Socket select() [efficient waiting] feature

Analysis of support in underlying implementations

Implementation	select()	poll()	custom (select-like)	End result
SBCL (non-Win32)	Yes (out of the box)	Yes (through FFI)	No	Yes
SBCL (Win32)	No	No	Maybe, through FFI	maybe
CLISP	No	No	Yes (SOCKETS:STREAM-STATUS, see below)	Yes
CMUCL	Yes (out of the box)	Yes (through FFI)	No	Yes
Scieneer	Probably (stems from CMU)	Yes (through FFI)	No	Yes
Allegro	Yes (through FFI using socket-os-fd; different on Windows and Unix...)	No (not on Windows)	Yes, using mp:wait-for-input-available (input select() only)	Yes
OpenMCL	Yes, by using several CCL package internals		It provides PROCESS-INPUT-WAIT which works on 1 handle (what good is THAT!?)	Yes
LispWorks? (non-Win32)	No	No	system:wait-for-input-streams (input only), but only on Unix	Yes
LispWorks? (Win32)	No	No	Yes: through FFI	Yes
ECL	Yes (using clines)	Yes (using clines)	No	Yes
ArmedBear?	Can depend on the Java Selectors and Channels achitecture			Yes

CLISP

See ​http://clisp.cons.org/impnotes/socket.html#so-status.

SBCL

See sb-unix:unix-select.

CMUCL

See unix:unix-select.

LispWorks

Unfortunately system:wait-for-input-streams is only available on LispWorks 5.0 and higher. That shouldn't be a problem, since even the personal addition is available in a 5.0 version now (it used to be available in 4.4, even when 5.0 was out for paying customers for a while).

OpenMCL

The PROCESS-INPUT-WAIT routine simply hasn't been written with multiple sockets/streams in mind. Luckily, we have insight into the CCL package and write our own. (This ends up using an FFI-binding to select()).