When to parallelize code

Before you start parallelizing code, you should understand whether the particular code is a good candidate for parallelization or not. There are some typical examples where parallelization is particularly simple, and there are some where it is really hard to implement.

One of the most common examples is executing long parts of code in the main thread. In Delphi, the main thread is the only one responsible for managing the user interface. If it is running a long task and not processing user interface events, then the user interface is blocked. We can solve this problem by moving the long task into a background thread, which will allow the main thread to manage the user interface. A responsive program makes for a happy user, as I like to say.

Note

Android applications have a separate thread dedicated to running the user interface – the UI thread. This thread is similar to the main thread on Windows as you should not run any long-running operations...