- ;; Kernel support for futexes (so-called "fast userspace mutexes") is
- ;; available in Linux 2.6 and some versions of 2.4 (Red Hat vendor
- ;; kernels, possibly other vendors too). We can take advantage of
- ;; these to do faster and probably more reliable mutex and condition
- ;; variable support. An SBCL built with this feature will fall back
- ;; to the old system if the futex() syscall is not available at
- ;; runtime
- ; :sb-futex
-
- ;; Package locking support.
- ; :sb-package-locks
-
+ ;; lutex support
+ ;;
+ ;; While on linux we are able to use futexes for our locking
+ ;; primitive, on other platforms we don't have this luxury. NJF's
+ ;; lutexes present a locking API similar to the futex-based API that
+ ;; allows for sb-thread support on x86 OS X, Solaris and
+ ;; FreeBSD.
+ ;;
+ ; :sb-lutex
+
+ ;; On some operating systems the FS segment register (used for SBCL's
+ ;; thread local storage) is not reliably preserved in signal
+ ;; handlers, so we need to restore its value from the pthread thread
+ ;; local storage.
+ ; :restore-tls-segment-register-from-tls
+
+ ;; Support for detection of unportable code (when applied to the
+ ;; COMMON-LISP package, or SBCL-internal pacakges) or bad-neighbourly
+ ;; code (when applied to user-level packages), relating to material
+ ;; alteration to packages or to bindings in symbols in packages.
+ :sb-package-locks
+
+ ;; Support for the entirety of the 21-bit character space defined by
+ ;; the Unicode consortium, rather than the classical 8-bit ISO-8859-1
+ ;; character set.
+ :sb-unicode
+
+ ;; Support for a full evaluator that can execute all the CL special
+ ;; forms, as opposed to the traditional SBCL evaluator which called
+ ;; COMPILE for everything complicated.
+ :sb-eval
+
+ ;; Record source location information for variables, classes, conditions,
+ ;; packages, etc. Gives much better information on M-. in Slime, but
+ ;; increases core size by about 100kB.
+ :sb-source-locations
+