= 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()).