Hi all, please see the attached Test8007918Regression.java.
There seems to be a regression caused by this patch:
http://hg.openjdk.java.net/jdk7u/jdk7u-dev/jdk/rev/90c9f1577a0b
As the small testcase demonstrates, creating a JPEGImageWriter and
calling setOutput causes it to live permanently. This is due to JNI
global (non-weak) reference in sun/awt/image/jpeg/imageioJPEG.c.
Is it acceptable to simply make this reference weak ? This should bring
object lifetimes back to how they were before this patch. Attached is a
patch that, from my tests, fixes the issue.
Thanks & happy hacking,
-Adam
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Iterator;
import javax.imageio.ImageWriter;
import javax.imageio.spi.IIORegistry;
import javax.imageio.spi.ImageWriterSpi;
import javax.imageio.stream.MemoryCacheImageOutputStream;
/*
* Demonstrates an out of memory error using JPEGImageWriter.
*
* This is a regression that seems to be caused by the fix for bug 8007918:
* http://hg.openjdk.java.net/jdk7u/jdk7u-dev/jdk/rev/90c9f1577a0b
*
* The result of the patch is that JPEGImageWriter will retain itself
* via a global (non-weak) JNI reference on a call to setOutput().
*/
public class Test8007918Regression {
private static int amountOfJpegImageWritersToCreate = 90000;
private static int gcGenerationsToRun = 2;
/* Run GC every 1000 creations*/
private static int amountBeforeGC = 1000;
public static ImageWriterSpi getJpegImageWriterSpi() {
Iterator<ImageWriterSpi> spiIter = IIORegistry.getDefaultInstance().getServiceProviders(ImageWriterSpi.class, true);
while (spiIter.hasNext()) {
ImageWriterSpi spi = spiIter.next();
/* Assumption: JPEG is in the implementation class name for the JPEG image writer SPI */
String classname = spi.getClass().getSimpleName();
if (classname.toLowerCase().contains("jpeg")) {
return spi;
}
}
throw new RuntimeException("No JPEG image writer SPI found.");
}
public static void printMemoryUsage() {
long total = Runtime.getRuntime().totalMemory();
long free = Runtime.getRuntime().freeMemory();
System.out.print("TOTAL: " + total/1024 + "Kb");
System.out.print("\tFREE: " + free/1024 + "Kb");
System.out.println("\tUSED: " + (total - free)/1024 + "Kb");
}
public static void main(String[] args) throws IOException {
ImageWriterSpi jpegSpi = getJpegImageWriterSpi();
System.out.println("Before JPEGImageWriter creations: ");
printMemoryUsage();
for (int i = 1; i <= amountOfJpegImageWritersToCreate; i++) {
ImageWriter jpegWriter = jpegSpi.createWriterInstance();
/* setOutput calls native setDest which seems to create a circular reference via a
* streamBuffer in jdk/src/share/native/sun/awt/image/jpeg/imageioJPEG.c.
* The actual output stream is arbitrary. */
jpegWriter.setOutput(new MemoryCacheImageOutputStream(new ByteArrayOutputStream()));
if (i % amountBeforeGC == 0) {
for (int runs = 0; runs < gcGenerationsToRun; runs++) {
System.gc();
}
System.out.println("After " + i + " JPEGImageWriter creations:");
printMemoryUsage();
}
}
}
}diff --git a/src/share/native/sun/awt/image/jpeg/imageioJPEG.c b/src/share/native/sun/awt/image/jpeg/imageioJPEG.c
--- a/src/share/native/sun/awt/image/jpeg/imageioJPEG.c
+++ b/src/share/native/sun/awt/image/jpeg/imageioJPEG.c
@@ -192,7 +192,7 @@ static void unpinStreamBuffer(JNIEnv *en
*/
static void resetStreamBuffer(JNIEnv *env, streamBufferPtr sb) {
if (sb->stream != NULL) {
- (*env)->DeleteGlobalRef(env, sb->stream);
+ (*env)->DeleteWeakGlobalRef(env, sb->stream);
sb->stream = NULL;
}
unpinStreamBuffer(env, sb, NULL);
@@ -581,7 +581,7 @@ static void imageio_set_stream(JNIEnv *e
/* Now we need a new global reference for the stream */
if (stream != NULL) { // Fix for 4411955
- sb->stream = (*env)->NewGlobalRef(env, stream);
+ sb->stream = (*env)->NewWeakGlobalRef(env, stream);
if (sb->stream == NULL) {
JNU_ThrowByName(env,
"java/lang/OutOfMemoryError",
