> If the file descriptors aren't dup'ed, that should be fixed on MacOS > and not SANE. That's one of the basic Unix functions and if it doesn't > work, it's just not Unix. > > However, bugs in fork would harm a lot of other applications so I > wonder if this is the real reason.
There are no bugs in fork() or with file descriptors (or at least, none relevant to the current discussion). The problem is that Mac OS X IO access is not (and indeed cannot be) made through file descriptors. The Darwin IO libraries are another breed completely. See http://developer.apple.com/techpubs/macosx/Darwin/IOKit/DeviceInterfaces/SCS IArchitectureModel/SAMDocPage.html The problem is that after you call (*taskinferface->ObtainExclusiveAccess)() a fork()ed thread is then denied access because the first thread has exclusive access. Phil
