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test/hotspot/jtreg/runtime/CompressedOops/CompressedClassPointersEncodingScheme.java

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  1 /*
  2  * Copyright (c) 2013, 2023, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */

 25  * @test
 26  * @summary Testing that, faced with a given (possibly odd) mapping address of class space, the encoding
 27  *          scheme fits the address
 28  * @requires vm.bits == 64 & !vm.graal.enabled & vm.debug == true
 29  * @requires vm.flagless
 30  * @library /test/lib
 31  * @modules java.base/jdk.internal.misc
 32  *          java.management
 33  * @run driver CompressedClassPointersEncodingScheme
 34  */
 35 
 36 import jdk.test.lib.Platform;
 37 import jdk.test.lib.process.OutputAnalyzer;
 38 import jdk.test.lib.process.ProcessTools;
 39 import jtreg.SkippedException;
 40 
 41 import java.io.IOException;
 42 
 43 public class CompressedClassPointersEncodingScheme {
 44 
 45     private static void test(long forceAddress, long classSpaceSize, long expectedEncodingBase, int expectedEncodingShift) throws IOException {
 46         String forceAddressString = String.format("0x%016X", forceAddress).toLowerCase();
 47         String expectedEncodingBaseString = String.format("0x%016X", expectedEncodingBase).toLowerCase();
 48         ProcessBuilder pb = ProcessTools.createLimitedTestJavaProcessBuilder(
 49                 "-Xshare:off", // to make CompressedClassSpaceBaseAddress work
 50                 "-XX:+UnlockDiagnosticVMOptions",
 51                 "-XX:-UseCompressedOops", // keep VM from optimizing heap location



 52                 "-XX:CompressedClassSpaceBaseAddress=" + forceAddress,
 53                 "-XX:CompressedClassSpaceSize=" + classSpaceSize,
 54                 "-Xmx128m",
 55                 "-Xlog:metaspace*",
 56                 "-version");
 57         OutputAnalyzer output = new OutputAnalyzer(pb.start());
 58 
 59         output.reportDiagnosticSummary();
 60 
 61         // We ignore cases where we were not able to map at the force address
 62         if (output.contains("reserving class space failed")) {
 63             throw new SkippedException("Skipping because we cannot force ccs to " + forceAddressString);

 64         }
 65 
 66         output.shouldHaveExitValue(0);
 67         output.shouldContain("Narrow klass base: " + expectedEncodingBaseString + ", Narrow klass shift: " + expectedEncodingShift);
 68     }
 69 
 70     final static long K = 1024;
 71     final static long M = K * 1024;
 72     final static long G = M * 1024;
 73     public static void main(String[] args) throws Exception {
 74         // Test ccs nestling right at the end of the 4G range
 75         // Expecting base=0, shift=0
 76         test(4 * G - 128 * M, 128 * M, 0, 0);
 77 





















 78         // add more...
 79 



















 80     }
 81 }

  1 /*
  2  * Copyright (c) 2013, 2024, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  */

