Processes(IM: O)

Inside Macintosh: Overview /

Chapter 9 - Processes
Your application is usually only one of several applications that a user has open at one time. Your application must therefore share the available system resources such as the central processing unit (CPU) and the available random-access memory (RAM). The Macintosh Operating System uses a very simple and elegant method for your application to coordinate its actions with those of other open applications. The Process Manager sends events, through the Event Manager, to your application informing it of impending changes in your application's processing status. Your application needs to respond to those events in the appropriate way to ensure the smooth operation of all open applications.
This chapter describes what you need to do to ensure that your application operates smoothly in the Macintosh Operating System. It describes how your application is launched and how the Operating System controls access to the CPU and other system resources to create a cooperative multitasking environment in which your application and any other open applications execute. This environment is managed primarily by the Process Manager, which is responsible for launching processes, scheduling their use of the available system resources, and handling their termination. This chapter shows how to

indicate the desired size of your application's memory partition
suspend your application's execution when another application needs the CPU
resume execution when your application regains control of the CPU
terminate your application when the user quits or when a serious error occurs
determine what software and hardware features are available on a particular machine

For a complete description of the cooperative multitasking environment, see the chapter "Process Manager" in Inside Macintosh: Processes. For a complete description of how to handle suspend and resume events, see the chapter "Event Manager" in Inside Macintosh: Macintosh Toolbox Essentials.

Chapter Contents

About Processes

Specifying Processing Options

Handling Suspend and Resume Events

Handling Null Events

Quitting an Application

Handling Errors

Checking the Operating Environment