[thread-safety] understand that Pools.Pool.acquire returns ownership

Summary: We had a model for `Pools.SimplePool`, but were missing models for `Pools.Pool`. Since `SimplePool` and `SynchronizedPool` both extend `Pool`, modeling it should cover all of the cases.

Reviewed By: ngorogiannis

Differential Revision: D5236280

fbshipit-source-id: 9bbdb25

infer/src/checkers/ThreadSafety.ml

@@ -330,7 +330,7 @@ module TransferFunctions (CFG : ProcCfg.S) = struct
             | ("android.app.Activity" | "android.view.View"), "findViewById" ->
                 (* assume findViewById creates fresh View's (note: not always true) *)
                 true
-            | "android.support.v4.util.Pools$SimplePool", "acquire" ->
+            | "android.support.v4.util.Pools$Pool", "acquire" ->
                 (* a pool should own all of its objects *)
                 true
             | _ ->

infer/tests/codetoanalyze/java/threadsafety/Containers.java

@@ -24,6 +24,7 @@ import android.support.v4.util.Pools.SynchronizedPool;
 import android.support.v4.util.SparseArrayCompat;
 import android.util.SparseArray;
 import android.support.v4.util.SimpleArrayMap;
+import android.support.v4.util.Pools;
 import android.support.v4.util.Pools.SimplePool;
 
 class ContainerWrapper {
@@ -175,7 +176,7 @@ class Containers {
 
   static boolean sUsePooling;
 
-  private Obj poolWrapper() {
+  private Obj poolWrapper1() {
     Obj obj = sUsePooling ? sPool.acquire() : null;
     if (obj == null) {
       obj = new Obj();
@@ -184,8 +185,28 @@ class Containers {
     return obj;
   }
 
-  void poolWrapperOk() {
-    Obj obj = poolWrapper();
+  void poolWrapperOk1() {
+    Obj obj = poolWrapper1();
+    obj.f = new Object();
+  }
+
+  private Pools.Pool<Obj> mPool;
+  private boolean mIsSync;
+
+  private Obj poolWrapper2() {
+    Obj item;
+    if (mIsSync) {
+      synchronized (this) {
+        item = mPool.acquire();
+      }
+    } else {
+      item = mPool.acquire();
+    }
+    return item;
+  }
+
+  void poolWrapperOk2() {
+    Obj obj = poolWrapper2();
     obj.f = new Object();
   }
 
@@ -265,4 +286,5 @@ class Containers {
     }
     simplePool.release(a);
   }
+
 }