summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--NEWS25
1 files changed, 22 insertions, 3 deletions
diff --git a/NEWS b/NEWS
index 809f5ac63..9a364cc46 100644
--- a/NEWS
+++ b/NEWS
@@ -9,7 +9,26 @@ Please send Guile bug reports to bug-guile@gnu.org.
Changes in 2.1.5 (changes since the 2.1.4 alpha release):
* Notable changes
-* New interfaces
+** Lightweight pre-emptive threading primitives
+
+The compiler now inserts special "handle-interrupts" opcodes before each
+call, return, and loop back-edge. This allows the user to interrupt any
+computation and to accurately profile code using interrupts. It used to
+be that interrupts were run by calling a C function from the VM; now
+interrupt thunks are run directly from the VM. This allows interrupts
+to save a delimited continuation and, if the continuation was
+established from the same VM invocation (the usual restriction), that
+continuation can then be resumed. In this way users can implement
+lightweight pre-emptive threading facilities.
+
+** with-dynamic-state in VM
+
+Similarly, `with-dynamic-state' no longer recurses out of the VM,
+allowing captured delimited continuations that include a
+`with-dynamic-state' invocation to be resumed. This is a precondition
+to allow lightweight threading libraries to establish a dynamic state
+per thread.
+
* Performance improvements
** Mutexes are now faster under contention
@@ -96,8 +115,8 @@ dynamic state simply captures the current values, and calling
`with-dynamic-state' copies those values into the Guile virtual machine
instead of aliasing them in a way that could allow them to be mutated in
place. This change allows Guile's fluid variables to be thread-safe.
-To capture the locations of a dynamic state, use partial continuations
-instead.
+To capture the locations of a dynamic state, capture a
+`with-dynamic-state' invocation using partial continuations instead.
* New deprecations
** Arbiters deprecated