MappingAvailable is called in two circumstances. The first case is when a new streaming irp arrives. After the IRP is added to the mapping queue MappingAvailable is called if the driver is currently starved (the stream is new or the previous call to GetMapping failed). The second case is in response to setting the pin position via position property. The lock issue across GetMapping and ReleaseMapping has been complicated since the WavePci port was written back in the Win98 days. Unfortunately, if you attempt to hold a spinlock for your mapping list when you call these routines you'll likely deadlock with the spinlock that portcls uses to protect access to it's mapping and unmapping queues. I don't have the code in front of me at the moment but I'll take a closer look tomorrow at the portcls and WDK sample code and respond with a little more detail. Incidentally, portcls doesn't care at all about your tag values other than that the outstanding tags at any given moment be unique. They can be monotonically increasing if you like, or they could be addresses into list of mappings. It's up to you. Ken ________________________________________ From: wdmaudiodev-bounce@xxxxxxxxxxxxx [wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages [jeff@xxxxxxxxxxxxxxxx] Sent: Monday, March 26, 2007 6:58 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: WavePCI issue with multiple processors Hi Eugene, > A probability of that a new mapping becomes available exactly within > this window, is almost zero. You're right, of course. I was thinking I had to reacquire my spin lock after the unsuccessful call to GetMapping, but looking at it now, that's not necessary, and I can just call InterlockedDecrement on my InAcquisitionLoop variable and exit. > And a well-optimized driver itself cannot guarantee that all Windows > audio subsystems will function quickly and reliably. Even DirectSound > with hardware buffers introduces a significant overhead and software > buffers and/or MME introduce much more overhead. So you can achieve a > reproducible high performance only if your well-optimized application > uses your well-optimized audio driver directly via its wave/topology > interfaces. For this particular application, I'm using the Vista Core Audio API in exclusive mode, and this was when some of the wrinkles in my WavePCI drivers started showing up. I'm now using your suggestion with the interlocked InAcquisitionLoop variable and so far it's all hanging in there! Thanks for your help. Jeff ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.com/ ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.com/