Question

Does a System.Timers.Timer elapse on a separate thread than the thread that created it?

Lets say I have a class with a timer that fires every 5 seconds. When the timer fires, in the elapsed method, some object is modified. Lets say it takes a long time to modify this object, like 10 seconds. Is it possible that I will run into thread collisions in this scenario?

Answer 1

For System.Timers.Timer:

See Brian Gideon’s answer below

For System.Threading.Timer:

MSDN Documentation on Timers states:

The System.Threading.Timer class makes
callbacks on a ThreadPool thread and
does not use the event model at all.

So indeed the timer elapses on a different thread.