Re: Announcement: libdc1394 for Mac OS

Hi David,

We recently discovered a bug in the user-space NuDCL code which causes problems when update-lists are attached to NuDCLs.

The problem is that the IOFireWireLib code incorrectly calculates the size of the export data for NuDCLs that contain update-lists. The export data is the serialization of the user-space DCLs which is sent into the kernel and used to generate corresponding kernel-space DCLs.

The bug, (which still exists in 10.4.7) only occurs on Intel-based systems. PPC systems are unaffected by this bug.

We are tracking this problem, and hope to have a fix in a future software update.

In the mean time, a work-around is to not include update-lists in NuDCLs, and instead, manually call (*localIsocPort)->Notify(...) with type kFWNuDCLUpdateNotification in the your DCL callbacks. Note that you can include up to 30 DCLs in each call to (*localIsocPort)->Notify(...).

Hope that helps.

Andy Yanowitz

FireWire Software Engineer

Apple Computer, Inc.

email@hidden

On Jul 31, 2006, at 10:58 PM, David Moore wrote:

1. I had a really hard time getting SetDCLUpdateList() to do the right

thing. If my list was too long (several hundred DCLs), it simply

crashed somewhere in the bowels of Mac OS X when creating the

LocalIsochPort. If the list was shorter, it worked for most of the DCL

program, except I had a mysterious problem where my last DCL's callback

was getting called with a NULL Refcon, despite me setting it to be

non-NULL. I ended up not enabling any updates at all.