class_linker: Add support for resolving method types.

- Add a new fixed size dex cache array for resolved method types.
  The size of this array is set to 1024.
- Also introduces a new runtime flag that controls this feature.

Test: make test-art-host
Bug: 30550796

Change-Id: I147b33398d71ee21f2e91b418d3700d4630801ff
diff --git a/runtime/mirror/dex_cache_test.cc b/runtime/mirror/dex_cache_test.cc
index ac04200..12301b8 100644
--- a/runtime/mirror/dex_cache_test.cc
+++ b/runtime/mirror/dex_cache_test.cc
@@ -31,6 +31,14 @@
 
 class DexCacheTest : public CommonRuntimeTest {};
 
+class DexCacheMethodHandlesTest : public DexCacheTest {
+ protected:
+  virtual void SetUpRuntimeOptions(RuntimeOptions* options) OVERRIDE {
+    CommonRuntimeTest::SetUpRuntimeOptions(options);
+    options->push_back(std::make_pair("-Xexperimental:method-handles", nullptr));
+  }
+};
+
 TEST_F(DexCacheTest, Open) {
   ScopedObjectAccess soa(Thread::Current());
   StackHandleScope<1> hs(soa.Self());
@@ -46,21 +54,35 @@
   EXPECT_EQ(java_lang_dex_file_->NumTypeIds(),   dex_cache->NumResolvedTypes());
   EXPECT_EQ(java_lang_dex_file_->NumMethodIds(), dex_cache->NumResolvedMethods());
   EXPECT_EQ(java_lang_dex_file_->NumFieldIds(),  dex_cache->NumResolvedFields());
+  // This should always be zero because the -Xexperimental:method-handles isn't
+  // set.
+  EXPECT_EQ(0u, dex_cache->NumResolvedMethodTypes());
+}
+
+TEST_F(DexCacheMethodHandlesTest, Open) {
+  ScopedObjectAccess soa(Thread::Current());
+  StackHandleScope<1> hs(soa.Self());
+  ASSERT_TRUE(java_lang_dex_file_ != nullptr);
+  Handle<DexCache> dex_cache(
+      hs.NewHandle(class_linker_->AllocDexCache(soa.Self(),
+                                                *java_lang_dex_file_,
+                                                Runtime::Current()->GetLinearAlloc())));
+
+  EXPECT_TRUE(dex_cache->StaticMethodTypeSize() == dex_cache->NumResolvedMethodTypes()
+      || java_lang_dex_file_->NumProtoIds() == dex_cache->NumResolvedMethodTypes());
 }
 
 TEST_F(DexCacheTest, LinearAlloc) {
   ScopedObjectAccess soa(Thread::Current());
   jobject jclass_loader(LoadDex("Main"));
   ASSERT_TRUE(jclass_loader != nullptr);
-  Runtime* const runtime = Runtime::Current();
-  ClassLinker* const class_linker = runtime->GetClassLinker();
   StackHandleScope<1> hs(soa.Self());
   Handle<mirror::ClassLoader> class_loader(hs.NewHandle(
       soa.Decode<mirror::ClassLoader>(jclass_loader)));
-  mirror::Class* klass = class_linker->FindClass(soa.Self(), "LMain;", class_loader);
+  mirror::Class* klass = class_linker_->FindClass(soa.Self(), "LMain;", class_loader);
   ASSERT_TRUE(klass != nullptr);
   LinearAlloc* const linear_alloc = klass->GetClassLoader()->GetAllocator();
-  EXPECT_NE(linear_alloc, runtime->GetLinearAlloc());
+  EXPECT_NE(linear_alloc, runtime_->GetLinearAlloc());
   EXPECT_TRUE(linear_alloc->Contains(klass->GetDexCache()->GetResolvedMethods()));
 }
 
