We have a use case where we receive a LOT of processing orders in one
Thread in a TCP socket and we have to perform the drawing in the JavaFX
Thread, but also we must wait until the effective drawing has finished
before ordering a new drawing (because otherwise some parameters could have
changed in the middle of the drawing so the rsulting image could be
inconsistent). We use Platform.runLater with a future in our case like:
FutureTask<?> future = new FutureTask<>(runnable, null);
Platform.runLater(future);
try {
future.get();
return true;
} catch...
I don't know if this is a valid pattern. Of course the Thread which handle
this code has to be different from the Thread which handle the socket
reception in our case.
Hervé
2016-11-02 22:13 GMT+01:00 Kevin Rushforth <kevin.rushfo...@oracle.com>:
> We use runAndWait (using a CountDownLatch) in many of our unit tests. You
> might take a look at:
>
> tests/system/src/test/java/test/util/Util.java
>
> Its runAndWait method also handles propagating runtime exceptions and
> errors (e.g., assertion failures) from the body of the runAndWait back to
> the caller.
>
> -- Kevin
>
>
> Benjamin Gudehus wrote:
>
>> I wonder, if it is possible to test JavaFX applications without blocking
>> the main thread. User interactions could be completely simulated by using
>> Event.fireEvent(...) and we could enqueue assertions in the JavaFX
>> application thread, in which case the assertion library needs to support
>> asynchronous assertions.
>>
>> On Wed, Nov 2, 2016 at 9:02 PM, Stefan Fuchs <snfu...@gmx.de <mailto:
>> snfu...@gmx.de>> wrote:
>>
>> Hi,
>>
>> in my experience blocking your working thread for the JavaFX
>> application thread is almost always a sign of bad application design.
>> You can easily deadlock your application. In our quite complex
>> JavaFX Application, we could eliminate almost all of its uses.
>>
>> However, in one case it is still needed: In a thread we
>> sequentially prepare several images in the background, create a
>> snapshot and save them as jpegs.
>> Here we use java.util.concurrent.CountDownLatch to simulate
>> PlatformImpl.runAndWait.
>>
>> final WritableImage image = new WritableImage((int)
>> targetWidth, (int) targetHeight);
>> final CountDownLatch countDownLatch = new CountDownLatch(1);
>> Platform.runLater(() -> {
>>
>> /* render and snapshot image */
>>
>> countDownLatch.countDown();
>> });
>>
>> boolean released = countDownLatch.await(10, TimeUnit.SECONDS);
>> if (!released) {
>> Logger.getLogger(getClass()).error("Timeout reached,
>> while waiting for snapshot");
>> return null;
>> }
>>
>> return image;
>>
>>
>>
>> What I would like to see implemented is a method, we call
>> runNowOrLater.
>>
>> That is, if I'm on the JavaFX ApplicationThread execute the
>> Runnable immediately, if not call Platform.runLater().
>> With this method I have not to worry, if I'm on the JavaFX
>> Application thread or not and I avoid flooding the event queue
>> with calls to Platform.runLater, that could have been executed
>> directly.
>>
>> So basically:
>>
>> public static void runNowOrLater(final Runnable runnable) {
>> if (Platform.isFxApplicationThread()) {
>> runnable.run();
>> } else {
>> Platform.runLater(runnable);
>> }
>> }
>>
>> -- Stefan
>>
>>
>>
>>
>> Hi, Kevin. Thanks for the info!
>>
>> On Wed, Nov 2, 2016 at 5:36 PM, Kevin Rushforth
>> <kevin.rushfo...@oracle.com <mailto:kevin.rushfo...@oracle.com>>
>> wrote:
>>
>> No. This isn't something we will do for JDK 9, which is
>> feature complete
>> (with an exception process for critical requests,
>> especially relating to
>> Jigsaw). I note in this case that it isn't clear whether
>> we want to do this
>> one at all.
>>
>> -- Kevin
>>
>>
>>
>> Benjamin Gudehus wrote:
>>
>> Hey!
>>
>> Are there plans to expose this API [1] in JavaFX 9?
>>
>> // NOTE: Add the following if we decide to expose it
>> publicly
>> // public static void runAndWait(Runnable runnable) {
>> // PlatformImpl.runAndWait(runnable);
>> // }
>>
>> [1] http://hg.openjdk.java.net/openjfx/9-dev/rt/file/
>> <http://hg.openjdk.java.net/openjfx/9-dev/rt/file/>
>> 6edd0c3c01f4/modules/javafx.gr
>> <http://javafx.gr>aphics/src/main/java/javafx/
>> application/Platform.java#l148
>>
>> --Benjamin
>>
>>
>>
>>
>>
