README.md
1# The Part of Memory Base Libraries
2
3- [Introduction](#section_introduction)
4- [Architecture](#section_architecture)
5- [Directory Structure](#section_catalogue)
6- [Memory Base Libraries](#section_libraries)
7 - [libdmabufheap system library](#section_libdmabufheap)
8 - [libmeminfo system library (planning)](#section_libmeminfo)
9 - [libmemleak system library (planning)](#section_libmemleak)
10 - [libpurgeable system library (planning)](#section_libpurgeable)
11 - [libspeculative system library (planning)](#section_libspeculative)
12- [Usage Guidelines](#section_usage)
13- [Repositories Involved](#section_projects)
14
15## Introduction<a name="section_introduction"></a>
16
17The part of *Memory base libraries* belongs to the subsystem named *Utils Subsystem*. It provides the system library for upper-layer services to operate memory, ensuring the stability of upper-layer services.
18
19## Architecture<a name="section_architecture"></a>
20
21**Figure 1** Memory Base Libraries architecture
22
23
24
25| Memory Base Libraries | User |
26| -------------- | -------------------------- |
27| libdmabufheap | multimedia service |
28| libmeminfo | memory manager service |
29| libmemleak | memory manager service |
30| libpurgeable | graphic service (planning) |
31| libspeculative | system service (planning) |
32
33## Directory Structure<a name="section_catalogue"></a>
34
35```
36/utils/memory
37├── libdmabufheap # DMA (Direct Memory Access) memory allocation system library
38│ ├── include # DMA memory allocation system library header directory
39│ ├── src # DMA memory allocation system library source directory
40│ └── test # DMA memory allocation system library usecase directory
41├── libmeminfo # Memory footprint management library
42├── libmemleak # Memory leak detection library
43├── libpurgeable # Purgeable memory management library
44└── libspeculative # Speculative memory management library
45```
46
47## Memory Base Libraries<a name="section_libraries"></a>
48
49*Memory base libraries* is a component of the system library that integrates memory operations and manages them in a unified manner.
50
51### libdmabufheap system library<a name="section_libdmabufheap"></a>
52
53The memory system library provides interfaces for the multimedia service to allocate and share shared memory. By allocating and sharing memory between hardware devices and user space, zero-copy memory between devices and processes is implemented to improve execution efficiency.
54
55### libmeminfo system library (planning)<a name="section_libmeminfo"></a>
56
57It provides interfaces for memory usage queries. It is used for memory footprint query, low memory killing and other scenarios.
58
59### libmemleak system library (planning)<a name="section_libmemleak"></a>
60
61It cooperates with malloc_debug to detect memory leaks of native heap.
62
63### libpurgeable system library (planning)<a name="section_libpurgeable"></a>
64
65It provides management interfaces for discardable-type memory.
66
67### libspeculative system library (planning)<a name="section_libspeculative"></a>
68
69It provides management interfaces for speculative-type memory. It is mainly used by system services for data pre-loading.
70
71## Usage Guidelines<a name="section_usage"></a>
72
73System developers can add or remove this part by configuring the product definition JSON file under **/productdefine/common/products** to enable or disable this part:
74
75` "utils:utils_memory":{} `
76
77## Repositories Involved<a name="section_projects"></a>
78
79[utils](https://gitee.com/openharmony/utils)
README_ZH.md
1# 内存基础库部件
2
3- [简介](#section_introduction)
4- [部件架构](#section_architecture)
5- [目录](#section_catalogue)
6- [内存基础库](#section_libraries)
7 - [libdmabufheap系统库](#section_libdmabufheap)
8 - [libmeminfo系统库（规划中）](#section_libmeminfo)
9 - [libmemleak系统库（规划中）](#section_libmemleak)
10 - [libpurgeable系统库（规划中）](#section_libpurgeable)
11 - [libspeculative系统库（规划中）](#section_libspeculative)
12- [使用说明](#section_usage)
13- [相关仓](#section_projects)
14
15## 简介<a name="section_introduction"></a>
16
17内存基础库部件位于公共基础库子系统中，为上层业务提供对应的操作内存的系统库，保证上层业务的稳定性。
18
19## 部件架构<a name="section_architecture"></a>
20
21**图1** 内存基础库部件架构图
22
23
24
25| 内存基础库 | 使用者 |
26| -------------- | -------------------------- |
27| libdmabufheap | 多媒体相关服务 |
28| libmeminfo | 内存管理服务 |
29| libmemleak | 内存管理服务 |
30| libpurgeable | 图形图像相关服务（规划中） |
31| libspeculative | 系统服务（规划中） |
32
33## 目录<a name="section_catalogue"></a>
34
35```
36/utils/memory
37├── libdmabufheap # DMA (Direct Memory Access) 内存分配链接库
38│ ├── include # DMA内存分配链接库头文件目录
39│ ├── src # DMA内存分配链接库源代码目录
40│ └── test # DMA内存分配链接库自测用例目录
41├── libmeminfo # 内存占用查询库
42├── libmemleak # 内存泄漏检测库
43├── libpurgeable # 可丢弃类型内存管理库
44└── libspeculative # 投机类型内存管理库
45```
46
47## 内存基础库<a name="section_libraries"></a>
48
49内存基础库是集成内存操作的系统库的部件，对内存操作的系统库进行统一管理。
50
51### libdmabufheap系统库<a name="section_libdmabufheap"></a>
52
53为多媒体相关服务提供分配共享内存的接口，通过在硬件设备和用户空间之间分配和共享内存，实现
54设备、进程间零拷贝内存，提升执行效率。
55
56### libmeminfo系统库（规划中）<a name="section_libmeminfo"></a>
57
58提供内存占用查询接口，用于内存占用信息查询、低内存查杀等场景。
59
60### libmemleak系统库（规划中）<a name="section_libmemleak"></a>
61
62配合malloc_debug做native heap内存泄漏检测。
63
64### libpurgeable系统库（规划中）<a name="section_libpurgeable"></a>
65
66提供可丢弃类型内存的管理接口。
67
68### libspeculative系统库（规划中）<a name="section_libspeculative"></a>
69
70提供投机类型内存管理接口，用于缓存预读。
71
72## 使用说明<a name="section_usage"></a>
73
74系统开发者可以通过配置productdefine/common/products下的产品定义json文件，增加或移除本部件，来启用或停用本部件。
75
76` "utils:utils_memory":{} `
77
78## 相关仓<a name="section_projects"></a>
79
80[公共基础库子系统](https://gitee.com/openharmony/utils)
