DefaultEventBus: avoid publishing events nobody is interested in

dscho · dscho · commit a24bf7bdad50 · 2013-08-15T11:18:51.000-05:00
The AWT EventQueue is really slow: EventQueue.invokeAndWait() can take
up to 30x as long as creating a new thread and starting it on the
provided Runnable.

If there is not even a subscriber to the event we are about to send,
let's just not bother.

Signed-off-by: Johannes Schindelin &lt;johannes.schindelin@gmx.de&gt;
diff --git a/src/main/java/org/scijava/event/DefaultEventBus.java b/src/main/java/org/scijava/event/DefaultEventBus.java
@@ -190,6 +190,7 @@ private void publishNow(final Object event, final String topic,
 		@SuppressWarnings("rawtypes") final List vetoSubscribers,
 		final StackTraceElement[] callingStack)
 	{
+		if (subscribers == null || subscribers.isEmpty()) return;
 		try {
 			threadService.invoke(new Runnable() {
 
@@ -216,6 +217,7 @@ private void publishLater(final Object event, final String topic,
 		@SuppressWarnings("rawtypes") final List vetoSubscribers,
 		final StackTraceElement[] callingStack)
 	{
+		if (subscribers == null || subscribers.isEmpty()) return;
 		threadService.run(new Runnable() {
 
 			@Override

Original file line number	Diff line number	Diff line change
`@@ -190,6 +190,7 @@ private void publishNow(final Object event, final String topic,`
`190`	`190`	`@SuppressWarnings("rawtypes") final List vetoSubscribers,`
`191`	`191`	`final StackTraceElement[] callingStack)`
`192`	`192`	`{`
	`193`	`+ if (subscribers == null \|\| subscribers.isEmpty()) return;`
`193`	`194`	`try {`
`194`	`195`	`threadService.invoke(new Runnable() {`
`195`	`196`
`@@ -216,6 +217,7 @@ private void publishLater(final Object event, final String topic,`
`216`	`217`	`@SuppressWarnings("rawtypes") final List vetoSubscribers,`
`217`	`218`	`final StackTraceElement[] callingStack)`
`218`	`219`	`{`
	`220`	`+ if (subscribers == null \|\| subscribers.isEmpty()) return;`
`219`	`221`	`threadService.run(new Runnable() {`
`220`	`222`
`221`	`223`	`@Override`