what is exception detected by select? is type of socket exception? But socket no throw exception in c or c++ under linux.
You mean the third fd_set passed to select()? That just detects
any OOB (out-of-band) data on the sockets... (Or, for non-blocking
sockets in the middle of a connect() call, I think it might also
detect failure to connect... I'm not sure about that, though...) It
doesn't mean "exception" in the sense of the word as used by
wacky OOP languages... In fact, I'd say it's just a fairly poor
choice of terms, since labeling OOB data as an "exception" seems
rather strange... But, what can you do? Some things are just
the way they are, no matter how weird and wrong they are... ;-)
Handling Exceptions::
Select the node or groups of nodes for which you want to create an exception path. Right-click the exception path, then select Delete from the drop-down menu.
http://e-docs.bea.com/wli/docs92/bpguide/bpguideException.htmlHOME |
The primary rationale for the "exception" return in reference to out of band data is that if the socket is not set to queue oob in the regular read queue ... then the application will have to do a read with the OOB flag set (or similar) instead of a "normal" read... and its simply a notification to do such...
Handling PL/SQL Errors::
After an exception handler runs, the current block stops executing and the if the SELECT INTO statement raises a ZERO_DIVIDE exception, the local handler
http://download-uk.oracle.com/docs/cd/B19306_01/appdev.102/b14261/errors.htmHOME |
Having said that... it should be mentioned that the spec ( yes Rob, Im quoting POSIX specs again! :-P ) also says that if there is a OOB mark in the regular read queue (e.g. OOB is set for the socket and an OOB msg has come thru) that the "exeption" will also be generated...
That second requirement does seem a bit odd to me... not sure why they did it that way... since (imho) if apps are using the OOB mechanism, it would be for "higher priority" type msgs... and you should most likely be using the setup described in the first paragraph (all normal reads and OOB not set ~ explicit OOB read if that type of msg is incoming)...
Anyway... the rest of the "exceptions" which cause select to return are actually true errors... not jst exeptional conditions...
Michael
 How much does getting a small tattoo on your hip/stomach hurt?
 Do anyone else have an itchy anus? ?
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select exception