Upstream Android JNI code, allowing us to use more ScopedJava references.

base/android/scoped_java_ref_unittest.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/android/scoped_java_ref.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace android {
 
 namespace {
 int g_local_refs = 0;
 int g_global_refs = 0;
 
+JNINativeInterface g_previous_functions = {0};
+
 jobject NewGlobalRef(JNIEnv* env, jobject obj) {
   ++g_global_refs;
-  return AttachCurrentThread()->NewGlobalRef(obj);
+  return g_previous_functions.NewGlobalRef(env, obj);
 }
 
 void DeleteGlobalRef(JNIEnv* env, jobject obj) {
   --g_global_refs;
-  return AttachCurrentThread()->DeleteGlobalRef(obj);
+  return g_previous_functions.DeleteGlobalRef(env, obj);
 }
 
 jobject NewLocalRef(JNIEnv* env, jobject obj) {
   ++g_local_refs;
-  return AttachCurrentThread()->NewLocalRef(obj);
+  return g_previous_functions.NewLocalRef(env, obj);
 }
 
 void DeleteLocalRef(JNIEnv* env, jobject obj) {
   --g_local_refs;
-  return AttachCurrentThread()->DeleteLocalRef(obj);
+  return g_previous_functions.DeleteLocalRef(env, obj);
 }
 }  // namespace
 
 class ScopedJavaRefTest : public testing::Test {
  protected:
   virtual void SetUp() {
     g_local_refs = 0;
     g_global_refs = 0;
     JNIEnv* env = AttachCurrentThread();
-    counting_env = *env;
-    counting_functions = *counting_env.functions;
-    counting_functions.NewGlobalRef = &NewGlobalRef;
-    counting_functions.DeleteGlobalRef = &DeleteGlobalRef;
-    counting_functions.NewLocalRef = &NewLocalRef;
-    counting_functions.DeleteLocalRef = &DeleteLocalRef;
-    counting_env.functions = &counting_functions;
+    g_previous_functions = *env->functions;
+    // We inject our own functions in JNINativeInterface so we can keep track
+    // of the reference counting ourselves.
+    JNINativeInterface* native_interface =
+        const_cast<JNINativeInterface*>(env->functions);
+    native_interface->NewGlobalRef = &NewGlobalRef;
+    native_interface->DeleteGlobalRef = &DeleteGlobalRef;
+    native_interface->NewLocalRef = &NewLocalRef;
+    native_interface->DeleteLocalRef = &DeleteLocalRef;
   }
 
-  // Special JNI env configured in SetUp to count in and out all local & global
-  // reference instances. Be careful to only use this with the ScopedJavaRef
-  // classes under test, else it's easy to get system references counted in
-  // here too.
-  JNIEnv counting_env;
-  JNINativeInterface counting_functions;
+  virtual void TearDown() {
+    JNIEnv* env = AttachCurrentThread();
+    *(const_cast<JNINativeInterface*>(env->functions)) = g_previous_functions;
+  }
 };
 
 // The main purpose of this is testing the various conversions compile.
 TEST_F(ScopedJavaRefTest, Conversions) {
   JNIEnv* env = AttachCurrentThread();
-  ScopedJavaLocalRef<jstring> str(env, ConvertUTF8ToJavaString(env, "string"));
+  ScopedJavaLocalRef<jstring> str = ConvertUTF8ToJavaString(env, "string");
   ScopedJavaGlobalRef<jstring> global(str);
   {
     ScopedJavaGlobalRef<jobject> global_obj(str);
     ScopedJavaLocalRef<jobject> local_obj(global);
     const JavaRef<jobject>& obj_ref1(str);
     const JavaRef<jobject>& obj_ref2(global);
     EXPECT_TRUE(env->IsSameObject(obj_ref1.obj(), obj_ref2.obj()));
     EXPECT_TRUE(env->IsSameObject(global_obj.obj(), obj_ref2.obj()));
   }
   global.Reset(str);
   const JavaRef<jstring>& str_ref = str;
-  EXPECT_EQ("string", ConvertJavaStringToUTF8(env, str_ref.obj()));
+  EXPECT_EQ("string", ConvertJavaStringToUTF8(str_ref));
   str.Reset();
 }
 
 TEST_F(ScopedJavaRefTest, RefCounts) {
+  JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jstring> str;
-  str.Reset(&counting_env, ConvertUTF8ToJavaString(AttachCurrentThread(),
-                                                   "string"));
+  // The ConvertJavaStringToUTF8 below creates a new string that would normally
+  // return a local ref. We simulate that by starting the g_local_refs count at
+  // 1.
+  g_local_refs = 1;
+  str.Reset(ConvertUTF8ToJavaString(env, "string"));
   EXPECT_EQ(1, g_local_refs);
   EXPECT_EQ(0, g_global_refs);
-
   {
     ScopedJavaGlobalRef<jstring> global_str(str);
     ScopedJavaGlobalRef<jobject> global_obj(global_str);
     EXPECT_EQ(1, g_local_refs);
     EXPECT_EQ(2, g_global_refs);
 
-    ScopedJavaLocalRef<jstring> str2(&counting_env, str.Release());
+    ScopedJavaLocalRef<jstring> str2(env, str.Release());
     EXPECT_EQ(1, g_local_refs);
     {
       ScopedJavaLocalRef<jstring> str3(str2);
       EXPECT_EQ(2, g_local_refs);
     }
     EXPECT_EQ(1, g_local_refs);
     str2.Reset();
     EXPECT_EQ(0, g_local_refs);
     global_str.Reset();
     EXPECT_EQ(1, g_global_refs);
     ScopedJavaGlobalRef<jobject> global_obj2(global_obj);
     EXPECT_EQ(2, g_global_refs);
   }
 
   EXPECT_EQ(0, g_local_refs);
   EXPECT_EQ(0, g_global_refs);
 }
 
 }  // namespace android
 }  // namespace base