Revert "lambda: Experimental support for capture-variable and liberate-variable"

Test fails.

This reverts commit b72123440d8541362ebdb131436f9dbdda5fd329.

Change-Id: Ic9ed92f8c826d8465eb36b746dc44af05caf041c
diff --git a/runtime/lambda/box_table.cc b/runtime/lambda/box_table.cc
index 8eef10b..26575fd 100644
--- a/runtime/lambda/box_table.cc
+++ b/runtime/lambda/box_table.cc
@@ -18,8 +18,6 @@
 #include "base/mutex.h"
 #include "common_throws.h"
 #include "gc_root-inl.h"
-#include "lambda/closure.h"
-#include "lambda/leaking_allocator.h"
 #include "mirror/method.h"
 #include "mirror/object-inl.h"
 #include "thread.h"
@@ -28,53 +26,11 @@
 
 namespace art {
 namespace lambda {
-// Temporarily represent the lambda Closure as its raw bytes in an array.
-// TODO: Generate a proxy class for the closure when boxing the first time.
-using BoxedClosurePointerType = mirror::ByteArray*;
-
-static mirror::Class* GetBoxedClosureClass() SHARED_REQUIRES(Locks::mutator_lock_) {
-  return mirror::ByteArray::GetArrayClass();
-}
-
-namespace {
-  // Convenience functions to allocating/deleting box table copies of the closures.
-  struct ClosureAllocator {
-    // Deletes a Closure that was allocated through ::Allocate.
-    static void Delete(Closure* ptr) {
-      delete[] reinterpret_cast<char*>(ptr);
-    }
-
-    // Returns a well-aligned pointer to a newly allocated Closure on the 'new' heap.
-    static Closure* Allocate(size_t size) {
-      DCHECK_GE(size, sizeof(Closure));
-
-      // TODO: Maybe point to the interior of the boxed closure object after we add proxy support?
-      Closure* closure = reinterpret_cast<Closure*>(new char[size]);
-      DCHECK_ALIGNED(closure, alignof(Closure));
-      return closure;
-    }
-  };
-}  // namespace
 
 BoxTable::BoxTable()
   : allow_new_weaks_(true),
     new_weaks_condition_("lambda box table allowed weaks", *Locks::lambda_table_lock_) {}
 
-BoxTable::~BoxTable() {
-  // Free all the copies of our closures.
-  for (auto map_iterator = map_.begin(); map_iterator != map_.end(); ++map_iterator) {
-    std::pair<UnorderedMapKeyType, ValueType>& key_value_pair = *map_iterator;
-
-    Closure* closure = key_value_pair.first;
-
-    // Remove from the map first, so that it doesn't try to access dangling pointer.
-    map_iterator = map_.Erase(map_iterator);
-
-    // Safe to delete, no dangling pointers.
-    ClosureAllocator::Delete(closure);
-  }
-}
-
 mirror::Object* BoxTable::BoxLambda(const ClosureType& closure) {
   Thread* self = Thread::Current();
 
@@ -102,29 +58,22 @@
 
   // Release the lambda table lock here, so that thread suspension is allowed.
 
-  // Convert the Closure into a managed byte[] which will serve
+  // Convert the ArtMethod into a java.lang.reflect.Method which will serve
   // as the temporary 'boxed' version of the lambda. This is good enough
   // to check all the basic object identities that a boxed lambda must retain.
-  // It's also good enough to contain all the captured primitive variables.
 
   // TODO: Boxing an innate lambda (i.e. made with create-lambda) should make a proxy class
   // TODO: Boxing a learned lambda (i.e. made with unbox-lambda) should return the original object
-  BoxedClosurePointerType closure_as_array_object =
-      mirror::ByteArray::Alloc(self, closure->GetSize());
-
+  mirror::Method* method_as_object =
+      mirror::Method::CreateFromArtMethod(self, closure);
   // There are no thread suspension points after this, so we don't need to put it into a handle.
 
-  if (UNLIKELY(closure_as_array_object == nullptr)) {
+  if (UNLIKELY(method_as_object == nullptr)) {
     // Most likely an OOM has occurred.
     CHECK(self->IsExceptionPending());
     return nullptr;
   }
 
-  // Write the raw closure data into the byte[].
-  closure->CopyTo(closure_as_array_object->GetRawData(sizeof(uint8_t),  // component size
-                                                      0 /*index*/),     // index
-                  closure_as_array_object->GetLength());
-
   // The method has been successfully boxed into an object, now insert it into the hash map.
   {
     MutexLock mu(self, *Locks::lambda_table_lock_);
@@ -138,56 +87,38 @@
       return value.Read();
     }
 
-    // Otherwise we need to insert it into the hash map in this thread.
-
-    // Make a copy for the box table to keep, in case the closure gets collected from the stack.
-    // TODO: GC may need to sweep for roots in the box table's copy of the closure.
-    Closure* closure_table_copy = ClosureAllocator::Allocate(closure->GetSize());
-    closure->CopyTo(closure_table_copy, closure->GetSize());
-
-    // The closure_table_copy needs to be deleted by us manually when we erase it from the map.
-
-    // Actually insert into the table.
-    map_.Insert({closure_table_copy, ValueType(closure_as_array_object)});
+    // Otherwise we should insert it into the hash map in this thread.
+    map_.Insert(std::make_pair(closure, ValueType(method_as_object)));
   }
 
-  return closure_as_array_object;
+  return method_as_object;
 }
 
 bool BoxTable::UnboxLambda(mirror::Object* object, ClosureType* out_closure) {
   DCHECK(object != nullptr);
   *out_closure = nullptr;
 
