/*
* Copyright (c) 2002, 2009, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.nio.ch;
// Special-purpose data structure for sets of native threads
class NativeThreadSet {
private long[] elts;
private int used = 0;
private boolean waitingToEmpty;
NativeThreadSet(int n) {
elts = new long[n];
}
// Adds the current native thread to this set, returning its index so that
// it can efficiently be removed later.
//
int add() {
long th = NativeThread.current();
// 0 and -1 are treated as placeholders, not real thread handles
if (th == 0)
th = -1;
synchronized (this) {
int start = 0;
if (used >= elts.length) {
int on = elts.length;
int nn = on * 2;
long[] nelts = new long[nn];
System.arraycopy(elts, 0, nelts, 0, on);
elts = nelts;
start = on;
}
for (int i = start; i < elts.length; i++) {
if (elts[i] == 0) {
elts[i] = th;
used++;
return i;
}
}
assert false;
return -1;
}
}
// Removes the thread at the given index.
//
void remove(int i) {
synchronized (this) {
elts[i] = 0;
used--;
if (used == 0 && waitingToEmpty)
notifyAll();
}
}
// Signals all threads in this set.
//
void signalAndWait() {
synchronized (this) {
int u = used;
int n = elts.length;
for (int i = 0; i < n; i++) {
long th = elts[i];
if (th == 0)
continue;
if (th != -1)
NativeThread.signal(th);
if (--u == 0)
break;
}
waitingToEmpty = true;
boolean interrupted = false;
while (used > 0) {
try {
wait();
} catch (InterruptedException e) {
interrupted = true;
}
}
if (interrupted)
Thread.currentThread().interrupt();
}
}
}