base/android/jni_android_unittest.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/android/jni_android.h"
   6
   7 #include "base/at_exit.h"
   8 #include "base/logging.h"
   9 #include "testing/gtest/include/gtest/gtest.h"
  10
  11 namespace base {
  12 namespace android {
  13
  14 namespace {
  15
  16 const char kJavaLangObject[] = "java/lang/Object";
  17 const char kGetClass[] = "getClass";
  18 const char kToString[] = "toString";
  19 const char kReturningJavaLangClass[] = "()Ljava/lang/Class;";
  20 const char kReturningJavaLangString[] = "()Ljava/lang/String;";
  21
  22 const char* g_last_method;
  23 const char* g_last_jni_signature;
  24 jmethodID g_last_method_id;
  25
  26 const JNINativeInterface* g_previous_functions;
  27
  28 jmethodID GetMethodIDWrapper(JNIEnv* env, jclass clazz, const char* method,
  29                              const char* jni_signature) {
  30   g_last_method = method;
  31   g_last_jni_signature = jni_signature;
  32   g_last_method_id = g_previous_functions->GetMethodID(env, clazz, method,
  33                                                        jni_signature);
  34   return g_last_method_id;
  35 }
  36
  37 }  // namespace
  38
  39 class JNIAndroidTest : public testing::Test {
  40  protected:
  41   virtual void SetUp() {
  42     JNIEnv* env = AttachCurrentThread();
  43     g_previous_functions = env->functions;
  44     hooked_functions = *g_previous_functions;
  45     env->functions = &hooked_functions;
  46     hooked_functions.GetMethodID = &GetMethodIDWrapper;
  47   }
  48
  49   virtual void TearDown() {
  50     JNIEnv* env = AttachCurrentThread();
  51     env->functions = g_previous_functions;
  52     Reset();
  53   }
  54
  55   void Reset() {
  56     g_last_method = 0;
  57     g_last_jni_signature = 0;
  58     g_last_method_id = NULL;
  59   }
  60   // Needed to cleanup the cached method map in the implementation between
  61   // runs (e.g. if using --gtest_repeat)
  62   base::ShadowingAtExitManager exit_manager;
  63   // From JellyBean release, the instance of this struct provided in JNIEnv is
  64   // read-only, so we deep copy it to allow individual functions to be hooked.
  65   JNINativeInterface hooked_functions;
  66 };
  67
  68 TEST_F(JNIAndroidTest, GetMethodIDFromClassNameCaching) {
  69   JNIEnv* env = AttachCurrentThread();
  70
  71   Reset();
  72   jmethodID id1 = GetMethodIDFromClassName(env, kJavaLangObject, kGetClass,
  73                                            kReturningJavaLangClass);
  74   EXPECT_STREQ(kGetClass, g_last_method);
  75   EXPECT_STREQ(kReturningJavaLangClass, g_last_jni_signature);
  76   EXPECT_EQ(g_last_method_id, id1);
  77
  78   Reset();
  79   jmethodID id2 = GetMethodIDFromClassName(env, kJavaLangObject, kGetClass,
  80                                            kReturningJavaLangClass);
  81   EXPECT_STREQ(0, g_last_method);
  82   EXPECT_STREQ(0, g_last_jni_signature);
  83   EXPECT_EQ(NULL, g_last_method_id);
  84   EXPECT_EQ(id1, id2);
  85
  86   Reset();
  87   jmethodID id3 = GetMethodIDFromClassName(env, kJavaLangObject, kToString,
  88                                            kReturningJavaLangString);
  89   EXPECT_STREQ(kToString, g_last_method);
  90   EXPECT_STREQ(kReturningJavaLangString, g_last_jni_signature);
  91   EXPECT_EQ(g_last_method_id, id3);
  92 }
  93
  94 namespace {
  95
  96 base::subtle::AtomicWord g_atomic_id = 0;
  97 int LazyMethodIDCall(JNIEnv* env, jclass clazz, int p) {
  98   jmethodID id = base::android::MethodID::LazyGet<
  99       base::android::MethodID::TYPE_STATIC>(
 100       env, clazz,
 101       "abs",
 102       "(I)I",
 103       &g_atomic_id);
 104
 105   return env->CallStaticIntMethod(clazz, id, p);
 106 }
 107
 108 int MethodIDCall(JNIEnv* env, jclass clazz, jmethodID id, int p) {
 109   return env->CallStaticIntMethod(clazz, id, p);
 110 }
 111
 112 }  // namespace
 113
 114 TEST(JNIAndroidMicrobenchmark, MethodId) {
 115   JNIEnv* env = AttachCurrentThread();
 116   ScopedJavaLocalRef<jclass> clazz(GetClass(env, "java/lang/Math"));
 117   base::Time start_lazy = base::Time::Now();
 118   int o = 0;
 119   for (int i = 0; i < 1024; ++i)
 120     o += LazyMethodIDCall(env, clazz.obj(), i);
 121   base::Time end_lazy = base::Time::Now();
 122
 123   jmethodID id = reinterpret_cast<jmethodID>(g_atomic_id);
 124   base::Time start = base::Time::Now();
 125   for (int i = 0; i < 1024; ++i)
 126     o += MethodIDCall(env, clazz.obj(), id, i);
 127   base::Time end = base::Time::Now();
 128
 129   // On a Galaxy Nexus, results were in the range of:
 130   // JNI LazyMethodIDCall (us) 1984
 131   // JNI MethodIDCall (us) 1861
 132   LOG(ERROR) << "JNI LazyMethodIDCall (us) " <<
 133       base::TimeDelta(end_lazy - start_lazy).InMicroseconds();
 134   LOG(ERROR) << "JNI MethodIDCall (us) " <<
 135       base::TimeDelta(end - start).InMicroseconds();
 136   LOG(ERROR) << "JNI " << o;
 137 }
 138
 139
 140 }  // namespace android
 141 }  // namespace base