The simple code above is a cheap way to set objects colliding with an exploding incendiary grenade afire.
It is timed to last for 45 steps, and may affect several objects simultaneously (yes, expensive).
With previous version, had not ever noticed any problem using these built in particle systems, but now this particular code slows the game to a crawl (0.1 FPS), and does not let go of the framerate even after the creating object is destroyed. I have not noticed any issues with any home-brew particle systems, only this one bit that uses the built-ins.
I am vaguely aware of some memory leaks in GM that prompt me to clear system memory between runs, and how it leaves the desktop partially unrendered on several machines (upper half of top icon row not drawn) when closing sometimes, but this is a new one.
Any chance that the particle system isn't getting destroyed properly with the built-in effects? I'd blame it on the machine, but GM8 and GM7 seemed fine, and the frame rate stays trashed after the offending object is destroyed.