Create a scoped arena allocator and use that for LVN.
This saves more than 0.5s of boot.oat compilation time
on Nexus 5.
TODO: Move other stuff to the scoped allocator. This CL
alone increases the peak memory allocation. By reusing
the memory for other parts of the compilation we should
reduce this overhead.
Change-Id: Ifbc00aab4f3afd0000da818dfe68b96713824a08
diff --git a/compiler/utils/debug_stack.h b/compiler/utils/debug_stack.h
new file mode 100644
index 0000000..2e02b43
--- /dev/null
+++ b/compiler/utils/debug_stack.h
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_UTILS_DEBUG_STACK_H_
+#define ART_COMPILER_UTILS_DEBUG_STACK_H_
+
+#include "base/logging.h"
+#include "base/macros.h"
+#include "globals.h"
+
+namespace art {
+
+// Helper classes for reference counting to enforce construction/destruction order and
+// usage of the top element of a stack in debug mode with no overhead in release mode.
+
+// Reference counter. No references allowed in destructor or in explicitly called CheckNoRefs().
+template <bool kIsDebug>
+class DebugStackRefCounterImpl;
+// Reference. Allows an explicit check that it's the top reference.
+template <bool kIsDebug>
+class DebugStackReferenceImpl;
+// Indirect top reference. Checks that the reference is the top reference when used.
+template <bool kIsDebug>
+class DebugStackIndirectTopRefImpl;
+
+typedef DebugStackRefCounterImpl<kIsDebugBuild> DebugStackRefCounter;
+typedef DebugStackReferenceImpl<kIsDebugBuild> DebugStackReference;
+typedef DebugStackIndirectTopRefImpl<kIsDebugBuild> DebugStackIndirectTopRef;
+
+// Non-debug mode specializations. This should be optimized away.
+
+template <>
+class DebugStackRefCounterImpl<false> {
+ public:
+ size_t IncrementRefCount() { return 0u; }
+ void DecrementRefCount() { }
+ size_t GetRefCount() const { return 0u; }
+ void CheckNoRefs() const { }
+};
+
+template <>
+class DebugStackReferenceImpl<false> {
+ public:
+ explicit DebugStackReferenceImpl(DebugStackRefCounterImpl<false>* counter) { UNUSED(counter); }
+ DebugStackReferenceImpl(const DebugStackReferenceImpl& other) = default;
+ DebugStackReferenceImpl& operator=(const DebugStackReferenceImpl& other) = default;
+ void CheckTop() { }
+};
+
+template <>
+class DebugStackIndirectTopRefImpl<false> {
+ public:
+ explicit DebugStackIndirectTopRefImpl(DebugStackReferenceImpl<false>* ref) { UNUSED(ref); }
+ DebugStackIndirectTopRefImpl(const DebugStackIndirectTopRefImpl& other) = default;
+ DebugStackIndirectTopRefImpl& operator=(const DebugStackIndirectTopRefImpl& other) = default;
+ void CheckTop() { }
+};
+
+// Debug mode versions.
+
+template <bool kIsDebug>
+class DebugStackRefCounterImpl {
+ public:
+ DebugStackRefCounterImpl() : ref_count_(0u) { }
+ ~DebugStackRefCounterImpl() { CheckNoRefs(); }
+ size_t IncrementRefCount() { return ++ref_count_; }
+ void DecrementRefCount() { --ref_count_; }
+ size_t GetRefCount() const { return ref_count_; }
+ void CheckNoRefs() const { CHECK_EQ(ref_count_, 0u); }
+
+ private:
+ size_t ref_count_;
+};
+
+template <bool kIsDebug>
+class DebugStackReferenceImpl {
+ public:
+ explicit DebugStackReferenceImpl(DebugStackRefCounterImpl<kIsDebug>* counter)
+ : counter_(counter), ref_count_(counter->IncrementRefCount()) {
+ }
+ DebugStackReferenceImpl(const DebugStackReferenceImpl& other)
+ : counter_(other.counter_), ref_count_(counter_->IncrementRefCount()) {
+ }
+ DebugStackReferenceImpl& operator=(const DebugStackReferenceImpl& other) {
+ CHECK(counter_ == other.counter_);
+ return *this;
+ }
+ ~DebugStackReferenceImpl() { counter_->DecrementRefCount(); }
+ void CheckTop() { CHECK_EQ(counter_->GetRefCount(), ref_count_); }
+
+ private:
+ DebugStackRefCounterImpl<true>* counter_;
+ size_t ref_count_;
+};
+
+template <bool kIsDebug>
+class DebugStackIndirectTopRefImpl {
+ public:
+ explicit DebugStackIndirectTopRefImpl(DebugStackReferenceImpl<kIsDebug>* ref)
+ : ref_(ref) {
+ CheckTop();
+ }
+ DebugStackIndirectTopRefImpl(const DebugStackIndirectTopRefImpl& other)
+ : ref_(other.ref_) {
+ CheckTop();
+ }
+ DebugStackIndirectTopRefImpl& operator=(const DebugStackIndirectTopRefImpl& other) {
+ CHECK(ref_ == other->ref_);
+ CheckTop();
+ return *this;
+ }
+ ~DebugStackIndirectTopRefImpl() {
+ CheckTop();
+ }
+ void CheckTop() {
+ ref_->CheckTop();
+ }
+
+ private:
+ DebugStackReferenceImpl<kIsDebug>* ref_;
+};
+
+} // namespace art
+
+#endif // ART_COMPILER_UTILS_DEBUG_STACK_H_