[thread-safety] don't report on protected reads

Summary:
*Unless* the unprotected write runs on the main thread and the read doesn't.
Otherwise, we'll already report on the unprotected write, and we don't want to duplicate.

Reviewed By: peterogithub

Differential Revision: D4798357

fbshipit-source-id: 5de06a0

infer/src/checkers/ThreadSafety.ml

@@ -1100,13 +1100,15 @@ let report_unsafe_accesses ~should_report aggregated_access_map =
               update_reported access pname reported_acc
             end
       | Access.Read, AccessPrecondition.Protected ->
-          (* protected read. report unprotected writes as conflicts *)
+          (* protected read. report unprotected, threaded writes as conflicts *)
           let unprotected_writes =
             List.filter
-              ~f:(fun (access, pre, _, _, _) ->
+              ~f:(fun (access, pre, other_threaded, _, _) ->
                   match pre with
-                  | AccessPrecondition.Unprotected _ -> TraceElem.is_write access
+                  | AccessPrecondition.Unprotected _ ->
-                  | _ -> false)
+                      TraceElem.is_write access && (other_threaded && not threaded)
+                  | _ ->
+                      false)
               accesses in
           if List.is_empty unprotected_writes
           then

infer/tests/codetoanalyze/java/threadsafety/ReadWriteRaces.java

@@ -109,17 +109,4 @@ class ReadWriteRaces {
     }
   }
 
-  // write outside sync, read inside of sync races
-
-  Object field4;
-
-  public void unprotectedWrite4Bad() {
-    this.field4 = new Object();
-  }
-
-  public synchronized Object protectedRead4Bad() {
-    return this.field4;
-  }
-
-
 }

infer/tests/codetoanalyze/java/threadsafety/issues.exp

@@ -63,7 +63,6 @@ codetoanalyze/java/threadsafety/Ownership.java, void Ownership.writeToOwnedInCal
 codetoanalyze/java/threadsafety/RaceWithMainThread.java, void RaceWithMainThread.readProtectedUnthreadedBad(), 3, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.RaceWithMainThread.f]
 codetoanalyze/java/threadsafety/RaceWithMainThread.java, void RaceWithMainThread.read_unprotected_unthreaded_Bad(), 2, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.RaceWithMainThread.f]
 codetoanalyze/java/threadsafety/ReadWriteRaces.java, Object ReadWriteRaces.callUnprotecteReadInCallee(), 1, THREAD_SAFETY_VIOLATION, [call to Object ReadWriteRaces.unprotectedReadInCallee(),access to codetoanalyze.java.checkers.ReadWriteRaces.field1]
-codetoanalyze/java/threadsafety/ReadWriteRaces.java, Object ReadWriteRaces.protectedRead4Bad(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ReadWriteRaces.field4]
 codetoanalyze/java/threadsafety/ReadWriteRaces.java, Object ReadWriteRaces.unprotectedRead1(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ReadWriteRaces.field1]
 codetoanalyze/java/threadsafety/ReadWriteRaces.java, Object ReadWriteRaces.unprotectedRead2(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ReadWriteRaces.field2]
 codetoanalyze/java/threadsafety/ReadWriteRaces.java, Object ReadWriteRaces.unprotectedRead3(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ReadWriteRaces.field3]
@@ -71,7 +70,6 @@ codetoanalyze/java/threadsafety/ReadWriteRaces.java, void ReadWriteRaces.m1(), 2
 codetoanalyze/java/threadsafety/ReadWriteRaces.java, void ReadWriteRaces.m2(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ReadWriteRaces.racy]
 codetoanalyze/java/threadsafety/ReadWriteRaces.java, void ReadWriteRaces.m3(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ReadWriteRaces.racy]
 codetoanalyze/java/threadsafety/ReadWriteRaces.java, void ReadWriteRaces.readInCalleeOutsideSyncBad(int), 1, THREAD_SAFETY_VIOLATION, [call to int C.get(),access to codetoanalyze.java.checkers.C.x]
-codetoanalyze/java/threadsafety/ReadWriteRaces.java, void ReadWriteRaces.unprotectedWrite4Bad(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ReadWriteRaces.field4]
 codetoanalyze/java/threadsafety/ThreadSafeExample.java, void ExtendsThreadSafeExample.newmethodBad(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ExtendsThreadSafeExample.field]
 codetoanalyze/java/threadsafety/ThreadSafeExample.java, void ExtendsThreadSafeExample.tsOK(), 1, THREAD_SAFETY_VIOLATION, [access to codetoanalyze.java.checkers.ExtendsThreadSafeExample.field]
 codetoanalyze/java/threadsafety/ThreadSafeExample.java, void ThreadSafeExample.callPublicMethodBad(), 1, THREAD_SAFETY_VIOLATION, [call to void ThreadSafeExample.assignInPrivateMethodOk(),access to codetoanalyze.java.checkers.ThreadSafeExample.f]