Using background threads for long processes in MFC

15 Apr 2003 11:20 mfc mfc-background-threads

It’s not easy to write a Windows program that takes a long time to do something and yet still seems responsive to the user. Consider that you’ve got a single task that needs to be finished:

The task is going to take too long to simply use an hourglass.
Progress reporting (percentages, for example) is relatively infrequent.

This article will lay out a couple of different ways to solve this problem. It’s broken down into reasonably-sized sections:

Introduction (this post; 15 Apr 2003 11:20 )
Sidebar: The Task ( 15 Apr 2003 11:30 )
Foreground Thread 1 ( 15 Apr 2003 11:41 )
Foreground Thread 2 ( 15 Apr 2003 11:42 )
Foreground Thread 3 ( 15 Apr 2003 11:43 )
Background Thread 1 ( 15 Apr 2003 11:51 )
Background Thread 2 ( 15 Apr 2003 11:52 )
Background Thread 3 ( 15 Apr 2003 11:53 )
Background Thread 4 ( 15 Apr 2003 11:54 )

Test Harness

We’ll start with a test program. The simplest thing to do is to fire up Visual C++ and generate a brand-new MFC dialog application. We can then put buttons on it, so that we can experiment with different ways to schedule the task.