Timothy Lochner

One major recurring problem with all these Async talks at #CppCon is that they assume the program starts with main(), or you will eventually wait. For simple “script-like” applications that’s fine. For anything larger, it’s insufficient.

If we want a paradigm of parallelism we have to stop thinking that your program’s entry point is main. A parallel applications’s entry point is the first task. That task spawns more tasks. When there are no active tasks, the program is ready to exit.

Main() should initialize your tasks queue and launch Task0. You real application starts there. Wait of any kind should be forbidden. If you truly can’t continue execution until some condition is met, you reschedule the current task.

Your application “loop” is done by the tail task scheduling the head task again. This sort of looping is rarely addressed. Yeah we get parallel loops. Those aren’t the challenging part. Those are “embarrassingly” easy.

We need to talk about the entire application being a parallel/concurrent application, starting from your entry point.