Revert "Basic obsolete methods support"

This reverts commit d8936da27b792d1ca02e59c92456a1a53c7b9905.

Reason for revert: Some sort of race in JIT

Change-Id: Ibb4e520bb0721d6d7aa2c841a52eb5baff07740e
diff --git a/runtime/art_method-inl.h b/runtime/art_method-inl.h
index c78db3e..ef03bb3 100644
--- a/runtime/art_method-inl.h
+++ b/runtime/art_method-inl.h
@@ -134,7 +134,8 @@
   // NOTE: Unchecked, i.e. not throwing AIOOB. We don't even know the length here
   // without accessing the DexCache and we don't want to do that in release build.
   DCHECK_LT(method_index,
-            GetInterfaceMethodIfProxy(pointer_size)->GetDexCache()->NumResolvedMethods());
+            GetInterfaceMethodIfProxy(pointer_size)->GetDeclaringClass()
+                ->GetDexCache()->NumResolvedMethods());
   ArtMethod* method = mirror::DexCache::GetElementPtrSize(GetDexCacheResolvedMethods(pointer_size),
                                                           method_index,
                                                           pointer_size);
@@ -153,7 +154,8 @@
   // NOTE: Unchecked, i.e. not throwing AIOOB. We don't even know the length here
   // without accessing the DexCache and we don't want to do that in release build.
   DCHECK_LT(method_index,
-            GetInterfaceMethodIfProxy(pointer_size)->GetDexCache()->NumResolvedMethods());
+            GetInterfaceMethodIfProxy(pointer_size)->GetDeclaringClass()
+                ->GetDexCache()->NumResolvedMethods());
   DCHECK(new_method == nullptr || new_method->GetDeclaringClass() != nullptr);
   mirror::DexCache::SetElementPtrSize(GetDexCacheResolvedMethods(pointer_size),
                                       method_index,
@@ -184,7 +186,8 @@
 inline mirror::Class* ArtMethod::GetDexCacheResolvedType(dex::TypeIndex type_index,
                                                          PointerSize pointer_size) {
   if (kWithCheck) {
-    mirror::DexCache* dex_cache = GetInterfaceMethodIfProxy(pointer_size)->GetDexCache();
+    mirror::DexCache* dex_cache =
+        GetInterfaceMethodIfProxy(pointer_size)->GetDeclaringClass()->GetDexCache();
     if (UNLIKELY(type_index.index_ >= dex_cache->NumResolvedTypes())) {
       ThrowArrayIndexOutOfBoundsException(type_index.index_, dex_cache->NumResolvedTypes());
       return nullptr;
@@ -330,7 +333,7 @@
 }
 
 inline const DexFile::CodeItem* ArtMethod::GetCodeItem() {
-  return GetDexFile()->GetCodeItem(GetCodeItemOffset());
+  return GetDeclaringClass()->GetDexFile().GetCodeItem(GetCodeItemOffset());
 }
 
 inline bool ArtMethod::IsResolvedTypeIdx(dex::TypeIndex type_idx, PointerSize pointer_size) {
@@ -395,20 +398,11 @@
 }
 
 inline mirror::DexCache* ArtMethod::GetDexCache() {
-  if (LIKELY(!IsObsolete())) {
-    return GetDeclaringClass()->GetDexCache();
-  } else {
-    DCHECK(!IsProxyMethod());
+  DCHECK(!IsProxyMethod());
+  if (UNLIKELY(IsObsolete())) {
     return GetObsoleteDexCache();
-  }
-}
-
-inline mirror::StringDexCacheType* ArtMethod::GetDexCacheStrings() {
-  if (LIKELY(!IsObsolete())) {
-    return GetDeclaringClass()->GetDexCacheStrings();
   } else {
-    DCHECK(!IsProxyMethod());
-    return GetObsoleteDexCache()->GetStrings();
+    return GetDeclaringClass()->GetDexCache();
   }
 }
 
diff --git a/runtime/art_method.h b/runtime/art_method.h
index 83ed1db..3bc6f5d 100644
--- a/runtime/art_method.h
+++ b/runtime/art_method.h
@@ -27,7 +27,6 @@
 #include "invoke_type.h"
 #include "method_reference.h"
 #include "modifiers.h"
-#include "mirror/dex_cache.h"
 #include "mirror/object.h"
 #include "obj_ptr.h"
 #include "read_barrier_option.h"
@@ -221,12 +220,6 @@
     return !IsIntrinsic() && (GetAccessFlags() & kAccObsoleteMethod) != 0;
   }
 
