[thread-safety] add @AssumeThreadSafe annotation to assume thread-safety of a method without checking it

Reviewed By: peterogithub

Differential Revision: D4433402

fbshipit-source-id: 742ad51

infer/annotations/com/facebook/infer/annotation/AssumeThreadSafe.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2004 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.infer.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/** assume that a method is thread-safe without actually checking it (as opposed to @ThreadSafe,
+    which does check). useful for suppressing warnings involving benign races */
+
+@Target({ ElementType.METHOD })
+@Retention(RetentionPolicy.CLASS)
+public @interface AssumeThreadSafe {
+}

infer/src/checkers/ThreadSafety.ml

@@ -315,6 +315,9 @@ let runs_on_ui_thread proc_desc =
     (fun annot -> Annotations.ia_is_ui_thread annot || Annotations.ia_is_on_event annot)
     proc_desc
 
+let is_assumed_thread_safe pdesc =
+  is_annotated Annotations.ia_is_assume_thread_safe pdesc
+
 (* return true if we should compute a summary for the procedure. if this returns false, we won't
    analyze the procedure or report any warnings on it *)
 (* note: in the future, we will want to analyze the procedures in all of these cases in order to
@@ -326,7 +329,8 @@ let should_analyze_proc pdesc tenv =
   not (is_call_to_builder_class_method pn) &&
   not (is_call_to_immutable_collection_method tenv pn) &&
   not (runs_on_ui_thread pdesc) &&
-  not (is_thread_confined_method tenv pdesc)
+  not (is_thread_confined_method tenv pdesc) &&
+  not (is_assumed_thread_safe pdesc)
 
 (* return true if we should report on unprotected accesses during the procedure *)
 let should_report_on_proc (_, tenv, proc_name, proc_desc) =

infer/src/checkers/annotations.ml

@@ -123,6 +123,7 @@ let guarded_by = "GuardedBy"
 let thread_safe = "ThreadSafe"
 let thread_safe_method = "ThreadSafeMethod"
 let not_thread_safe = "NotThreadSafe"
+let assume_thread_safe = "AssumeThreadSafe"
 let ui_thread = "UiThread"
 let any_thread = "AnyThread"
 let for_ui_thread = "ForUiThread"
@@ -138,6 +139,9 @@ let ia_is_thread_safe ia =
 let ia_is_thread_safe_method ia =
   ia_ends_with ia thread_safe_method
 
+let ia_is_assume_thread_safe ia =
+  ia_ends_with ia assume_thread_safe
+
 let ia_is_nullable ia =
   ia_ends_with ia nullable
 

infer/src/checkers/annotations.mli

@@ -102,6 +102,7 @@ val ia_is_guarded_by : Annot.Item.t -> bool
 val ia_is_not_thread_safe : Annot.Item.t -> bool
 val ia_is_thread_safe : Annot.Item.t -> bool
 val ia_is_thread_safe_method : Annot.Item.t -> bool
+val ia_is_assume_thread_safe : Annot.Item.t -> bool
 val ia_is_ui_thread : Annot.Item.t -> bool
 val ia_is_thread_confined : Annot.Item.t -> bool
 

infer/tests/codetoanalyze/java/threadsafety/Annotations.java

@@ -18,6 +18,7 @@ import javax.annotation.concurrent.ThreadSafe;
 
 import android.support.annotation.UiThread;
 
+import com.facebook.infer.annotation.AssumeThreadSafe;
 import com.facebook.infer.annotation.ThreadConfined;
 
 /** tests for classes and method annotations that are meaningful w.r.t thread-safety */
@@ -88,4 +89,9 @@ class Annotations {
     this.f = new Object();
   }
 
+  @AssumeThreadSafe
+  public void assumeThreadSafeOk() {
+    this.f = new Object();
+  }
+
 }