On Wed, 11 Jun 2025 15:04:21 GMT, Prasanta Sadhukhan <psadhuk...@openjdk.org>
wrote:
>> ImageIcon.getNextID uses `mediaTrackerID ` which do not detect overflow.
>>
>> Theoretically there is a possibility that there can be overflow in the long
>> time run or for large number of created "imageIcon"
>>
>> Made sure there is no overflow and treat that loadImage as ABORTED
>>
>> No regression testcase as it addresses theoretical possibility..
>
> Prasanta Sadhukhan has updated the pull request incrementally with one
> additional commit since the last revision:
>
> Reset mediaTrackerID if it overflows
Here's the test case that I used. (Thanks to @mickleness for the code, setting
an image significantly increased the performance of the test; my initial test
loaded an image from the disk for each instance of `ImageIcon`, and it took
more than 6 hours to overflow `mediaTrackerId` into negative values.)
<details>
<summary><code>ImageIconOverflow.java</code></summary>
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.stream.IntStream;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import static java.awt.image.BufferedImage.TYPE_INT_RGB;
public class ImageIconOverflow {
private static final String IMAGE_FILENAME = "image.png";
public static void main(String[] args) throws IOException {
createImage();
final Image image =
Toolkit.getDefaultToolkit().createImage("onepixel.gif");
IntStream.range(0, Integer.MAX_VALUE - 1)
.forEach((c) -> new ImageIcon(image));
System.out.println("---");
new ImageIcon(IMAGE_FILENAME);
System.out.println("+++");
new ImageIcon(IMAGE_FILENAME);
new ImageIcon(IMAGE_FILENAME);
System.out.println("###");
IntStream.range(0, Integer.MAX_VALUE - 1)
.forEach((c) -> new ImageIcon(image));
System.out.println("---");
new ImageIcon(IMAGE_FILENAME);
System.out.println("+++");
new ImageIcon(IMAGE_FILENAME);
new ImageIcon(IMAGE_FILENAME);
}
private static void createImage() throws IOException {
BufferedImage image = new BufferedImage(1, 1, TYPE_INT_RGB);
Graphics g = image.getGraphics();
g.fillRect(0, 0, image.getWidth(), image.getHeight());
g.dispose();
File file = new File(IMAGE_FILENAME);
ImageIO.write(image, "png", file);
file.deleteOnExit();
}
}
</details>
I also modified `IconImage.java` to print the id.
<details>
<summary>Diff for <code>ImageIcon.java</code></summary>
diff --git a/src/java.desktop/share/classes/javax/swing/ImageIcon.java
b/src/java.desktop/share/classes/javax/swing/ImageIcon.java
index 2bae31ba31f..8638da90567 100644
--- a/src/java.desktop/share/classes/javax/swing/ImageIcon.java
+++ b/src/java.desktop/share/classes/javax/swing/ImageIcon.java
@@ -296,6 +296,13 @@ protected void loadImage(Image image) {
synchronized(mTracker) {
int id = getNextID();
+ if (id <= 0x8000000F
+ || (id >= 0 && id <= 0x0000000F)
+ || id > 0x7ffffff0) {
+ System.out.println("ImageIcon.id=" + String.format("%08x", id)
+ + " " + id);
+ }
+
mTracker.addImage(image, id);
try {
mTracker.waitForID(id, 0);
</details>
In 25 minutes, the case overflowed twice: from positive into negative, and then
from negative into positive.
ImageIcon.id=00000001 1
ImageIcon.id=00000002 2
...
ImageIcon.id=7ffffffd 2147483645
ImageIcon.id=7ffffffe 2147483646
---
ImageIcon.id=7fffffff 2147483647
+++
ImageIcon.id=80000000 -2147483648
ImageIcon.id=80000001 -2147483647
###
ImageIcon.id=80000002 -2147483646
...
ImageIcon.id=8000000f -2147483633
---
ImageIcon.id=00000000 0
+++
ImageIcon.id=00000001 1
ImageIcon.id=00000002 2
Thus, I think there's nothing to fix.
Yes, `IconImage.mediaTrackerId` can overflow, but it's not an issue.
Therefore, I propose to close the bug as *‘Not an Issue’* or *‘Won't Fix’*.
Prasanta's second [commit
fd2ad26](https://github.com/openjdk/jdk/pull/25666/commits/fd2ad261356ec85585fe2f838ccc1273dd90b390)
resolves the problem with overflow the way that [I
suggested](https://github.com/openjdk/jdk/pull/25666#issuecomment-2962726712).
But it fixes the potential problem that doesn't affect the behaviour of
`ImageIcon` that is proved by the test in this comment.
-------------
PR Comment: https://git.openjdk.org/jdk/pull/25666#issuecomment-2967332196