-  void SetIsObsolete() {
-    // TODO We should really support redefining intrinsic if possible.
-    DCHECK(!IsIntrinsic());
-    SetAccessFlags(GetAccessFlags() | kAccObsoleteMethod);
-  }
-
   template <ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
   bool IsNative() {
     return (GetAccessFlags<kReadBarrierOption>() & kAccNative) != 0;
@@ -333,10 +326,6 @@
   ALWAYS_INLINE ArtMethod* GetDexCacheResolvedMethod(uint16_t method_index,
                                                      PointerSize pointer_size)
       REQUIRES_SHARED(Locks::mutator_lock_);
-
-  ALWAYS_INLINE mirror::StringDexCacheType* GetDexCacheStrings()
-      REQUIRES_SHARED(Locks::mutator_lock_);
-
   ALWAYS_INLINE void SetDexCacheResolvedMethod(uint16_t method_index,
                                                ArtMethod* new_method,
                                                PointerSize pointer_size)
diff --git a/runtime/entrypoints/entrypoint_utils-inl.h b/runtime/entrypoints/entrypoint_utils-inl.h
index 14c9c21..f6eeffc 100644
--- a/runtime/entrypoints/entrypoint_utils-inl.h
+++ b/runtime/entrypoints/entrypoint_utils-inl.h
@@ -563,7 +563,7 @@
       HandleWrapperObjPtr<mirror::Object> h_this(hs2.NewHandleWrapper(this_object));
       Handle<mirror::Class> h_referring_class(hs2.NewHandle(referrer->GetDeclaringClass()));
       const dex::TypeIndex method_type_idx =
-          referrer->GetDexFile()->GetMethodId(method_idx).class_idx_;
+          h_referring_class->GetDexFile().GetMethodId(method_idx).class_idx_;
       mirror::Class* method_reference_class = class_linker->ResolveType(method_type_idx, referrer);
       if (UNLIKELY(method_reference_class == nullptr)) {
         // Bad type idx.
@@ -673,7 +673,8 @@
                                size_t expected_size) {
   ScopedAssertNoThreadSuspension ants(__FUNCTION__);
   ArtField* resolved_field =
-      referrer->GetDexCache()->GetResolvedField(field_idx, kRuntimePointerSize);
+      referrer->GetDeclaringClass()->GetDexCache()->GetResolvedField(field_idx,
+                                                                     kRuntimePointerSize);
   if (UNLIKELY(resolved_field == nullptr)) {
     return nullptr;
   }
@@ -732,7 +733,7 @@
   }
   mirror::Class* referring_class = referrer->GetDeclaringClass();
   ArtMethod* resolved_method =
-      referrer->GetDexCache()->GetResolvedMethod(method_idx, kRuntimePointerSize);
+      referring_class->GetDexCache()->GetResolvedMethod(method_idx, kRuntimePointerSize);
   if (UNLIKELY(resolved_method == nullptr)) {
     return nullptr;
   }
@@ -758,9 +759,9 @@
   } else if (type == kSuper) {
     // TODO This lookup is rather slow.
     dex::TypeIndex method_type_idx =
-        referrer->GetDexFile()->GetMethodId(method_idx).class_idx_;
+        referring_class->GetDexFile().GetMethodId(method_idx).class_idx_;
     mirror::Class* method_reference_class =
-        referrer->GetDexCache()->GetResolvedType(method_type_idx);
+        referring_class->GetDexCache()->GetResolvedType(method_type_idx);
     if (method_reference_class == nullptr) {
       // Need to do full type resolution...
       return nullptr;
diff --git a/runtime/instrumentation.cc b/runtime/instrumentation.cc
index 3956af4..870d1ae 100644
--- a/runtime/instrumentation.cc
+++ b/runtime/instrumentation.cc
@@ -557,10 +557,8 @@
 }
 
 Instrumentation::InstrumentationLevel Instrumentation::GetCurrentInstrumentationLevel() const {
-  if (interpreter_stubs_installed_ && interpret_only_) {
+  if (interpreter_stubs_installed_) {
     return InstrumentationLevel::kInstrumentWithInterpreter;
-  } else if (interpreter_stubs_installed_) {
-    return InstrumentationLevel::kInstrumentWithInterpreterAndJit;
   } else if (entry_exit_stubs_installed_) {
     return InstrumentationLevel::kInstrumentWithInstrumentationStubs;
   } else {
@@ -568,14 +566,6 @@
   }
 }
 
-bool Instrumentation::RequiresInstrumentationInstallation(InstrumentationLevel new_level) const {
-  // We need to reinstall instrumentation if we go to a different level or if the current level is
-  // kInstrumentWithInterpreterAndJit since that level does not force all code to always use the
-  // interpreter and so we might have started running optimized code again.
-  return new_level == InstrumentationLevel::kInstrumentWithInterpreterAndJit ||
-      GetCurrentInstrumentationLevel() != new_level;
-}
-
 void Instrumentation::ConfigureStubs(const char* key, InstrumentationLevel desired_level) {
   // Store the instrumentation level for this key or remove it.
   if (desired_level == InstrumentationLevel::kInstrumentNothing) {
@@ -595,7 +585,8 @@
   interpret_only_ = (requested_level == InstrumentationLevel::kInstrumentWithInterpreter) ||
                     forced_interpret_only_;
 
-  if (!RequiresInstrumentationInstallation(requested_level)) {
+  InstrumentationLevel current_level = GetCurrentInstrumentationLevel();
+  if (requested_level == current_level) {
     // We're already set.
     return;
   }
@@ -604,7 +595,7 @@
   Locks::mutator_lock_->AssertExclusiveHeld(self);
   Locks::thread_list_lock_->AssertNotHeld(self);
   if (requested_level > InstrumentationLevel::kInstrumentNothing) {
-    if (requested_level >= InstrumentationLevel::kInstrumentWithInterpreterAndJit) {
+    if (requested_level == InstrumentationLevel::kInstrumentWithInterpreter) {
       interpreter_stubs_installed_ = true;
       entry_exit_stubs_installed_ = true;
     } else {
@@ -851,8 +842,7 @@
 void Instrumentation::DisableDeoptimization(const char* key) {
   CHECK_EQ(deoptimization_enabled_, true);
   // If we deoptimized everything, undo it.
-  InstrumentationLevel level = GetCurrentInstrumentationLevel();
-  if (level == InstrumentationLevel::kInstrumentWithInterpreter) {
+  if (interpreter_stubs_installed_) {
     UndeoptimizeEverything(key);
   }
   // Undeoptimized selected methods.
@@ -879,14 +869,6 @@
   return !deoptimization_enabled_ && !interpreter_stubs_installed_;
 }
 
