High CPU load on Darwin (Crystal 0.7.2)

[Nightforge]

Hello!

Issue with crystal compiler 0.7.2 on OS X - high CPU load
Test code is:

puts "Hello from Crystal language!"
sleep 60

I test the same code on os x with 0.7.1 - has no issues. Crystal compiler for linux (0.7.1 and 0.7.2) also has no this issue.

[tommasop]

Same issue here with the simple http server code.

100% cpu loading

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IN OBSCURO MIRANDA RELUCENT

On May 29, 2015, at 3:29 PM, Nightforge [email protected] wrote:

Hello!

Issue with crystal compiler 0.7.2 on OS X - high CPU load
Test code is:

puts "Hello from Crystal language!"sleep 60

I test the same code on os x with 0.7.1 - has no issues. Crystal compiler for linux (0.7.1 and 0.7.2) also has no this issue.

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[asterite]

Seems it has something to do with the change to STDOUT (and others) from CFileIO to FileDescriptorIO and non-blocking IO for that. Not sure yet why it's happening.

[waj]

The problem is that libevent is raising the "write" event for the STDOUT all the time, even though the event is registered with the ET (edge triggered) flag: https://github.com/manastech/crystal/blob/master/src/concurrent/scheduler.cr#L24

I'll investigate this further to find a solution. Thanks for reporting!

[asterite]

In IRC @jhass confirmed this doesn't happen in linux, so maybe it's a bug in libevent for mac, but we'll have to investigate.

[waj]

The solution could be more elegant... but it works for now. @Nightforge, @tommasop could you confirm if this fixes the issue?

[Nightforge]

Confirmed!

[tommasop]

Confirmed!