OpenCover Console uses 1 CPU to 100%

[philippjenni]

Hi,

On my Build Server (Win 2012) uses the opencover alway a cpu to 100%. I have 2 CPU in the server and the opencover.console process uses 50% of cpu load. A second opencover process uses also 50% cpu.

Any idees?

[sawilde]

That is expected as there is a lot of information flowing from the profiler to the host. If you are not bothered about accurate visit counts then you can use the -threshold: option see wiki

[philippjenni]

I have set the threshold parameter to 1, but i doesn't have an impact to the cpu load of the opencover.console process.

[sawilde]

Oh it has an impact as it will not be processing as much data you just can't see it.

Unfortunately that is the way it works - it has a Thread.Yield() in a loop whilst checking to see if any new messages have come in - if any other process wants the CPU they should get it.

https://msdn.microsoft.com/en-us/library/system.threading.thread.yield(v=vs.110).aspx

[philippjenni]

The problem is, that build server which covers the code is running on a virtual environment. On each code covering cycle risies the environment an high cpu alert.

[sawilde]

There may be something that could be done but I don't want to drop performance as that has been an issue in the past.

[molnargab]

Yield returns a bool. How about we added a sleep if yield was unsuccessful (which we think it was)?

Since we're already busy-waiting for data being consumed, it shouldn't hurt performance that much, though it would reduce CPU utilization.

[sawilde]

@molnargab yup, that was my thinking as well

[molnargab]

@philippjenni, could you check the CPU utilization with CI build 4.6.234?

[ddur]

AppVeyor is free build server

[philippjenni]

Yes i will try this