Introduce Signature type to avoid string comparisons.

Method resolution currently creates strings to then compare with strings formed
from methods in other dex files. The temporary strings are purely created for
the sake of comparisons. This change creates a new Signature type that
represents a method signature but not as a string. This type supports
comparisons and so can be used when searching for methods in resolution.

With this change malloc is no longer the hottest method during dex2oat (now its
memset) and allocations during verification have been reduced. The verifier is
commonly what is populating the dex cache for methods and fields not declared
in the dex file itself.

Change-Id: I5ef0542823fbcae868aaa4a2457e8da7df0e9dae

2 files changed, 86 insertions, 13 deletions

diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 287e8b0..c6db5b9 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -325,7 +325,7 @@ void Class::SetClassLoader(ClassLoader* new_class_loader) {
   SetFieldObject(OFFSET_OF_OBJECT_MEMBER(Class, class_loader_), new_class_loader, false);
 }
 
-ArtMethod* Class::FindInterfaceMethod(const StringPiece& name, const StringPiece& signature) const {
+ArtMethod* Class::FindInterfaceMethod(const StringPiece& name, const Signature& signature) const {
   // Check the current class before checking the interfaces.
   ArtMethod* method = FindDeclaredVirtualMethod(name, signature);
   if (method != NULL) {
@@ -361,12 +361,23 @@ ArtMethod* Class::FindInterfaceMethod(const DexCache* dex_cache, uint32_t dex_me
   return NULL;
 }
 
-
 ArtMethod* Class::FindDeclaredDirectMethod(const StringPiece& name, const StringPiece& signature) const {
   MethodHelper mh;
   for (size_t i = 0; i < NumDirectMethods(); ++i) {
     ArtMethod* method = GetDirectMethod(i);
     mh.ChangeMethod(method);
+    if (name == mh.GetNameAsStringPiece() && mh.GetSignature() == signature) {
+      return method;
+    }
+  }
+  return NULL;
+}
+
+ArtMethod* Class::FindDeclaredDirectMethod(const StringPiece& name, const Signature& signature) const {
+  MethodHelper mh;
+  for (size_t i = 0; i < NumDirectMethods(); ++i) {
+    ArtMethod* method = GetDirectMethod(i);
+    mh.ChangeMethod(method);
     if (name == mh.GetNameAsStringPiece() && signature == mh.GetSignature()) {
       return method;
     }
@@ -396,6 +407,16 @@ ArtMethod* Class::FindDirectMethod(const StringPiece& name, const StringPiece& s
   return NULL;
 }
 
+ArtMethod* Class::FindDirectMethod(const StringPiece& name, const Signature& signature) const {
+  for (const Class* klass = this; klass != NULL; klass = klass->GetSuperClass()) {
+    ArtMethod* method = klass->FindDeclaredDirectMethod(name, signature);
+    if (method != NULL) {
+      return method;
+    }
+  }
+  return NULL;
+}
+
 ArtMethod* Class::FindDirectMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const {
   for (const Class* klass = this; klass != NULL; klass = klass->GetSuperClass()) {
     ArtMethod* method = klass->FindDeclaredDirectMethod(dex_cache, dex_method_idx);
@@ -406,8 +427,20 @@ ArtMethod* Class::FindDirectMethod(const DexCache* dex_cache, uint32_t dex_metho
   return NULL;
 }
 
+ArtMethod* Class::FindDeclaredVirtualMethod(const StringPiece& name, const StringPiece& signature) const {
+  MethodHelper mh;
+  for (size_t i = 0; i < NumVirtualMethods(); ++i) {
+    ArtMethod* method = GetVirtualMethod(i);
+    mh.ChangeMethod(method);
+    if (name == mh.GetNameAsStringPiece() && mh.GetSignature() == signature) {
+      return method;
+    }
+  }
+  return NULL;
+}
+
 ArtMethod* Class::FindDeclaredVirtualMethod(const StringPiece& name,
-                                         const StringPiece& signature) const {
+                                            const Signature& signature) const {
   MethodHelper mh;
   for (size_t i = 0; i < NumVirtualMethods(); ++i) {
     ArtMethod* method = GetVirtualMethod(i);
@@ -441,6 +474,16 @@ ArtMethod* Class::FindVirtualMethod(const StringPiece& name, const StringPiece&
   return NULL;
 }
 
