roy@phri.UUCP (Roy Smith) (05/25/88)
I've run across what seems to be an inconsistancy in the way
exceptional conditions are handled in 4.[23]BSD. When OOB data is pending
on a socket, a select(2) for exceptions on the socket descriptor will
return; in addition, a SIGURG is sent. If you have a pty in TIOCPKT or
TIOCUCNTL mode and a control packet or ioctl command comes in, you also
break out of a select(2), but no SIGURG is sent.
Is there some reason why one sends a SIGURG but not the other? Are
there any other conditions in the system other than OOB data and the
TIOCPKT/TIOCUCNTL cases described above which generate exceptional
conditions? Do they send SIGURGs and/or break out of selects? Should they?
--
Roy Smith, System Administrator
Public Health Research Institute
455 First Avenue, New York, NY 10016
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