1.0.41.7: threads: Document BARRIER macro and implicit barriers.

  * Not much to say, new manual subsection under Threading.

  * Also added a NEWS entry for barriers.

diff --git a/NEWS b/NEWS
index 4cdd5ea..d8deb5c 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,8 @@
 changes relative to sbcl-1.0.41
   * optimization: the default implementation of
     COMPUTE-DISCRIMINATING-FUNCTION does much less wasted work.
+  * enhancement: Explicit memory barrier operations are now available for use
+    by multithreaded code.  See documentation for details.
 
 changes in sbcl-1.0.41 relative to sbcl-1.0.40:
   * optimization: validity of observed keyword initargs to MAKE-INSTANCE is

diff --git a/doc/manual/threading.texinfo b/doc/manual/threading.texinfo
index 3fc374a..56a73e7 100644 (file)
--- a/doc/manual/threading.texinfo
+++ b/doc/manual/threading.texinfo
@@ -23,6 +23,7 @@ directions.
 * Mutex Support::               
 * Semaphores::                  
 * Waitqueue/condition variables::  
+* Barriers::                    
 * Sessions/Debugging::          
 * Foreign threads::             
 * Implementation (Linux x86/x86-64)::  
@@ -245,6 +246,36 @@ it.
 @include fun-sb-thread-condition-notify.texinfo
 @include fun-sb-thread-condition-broadcast.texinfo
 
+@node Barriers
+@comment  node-name,  next,  previous,  up
+@section Barriers
+
+These are based on the Linux kernel barrier design, which is in turn
+based on the Alpha CPU memory model.  They are presently implemented for
+x86, x86-64, and PPC systems, and behave as compiler barriers on all
+other CPUs.
+
+In addition to explicit use of the @code{sb-thread:barrier} macro, the
+following functions and macros also serve as @code{:memory} barriers:
+
+@itemize
+@item
+@code{sb-ext:atomic-decf} and @code{sb-ext:atomic-incf}.
+@item
+@code{sb-ext:compare-and-swap}.
+@item
+@code{sb-thread:get-mutex}, @code{sb-thread:release-mutex},
+@code{sb-thread:with-mutex} and @code{sb-thread:with-recursive-lock}.
+@item
+@code{sb-thread:signal-semaphore}, @code{sb-thread:try-semaphore} and
+@code{sb-thread:wait-on-semaphore}.
+@item
+@code{sb-thread:condition-wait}, @code{sb-thread:condition-notify} and
+@code{sb-thread:condition-broadcast}.
+@end itemize
+
+@include macro-sb-thread-barrier.texinfo
+
 @node Sessions/Debugging
 @comment  node-name,  next,  previous,  up
 @section Sessions/Debugging

diff --git a/version.lisp-expr b/version.lisp-expr
index fda02a9..432bb89 100644 (file)
--- a/version.lisp-expr
+++ b/version.lisp-expr
@@ -17,4 +17,4 @@
 ;;; checkins which aren't released. (And occasionally for internal
 ;;; versions, especially for internal versions off the main CVS
 ;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
-"1.0.41.6"
+"1.0.41.7"