-// TODO we don't check deoptimization_enabled_ because currently there isn't really any support for
-// multiple users of instrumentation. Since this is just a temporary state anyway pending work to
-// ensure that the current_method doesn't get kept across suspend points this should be okay.
-// TODO Remove once b/33630159 is resolved.
-void Instrumentation::ReJitEverything(const char* key) {
-  ConfigureStubs(key, InstrumentationLevel::kInstrumentWithInterpreterAndJit);
-}
-
 void Instrumentation::DeoptimizeEverything(const char* key) {
   CHECK(deoptimization_enabled_);
   ConfigureStubs(key, InstrumentationLevel::kInstrumentWithInterpreter);
diff --git a/runtime/instrumentation.h b/runtime/instrumentation.h
index 872efac..1e5fcf2 100644
--- a/runtime/instrumentation.h
+++ b/runtime/instrumentation.h
@@ -133,9 +133,6 @@
   enum class InstrumentationLevel {
     kInstrumentNothing,                   // execute without instrumentation
     kInstrumentWithInstrumentationStubs,  // execute with instrumentation entry/exit stubs
-    kInstrumentWithInterpreterAndJit,     // execute with interpreter initially and later the JIT
-                                          // (if it is enabled). This level is special in that it
-                                          // always requires re-instrumentation.
     kInstrumentWithInterpreter            // execute with interpreter
   };
 
@@ -166,13 +163,6 @@
   }
   bool ShouldNotifyMethodEnterExitEvents() const REQUIRES_SHARED(Locks::mutator_lock_);
 
-  // Executes everything with the interpreter/jit (if available).
-  void ReJitEverything(const char* key)
-      REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
-      REQUIRES(!Locks::thread_list_lock_,
-               !Locks::classlinker_classes_lock_,
-               !deoptimized_methods_lock_);
-
   // Executes everything with interpreter.
   void DeoptimizeEverything(const char* key)
       REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_)
@@ -445,10 +435,6 @@
  private:
   InstrumentationLevel GetCurrentInstrumentationLevel() const;
 
-  // Returns true if moving to the given instrumentation level requires the installation of stubs.
-  // False otherwise.
-  bool RequiresInstrumentationInstallation(InstrumentationLevel new_level) const;
-
   // Does the job of installing or removing instrumentation code within methods.
   // In order to support multiple clients using instrumentation at the same time,
   // the caller must pass a unique key (a string) identifying it so we remind which
diff --git a/runtime/interpreter/interpreter_common.h b/runtime/interpreter/interpreter_common.h
index 02a99e7..c9a5b44 100644
--- a/runtime/interpreter/interpreter_common.h
+++ b/runtime/interpreter/interpreter_common.h
@@ -249,16 +249,17 @@
     }
   }
   ArtMethod* method = shadow_frame.GetMethod();
+  ObjPtr<mirror::Class> declaring_class = method->GetDeclaringClass();
   // MethodVerifier refuses methods with string_idx out of bounds.
   DCHECK_LT(string_idx.index_ % mirror::DexCache::kDexCacheStringCacheSize,
-            method->GetDexFile()->NumStringIds());
+            declaring_class->GetDexFile().NumStringIds());
   ObjPtr<mirror::String> string_ptr =
-      mirror::StringDexCachePair::Lookup(method->GetDexCacheStrings(),
+      mirror::StringDexCachePair::Lookup(declaring_class->GetDexCacheStrings(),
                                          string_idx.index_,
                                          mirror::DexCache::kDexCacheStringCacheSize).Read();
   if (UNLIKELY(string_ptr == nullptr)) {
     StackHandleScope<1> hs(self);
-    Handle<mirror::DexCache> dex_cache(hs.NewHandle(method->GetDexCache()));
+    Handle<mirror::DexCache> dex_cache(hs.NewHandle(declaring_class->GetDexCache()));
     string_ptr = Runtime::Current()->GetClassLinker()->ResolveString(*method->GetDexFile(),
                                                                      string_idx,
                                                                      dex_cache);
diff --git a/runtime/jit/jit_code_cache.cc b/runtime/jit/jit_code_cache.cc
index 38c4728..93f50ad 100644
--- a/runtime/jit/jit_code_cache.cc
+++ b/runtime/jit/jit_code_cache.cc
@@ -624,38 +624,6 @@
   return CodeCacheSizeLocked();
 }
 
