On Wed, 1 Jun 2022 23:13:57 GMT, Sergey Bylokhov <s...@openjdk.org> wrote:
>> I remember IDEs used to suggest using correctly sized arrays in the calls to
>> `toArray`. Now they suggest using zero-sized array.
>>
>> My idea was to resolve the warning raised by the IDE to reduce the number of
>> yellow highlights on the file outline.
>>
>> I agree the performance gain if any is negligible in this case: we don't
>> expect many icons, probably no more than 3.
>
> The IDE warning was changed based on the article above. Did you have a chance
> to reproduce a possible race caused by data change after the size() was
> called?
I can reproduce it by this code example:
class Scratch {
static volatile Throwable failed;
static volatile long endtime;
public static void main(String[] args) throws Exception {
if (!SystemTray.isSupported()) {
return; // passed if SystemTray is not supported
}
SystemTray st = SystemTray.getSystemTray();
endtime = System.nanoTime() + TimeUnit.SECONDS.toNanos(5);
Thread thread1 = new Thread(() -> {
while (!isComplete()) {
try {
st.add(new TrayIcon(new BufferedImage(10, 10,
BufferedImage.TYPE_INT_ARGB)));
} catch (AWTException e) {
failed = e;
}
}
});
Thread thread2 = new Thread(() -> {
while (!isComplete()) {
try {
st.add(new TrayIcon(new BufferedImage(10, 10,
BufferedImage.TYPE_INT_ARGB)));
} catch (AWTException e) {
failed = e;
}
}
});
Thread thread3 = new Thread(() -> {
while (!isComplete()) {
TrayIcon[] icons = st.getTrayIcons();
if (icons.length > 0) {
st.remove(icons[0]);
}
}
});
Thread thread4 = new Thread(() -> {
while (!isComplete()) {
TrayIcon[] icons = st.getTrayIcons();
if (icons.length > 0 && icons[icons.length - 1] == null) {
failed = new RuntimeException(
"icon is null:" + Arrays.toString(icons));
}
}
});
thread1.start();
thread2.start();
thread3.start();
thread4.start();
thread1.join();
thread2.join();
thread3.join();
thread4.join();
for (TrayIcon icon : st.getTrayIcons()) {
st.remove(icon); // cleanup
}
if (failed != null) {
System.err.println("Test failed");
throw new RuntimeException(failed);
}
}
private static boolean isComplete() {
return endtime - System.nanoTime() < 0 || failed != null;
}
}
-------------
PR: https://git.openjdk.java.net/jdk/pull/8850
