tailieunhanh - Web Server Programming phần 2

Thói quen của bạn sẽ được gọi để trả về kết quả của một hoạt động so sánh trên hai yếu tố từ mảng - những yếu tố này sẽ phải được đặt trong các biến toàn cầu $ a và $ b trước khi các cuộc gọi đến chương trình con của bạn. (Này sử dụng các biến toàn cầu cụ thể là những gì làm cho những chương trình con loại khác nhau | Apache s processes 49 collection pool of pre-forked processes to reduce the time delays and costs that are associated with the creation of new processes. There is a principal process the chief that monitors the port socket combination where TCP IP connection requests are received from clients. This chief process never handles any HTTP requests from the clients instead it distributes this work to subordinate processes the tribesmen . Each Apache tribesman acts as a serial server dealing with one client at a time. When a tribesman process finishes with a client it returns to the pool managed by the chief. As well as being responsible for the distribution of work the chief process is also responsible adjusting the number of child tribesmen processes. If there are too few tribesmen clients requests will be delayed if there are too many tribesmen system resources are wasted the computer may have other work it could do and such work may be slowed if most of the main memory is allocated to Apache processes . The Apache process group is started and stopped using scripts supplied as part of the package the Windows version of Apache is installed with start and stop shortcuts in the Start menu . The first Apache process that is created becomes the chief it reads the configuration files and forks a number of child processes. These child processes all immediately block at locks controlled by the chief. The chief process and its children share some memory this is implementation-dependent it may be a shared file rather than a shared memory segment . This shared memory scoreboard structure holds data that the chief uses to monitor its tribesmen and the lock structures that the chief uses to control operations by tribesmen. When the chief has created its initial pool of tribesmen it starts to monitor its socket for the HTTP port usually port 80 blocking until there is input at this socket. When a client attempts a TCP IP connection the socket is activated and the chief process .