-// This invalidates old_method. Once this function returns one can no longer use old_method to
-// execute code unless it is fixed up. This fixup will happen later in the process of installing a
-// class redefinition.
-// TODO We should add some info to ArtMethod to note that 'old_method' has been invalidated and
-// shouldn't be used since it is no longer logically in the jit code cache.
-// TODO We should add DCHECKS that validate that the JIT is paused when this method is entered.
-void JitCodeCache::MoveObsoleteMethod(ArtMethod* old_method, ArtMethod* new_method) {
-  MutexLock mu(Thread::Current(), lock_);
-  // Update ProfilingInfo to the new one.
-  if (old_method->GetProfilingInfo(kRuntimePointerSize) != nullptr) {
-    DCHECK_EQ(old_method->GetProfilingInfo(kRuntimePointerSize)->GetMethod(), old_method);
-    ProfilingInfo* info = old_method->GetProfilingInfo(kRuntimePointerSize);
-    // Since the JIT should be paused and all threads suspended by the time this is called these
-    // checks should always pass.
-    DCHECK(!info->IsInUseByCompiler());
-    new_method->SetProfilingInfo(info);
-    info->method_ = new_method;
-  }
-  // Update method_code_map_ to point to the new method.
-  for (auto& it : method_code_map_) {
-    if (it.second == old_method) {
-      it.second = new_method;
-    }
-  }
-  // Update osr_code_map_ to point to the new method.
-  auto code_map = osr_code_map_.find(old_method);
-  if (code_map != osr_code_map_.end()) {
-    osr_code_map_.Put(new_method, code_map->second);
-    osr_code_map_.erase(old_method);
-  }
-}
-
 size_t JitCodeCache::CodeCacheSizeLocked() {
   return used_memory_for_code_;
 }
diff --git a/runtime/jit/jit_code_cache.h b/runtime/jit/jit_code_cache.h
index 5bfe661..30e2efb 100644
--- a/runtime/jit/jit_code_cache.h
+++ b/runtime/jit/jit_code_cache.h
@@ -217,11 +217,6 @@
   void DisallowInlineCacheAccess() REQUIRES(!lock_);
   void BroadcastForInlineCacheAccess() REQUIRES(!lock_);
 
-  // Notify the code cache that the method at the pointer 'old_method' is being moved to the pointer
-  // 'new_method' since it is being made obsolete.
-  void MoveObsoleteMethod(ArtMethod* old_method, ArtMethod* new_method)
-      REQUIRES(!lock_) REQUIRES(Locks::mutator_lock_);
-
  private:
   // Take ownership of maps.
   JitCodeCache(MemMap* code_map,
diff --git a/runtime/jit/profiling_info.h b/runtime/jit/profiling_info.h
index 9fbf2e3..9902bb5 100644
--- a/runtime/jit/profiling_info.h
+++ b/runtime/jit/profiling_info.h
@@ -128,9 +128,7 @@
   const uint32_t number_of_inline_caches_;
 
   // Method this profiling info is for.
-  // Not 'const' as JVMTI introduces obsolete methods that we implement by creating new ArtMethods.
-  // See JitCodeCache::MoveObsoleteMethod.
-  ArtMethod* method_;
+  ArtMethod* const method_;
 
   // Whether the ArtMethod is currently being compiled. This flag
   // is implicitly guarded by the JIT code cache lock.
diff --git a/runtime/mirror/dex_cache.h b/runtime/mirror/dex_cache.h
index 6f88cc5..ec265e5 100644
--- a/runtime/mirror/dex_cache.h
+++ b/runtime/mirror/dex_cache.h
@@ -19,6 +19,7 @@
 
 #include "array.h"
 #include "art_field.h"
+#include "art_method.h"
 #include "class.h"
 #include "dex_file_types.h"
 #include "object.h"
@@ -26,7 +27,6 @@
 
 namespace art {
 
-class ArtMethod;
 struct DexCacheOffsets;
 class DexFile;
 class ImageWriter;
diff --git a/runtime/openjdkjvmti/ti_redefine.cc b/runtime/openjdkjvmti/ti_redefine.cc
index 429409a..d0349b9 100644
--- a/runtime/openjdkjvmti/ti_redefine.cc
+++ b/runtime/openjdkjvmti/ti_redefine.cc
@@ -38,8 +38,6 @@
 #include "events-inl.h"
 #include "gc/allocation_listener.h"
 #include "instrumentation.h"
-#include "jit/jit.h"
-#include "jit/jit_code_cache.h"
 #include "jni_env_ext-inl.h"
 #include "jvmti_allocator.h"
 #include "mirror/class.h"
@@ -51,142 +49,6 @@
 
