From: David Flanagan <david@...>
Date: 2007-08-10T13:53:59+09:00
Subject: Re: priorities of newly-created threads

Nobu,

I didn't know that about threads in Linux.  Looks like Java has had the 
same limitation for years, and I never knew it!  Thanks for the 
explanation.

Still, I think that you ought to pretend that threads have priorities, 
for the sake of API compatibility, even though they are meaningless.

Thread.current.priority = 2  # Allowed, but does nothing on Linux
Thread.current.priority           # => 2: because we're pretending
t = Thread.new { sleep }.priority # => 0: I think it should be 2

Even though it is meaningless, I think that last line of code should 
return 2.  Or the second line of code should always return 0.

	David

Nobuyoshi Nakada wrote:
> Hi,
> 
> At Thu, 9 Aug 2007 08:38:41 +0900,
> David Flanagan wrote in [ruby-core:11876]:
>> In Ruby 1.9, newly created threads start at priority 0.  I suspect that 
>> this is a bug.
> 
> The current VM uses native threads.  On linux, the scheduling
> policy is defaulted to SCHED_OTHER, and the priority is bound
> on 0 in that case.  Therefore, it's rather the restriction of
> the platform.
>