synchronized (StreamCloser.class) {
if (toCloseQueue == null) {
toCloseQueue =
new WeakHashMap<ImageInputStream, Object>();
}
toCloseQueue.put(iis, null);
if (streamCloser == null) {
final Runnable streamCloserRunnable = new Runnable() {
public void run() {
if (toCloseQueue != null) {
synchronized (StreamCloser.class) {
Set<ImageInputStream> set =
toCloseQueue.keySet();
// Make a copy of the set in order to avoid
// concurrent modification (the is.close()
// will in turn call removeFromQueue())
ImageInputStream[] streams =
new ImageInputStream[set.size()];
streams = set.toArray(streams);
for (ImageInputStream is : streams) {
if (is != null) {
try {
is.close();
} catch (IOException e) {
}
}
}
}
}
}
};
java.security.AccessController.doPrivileged(
new java.security.PrivilegedAction() {
public Object run() {
/* The thread must be a member of a thread group
* which will not get GCed before VM exit.
* Make its parent the top-level thread group.
*/
ThreadGroup tg =
Thread.currentThread().getThreadGroup();
for (ThreadGroup tgn = tg;
tgn != null;
tg = tgn, tgn = tg.getParent());
streamCloser = new Thread(tg, streamCloserRunnable);
Runtime.getRuntime().addShutdownHook(streamCloser);
return null;
}
});
}
}
