0N/A/*
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0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
2362N/A * published by the Free Software Foundation.
0N/A *
2362N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
0N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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2362N/A * questions.
2362N/A */
2362N/A
0N/A/* @test
0N/A * @bug 4076287
0N/A * @summary Invoking get on a SoftReference shouldn't pin the referent
0N/A * @run main/othervm -ms16m -mx16m Pin
0N/A * @author Peter Jones
0N/A * @author Mark Reinhold
0N/A */
0N/A
0N/A
0N/Aimport java.lang.ref.SoftReference;
0N/A
0N/Apublic class Pin {
0N/A
0N/A final static int NUM_BLOCKS = 128;
0N/A final static int BLOCK_SIZE = 32768;
0N/A
0N/A public static void main(String[] args) throws Exception {
0N/A
0N/A SoftReference[] blocks = new SoftReference[NUM_BLOCKS];
0N/A
0N/A byte[] block;
0N/A
0N/A System.err.println("Filling array with " + NUM_BLOCKS +
0N/A " SoftReferences to blocks of " +
0N/A BLOCK_SIZE + " bytes.");
0N/A
0N/A for (int i = 0; i < NUM_BLOCKS; ++ i) {
0N/A block = new byte[BLOCK_SIZE];
0N/A SoftReference ref = new SoftReference(block);
0N/A blocks[i] = ref;
}
block = null;
System.err.println("Allowing SoftReferences to be enqueued.");
System.gc();
Thread.sleep(1000);
/* -- Commenting out the following section will hide the bug -- */
System.err.println("Invoking get() on SoftReferences.");
for (int i = 0; i < NUM_BLOCKS; ++ i) {
block = (byte[]) blocks[i].get();
}
block = null;
/* -- end -- */
System.err.println("Forcing desperate garbage collection...");
java.util.Vector chain = new java.util.Vector();
try {
while (true) {
System.gc();
int[] hungry = new int[65536];
chain.addElement(hungry);
Thread.sleep(100); // yield, for what it's worth
}
} catch (OutOfMemoryError e) {
System.err.println("Got OutOfMemoryError, as expected.");
}
int emptyCount = 0, fullCount = 0;
System.err.print("Examining contents of array:");
for (int i = 0; i < NUM_BLOCKS; ++ i) {
block = (byte[]) blocks[i].get();
if (block == null) {
emptyCount++;
} else {
fullCount++;
}
}
System.err.println(" " + emptyCount + " empty, " +
fullCount + " full.");
if (emptyCount == 0)
throw new Exception("No SoftReference instances were cleared");
}
}