- ;; 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
+ ;; 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