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/*
* Copyright (c) 2014, 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.
*/
/*
* @test TestMemBarAcquire
* @bug 8048879
* @summary Tests optimization of MemBarAcquireNodes
* @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation
* compiler.membars.TestMemBarAcquire
*/
package compiler.membars;
public class TestMemBarAcquire {
private volatile static Object defaultObj = new Object();
private Object obj;
public TestMemBarAcquire(Object param) {
// Volatile load. MemBarAcquireNode is added after the
// load to prevent following loads from floating up past.
// StoreNode is added to store result of load in 'obj'.
this.obj = defaultObj;
// Overrides 'obj' and therefore makes previous StoreNode
// and the corresponding LoadNode useless. However, the
// LoadNode is still connected to the MemBarAcquireNode
// that should now release the reference.
this.obj = param;
}
public static void main(String[] args) throws Exception {
// Make sure TestMemBarAcquire::<init> is compiled
for (int i = 0; i < 100000; ++i) {
TestMemBarAcquire p = new TestMemBarAcquire(new Object());
}
}
}
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