 namespace openjdkjvmti {
 
-// This visitor walks thread stacks and allocates and sets up the obsolete methods. It also does
-// some basic sanity checks that the obsolete method is sane.
-class ObsoleteMethodStackVisitor : public art::StackVisitor {
- protected:
-  ObsoleteMethodStackVisitor(
-      art::Thread* thread,
-      art::LinearAlloc* allocator,
-      const std::unordered_set<art::ArtMethod*>& obsoleted_methods,
-      /*out*/std::unordered_map<art::ArtMethod*, art::ArtMethod*>* obsolete_maps,
-      /*out*/bool* success,
-      /*out*/std::string* error_msg)
-        : StackVisitor(thread,
-                       /*context*/nullptr,
-                       StackVisitor::StackWalkKind::kIncludeInlinedFrames),
-          allocator_(allocator),
-          obsoleted_methods_(obsoleted_methods),
-          obsolete_maps_(obsolete_maps),
-          success_(success),
-          is_runtime_frame_(false),
-          error_msg_(error_msg) {}
-
-  ~ObsoleteMethodStackVisitor() OVERRIDE {}
-
- public:
-  // Returns true if we successfully installed obsolete methods on this thread, filling
-  // obsolete_maps_ with the translations if needed. Returns false and fills error_msg_ if we fail.
-  // The stack is cleaned up when we fail.
-  static bool UpdateObsoleteFrames(
-      art::Thread* thread,
-      art::LinearAlloc* allocator,
-      const std::unordered_set<art::ArtMethod*>& obsoleted_methods,
-      /*out*/std::unordered_map<art::ArtMethod*, art::ArtMethod*>* obsolete_maps,
-      /*out*/std::string* error_msg) REQUIRES(art::Locks::mutator_lock_) {
-    bool success = true;
-    ObsoleteMethodStackVisitor visitor(thread,
-                                       allocator,
-                                       obsoleted_methods,
-                                       obsolete_maps,
-                                       &success,
-                                       error_msg);
-    visitor.WalkStack();
-    if (!success) {
-      RestoreFrames(thread, *obsolete_maps);
-      return false;
-    } else {
-      return true;
-    }
-  }
-
-  static void RestoreFrames(
-      art::Thread* thread ATTRIBUTE_UNUSED,
-      const std::unordered_map<art::ArtMethod*, art::ArtMethod*>& obsolete_maps ATTRIBUTE_UNUSED)
-        REQUIRES(art::Locks::mutator_lock_) {
-    LOG(FATAL) << "Restoring stack frames is not yet supported.";
-  }
-
-  bool VisitFrame() OVERRIDE REQUIRES(art::Locks::mutator_lock_) {
-    art::ArtMethod* old_method = GetMethod();
-    // TODO REMOVE once either current_method doesn't stick around through suspend points or deopt
-    // works through runtime methods.
-    bool prev_was_runtime_frame_ = is_runtime_frame_;
-    is_runtime_frame_ = old_method->IsRuntimeMethod();
-    if (obsoleted_methods_.find(old_method) != obsoleted_methods_.end()) {
-      // This works since when we deoptimize we set shadow frames for all frames until a
-      // native/runtime transition and for those set the return PC to a function that will complete
-      // the deoptimization. This does leave us with the unfortunate side-effect that frames just
-      // below runtime frames cannot be deoptimized at the moment.
-      // TODO REMOVE once either current_method doesn't stick around through suspend points or deopt
-      // works through runtime methods.
-      // TODO b/33616143
-      if (!IsShadowFrame() && prev_was_runtime_frame_) {
-        *error_msg_ = art::StringPrintf("Deoptimization failed due to runtime method in stack.");
-        *success_ = false;
-        return false;
-      }
-      // We cannot ensure that the right dex file is used in inlined frames so we don't support
-      // redefining them.
-      DCHECK(!IsInInlinedFrame()) << "Inlined frames are not supported when using redefinition";
-      // TODO We should really support intrinsic obsolete methods.
-      // TODO We should really support redefining intrinsics.
-      // We don't support intrinsics so check for them here.
-      DCHECK(!old_method->IsIntrinsic());
-      art::ArtMethod* new_obsolete_method = nullptr;
-      auto obsolete_method_pair = obsolete_maps_->find(old_method);
-      if (obsolete_method_pair == obsolete_maps_->end()) {
-        // Create a new Obsolete Method and put it in the list.
-        art::Runtime* runtime = art::Runtime::Current();
-        art::ClassLinker* cl = runtime->GetClassLinker();
-        auto ptr_size = cl->GetImagePointerSize();
-        const size_t method_size = art::ArtMethod::Size(ptr_size);
-        auto* method_storage = allocator_->Alloc(GetThread(), method_size);
-        if (method_storage == nullptr) {
-          *success_ = false;
-          *error_msg_ = art::StringPrintf("Unable to allocate storage for obsolete version of '%s'",
-                                          old_method->PrettyMethod().c_str());
-          return false;
-        }
-        new_obsolete_method = new (method_storage) art::ArtMethod();
-        new_obsolete_method->CopyFrom(old_method, ptr_size);
-        new_obsolete_method->SetIsObsolete();
-        obsolete_maps_->insert({old_method, new_obsolete_method});
-        // Update JIT Data structures to point to the new method.
-        art::jit::Jit* jit = art::Runtime::Current()->GetJit();
-        if (jit != nullptr && jit->GetCodeCache()->ContainsMethod(old_method)) {
-          // Notify the JIT we are making this obsolete method. It will update it's maps and change
-          // entrypoint etc over.
-          jit->GetCodeCache()->MoveObsoleteMethod(old_method, new_obsolete_method);
-        }
-        DCHECK_EQ(new_obsolete_method->GetDeclaringClass(), old_method->GetDeclaringClass());
-      } else {
-        new_obsolete_method = obsolete_method_pair->second;
-      }
-      DCHECK(new_obsolete_method != nullptr);
-      SetMethod(new_obsolete_method);
-    }
-    *success_ = true;
-    return true;
-  }
-
- private:
-  // The linear allocator we should use to make new methods.
-  art::LinearAlloc* allocator_;
-  // The set of all methods which could be obsoleted.
-  const std::unordered_set<art::ArtMethod*>& obsoleted_methods_;
-  // A map from the original to the newly allocated obsolete method for frames on this thread. The
-  // values in this map must be added to the obsolete_methods_ (and obsolete_dex_caches_) fields of
-  // the redefined classes ClassExt by the caller.
-  std::unordered_map<art::ArtMethod*, art::ArtMethod*>* obsolete_maps_;
-  bool* success_;
-  // TODO REMOVE once either current_method doesn't stick around through suspend points or deopt
-  // works through runtime methods.
-  bool is_runtime_frame_;
-  std::string* error_msg_;
-};
-
-
 // Moves dex data to an anonymous, read-only mmap'd region.
 std::unique_ptr<art::MemMap> Redefiner::MoveDataToMemMap(const std::string& original_location,
                                                          jint data_len,
@@ -210,8 +72,6 @@
   return map;
 }
 
