Implement debug-on-event

2 files changed, 10 insertions, 0 deletions

diff --git a/etc/ChangeLog b/etc/ChangeLog
index 24f44b9d0e8..73cee7763db 100644
--- a/etc/ChangeLog
+++ b/etc/ChangeLog
@@ -1,3 +1,8 @@
+2011-04-26  Daniel Colascione  <dan.colascione@gmail.com>
+
+        * Document debug-on-event default behavior and utility for
+        debugging.
+
 2011-04-22  Noah Friedman  <friedman@splode.com>
 
         * emacs-buffer.gdb: Add trailing underscores to appropriate member
diff --git a/etc/DEBUG b/etc/DEBUG
index c8fd48c6bfa..625a76ac952 100644
--- a/etc/DEBUG
+++ b/etc/DEBUG
@@ -405,6 +405,11 @@ stepping, you will see where the loop starts and ends.  Also, examine
 the data being used in the loop and try to determine why the loop does
 not exit when it should.
 
+You can also trying sending Emacs SIGUSR2, which, if `debug-on-event'
+has its default value, will cause Emacs to attempt to break it out of
+its current loop and into the Lisp debugger.  This feature is useful
+when a C-level debugger is not conveniently available.
+
 ** If certain operations in Emacs are slower than they used to be, here
 is some advice for how to find out why.