-  Thread* self = Thread::Current();
-
   // Note that we do not need to access lambda_table_lock_ here
   // since we don't need to look at the map.
 
   mirror::Object* boxed_closure_object = object;
 
-  // Raise ClassCastException if object is not instanceof byte[]
-  if (UNLIKELY(!boxed_closure_object->InstanceOf(GetBoxedClosureClass()))) {
-    ThrowClassCastException(GetBoxedClosureClass(), boxed_closure_object->GetClass());
+  // Raise ClassCastException if object is not instanceof java.lang.reflect.Method
+  if (UNLIKELY(!boxed_closure_object->InstanceOf(mirror::Method::StaticClass()))) {
+    ThrowClassCastException(mirror::Method::StaticClass(), boxed_closure_object->GetClass());
     return false;
   }
 
   // TODO(iam): We must check that the closure object extends/implements the type
-  // specified in [type id]. This is not currently implemented since it's always a byte[].
+  // specified in [type id]. This is not currently implemented since it's always a Method.
 
   // If we got this far, the inputs are valid.
-  // Shuffle the byte[] back into a raw closure, then allocate it, copy, and return it.
-  BoxedClosurePointerType boxed_closure_as_array =
-      down_cast<BoxedClosurePointerType>(boxed_closure_object);
+  // Write out the java.lang.reflect.Method's embedded ArtMethod* into the vreg target.
+  mirror::AbstractMethod* boxed_closure_as_method =
+      down_cast<mirror::AbstractMethod*>(boxed_closure_object);
 
-  const int8_t* unaligned_interior_closure = boxed_closure_as_array->GetData();
-
-  // Allocate a copy that can "escape" and copy the closure data into that.
-  Closure* unboxed_closure =
-      LeakingAllocator::MakeFlexibleInstance<Closure>(self, boxed_closure_as_array->GetLength());
-  // TODO: don't just memcpy the closure, it's unsafe when we add references to the mix.
-  memcpy(unboxed_closure, unaligned_interior_closure, boxed_closure_as_array->GetLength());
-
-  DCHECK_EQ(unboxed_closure->GetSize(), static_cast<size_t>(boxed_closure_as_array->GetLength()));
+  ArtMethod* unboxed_closure = boxed_closure_as_method->GetArtMethod();
+  DCHECK(unboxed_closure != nullptr);
 
   *out_closure = unboxed_closure;
   return true;
@@ -196,7 +127,7 @@
 BoxTable::ValueType BoxTable::FindBoxedLambda(const ClosureType& closure) const {
   auto map_iterator = map_.Find(closure);
   if (map_iterator != map_.end()) {
-    const std::pair<UnorderedMapKeyType, ValueType>& key_value_pair = *map_iterator;
+    const std::pair<ClosureType, ValueType>& key_value_pair = *map_iterator;
     const ValueType& value = key_value_pair.second;
 
     DCHECK(!value.IsNull());  // Never store null boxes.
@@ -226,7 +157,7 @@
    */
   std::vector<ClosureType> remove_list;
   for (auto map_iterator = map_.begin(); map_iterator != map_.end(); ) {
-    std::pair<UnorderedMapKeyType, ValueType>& key_value_pair = *map_iterator;
+    std::pair<ClosureType, ValueType>& key_value_pair = *map_iterator;
 
     const ValueType& old_value = key_value_pair.second;
 
@@ -235,15 +166,10 @@
     mirror::Object* new_value = visitor->IsMarked(old_value_raw);
 
     if (new_value == nullptr) {
-      // The object has been swept away.
       const ClosureType& closure = key_value_pair.first;
-
+      // The object has been swept away.
       // Delete the entry from the map.
-      map_iterator = map_.Erase(map_iterator);
-
-      // Clean up the memory by deleting the closure.
-      ClosureAllocator::Delete(closure);
-
+      map_iterator = map_.Erase(map_.Find(closure));
     } else {
       // The object has been moved.
       // Update the map.
@@ -282,33 +208,16 @@
   new_weaks_condition_.Broadcast(self);
 }
 
-void BoxTable::EmptyFn::MakeEmpty(std::pair<UnorderedMapKeyType, ValueType>& item) const {
-  item.first = nullptr;
-
-  Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
-  item.second = ValueType();  // Also clear the GC root.
-}
-
-bool BoxTable::EmptyFn::IsEmpty(const std::pair<UnorderedMapKeyType, ValueType>& item) const {
-  return item.first == nullptr;
-}
-
-bool BoxTable::EqualsFn::operator()(const UnorderedMapKeyType& lhs,
-                                    const UnorderedMapKeyType& rhs) const {
+bool BoxTable::EqualsFn::operator()(const ClosureType& lhs, const ClosureType& rhs) const {
   // Nothing needs this right now, but leave this assertion for later when
   // we need to look at the references inside of the closure.
-  Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
+  if (kIsDebugBuild) {
+    Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
+  }
 
-  return lhs->ReferenceEquals(rhs);
-}
-
-size_t BoxTable::HashFn::operator()(const UnorderedMapKeyType& key) const {
-  const lambda::Closure* closure = key;
-  DCHECK_ALIGNED(closure, alignof(lambda::Closure));
-
-  // Need to hold mutator_lock_ before calling into Closure::GetHashCode.
-  Locks::mutator_lock_->AssertSharedHeld(Thread::Current());
-  return closure->GetHashCode();
+  // TODO: Need rework to use read barriers once closures have references inside of them that can
+  // move. Until then, it's safe to just compare the data inside of it directly.
+  return lhs == rhs;
 }
 
 }  // namespace lambda