name : heap-statistics.h // Copyright 2021 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef INCLUDE_CPPGC_HEAP_STATISTICS_H_ #define INCLUDE_CPPGC_HEAP_STATISTICS_H_ #include <cstddef> #include <cstdint> #include <string> #include <vector> namespace cppgc { /** * `HeapStatistics` contains memory consumption and utilization statistics for a * cppgc heap. */ struct HeapStatistics final { /** * Specifies the detail level of the heap statistics. Brief statistics contain * only the top-level allocated and used memory statistics for the entire * heap. Detailed statistics also contain a break down per space and page, as * well as freelist statistics and object type histograms. Note that used * memory reported by brief statistics and detailed statistics might differ * slightly. */ enum DetailLevel : uint8_t { kBrief, kDetailed, }; /** * Object statistics for a single type. */ struct ObjectStatsEntry { /** * Number of allocated bytes. */ size_t allocated_bytes; /** * Number of allocated objects. */ size_t object_count; }; /** * Page granularity statistics. For each page the statistics record the * allocated memory size and overall used memory size for the page. */ struct PageStatistics { /** Overall committed amount of memory for the page. */ size_t committed_size_bytes = 0; /** Resident amount of memory held by the page. */ size_t resident_size_bytes = 0; /** Amount of memory actually used on the page. */ size_t used_size_bytes = 0; /** Statistics for object allocated on the page. Filled only when * NameProvider::SupportsCppClassNamesAsObjectNames() is true. */ std::vector<ObjectStatsEntry> object_statistics; }; /** * Statistics of the freelist (used only in non-large object spaces). For * each bucket in the freelist the statistics record the bucket size, the * number of freelist entries in the bucket, and the overall allocated memory * consumed by these freelist entries. */ struct FreeListStatistics { /** bucket sizes in the freelist. */ std::vector<size_t> bucket_size; /** number of freelist entries per bucket. */ std::vector<size_t> free_count; /** memory size consumed by freelist entries per size. */ std::vector<size_t> free_size; }; /** * Space granularity statistics. For each space the statistics record the * space name, the amount of allocated memory and overall used memory for the * space. The statistics also contain statistics for each of the space's * pages, its freelist and the objects allocated on the space. */ struct SpaceStatistics { /** The space name */ std::string name; /** Overall committed amount of memory for the heap. */ size_t committed_size_bytes = 0; /** Resident amount of memory held by the heap. */ size_t resident_size_bytes = 0; /** Amount of memory actually used on the space. */ size_t used_size_bytes = 0; /** Statistics for each of the pages in the space. */ std::vector<PageStatistics> page_stats; /** Statistics for the freelist of the space. */ FreeListStatistics free_list_stats; }; /** Overall committed amount of memory for the heap. */ size_t committed_size_bytes = 0; /** Resident amount of memory held by the heap. */ size_t resident_size_bytes = 0; /** Amount of memory actually used on the heap. */ size_t used_size_bytes = 0; /** Detail level of this HeapStatistics. */ DetailLevel detail_level; /** Statistics for each of the spaces in the heap. Filled only when * `detail_level` is `DetailLevel::kDetailed`. */ std::vector<SpaceStatistics> space_stats; /** * Vector of `cppgc::GarbageCollected` type names. */ std::vector<std::string> type_names; }; } // namespace cppgc #endif // INCLUDE_CPPGC_HEAP_STATISTICS_H_