57 lines
2.2 KiB
Java
57 lines
2.2 KiB
Java
/*
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* Copyright (c) 2016, 2018, Red Hat, Inc. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/**
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* @test
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* @key stress randomness
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* @summary Logic that moves a null check in the expanded barrier may cause a memory access that doesn't depend on the barrier to bypass the null check
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* @requires vm.gc.Shenandoah
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* @requires vm.flavor == "server"
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* @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:-TieredCompilation
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* -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC
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* -XX:+StressGCM -XX:+StressLCM TestExpandedWBLostNullCheckDep
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*/
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public class TestExpandedWBLostNullCheckDep {
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static void test(int i, int[] arr) {
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// arr.length depends on a null check for arr
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if (i < 0 || i >= arr.length) {
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}
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// The write barrier here also depends on the null check. The
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// null check is moved in the barrier to enable implicit null
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// checks. The null check must not be moved arr.length
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arr[i] = 0x42;
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}
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static public void main(String[] args) {
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int[] int_arr = new int[10];
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for (int i = 0; i < 20000; i++) {
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test(0, int_arr);
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}
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try {
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test(0, null);
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} catch (NullPointerException npe) {}
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}
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}
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