Apple

Message: 13
Date: Tue, 13 Oct 2009 11:40:26 -0700
From: Jeff Moore <email@hidden>
Subject: Re: Recommended way to handle suspend/resume on notebooks
To: CoreAudio API <email@hidden>
Message-ID: <email@hidden">email@hidden>
Content-Type: text/plain; charset=iso-8859-1; format=flowed; delsp=yes

You should always feel free to report bugs.

It might help matters if you were able to simplify things in your set-
up to eliminate variables since it doesn't seem to affect other
applications. I'd also be very curious as to what the telemetry says
about the cause of the overloads. For example, there's a world of
difference between the overload being caused by errors from the kernel
trap and overloads caused by scheduling latency or the IOProc taking
too long.

All that said, there may be a more simple cause. One thing that caught
my eye was your description of how the system was sleeping and waking
in fits and starts. I've seen that happen in processes that have
blocked on the HAL's notification thread. One thing that changed in
SnowLeopard is that by default, the HAL will use the process's main
thread for it's notifications.

OK.

It is possible that the main thread in one of your processes has
blocked and is preventing the HAL from getting notifications. If this
is the problem, the fix is pretty simple. Just be sure to set the
system object property, kAudioHardwarePropertyRunLoop, to NULL. This
will cause the HAL to run it's own thread for handling notifications,
which was the default prior to SnowLeopard.