 25  * @test
 26  * @summary Testing that, faced with a given (possibly odd) mapping address of class space, the encoding
 27  *          scheme fits the address
 28  * @requires vm.bits == 64 & !vm.graal.enabled & vm.debug == true
 29  * @requires vm.flagless
 30  * @library /test/lib
 31  * @modules java.base/jdk.internal.misc
 32  *          java.management
 33  * @run driver CompressedClassPointersEncodingScheme
 34  */
 35 
 36 import jdk.test.lib.Platform;
 37 import jdk.test.lib.process.OutputAnalyzer;
 38 import jdk.test.lib.process.ProcessTools;
 39 import jtreg.SkippedException;
 40 
 41 import java.io.IOException;
 42 
 43 public class CompressedClassPointersEncodingScheme {
 44 
 45     private static void test(long forceAddress, boolean COH, long classSpaceSize, long expectedEncodingBase, int expectedEncodingShift) throws IOException {
 46         String forceAddressString = String.format("0x%016X", forceAddress).toLowerCase();
 47         String expectedEncodingBaseString = String.format("0x%016X", expectedEncodingBase).toLowerCase();
 48         ProcessBuilder pb = ProcessTools.createLimitedTestJavaProcessBuilder(
 49                 "-Xshare:off", // to make CompressedClassSpaceBaseAddress work
 50                 "-XX:+UnlockDiagnosticVMOptions",
 51                 "-XX:-UseCompressedOops", // keep VM from optimizing heap location
 52                 "-XX:+UnlockExperimentalVMOptions",
 53                 "-XX:" + (COH ? "+" : "-") + "UseCompactObjectHeaders",
 54                 "-XX:" + (COH ? "+" : "-") + "UseObjectMonitorTable",
 55                 "-XX:CompressedClassSpaceBaseAddress=" + forceAddress,
 56                 "-XX:CompressedClassSpaceSize=" + classSpaceSize,
 57                 "-Xmx128m",
 58                 "-Xlog:metaspace*",
 59                 "-version");
 60         OutputAnalyzer output = new OutputAnalyzer(pb.start());
 61 
 62         output.reportDiagnosticSummary();
 63 
 64         // We ignore cases where we were not able to map at the force address
 65         if (output.contains("reserving class space failed")) {
 66             System.out.println("Skipping because we cannot force ccs to " + forceAddressString);
 67             return;
 68         }
 69 
 70         output.shouldHaveExitValue(0);
 71         output.shouldContain("Narrow klass base: " + expectedEncodingBaseString + ", Narrow klass shift: " + expectedEncodingShift);
 72     }
 73 
 74     final static long K = 1024;
 75     final static long M = K * 1024;
 76     final static long G = M * 1024;
 77     public static void main(String[] args) throws Exception {
 78         // Test ccs nestling right at the end of the 4G range
 79         // Expecting base=0, shift=0
 80         test(4 * G - 128 * M, false, 128 * M, 0, 0);
 81 
 82         // Test ccs nestling right at the end of the 32G range
 83         // Expecting:
 84         // - non-aarch64: base=0, shift=3
 85         // - aarch64: base to start of class range, shift 0
 86         if (Platform.isAArch64()) {
 87             // The best we can do on aarch64 is to be *near* the end of the 32g range, since a valid encoding base
 88             // on aarch64 must be 4G aligned, and the max. class space size is 3G.
 89             long forceAddress = 0x7_0000_0000L; // 28g, and also a valid EOR immediate
 90             test(forceAddress, false, 3 * G, forceAddress, 0);
 91         } else {
 92             test(32 * G - 128 * M, false, 128 * M, 0, 3);
 93         }
 94 
 95         // Test ccs starting *below* 4G, but extending upwards beyond 4G. All platforms except aarch64 should pick
 96         // zero based encoding.
 97         if (Platform.isAArch64()) {
 98             long forceAddress = 0xC000_0000L; // make sure we have a valid EOR immediate
 99             test(forceAddress, false, G + (128 * M), forceAddress, 0);
100         } else {
101             test(4 * G - 128 * M, false, 2 * 128 * M, 0, 3);
102         }
103         // add more...
104 
105         // Compact Object Header Mode with tiny classpointers
106         // On all platforms we expect the VM to chose the smallest possible shift value needed to cover the encoding range
107         long forceAddress = 30 * G;
108 
109         long ccsSize = 128 * M;
110         int expectedShift = 6;
111         test(forceAddress, true, ccsSize, forceAddress, expectedShift);
112 
113         ccsSize = 512 * M;
114         expectedShift = 8;
115         test(forceAddress, true, ccsSize, forceAddress, expectedShift);
116 
117         ccsSize = G;
118         expectedShift = 9;
119         test(forceAddress, true, ccsSize, forceAddress, expectedShift);
120 
121         ccsSize = 3 * G;
122         expectedShift = 10;
123         test(forceAddress, true, ccsSize, forceAddress, expectedShift);
124     }
125 }
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