =
   in
   let next x =
     let res = gen.next x in
+    (* see defn of gen above to see why res should never match Some (Procname _) *)
     match res with None -> None | Some (Procname _) -> assert false | Some (File _) as v -> v
   in
   {gen with next}
diff --git a/infer/src/backend/InferAnalyze.ml b/infer/src/backend/InferAnalyze.ml
index ceecd9cd1..f493fc3ac 100644
--- a/infer/src/backend/InferAnalyze.ml
+++ b/infer/src/backend/InferAnalyze.ml
@@ -119,10 +119,12 @@ let schedule sources =
     SyntacticCallGraph.make sources )
   else
     match Config.scheduler with
-    | SyntacticCallGraph ->
-        SyntacticCallGraph.make sources
     | File ->
         FileScheduler.make sources
+    | Restart ->
+        RestartScheduler.make sources
+    | SyntacticCallGraph ->
+        SyntacticCallGraph.make sources
 
 
 let analyze source_files_to_analyze =
diff --git a/infer/src/backend/RestartScheduler.ml b/infer/src/backend/RestartScheduler.ml
new file mode 100644
index 000000000..d557db215
--- /dev/null
+++ b/infer/src/backend/RestartScheduler.ml
@@ -0,0 +1,22 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+open! IStd
+
+(** This behaves exactly the same as the FileScheduler so far. The goal is that it will use a work
+    queue and proc locking to avoid repeating work and hopefully get some in process cache hits. *)
+let make sources =
+  let gen =
+    List.rev_map sources ~f:(fun sf -> SchedulerTypes.File sf)
+    |> List.permute ~random_state:(Random.State.make (Array.create ~len:1 0))
+    |> ProcessPool.TaskGenerator.of_list
+  in
+  let next x =
+    let res = gen.next x in
+    (* see defn of gen above to see why res should never match Some (Procname _) *)
+    match res with None -> None | Some (Procname _) -> assert false | Some (File _) as v -> v
+  in
+  {gen with next}
diff --git a/infer/src/backend/RestartScheduler.mli b/infer/src/backend/RestartScheduler.mli
new file mode 100644
index 000000000..d4b8fc626
--- /dev/null
+++ b/infer/src/backend/RestartScheduler.mli
@@ -0,0 +1,9 @@
+(*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *)
+open! IStd
+
+val make : SourceFile.t list -> SchedulerTypes.target ProcessPool.TaskGenerator.t
diff --git a/infer/src/base/Config.ml b/infer/src/base/Config.ml
index 5e5fea107..22a1110a2 100644
--- a/infer/src/base/Config.ml
+++ b/infer/src/base/Config.ml
@@ -92,7 +92,7 @@ type build_system =
   | BXcode
 [@@deriving compare]
 
-type scheduler = File | SyntacticCallGraph [@@deriving equal]
+type scheduler = File | Restart | SyntacticCallGraph [@@deriving equal]
 
 let equal_build_system = [%compare.equal: build_system]
 
@@ -2357,7 +2357,7 @@ and export_changed_functions_output =
 
 and scheduler =
   CLOpt.mk_symbol ~long:"scheduler" ~default:File ~eq:equal_scheduler
-    ~symbols:[("File", File); ("SyntacticCallGraph", SyntacticCallGraph)]
+    ~symbols:[("file", File); ("restart", Restart); ("callgraph", SyntacticCallGraph)]
     "Specify the scheduler used for the analysis phase"
 
 
diff --git a/infer/src/base/Config.mli b/infer/src/base/Config.mli
index 68a553938..90e5c0e74 100644
--- a/infer/src/base/Config.mli
+++ b/infer/src/base/Config.mli
@@ -25,7 +25,7 @@ type build_system =
   | BNdk
   | BXcode
 
-type scheduler = File | SyntacticCallGraph [@@deriving equal]
+type scheduler = File | Restart | SyntacticCallGraph [@@deriving equal]
 
 val equal_build_system : build_system -> build_system -> bool