Message: 2
Date: Wed, 16 Jan 2008 12:24:54 -0800
From: Jeff Moore <email@hidden>
Subject: Re: Recommended way to setup a timer in a CoreAudion
application?
To: CoreAudio API <email@hidden>
Message-ID: <email@hidden>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed; delsp=yes
As I've said previously, the IsRunning notification is probably the
most reliable notification the HAL provides. It doesn't lie. If it
reports that it is running. The IO thread is up and running because it
is supposed to be up and running. Note that this doesn't not
necessarily mean that IOProcs will be getting called as IO could have
been started by passing NULL as the IOProcID to AudioDeviceStart()
which just starts the hardware and the device's timing services.
The HAL also will stop and restart the IO thread (yielding appropriate
IsRunning notifications) across large scale driver state changes as
well as when the driver sends pause/resume messages which normally
bracket things like format changes. This is especially true of
aggregate devices which stop and then start again when any state
change that might affect the make up of an aggregate device happens
(for example, when the sample rate changes on one of the sub-devices).
Throw in the fact that you've had numerous misunderstandings about how
things work on the very basic level and I'd say that until you fully
debug this, you don't really know what is going on. I really encourage
you to drill down and find out more about the problem. I suspect that
you have made some faulty assumption again somewhere.