+ArtMethod* Class::FindVirtualMethod(const StringPiece& name, const Signature& signature) const {
+  for (const Class* klass = this; klass != NULL; klass = klass->GetSuperClass()) {
+    ArtMethod* method = klass->FindDeclaredVirtualMethod(name, signature);
+    if (method != NULL) {
+      return method;
+    }
+  }
+  return NULL;
+}
+
 ArtMethod* Class::FindVirtualMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const {
   for (const Class* klass = this; klass != NULL; klass = klass->GetSuperClass()) {
     ArtMethod* method = klass->FindDeclaredVirtualMethod(dex_cache, dex_method_idx);
@@ -451,6 +494,21 @@ ArtMethod* Class::FindVirtualMethod(const DexCache* dex_cache, uint32_t dex_meth
   return NULL;
 }
 
+ArtMethod* Class::FindClassInitializer() const {
+  for (size_t i = 0; i < NumDirectMethods(); ++i) {
+    ArtMethod* method = GetDirectMethod(i);
+    if (method->IsConstructor() && method->IsStatic()) {
+      if (kIsDebugBuild) {
+        MethodHelper mh(method);
+        CHECK_STREQ(mh.GetName(), "<clinit>");
+        CHECK_STREQ(mh.GetSignature().ToString().c_str(), "()V");
+      }
+      return method;
+    }
+  }
+  return NULL;
+}
+
 ArtField* Class::FindDeclaredInstanceField(const StringPiece& name, const StringPiece& type) {
   // Is the field in this class?
   // Interfaces are not relevant because they can't contain instance fields.
diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index 4f8ab7d..586151d 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -59,6 +59,7 @@ namespace art {
 
 struct ClassClassOffsets;
 struct ClassOffsets;
+class Signature;
 class StringPiece;
 
 namespace mirror {
@@ -565,39 +566,53 @@ class MANAGED Class : public StaticStorageBase {
   ArtMethod* FindVirtualMethodForInterface(ArtMethod* method) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) ALWAYS_INLINE;
 
-  ArtMethod* FindInterfaceMethod(const StringPiece& name, const StringPiece& descriptor) const
+  ArtMethod* FindVirtualMethodForVirtualOrInterface(ArtMethod* method) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  ArtMethod* FindInterfaceMethod(const StringPiece& name, const Signature& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   ArtMethod* FindInterfaceMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindVirtualMethodForVirtualOrInterface(ArtMethod* method) const
+  ArtMethod* FindDeclaredDirectMethod(const StringPiece& name, const StringPiece& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindDeclaredVirtualMethod(const StringPiece& name, const StringPiece& signature) const
+  ArtMethod* FindDeclaredDirectMethod(const StringPiece& name, const Signature& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindDeclaredVirtualMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
+  ArtMethod* FindDeclaredDirectMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindVirtualMethod(const StringPiece& name, const StringPiece& descriptor) const
+  ArtMethod* FindDirectMethod(const StringPiece& name, const StringPiece& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindVirtualMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
+  ArtMethod* FindDirectMethod(const StringPiece& name, const Signature& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindDeclaredDirectMethod(const StringPiece& name, const StringPiece& signature) const
+  ArtMethod* FindDirectMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindDeclaredDirectMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
+  ArtMethod* FindDeclaredVirtualMethod(const StringPiece& name, const StringPiece& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindDirectMethod(const StringPiece& name, const StringPiece& signature) const
+  ArtMethod* FindDeclaredVirtualMethod(const StringPiece& name, const Signature& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  ArtMethod* FindDirectMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
+  ArtMethod* FindDeclaredVirtualMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  ArtMethod* FindVirtualMethod(const StringPiece& name, const StringPiece& signature) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  ArtMethod* FindVirtualMethod(const StringPiece& name, const Signature& signature) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  ArtMethod* FindVirtualMethod(const DexCache* dex_cache, uint32_t dex_method_idx) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  ArtMethod* FindClassInitializer() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
   int32_t GetIfTableCount() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   IfTable* GetIfTable() const;