Hi Sascha,
I read your comments and look at your code with interest. It appears to
be an improved ThreadQueue implementation, but will require a lot of testing
to verify. Before I invest this time, I would like to know what problem it
is solving. I see your dislikes a - e, but these are not really problems,
only architectural critiques. Have you done any benchmarks that show that
the new SingleThreadQueue speeds up rendering? Your logical argument that
it should be more efficient is persuasive, but I have been surprised by
Java before.
respectfully,
Larry Becker
On 5/23/07, Sascha L. Teichmann <[EMAIL PROTECTED]> wrote:
Hi together,
as some of you may already know i have my dislikes against
ThreadQueue [1] (Hi, Larry!) see my mail [2]
a - It forks a new thread for any Runnable it processes.
b - It has an ugly busy wait loop inside.
c - The event listener for empty queue fires to often.
d - The default ThreadQueue is some kind of thread serializer.
e - The DB/WMS ThreadQueue has no public access.
Now I've written a sub class of ThreadQueue: SingleThreadQueue
(see attachment). This one deals with the issues a, b and d.
I also attached a patch against RenderingManager [3] to handle e.
The new class (to be placed in package
com.vividsolutions.jump.workbench.ui.renderer) is a drop-in
replacement for the default ThreadQueue in RenderingManager.
Not for the ThreadQueue that handles the DB/WMS layers.
Because Jon limited the number of parallel threads in default
queue to 1 I see no reason why to fork a new thread for each
Runnable it processes. Thread creation/shutdown is fairly
expensive. Instead a single background thread is started
which processes the Runnables one by one. If the thread
is idle for 30 secs it shuts itself down. If you have a lot
of (non-WMS/BB) layers this should improve performance
and save some resources. The processing itself is done
with a monitor (synchronized/wait/notify) so there is no
busy wait any more.
The DB/WMS ThreadQueue (real parallel threads) is left untouched
for the moment. Depending on my personal schedule I will send
a patch against this one too. Preliminary code with thread pooling
exists but it needs a bit more testing.
Find attached the new class and patches against RenderingManager and
the old ThreadQueue to bring it to work.
Comments are very welcome. :-)
Kind regrads,
Sascha
[1] com.vividsolutions.jump.workbench.ui.renderer.ThreadQueue
[2]
http://sourceforge.net/mailarchive/message.php?msg_name=4653389E.6000706%40intevation.de
[3] com.vividsolutions.jump.workbench.ui.renderer.RenderingManager
Index:
./src/com/vividsolutions/jump/workbench/ui/renderer/RenderingManager.java
===================================================================
RCS file:
/cvsroot/jump-pilot/openjump/src/com/vividsolutions/jump/workbench/ui/renderer/RenderingManager.java,v
retrieving revision 1.6
diff -u -r1.6 RenderingManager.java
---
./src/com/vividsolutions/jump/workbench/ui/renderer/RenderingManager.java
22 May 2007 18:47:12 -0000 1.6
+++
./src/com/vividsolutions/jump/workbench/ui/renderer/RenderingManager.java
24 May 2007 04:10:30 -0000
@@ -77,7 +77,7 @@
* non-database layers in parallel. In fact, it will make the GUI
less
* responsive. [Jon Aquino]
*/
- private ThreadQueue defaultRendererThreadQueue = new
ThreadQueue(1);
+ private ThreadQueue defaultRendererThreadQueue = new
SingleThreadQueue();
/**
* WMS and database processing are done on the server side, so
allow these
@@ -294,6 +294,10 @@
return defaultRendererThreadQueue;
}
+ public ThreadQueue getMultiRendererThreadQueue() {
+ return multiRendererThreadQueue;
+ }
+
public void dispose() {
repaintTimer.stop();
defaultRendererThreadQueue.dispose();
@@ -334,4 +338,4 @@
contentIDToRendererMap.remove(contentID);
}
-}
\ No newline at end of file
+}
Index:
./src/com/vividsolutions/jump/workbench/ui/renderer/ThreadQueue.java
===================================================================
RCS file:
/cvsroot/jump-pilot/openjump/src/com/vividsolutions/jump/workbench/ui/renderer/ThreadQueue.java,v
retrieving revision 1.1
diff -u -r1.1 ThreadQueue.java
---
./src/com/vividsolutions/jump/workbench/ui/renderer/ThreadQueue.java 16
Jun 2005 22:50:38 -0000 1.1
+++
./src/com/vividsolutions/jump/workbench/ui/renderer/ThreadQueue.java 24
May 2007 04:09:15 -0000
@@ -47,6 +47,10 @@
private Vector queuedRunnables = new Vector();
private int maxRunningThreads;
+ public ThreadQueue() {
+ this(1);
+ }
+
public ThreadQueue(final int maxRunningThreads) {
this.maxRunningThreads = maxRunningThreads;
}
@@ -95,7 +99,7 @@
public static interface Listener {
public void allRunningThreadsFinished();
}
- private void fireAllRunningThreadsFinished() {
+ protected void fireAllRunningThreadsFinished() {
//new ArrayList to avoid ConcurrentModificationException [Jon
Aquino]
for (Iterator i = new ArrayList(listeners).iterator(); i.hasNext();
) {
Listener listener = (Listener) i.next();
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