Apache web server for windows - 756 Part VI . Programming in Linux .
756 Part VI . Programming in Linux . Preemptive multitasking . Its multiuser design . Interprocess communication . The building blocks approach Let s take a closer look at each of these features. The Process Model The process model is the way that Linux creates and manages running processes. Provided that a process has the necessary privileges, it can create (or spawn) other processes, referred to as child processes. The parent process can also exchange data with child processes. Of course, the capability to create child processes is not unique to Linux, but the particular way in which Linux does so is characteristic of all UNIX-like systems. When a process calls the fork() system call, it creates an exact copy of itself. After being created by the fork() call, the child process typically calls one of a family of functions collectively known as exec(), providing a program to execute and any options or arguments to that program. Listing 28-1 illustrates the fork()/exec() process. Actually, the child process created when a process fork()s, isn t an exact duplicate of the parent. The process ID (PID) of the child process is different, as is the parent PID (PPID); any file locks held by the parent are reset, and any signals pending for the parent are cleared in the child. Listing 28-1: Simple fork() and exec() Sequence /* * forkexec.c - illustrate simple fork/exec usage */ #include
We recommend cheap and reliable webhost to host and run your web applications: Coldfusion Web Hosting services.