@@ -68,16 +90,14 @@
   ScopedObjectAccess soa(Thread::Current());
   jobject jclass_loader(LoadDex("Packages"));
   ASSERT_TRUE(jclass_loader != nullptr);
-  Runtime* const runtime = Runtime::Current();
-  ClassLinker* const class_linker = runtime->GetClassLinker();
   StackHandleScope<3> hs(soa.Self());
   Handle<mirror::ClassLoader> class_loader(hs.NewHandle(
       soa.Decode<mirror::ClassLoader>(jclass_loader)));
   Handle<mirror::Class> klass1 =
-      hs.NewHandle(class_linker->FindClass(soa.Self(), "Lpackage1/Package1;", class_loader));
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "Lpackage1/Package1;", class_loader));
   ASSERT_TRUE(klass1.Get() != nullptr);
   Handle<mirror::Class> klass2 =
-      hs.NewHandle(class_linker->FindClass(soa.Self(), "Lpackage2/Package2;", class_loader));
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "Lpackage2/Package2;", class_loader));
   ASSERT_TRUE(klass2.Get() != nullptr);
   EXPECT_EQ(klass1->GetDexCache(), klass2->GetDexCache());
 
@@ -92,5 +112,60 @@
   }
 }
 
+TEST_F(DexCacheMethodHandlesTest, TestResolvedMethodTypes) {
+  ScopedObjectAccess soa(Thread::Current());
+  jobject jclass_loader(LoadDex("MethodTypes"));
+  ASSERT_TRUE(jclass_loader != nullptr);
+
+  StackHandleScope<5> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(hs.NewHandle(
+      soa.Decode<mirror::ClassLoader>(jclass_loader)));
+
+  Handle<mirror::Class> method_types(
+      hs.NewHandle(class_linker_->FindClass(soa.Self(), "LMethodTypes;", class_loader)));
+  class_linker_->EnsureInitialized(soa.Self(), method_types, true, true);
+
+  ArtMethod* method1 = method_types->FindVirtualMethod(
+      "method1",
+      "(Ljava/lang/String;)Ljava/lang/String;",
+      kRuntimePointerSize);
+  ArtMethod* method2 = method_types->FindVirtualMethod(
+      "method2",
+      "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;",
+      kRuntimePointerSize);
+
+  const DexFile& dex_file = *(method1->GetDexFile());
+  Handle<mirror::DexCache> dex_cache = hs.NewHandle(
+      class_linker_->FindDexCache(Thread::Current(), dex_file));
+
+  const DexFile::MethodId& method1_id = dex_file.GetMethodId(method1->GetDexMethodIndex());
+  const DexFile::MethodId& method2_id = dex_file.GetMethodId(method2->GetDexMethodIndex());
+
+  Handle<mirror::MethodType> method1_type = hs.NewHandle(
+      class_linker_->ResolveMethodType(dex_file, method1_id.proto_idx_, dex_cache, class_loader));
+  Handle<mirror::MethodType> method2_type = hs.NewHandle(
+      class_linker_->ResolveMethodType(dex_file, method2_id.proto_idx_, dex_cache, class_loader));
+
+  EXPECT_EQ(method1_type.Get(), dex_cache->GetResolvedMethodType(method1_id.proto_idx_));
+  EXPECT_EQ(method2_type.Get(), dex_cache->GetResolvedMethodType(method2_id.proto_idx_));
+
+  // The MethodTypes dex file contains a single interface with two abstract
+  // methods. It must therefore contain precisely two method IDs.
+  ASSERT_EQ(2u, dex_file.NumProtoIds());
+  ASSERT_EQ(dex_file.NumProtoIds(), dex_cache->NumResolvedMethodTypes());
+  MethodTypeDexCacheType* method_types_cache = dex_cache->GetResolvedMethodTypes();
+
+  for (size_t i = 0; i < dex_file.NumProtoIds(); ++i) {
+    const MethodTypeDexCachePair pair = method_types_cache[i].load(std::memory_order_relaxed);
+    if (pair.index == method1_id.proto_idx_) {
+      ASSERT_EQ(method1_type.Get(), pair.object.Read());
+    } else if (pair.index == method2_id.proto_idx_) {
+      ASSERT_EQ(method2_type.Get(), pair.object.Read());
+    } else {
+      ASSERT_TRUE(false);
+    }
+  }
+}
+
 }  // namespace mirror
 }  // namespace art