memory mapped files c tutorial

There are three ways in which memory management works:1. Virtual memory, functions such as VirtualAlloc2. Heap, heapxxx function, malloc,new, etc.3. Memory-mapped files, Mapped fileMany people will be confused, but look at the pic

Memory-Mapped file principle First of all, what is the problem to be solved in this article?1. The difference and connection between virtual memory and memory-mapped file.2. The principle of the memory-

Memory-mapped files allow you to create and modify files that are too large to fit into memory. With a memory-mapped file, you can assume that the file has all been read into

is mapped to the process address space, the process can access the file like normal memory without having to call read (), write (), and so on. Mmap does not allocate space, but maps files to the address space of the calling process (but takes up your virutal memory), and then you can write

results:sum:0 time:1458sum:0 time:67sum:0 Time:8This shows that some or all of the files are mapped to memory after reading and writing, the speed will be much higher.This is because the memory-mapped file first maps the file on the external

mapped to the process address space, the process can access the file like normal memory without having to call read (), write (), and so on. Mmap does not allocate space, but maps files to the address space of the calling process (but takes up your virutal memory), and then you can write

Both stand-alone and mapped memory are used to handle program data problems. Independent storage can be used to temporarily save some of the program's unimportant data, mapped memory files can be used to solve the program data reading problems. When a program needs to load a

this core windows programming technology. Memory ing file Overview Memory file ing is also a memory management method for windows. It provides a unified memory management feature that allows applications to access files on disks through

length is not specified yet. To specify the size of the physical storage space required by the file ing object, you must use the CreateFileMapping () function to create a file ing kernel object to inform the System of the file size and file access method. After creating a file ing object, you must retain an address space area for the file data and submit the file data as a physical storage mapped to the region. The MapViewOfFile () function maps all

physical storage mapped to the region. The MapViewOfFile () function maps all or part of the object mapped to the process address space through system management. In this case, the use and processing of memory ing files are basically the same as that of file data normally loaded into the

Abstract: This paper presents a convenient and practical way to solve large files, such as reading, storage and other processing, combined with related programsThe code describes the specific implementation process.IntroductionFile operations are one of the most basic features of an application, and both the WIN32 API and MFC provide support for file processingNumbers and classes, commonly used CreateFile (), WriteFile (), ReadFile () with Win32 APIs,

programmer, we cannot consider how much memory the customer's machine can use when considering the program logic, it is also impossible to investigate in detail the actual physical memory address, but the OS will do this for us. Every running process will obtain a 4 GB memory address space, which is called virtual memory