Is select() implemented?

[Alexander D. Tarkhov]

Hello rtems users,

I use RTEMS 4.0.0, mips64orion, p4650

I have found some calls to 
int select(...)
in /libnetworking source tree but I can't find select() implementation. 
No headers, no asm defines...

Where is it?

Or it is not supposed to be used?

Thank you for all your comments,
Best regards,
Alexander Tarkhov