mmap file

algorithm 6 describes the pseudo code as shown.Figure 6 Linux Cache replacement algorithm descriptionMark_accessed (b) {if b.state== (unactive unreference) b.state = REFERENCE else if b.state = = (unactive REFERENCE) {b.state = (ACTIVE unreference) Add X to Tail of active_list} else if b.state = = (Active unreference) B.state = (ACTIVE REFERENCE)}reclaim () {if active_list not empty and scan_num Back to top of page5

First, the PHP system file processing /* PHP File System processing * All file processing is done using system functions. * is based on LINUX/UNIX system for Model * * File system processing function: * 1. All projects are inseparable from file processing * 2. You can save

1. Functions based on downloading files on the Web Public Function Putfile ($file _dir, $file _name) {$file _dir = Chop ($file _dir);//Remove extra spaces in the path//Get the path of the file to download if ($file

are three important concepts: compile, link, or link, and load ). The source program file is compiled into the target file, multiple target files are connected into a final executable file, and the executable file is loaded into the memory for running. This article focuses on the formats of executable files, so the lo

a specific byte alignment, relative to the beginning of the file. When installed on a device, ensure that alignment on a 4-byte boundary provides performance optimizations. When aligned, the Android system is able to read files using mmap (), even if they contain binary data with alignment restrictions, rather than copying all the data from the package. The benefit is that the amount consumed by running th

Linux file type and vice file name Always emphasize a concept, that is: Any device under Linux are files, not only that, even the interface of data communication has a proprietary file in charge ~ So, you will? solution, Linux file type is really a lot of ~ In addition to the general

unreference)B.state = (ACTIVE REFERENCE)}Reclaim () {If active_list not empty and scan_num{X = Head of Active_listif (x.state REFERENCE) = = 0Add X to Tail of inactive_listelse {X.state = ~referenceMove X to Tail of active_list}scan_num++}Scan_num = 0If Inactive_list not emptry and Scan_num max_scan2 {X = Head of Inactive_listif (x.state REFERENCE) = = 0Return Xelse {X.state = ACTIVE | UnreferenceMove X to Tail of active_list}scan_num++}Return NULL}Access (b) {If B is not in cache {If slot

Proc/pid/maps shows the memory regions and access rights mapped by the process. The operation set in the corresponding kernel is proc_pid_maps_op, and the specific export function is Show_map. A segment of the process's address space in the kernel is represented by a vm_area_struct struct, and all address spaces are stored in the Task->mm->mmap list.A file can be mapped to a memory area of the process, and

= (ACTIVE REFERENCE)}reclaim () {if active_list not empty and scan_num Back to top of page5 File cache related API and its implementationThere are many APIs related to file cache operation in the Linux kernel, which can be divided into two categories according to their usage: one is the related interface which is operated in copy mode, such as Read/write/sendfile, etc. The sendfile is no longer supported

PHP file packaging and downloading: Use the ZipArchive zip file that comes with PHP and download the packaged file. Summary: Four headers () are required for downloading files using PHP. For more information, see my another blog post: how PHP implements the download function? Detailed Process Analysis When calculating the fi