-// TODO This should handle doing multiple classes at once so we need to do less cleanup when things
-// go wrong.
 jvmtiError Redefiner::RedefineClass(ArtJvmTiEnv* env,
                                     art::Runtime* runtime,
                                     art::Thread* self,
@@ -252,8 +112,6 @@
     *error_msg = os.str();
     return ERR(INVALID_CLASS_FORMAT);
   }
-  // Stop JIT for the duration of this redefine.
-  art::jit::ScopedJitSuspend suspend_jit;
   // Get shared mutator lock.
   art::ScopedObjectAccess soa(self);
   art::StackHandleScope<1> hs(self);
@@ -434,109 +292,6 @@
   return true;
 }
 
-struct CallbackCtx {
-  Redefiner* const r;
-  art::LinearAlloc* allocator;
-  std::unordered_map<art::ArtMethod*, art::ArtMethod*> obsolete_map;
-  std::unordered_set<art::ArtMethod*> obsolete_methods;
-  bool success;
-  std::string* error_msg;
-
-  CallbackCtx(Redefiner* self, art::LinearAlloc* alloc, std::string* error)
-      : r(self), allocator(alloc), success(true), error_msg(error) {}
-};
-
-void DoRestoreObsoleteMethodsCallback(art::Thread* t, void* vdata) NO_THREAD_SAFETY_ANALYSIS {
-  CallbackCtx* data = reinterpret_cast<CallbackCtx*>(vdata);
-  ObsoleteMethodStackVisitor::RestoreFrames(t, data->obsolete_map);
-}
-
-void DoAllocateObsoleteMethodsCallback(art::Thread* t, void* vdata) NO_THREAD_SAFETY_ANALYSIS {
-  CallbackCtx* data = reinterpret_cast<CallbackCtx*>(vdata);
-  if (data->success) {
-    // Don't do anything if we already failed once.
-    data->success = ObsoleteMethodStackVisitor::UpdateObsoleteFrames(t,
-                                                                     data->allocator,
-                                                                     data->obsolete_methods,
-                                                                     &data->obsolete_map,
-                                                                     data->error_msg);
-  }
-}
-
-void Redefiner::AddAllDeclaredMethods(
-    art::mirror::Class* art_klass,
-    art::PointerSize ptr_size,
-    /*out*/std::unordered_set<art::ArtMethod*>* declared_methods) {
-  for (auto& m : art_klass->GetDeclaredMethods(ptr_size)) {
-    declared_methods->insert(&m);
-  }
-}
-
-bool Redefiner::AllocateObsoleteMethods(art::mirror::Class* art_klass) {
-  art::ScopedAssertNoThreadSuspension ns("No thread suspension during thread stack walking");
-  art::mirror::ClassExt* ext = art_klass->GetExtData();
-  CHECK(ext->GetObsoleteMethods() != nullptr);
-  CallbackCtx ctx(this, art_klass->GetClassLoader()->GetAllocator(), error_msg_);
-  AddAllDeclaredMethods(art_klass, art::kRuntimePointerSize, &ctx.obsolete_methods);
-  for (art::ArtMethod* old_method : ctx.obsolete_methods) {
-    if (old_method->IsIntrinsic()) {
-      *error_msg_ = art::StringPrintf("Method '%s' is intrinsic and cannot be made obsolete!",
-                                      old_method->PrettyMethod().c_str());
-      return false;
-    }
-  }
-  {
-    art::MutexLock mu(self_, *art::Locks::thread_list_lock_);
-    art::ThreadList* list = art::Runtime::Current()->GetThreadList();
-    list->ForEach(DoAllocateObsoleteMethodsCallback, static_cast<void*>(&ctx));
-    if (!ctx.success) {
-      list->ForEach(DoRestoreObsoleteMethodsCallback, static_cast<void*>(&ctx));
-      return false;
-    }
-  }
-  FillObsoleteMethodMap(art_klass, ctx.obsolete_map);
-  return true;
-}
-
-void Redefiner::FillObsoleteMethodMap(
-    art::mirror::Class* art_klass,
-    const std::unordered_map<art::ArtMethod*, art::ArtMethod*>& obsoletes) {
-  int32_t index = 0;
-  art::mirror::ClassExt* ext_data = art_klass->GetExtData();
-  art::mirror::PointerArray* obsolete_methods = ext_data->GetObsoleteMethods();
-  art::mirror::ObjectArray<art::mirror::DexCache>* obsolete_dex_caches =
-      ext_data->GetObsoleteDexCaches();
-  int32_t num_method_slots = obsolete_methods->GetLength();
-  // Find the first empty index.
-  for (; index < num_method_slots; index++) {
-    if (obsolete_methods->GetElementPtrSize<art::ArtMethod*>(
-          index, art::kRuntimePointerSize) == nullptr) {
-      break;
-    }
-  }
-  // Make sure we have enough space.
-  CHECK_GT(num_method_slots, static_cast<int32_t>(obsoletes.size() + index));
-  CHECK(obsolete_dex_caches->Get(index) == nullptr);
-  // Fill in the map.
-  for (auto& obs : obsoletes) {
-    obsolete_methods->SetElementPtrSize(index, obs.second, art::kRuntimePointerSize);
-    obsolete_dex_caches->Set(index, art_klass->GetDexCache());
-    index++;
-  }
-}
-
-// TODO It should be possible to only deoptimize the specific obsolete methods.
