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// Test of WeakReference
// Copyright (C) 2001 Red Hat, Inc.
// This file is part of Mauve.
// Mauve is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
// Mauve 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 for more details.
// You should have received a copy of the GNU General Public License
// along with Mauve; see the file COPYING. If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.
// Tags: JDK1.2
// In this test we make some assumptions about how the GC operates
// that are probably not quite sound. In particular we assume
// System.gc() will collect everything.
package gnu.testlet.java.lang.ref.WeakReference;
import gnu.testlet.Testlet;
import gnu.testlet.TestHarness;
import java.lang.ref.*;
public class weakref implements Testlet
{
static class Reffer extends Thread
{
ReferenceQueue q;
TestHarness harness;
WeakReference wr;
Integer twt;
public Reffer (ReferenceQueue q, TestHarness harness)
{
this.q = q;
this.harness = harness;
}
public void run()
{
twt = new Integer (23);
wr = new WeakReference (twt, q);
System.gc ();
Reference r = q.poll ();
harness.check (r, null, "live reference");
harness.check (wr.get (), twt);
}
}
public void test (TestHarness harness)
{
ReferenceQueue q = new ReferenceQueue ();
// Create reference in a separate thread so no inadvertent references
// to the contained object are left on the stack, which causes VM's that
// do conservative stack GC scans to report false negatives for this test.
Reffer reffer = new Reffer(q, harness);
reffer.start();
try {
reffer.join();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
WeakReference wr = reffer.wr;
// Weak reference "should" get cleared here
reffer.twt = null;
System.gc ();
Reference r = null;
try
{
r = q.remove (5 * 1000); // 5 seconds.
}
catch (InterruptedException _)
{
harness.debug (_);
}
harness.check (r, wr, "unreachable");
harness.check (wr.get (), null, "contents of weak reference");
}
}
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