Should preemptive threads use 100% CPU?

[Thom_McGrath]

Trying out preemptive threads in a console app, and it no matter how much sleep time I give the threads or the main event loop, the process uses exactly 100% CPU in activity monitor. Is this normal? I can’t imagine it would be, but I figured I’d ask.

Switching to cooperative brings the CPU down to normal levels.

[AlbertoD]

You are not the only one:
#77526 - Preemptive Thread burning 100% CPU

Edit: here a forum topic

Preemptive Thread uses 100% CPU

Here’s a simple app which has a loop in the main thread, and a loop in a Thread. Both loops spend most of their time sleeping, e.g. while true [... do some simple string operations ...] sleep(10) wend When run using a Cooperative thread, CPU usage is low (a few %) as expected. When run using a Preemptive thread, CPU usage is pegged at 100%. preemptiveCPU.zip (6.3 KB) Reported as https://tracker.xojo.com/xojoinc/xojo/-/issues/77526

[Thom_McGrath]

Thanks. For what it’s worth, I’m not using SleepCurrent myself, but that probably doesn’t matter. Mine is just DoEvents to run the main loop, and Self.Sleep inside the thread class.

[Mike_D]

If you can test the latest beta, please do.

[Thom_McGrath]

Technically it helped. But practically it did not. I was already on the beta, but was a build or two behind. So now I’m around 98% CPU instead of 100%. Progress!

[Ian_Kennedy]

Check the latest, if you haven’t already. Should help. If if doesn’t please report back on the issue.

[Thom_McGrath]

Yes when I started the topic I was behind. But my last comment is using the latest. It’s not fixed, at least not for console apps.