Caller context flags [PSARC/2007/632 FastTrack timeout 11/09/2007]

[James Carlson]

Rich.Brown at Sun.COM writes:
>      The first two new flags to be defined:
>      #define CC_WOULDBLOCK   0x1     /* set upon return by monitor */
>      #define CC_DONTBLOCK    0x2     /* set by caller */
> 
>      The caller sets CC_DONTBLOCK in cc_flags to direct the monitor not to
>      perform an operation that might block.  In the case where a monitor would
>      perform a blocking operation and CC_DONTBLOCK is set, the monitor
>      sets CC_WOULDBLOCK in the cc_flags and returns EAGAIN to the caller.

I'm not sure I understand how this is intended to be used.

What exactly is the caller supposed to do when he gets CC_WOULDBLOCK?
How long should he wait before trying again?  Or is it always possible
to detect this case and defer the operation until at can be run
without CC_DONTBLOCK?

-- 
James Carlson, Solaris Networking              <james.d.carlson at sun.com>
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