diff --git a/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
index 992f65058f..26699fc268 100644
--- a/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
+++ b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
@@ -1308,8 +1308,8 @@
BitBake allows installation of event handlers within
recipe and class files.
Events are triggered at certain points during operation,
- such as the beginning of operation against a given
- .bb, the start of a given task,
+ such as the beginning of an operation against a given recipe
+ (*.bb file), the start of a given task,
task failure, task success, and so forth.
The intent is to make it easy to do things like email
notification on build failure.
@@ -1337,6 +1337,27 @@
the name of the triggered event.
+
+ Because you probably are only interested in a subset of events,
+ you would likely use the [eventmask] flag
+ for your event handler to be sure that only certain events
+ trigger the handler.
+ Given the previous example, suppose you only wanted the
+ bb.build.TaskFailed event to trigger that
+ event handler.
+ Use the flag as follows:
+
+ addhandler myclass_eventhandler
+ myclass_eventhandler[eventmask] = "bb.build.TaskFailed"
+ python myclass_eventhandler() {
+ from bb.event import getName
+ from bb import data
+ print("The name of the Event is %s" % getName(e))
+ print("The file we run for is %s" % data.getVar('FILE', e.data, True))
+ }
+
+
+
During a standard build, the following common events might occur: