| // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #ifndef RUNTIME_VM_MEMORY_REGION_H_ |
| #define RUNTIME_VM_MEMORY_REGION_H_ |
| |
| #include "platform/assert.h" |
| #include "platform/unaligned.h" |
| #include "vm/allocation.h" |
| #include "vm/globals.h" |
| |
| namespace dart { |
| |
| // Memory regions are useful for accessing memory with bounds check in |
| // debug mode. They can be safely passed by value and do not assume ownership |
| // of the region. |
| class MemoryRegion : public ValueObject { |
| public: |
| MemoryRegion() : pointer_(nullptr), size_(0) {} |
| MemoryRegion(void* pointer, uword size) : pointer_(pointer), size_(size) {} |
| MemoryRegion(const MemoryRegion& other) : ValueObject() { *this = other; } |
| MemoryRegion& operator=(const MemoryRegion& other) { |
| pointer_ = other.pointer_; |
| size_ = other.size_; |
| return *this; |
| } |
| |
| void* pointer() const { return pointer_; } |
| uword size() const { return size_; } |
| void set_size(uword new_size) { size_ = new_size; } |
| |
| uword start() const { return reinterpret_cast<uword>(pointer_); } |
| uword end() const { return start() + size_; } |
| |
| template <typename T> |
| T Load(uword offset) const { |
| return *ComputeInternalPointer<T>(offset); |
| } |
| |
| template <typename T> |
| void Store(uword offset, T value) const { |
| *ComputeInternalPointer<T>(offset) = value; |
| } |
| |
| template <typename T> |
| void StoreUnaligned(uword offset, T value) const { |
| dart::StoreUnaligned(ComputeInternalPointer<T>(offset), value); |
| } |
| |
| template <typename T> |
| T* PointerTo(uword offset) const { |
| return ComputeInternalPointer<T>(offset); |
| } |
| |
| bool Contains(uword address) const { |
| return (address >= start()) && (address < end()); |
| } |
| |
| void CopyFrom(uword offset, const MemoryRegion& from) const; |
| |
| // Compute a sub memory region based on an existing one. |
| void Subregion(const MemoryRegion& from, uword offset, uword size) { |
| ASSERT(from.size() >= size); |
| ASSERT(offset <= (from.size() - size)); |
| pointer_ = reinterpret_cast<void*>(from.start() + offset); |
| size_ = size; |
| } |
| |
| // Compute an extended memory region based on an existing one. |
| void Extend(const MemoryRegion& region, uword extra) { |
| pointer_ = region.pointer(); |
| size_ = (region.size() + extra); |
| } |
| |
| private: |
| template <typename T> |
| T* ComputeInternalPointer(uword offset) const { |
| ASSERT(size() >= sizeof(T)); |
| ASSERT(offset <= size() - sizeof(T)); |
| return reinterpret_cast<T*>(start() + offset); |
| } |
| |
| void* pointer_; |
| uword size_; |
| }; |
| |
| } // namespace dart |
| |
| #endif // RUNTIME_VM_MEMORY_REGION_H_ |