After a process has been created, it starts running and does whatever it`s job is. However, nothing lasts forever, not even processes. In both UNIX and WINDOWS, after a process is created, both the parent and child have their own distinct address spaces. If either process changes a word in its address space, the change is not visible to the other running process.
The new process gets terminated by using any of the following conditions. They are normal exit, error exit, and fatal error, killed by another process. Normal exit and error exit are voluntary whereas fatal error and termination by another process are involuntary.
Most process terminate because they have done their work and get exited. When a compiler has complied the program given to it, the complier executes a system call to tell the operating system that it has finished. This call is exit in UNIX and Exit process in windows.
Screen-oriented programs also support voluntary termination. Word processors, internet browsers and similar programs always have an icon or menu item that the user can click to tell the process to remove any temporary files it has open and then terminate.
The second reason for termination is that the process discovers a fatal error. If a user types a certain command to compile the program and no such file exists, the complier simply exists. Screen oriented interactive process generally do not exit when given bad parameters. Instead they pop up a dialog box and ask the user to try again.
The third reason for termination is an error caused by the process, often due to a program bug. Examples include executing an illegal instruction, referencing nonexistent memory, or dividing by zero. In some systems, a process can tell the operating system that it wishes to handle certain errors itself, in which case the process is signaled instead of terminated when one of the errors occurs.
The fourth reason a process might terminate is that a process executes a system call telling the operating system to kill some other process. In UNIX this call is kill. The corresponding win32 function is Terminate Process. In both cases, the killer must have the necessary authorization to do in the kill.
Quick Note: Taking the Nonsense out of looking for the right spyware remover
If you really want to take the work out of looking for that right Spyware Protection from a go to the Internet and get a or a Free
Download, In order to prevent your vital information from being ripped from your computer get your Remover Today.
In some system when a process terminates, either voluntarily or otherwise, all process it created are killed immediately as well. Neither UNIX nor Windows works this way. Termination is very important.
