Reduce mark stack / allocation stack / live stack address space usage.
We now have upper bounds on the stack sizes so that we don't run out of
virtual addresses with large heaps.
Rename mark stack to atomic stack, which now takes any data type.
Added behaviour to force GC when the allocation stack becomes too full.
Added a new special map for reserving the oat file address range.
Change-Id: I5169dd98b5f5072ac67637798da50cb8fc68af2b
diff --git a/src/atomic_stack.h b/src/atomic_stack.h
new file mode 100644
index 0000000..3494861
--- /dev/null
+++ b/src/atomic_stack.h
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2012 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_SRC_ATOMIC_STACK_H_
+#define ART_SRC_ATOMIC_STACK_H_
+
+#include <string>
+
+#include "atomic_integer.h"
+#include "UniquePtr.h"
+#include "logging.h"
+#include "macros.h"
+#include "mem_map.h"
+#include "utils.h"
+
+namespace art {
+
+template <typename T>
+class AtomicStack {
+ public:
+ // Capacity is how many elements we can store in the stack.
+ static AtomicStack* Create(const std::string& name, size_t capacity) {
+ UniquePtr<AtomicStack> mark_stack(new AtomicStack(name, capacity));
+ mark_stack->Init();
+ return mark_stack.release();
+ }
+
+ ~AtomicStack(){
+
+ }
+
+ void Reset() {
+ DCHECK(mem_map_.get() != NULL);
+ DCHECK(begin_ != NULL);
+ front_index_ = 0;
+ back_index_ = 0;
+ int result = madvise(begin_, sizeof(T) * capacity_, MADV_DONTNEED);
+ if (result == -1) {
+ PLOG(WARNING) << "madvise failed";
+ }
+ }
+
+ // Beware: Mixing atomic pushes and atomic pops will cause ABA problem.
+
+ // Returns false if we overflowed the stack.
+ bool AtomicPushBack(const T& value) {
+ const int32_t index = back_index_++;
+ if (UNLIKELY(static_cast<size_t>(index) >= capacity_)) {
+ // Stack overflow.
+ back_index_--;
+ return false;
+ }
+ begin_[index] = value;
+ return true;
+ }
+
+ void PushBack(const T& value) {
+ int32_t index = back_index_;
+ DCHECK_LT(static_cast<size_t>(index), capacity_);
+ back_index_ = index + 1;
+ begin_[index] = value;
+ }
+
+ T PopBack() {
+ DCHECK_GT(back_index_, front_index_);
+ // Decrement the back index non atomically.
+ back_index_ = back_index_ - 1;
+ return begin_[back_index_];
+ }
+
+ T AtomicPopBack() {
+ // Decrement the back index non atomically.
+ int back_index = back_index_--;
+ DCHECK_GT(back_index, front_index_);
+ return begin_[back_index - 1];
+ }
+
+ // Take an item from the front of the stack.
+ T PopFront() {
+ int32_t index = front_index_;
+ DCHECK_LT(index, back_index_.get());
+ front_index_ = front_index_ + 1;
+ return begin_[index];
+ }
+
+ bool IsEmpty() const {
+ return Size() == 0;
+ }
+
+ size_t Size() const {
+ DCHECK_LE(front_index_, back_index_);
+ return back_index_ - front_index_;
+ }
+
+ T* Begin() {
+ return const_cast<Object**>(begin_ + front_index_);
+ }
+
+ T* End() {
+ return const_cast<Object**>(begin_ + back_index_);
+ }
+
+ size_t Capacity() const {
+ return capacity_;
+ }
+
+ // Will clear the stack.
+ void Resize(size_t new_capacity) {
+ capacity_ = new_capacity;
+ Init();
+ }
+
+ private:
+ AtomicStack(const std::string& name, const size_t capacity)
+ : name_(name),
+ back_index_(0),
+ front_index_(0),
+ begin_(NULL),
+ capacity_(capacity) {
+
+ }
+
+ // Size in number of elements.
+ void Init() {
+ mem_map_.reset(MemMap::MapAnonymous(name_.c_str(), NULL, capacity_ * sizeof(T), PROT_READ | PROT_WRITE));
+ if (mem_map_.get() == NULL) {
+ std::string maps;
+ ReadFileToString("/proc/self/maps", &maps);
+ LOG(FATAL) << "couldn't allocate mark stack\n" << maps;
+ }
+ byte* addr = mem_map_->Begin();
+ CHECK(addr != NULL);
+ begin_ = reinterpret_cast<T*>(addr);
+ Reset();
+ }
+
+ // Name of the mark stack.
+ std::string name_;
+
+ // Memory mapping of the atomic stack.
+ UniquePtr<MemMap> mem_map_;
+
+ // Back index (index after the last element pushed).
+ AtomicInteger back_index_;
+
+ // Front index, used for implementing PopFront.
+ AtomicInteger front_index_;
+
+ // Base of the atomic stack.
+ T* begin_;
+
+ // Maximum number of elements.
+ size_t capacity_;
+
+ DISALLOW_COPY_AND_ASSIGN(AtomicStack);
+};
+
+} // namespace art
+
+#endif // ART_SRC_MARK_STACK_H_