BUG: 100% CPU utilization - busy waiting?

[pawelkobojek]

Thanks for sharing this amazing software.

Describe the bug
Running Red Engine causes 100% CPU utilization. Maybe it's busy waiting?

To Reproduce
This simple app prints "Hello World" every 1 minute.

from redengine import RedEngine
app = RedEngine()

@app.task("every 1 minute")
def main():
    print("Hello World")

if __name__ == "__main__":
    app.run()

Expected behavior
CPU not utilized at all while waiting between running tasks.

Screenshots

Desktop (please complete the following information):

• OS: macOS 12.3, Linux (5.4.0-100-generic, Ubuntu, x86_64)
• Python version 3.10.4

Additional context
If there's some misconfiguration on my side I'd be grateful for tips.

[Miksus]

Thanks, it's always nice to hear people like it!

By default the tasks are run as processes which confuse some. Probably we should have a poll at some point which should be preferred. But this does not explain it as it creates the process every 1 minute and the task is minimal.

However, this is probably due to that the hibernating is by default non-existent (it checks conditions aggressively constantly). You can throttle the scheduler using:

app = RedEngine(config={'cycle_sleep': 2})

Seems this configuration is int accidentally so it's a bug at least in this perspective (this is passed to time.sleep and it seems to support floats). I'm not sure if we should have a non-zero default to prevent the resource hogging. Basically this means the scheduler waits this amount of seconds every time it goes through cycle which is looping a set of tasks.

Also, does this help to set this to one, for example? This is also undocumented (as the library is quite new).