0.9.6.50: stability before creativity

[sbcl.git] / src / code / signal.lisp

diff --git a/src/code/signal.lisp b/src/code/signal.lisp
index a4c5298..55eb7ca 100644 (file)
--- a/src/code/signal.lisp
+++ b/src/code/signal.lisp
@@ -45,18 +45,23 @@
   "Execute BODY in a context impervious to interrupts."
   (let ((name (gensym "WITHOUT-INTERRUPTS-BODY-")))
     `(flet ((,name () ,@body))
-       (if *interrupts-enabled*
-          (unwind-protect
-              (let ((*interrupts-enabled* nil))
-                (,name))
-            ;; FIXME: Does it matter that an interrupt coming in here
-            ;; could be executed before any of the pending interrupts?
-            ;; Or do incoming interrupts have the good grace to check
-            ;; whether interrupts are pending before executing themselves
-            ;; immediately?
-            (when *interrupt-pending*
-              (receive-pending-interrupt)))
-          (,name)))))
+      (if *interrupts-enabled*
+          (unwind-protect
+               (let ((*interrupts-enabled* nil))
+                 (,name))
+            ;; If we were interrupted in the protected section, then
+            ;; the interrupts are still blocked and it remains so
+            ;; until the pending interrupt is handled.
+            ;;
+            ;; If we were not interrupted in the protected section,
+            ;; but here, then even if the interrupt handler enters
+            ;; another WITHOUT-INTERRUPTS, the pending interrupt will
+            ;; be handled immediately upon exit from said
+            ;; WITHOUT-INTERRUPTS, so it is as if nothing has
+            ;; happened.
+            (when *interrupt-pending*
+              (receive-pending-interrupt)))
+          (,name)))))
 
 (sb!xc:defmacro with-interrupts (&body body)
   #!+sb-doc
@@ -65,8 +70,8 @@
   (let ((name (gensym)))
     `(flet ((,name () ,@body))
        (if *interrupts-enabled*
-          (,name)
-          (let ((*interrupts-enabled* t))
-            (when *interrupt-pending*
-              (receive-pending-interrupt))
-            (,name))))))
+           (,name)
+           (let ((*interrupts-enabled* t))
+             (when *interrupt-pending*
+               (receive-pending-interrupt))
+             (,name))))))