Marshall Schor created UIMA-4013:
------------------------------------
Summary: Reduce unneeded fixed flow controller sync contention
Key: UIMA-4013
URL: https://issues.apache.org/jira/browse/UIMA-4013
Project: UIMA
Issue Type: Improvement
Components: Core Java Framework
Affects Versions: 2.6.0SDK
Reporter: Marshall Schor
Priority: Minor
Fix For: 2.6.1SDK
The Fixed Flow Controller is designed to allow one instance to be used by
multiple copies of a UIMA pipeline, initialized from the same context. In
this case, only one initialize call is done; the others are no-ops. The
instance contains one update-able ArrayList - the list of delegates. This
array is normally only "read", but there are two defined interfaces to allow
dynamically altering it (addAnalysisEngines, and removeAnalysisEngines). The
current impl of this is a synchronized list. For the 99.99% of cases
(reading), this sync is not necessary, and causes some observable sync
contention.
Change this to a non-sync'ed "CopyOnWrite" implementation, to avoid this
contention. The downside is that current Flow objects in use while after this
call occurs will not see the update, but new ones will. This is probably a good
thing, because it seems that incorrect flows might occur if this was changed
while flows were in-progress. The documentation currently says these methods
are not currently called because UIMA doesn't support dynamically adding or
removing analysis engines to/from an aggregate.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