-// TODO ReJitEverything can (sort of) fail. In certain cases it will skip deoptimizing some frames.
-// If one of these frames is an obsolete method we have a problem. b/33616143
-// TODO This shouldn't be necessary once we can ensure that the current method is not kept in
-// registers across suspend points.
-// TODO Pending b/33630159
-void Redefiner::EnsureObsoleteMethodsAreDeoptimized() {
-  art::ScopedAssertNoThreadSuspension nts("Deoptimizing everything!");
-  art::instrumentation::Instrumentation* i = runtime_->GetInstrumentation();
-  i->ReJitEverything("libOpenJkdJvmti - Class Redefinition");
-}
-
 jvmtiError Redefiner::Run() {
   art::StackHandleScope<5> hs(self_);
   // TODO We might want to have a global lock (or one based on the class being redefined at least)
@@ -586,8 +341,7 @@
   art::ObjPtr<art::mirror::LongArray> original_dex_file_cookie(nullptr);
   if (!UpdateJavaDexFile(java_dex_file.Get(),
                          new_dex_file_cookie.Get(),
-                         &original_dex_file_cookie) ||
-      !AllocateObsoleteMethods(art_class.Get())) {
+                         &original_dex_file_cookie)) {
     // Release suspendAll
     runtime_->GetThreadList()->ResumeAll();
     // Get back shared mutator lock as expected for return.
@@ -603,20 +357,18 @@
     self_->TransitionFromSuspendedToRunnable();
     return result_;
   }
-  // Ensure that obsolete methods are deoptimized. This is needed since optimized methods may have
-  // pointers to their ArtMethod's stashed in registers that they then use to attempt to hit the
-  // DexCache.
-  // TODO This can fail (leave some methods optimized) near runtime methods (including
-  // quick-to-interpreter transition function).
-  // TODO Mingyao@ suggested we could maybe just do a retry loop instead of fixing the above.
-  // TODO We probably don't need this at all once we have a way to ensure that the
-  // current_art_method is never stashed in a (physical) register by the JIT and lost to the
-  // stack-walker.
-  EnsureObsoleteMethodsAreDeoptimized();
-  // TODO Verify the new Class.
-  // TODO   Failure then undo updates to class
-  // TODO Shrink the obsolete method maps if possible?
-  // TODO find appropriate class loader.
+  // Update the ClassObjects Keep the old DexCache (and other stuff) around so we can restore
+  // functions/fields.
+  // Verify the new Class.
+  //   Failure then undo updates to class
+  // Do stack walks and allocate obsolete methods
+  // Shrink the obsolete method maps if possible?
+  // TODO find appropriate class loader. Allocate new dex files array. Pause all java treads.
+  // Replace dex files array. Do stack scan + allocate obsoletes. Remove array if possible.
+  // TODO We might want to ensure that all threads are stopped for this!
+  // AddDexToClassPath();
+  // TODO
+  // Release suspendAll
   // TODO Put this into a scoped thing.
   runtime_->GetThreadList()->ResumeAll();
   // Get back shared mutator lock as expected for return.
@@ -669,23 +421,19 @@
     }
     const art::DexFile::ProtoId* proto_id = dex_file_->FindProtoId(method_return_idx,
                                                                    new_type_list);
-    // TODO Return false, cleanup.
     CHECK(proto_id != nullptr || old_type_list == nullptr);
+    // TODO Return false, cleanup.
     const art::DexFile::MethodId* method_id = dex_file_->FindMethodId(declaring_class_id,
                                                                       *new_name_id,
                                                                       *proto_id);
-    // TODO Return false, cleanup.
     CHECK(method_id != nullptr);
+    // TODO Return false, cleanup.
     uint32_t dex_method_idx = dex_file_->GetIndexForMethodId(*method_id);
     method.SetDexMethodIndex(dex_method_idx);
     linker->SetEntryPointsToInterpreter(&method);
     method.SetCodeItemOffset(dex_file_->FindCodeItemOffset(*class_def, dex_method_idx));
     method.SetDexCacheResolvedMethods(new_dex_cache->GetResolvedMethods(), image_pointer_size);
     method.SetDexCacheResolvedTypes(new_dex_cache->GetResolvedTypes(), image_pointer_size);
-    if (!method.IsNative()) {
-      // Reset profiling info.
-      method.SetProfilingInfo(nullptr);
-    }
   }
   // Update the class fields.
   // Need to update class last since the ArtMethod gets its DexFile from the class (which is needed
diff --git a/runtime/openjdkjvmti/ti_redefine.h b/runtime/openjdkjvmti/ti_redefine.h
index 2e3df0c..c819acd 100644
--- a/runtime/openjdkjvmti/ti_redefine.h
+++ b/runtime/openjdkjvmti/ti_redefine.h
@@ -64,8 +64,6 @@
 namespace openjdkjvmti {
 
 // Class that can redefine a single class's methods.
-// TODO We should really make this be driven by an outside class so we can do multiple classes at
-// the same time and have less required cleanup.
 class Redefiner {
  public:
   // Redefine the given class with the given dex data. Note this function does not take ownership of
@@ -126,15 +124,6 @@
   // in the future. For now we will just take the memory hit.
   bool EnsureClassAllocationsFinished() REQUIRES_SHARED(art::Locks::mutator_lock_);
 
-  // Ensure that obsolete methods are deoptimized. This is needed since optimized methods may have
-  // pointers to their ArtMethods stashed in registers that they then use to attempt to hit the
-  // DexCache.
-  // TODO Make this fallible
-  void EnsureObsoleteMethodsAreDeoptimized()
-      REQUIRES(art::Locks::mutator_lock_)
-      REQUIRES(!art::Locks::thread_list_lock_,
-               !art::Locks::classlinker_classes_lock_);
-
   art::mirror::ClassLoader* GetClassLoader() REQUIRES_SHARED(art::Locks::mutator_lock_);
 
   // This finds the java.lang.DexFile we will add the native DexFile to as part of the classpath.
@@ -173,17 +162,6 @@
   bool UpdateClass(art::ObjPtr<art::mirror::Class> mclass,
                    art::ObjPtr<art::mirror::DexCache> new_dex_cache)
       REQUIRES(art::Locks::mutator_lock_);
-
-  bool AllocateObsoleteMethods(art::mirror::Class* art_klass) REQUIRES(art::Locks::mutator_lock_);
-
-  void AddAllDeclaredMethods(art::mirror::Class* art_klass,
-                             art::PointerSize ptr_size,
-                             /*out*/std::unordered_set<art::ArtMethod*>* declared_methods)
-      REQUIRES_SHARED(art::Locks::mutator_lock_);
-
-  void FillObsoleteMethodMap(art::mirror::Class* art_klass,
-                             const std::unordered_map<art::ArtMethod*, art::ArtMethod*>& obsoletes)
-      REQUIRES(art::Locks::mutator_lock_);
 };
 
 }  // namespace openjdkjvmti
diff --git a/runtime/stack.cc b/runtime/stack.cc
index 726ca2f..792da88 100644
--- a/runtime/stack.cc
+++ b/runtime/stack.cc
@@ -614,23 +614,6 @@
   return result;
 }
 
-static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
-                                                                                uint32_t depth) {
-  CHECK_LT(depth, thread->GetInstrumentationStack()->size());
-  return thread->GetInstrumentationStack()->at(depth);
-}
-
-void StackVisitor::SetMethod(ArtMethod* method) {
-  DCHECK(GetMethod() != nullptr);
-  if (cur_shadow_frame_ != nullptr) {
-    cur_shadow_frame_->SetMethod(method);
-  } else {
-    DCHECK(cur_quick_frame_ != nullptr);
-    CHECK(!IsInInlinedFrame()) << "We do not support setting inlined method's ArtMethod!";
-      *cur_quick_frame_ = method;
-  }
-}
-
 static void AssertPcIsWithinQuickCode(ArtMethod* method, uintptr_t pc)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   if (method->IsNative() || method->IsRuntimeMethod() || method->IsProxyMethod()) {
@@ -792,8 +775,8 @@
 void StackVisitor::WalkStack(bool include_transitions) {
   DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
   CHECK_EQ(cur_depth_, 0U);
-  size_t instrumentation_stack_depth = 0;
   bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
+  uint32_t instrumentation_stack_depth = 0;
   size_t inlined_frames_count = 0;
 
   for (const ManagedStack* current_fragment = thread_->GetManagedStack();
@@ -856,7 +839,7 @@
           if (reinterpret_cast<uintptr_t>(GetQuickInstrumentationExitPc()) == return_pc) {
             CHECK_LT(instrumentation_stack_depth, thread_->GetInstrumentationStack()->size());
             const instrumentation::InstrumentationStackFrame& instrumentation_frame =
-                GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
+                thread_->GetInstrumentationStack()->at(instrumentation_stack_depth);
             instrumentation_stack_depth++;
             if (GetMethod() ==
                 Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAllCalleeSaves)) {
diff --git a/runtime/stack.h b/runtime/stack.h
index 9dceb29..b1e99e5 100644
--- a/runtime/stack.h
+++ b/runtime/stack.h
@@ -327,12 +327,6 @@
     }
   }
 
-  void SetMethod(ArtMethod* method) REQUIRES(Locks::mutator_lock_) {
-    DCHECK(method != nullptr);
-    DCHECK(method_ != nullptr);
-    method_ = method;
-  }
-
   ArtMethod* GetMethod() const REQUIRES_SHARED(Locks::mutator_lock_) {
     DCHECK(method_ != nullptr);
     return method_;
@@ -616,10 +610,6 @@
 
   ArtMethod* GetMethod() const REQUIRES_SHARED(Locks::mutator_lock_);
 
-  // Sets this stack frame's method pointer. This requires a full lock of the MutatorLock. This
-  // doesn't work with inlined methods.
-  void SetMethod(ArtMethod* method) REQUIRES(Locks::mutator_lock_);
-
   ArtMethod* GetOuterMethod() const {
     return *GetCurrentQuickFrame();
   }