/**
* Expert: decreases the refCount of this IndexReader instance. If the refCount drops to 0, then
* this reader is closed. If an exception is hit, the refCount is unchanged.
*
* @throws IOException in case an IOException occurs in doClose()
* @see #incRef
*/
public final void decRef() throws IOException {
// only check refcount here (don't call ensureOpen()), so we can
// still close the reader if it was made invalid by a child:
if (refCount.get() <= 0) {
throw new AlreadyClosedException("this IndexReader is closed");
}
final int rc = refCount.decrementAndGet();
if (rc == 0) {
closed = true;
Throwable throwable = null;
try {
doClose();
} catch (Throwable th) {
throwable = th;
} finally {
try {
reportCloseToParentReaders();
} finally {
notifyReaderClosedListeners(throwable);
}
}
} else if (rc < 0) {
throw new IllegalStateException(
"too many decRef calls: refCount is " + rc + " after decrement");
}
}
private void reportCloseToParentReaders() {
synchronized (parentReaders) {
for (IndexReader parent : parentReaders) {
parent.closedByChild = true;
// cross memory barrier by a fake write:
parent.refCount.addAndGet(0);
// recurse:
parent.reportCloseToParentReaders();
}
}
}