setting thread prioirty

Robert Collins
Mon Jun 25 16:57:00 GMT 2001

----- Original Message -----
From: "Brian Michael Genisio" <>
To: <>
Sent: Tuesday, June 26, 2001 2:31 AM
Subject: setting thread prioirty

> Hello,
> I was wondering if it is possible in cygwin for a thread to have a
> priority than it's parent.  That is, If I call a program with nice,
such as :
> nice -n -20 <command>
> And the program spawns a thread... I want the thread to run at Normal
> and the main thread to remain at high prioirity.
> I have tried setting the attribute to priority 0 with the
> pthread_attr_setschedparam.  Unfortunately, this does not work for me.
The two
> threads compete for processor, slowing down the entire system.

This should work :}. All my testcases seemed to run ok. Can you provide
a testcase showing the problem?.

If your problem is simple contention - that the pri 0 thread gets less
cpu than the -20 thread, then that is expected. If there are locking and
reosurce issues occuring I need a test case to demonstrate the problem,
and then I'll look into it.

> Before I was using threads, I had the two threads as separate
programs, and I
> could set each program to the level I chose... but IPC communication
was slow,
> or didnt work well enough for me.  So, I put them in the same thread,
and now
> they act as if I put the separate programs in high priority.
> Any Ideas?

If you haven't designed your cross-thread API carefully you may simply
be blocking each thread very often waiting on the other thread. On the
other hand there may be a bug *shrug*.
First thing for you to do: get the most recent developer snapshot
(currently that is 2001-jun-22) as there are lots of bugs fixed w.r.t.
threading. Revalidate your problem on that dll. Then start looking for a
testcase/at your syncronisation methods.


> Thanks,
> Brian
> --
> ---------------------------
>       \\|//   Brian Genisio
>       (o o)
> ~~oOOo~(_)~oOOo~~~~~~~~~~~~~~~~~~~~~~~~~~
> --
> Want to unsubscribe from this list?
> Check out:

Want to unsubscribe from this list?
Check out:

More information about the Cygwin mailing list