Aio: 'Resource Temporarily unavailable'

[Bourne]

 Hi all,

browsing the aio_suspend code, i have found out that if a timeout is 
specified to aio_suspend, and if the operation does not finish within 
the specified time, then ETIMEDOUT is returned which is returned as a 
'Resource Temporarily unavailable' error to the user program.

My question is, if such an error is encountered then is it a valid 
error( i.e, is it a common occurance ? ) OR is it something which should 
never happen but has happened  and something in glibc needs to be fixed ?

Kindly clarify. Pls Cc me.

Regards,
Bourne