| // Copyright (c) 2021, 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_VIRTUAL_MEMORY_COMPRESSED_H_ |
| #define RUNTIME_VM_VIRTUAL_MEMORY_COMPRESSED_H_ |
| |
| #include "vm/globals.h" |
| #include "vm/heap/page.h" |
| #include "vm/memory_region.h" |
| |
| namespace dart { |
| |
| #if defined(DART_COMPRESSED_POINTERS) |
| static constexpr intptr_t kCompressedHeapSize = 4 * GB; |
| static constexpr intptr_t kCompressedHeapAlignment = 4 * GB; |
| static constexpr intptr_t kCompressedPageSize = kPageSize; |
| static constexpr intptr_t kCompressedHeapNumPages = |
| kCompressedHeapSize / kPageSize; |
| static constexpr intptr_t kCompressedHeapBitmapSize = |
| kCompressedHeapNumPages / 8; |
| |
| #if !defined(DART_HOST_OS_FUCHSIA) |
| #define DART_COMPRESSED_HEAP |
| #endif // !defined(DART_HOST_OS_FUCHSIA) |
| #endif // defined(DART_COMPRESSED_POINTERS) |
| |
| #if defined(DART_COMPRESSED_HEAP) |
| |
| // Utilities for allocating memory within a contiguous region of memory, for use |
| // with compressed pointers. |
| class VirtualMemoryCompressedHeap : public AllStatic { |
| public: |
| // Initializes the compressed heap. The callee must allocate a region of |
| // kCompressedHeapSize bytes, aligned to kCompressedHeapSize. |
| static void Init(void* compressed_heap_region, size_t size); |
| |
| // Cleans up the compressed heap. The callee is responsible for freeing the |
| // region's memory. |
| static void Cleanup(); |
| |
| // Allocates a segment of the compressed heap with the given size. Returns a |
| // heap memory region if a large enough free segment can't be found. |
| static MemoryRegion Allocate(intptr_t size, intptr_t alignment); |
| |
| // Frees a segment. |
| static void Free(void* address, intptr_t size); |
| |
| // Returns whether the address is within the compressed heap. |
| static bool Contains(void* address); |
| |
| // Returns a pointer to the compressed heap region. |
| static void* GetRegion(); |
| |
| private: |
| static bool IsPageUsed(uword page_id); |
| static void SetPageUsed(uword page_id); |
| static void ClearPageUsed(uword page_id); |
| |
| static uword base_; |
| static uword size_; |
| static uint8_t* pages_; |
| static uword minimum_free_page_id_; |
| static Mutex* mutex_; |
| }; |
| |
| #endif // defined(DART_COMPRESSED_HEAP) |
| |
| } // namespace dart |
| |
| #endif // RUNTIME_VM_VIRTUAL_MEMORY_COMPRESSED_H_ |