|
/*
* Copyright (c) 2020, 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.
*
* 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 jdk.test.lib.util;
import java.lang.ref.PhantomReference;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.util.function.BooleanSupplier;
/**
* Utility class to invoke System.gc()
*/
public class ForceGC {
// The jtreg testing timeout factor.
private static final double TIMEOUT_FACTOR = Double.valueOf(
System.getProperty("test.timeout.factor", "1.0"));
/**
* Causes the current thread to wait until the {@code booleanSupplier}
* returns true, or a specific waiting time elapses. The waiting time
* is 1 second scaled with the jtreg testing timeout factor.
*
* @param booleanSupplier boolean supplier
* @return true if the {@code booleanSupplier} returns true, or false
* if did not complete after the specific waiting time.
*/
public static boolean wait(BooleanSupplier booleanSupplier) {
ReferenceQueue<Object> queue = new ReferenceQueue<>();
Object obj = new Object();
PhantomReference<Object> ref = new PhantomReference<>(obj, queue);
obj = null;
Reference.reachabilityFence(obj);
Reference.reachabilityFence(ref);
int retries = (int)(Math.round(1000L * TIMEOUT_FACTOR) / 200);
for (; retries >= 0; retries--) {
if (booleanSupplier.getAsBoolean()) {
return true;
}
System.gc();
try {
// The remove() will always block for the specified milliseconds
// if the reference has already been removed from the queue.
// But it is fine. For most cases, the 1st GC is sufficient
// to trigger and complete the cleanup.
queue.remove(200L);
} catch (InterruptedException ie) {
// ignore, the loop will try again
}
}
return booleanSupplier.getAsBoolean();
}
}
¤ Dauer der Verarbeitung: 0.22 Sekunden
(vorverarbeitet)
¤
|
Haftungshinweis
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung ist noch experimentell.
|
