Windows® via C/C++, Fifth Edition

Programming Priorities

So how is a process assigned a priority class? Well, when you call CreateProcess, you can pass the desired priority class in the fdwCreate parameter. Table 7-5 shows the priority class identifiers.

Table 7-5. Process Priority Classes

Priority Class	Symbolic Identifiers
Real-time	REALTIME_PRIORITY_CLASS
High	HIGH_PRIORITY_CLASS
Above normal	ABOVE_NORMAL_PRIORITY_CLASS
Normal	NORMAL_PRIORITY_CLASS
Below normal	BELOW_NORMAL_PRIORITY_CLASS
Idle	IDLE_PRIORITY_CLASS

It might seem odd that the process that creates a child process chooses the priority class at which the child process runs. Let’s consider Windows Explorer as an example. When you use Windows Explorer to run an application, the new process runs at normal priority. Windows Explorer ...