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 * Copyright (c) 2021, 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
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 *
 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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 */

/*
 * @test
 * @bug 8260349
 * @summary test that setting via the env-var and options file shows up as expected
 * @library /testlibrary
 * @run driver MaxMetaspaceSizeEnvVarTest
 */

import java.io.PrintWriter;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryPoolMXBean;
import java.util.NoSuchElementException;

import com.oracle.java.testlibrary.ProcessTools;
import com.oracle.java.testlibrary.OutputAnalyzer;

public class MaxMetaspaceSizeEnvVarTest {

    // This is the test class we exec, passing the MaxMetaspaceSize flag
    // by different mechanisms.
    static class Main {
        public static void main(String[] args) throws Exception {
            long expected = Long.parseLong(args[0]);
            MemoryPoolMXBean metaspaceMemoryPool =
                ManagementFactory.getPlatformMXBeans(MemoryPoolMXBean.class)
                .stream()
                .filter(pool -> "Metaspace".equals(pool.getName()))
                .findFirst()
                .orElseThrow(() -> new NoSuchElementException("No value present"));
            long max = metaspaceMemoryPool.getUsage().getMax();
            System.out.println("Metaspace max usage is " + max);
            if (max != expected) {
                throw new RuntimeException("Metaspace max " + max +
                                           " != " + expected);
            }
        }
    }

    static void report(String msg) {
        System.out.println(msg);
        System.err.println(msg);
    }

    public static void main(String... args) throws Exception {
        final String max = String.valueOf(9 * 1024 * 1024); // 9 MB
        final String flagRaw = "MaxMetaspaceSize=" + max;
        final String flag = "-XX:" + flagRaw;
        final String main = "MaxMetaspaceSizeEnvVarTest$Main";

        ProcessBuilder pb = null;
        OutputAnalyzer output = null;

        int test = 1;
        report("Test " + test + ": flag not set");

        Main.main(new String[] { "-1" });  // -1 == undefined size
        report("------ end Test " + test);
        test++;

        report("Test " + test + ": normal command-line flag");
        pb = ProcessTools.createJavaProcessBuilder(flag, main, max);
        output = new OutputAnalyzer(pb.start());
        output.shouldHaveExitValue(0);
        output.reportDiagnosticSummary();
        report("------ end Test " + test);
        test++;

        String[] envVars = {
            "_JAVA_OPTIONS",
            "JAVA_TOOL_OPTIONS"
        };

        for (String envVar :  envVars) {
            report("Test " + test + ": " + envVar + " env-var");
            pb = ProcessTools.createJavaProcessBuilder(main, max);
            pb.environment().put(envVar, flag);
            output = new OutputAnalyzer(pb.start());
            output.shouldHaveExitValue(0);
            output.reportDiagnosticSummary();
            report("------ end Test " + test);
            test++;
        }

        report("Test " + test + ": .hotspotrc file");
        final String rcFile = ".hotspotrc";
        final String rcFileFlag = "-XX:Flags=" + rcFile;

        PrintWriter pw = new PrintWriter(rcFile);
        pw.println(flagRaw);
        pw.close();
        pb = ProcessTools.createJavaProcessBuilder(rcFileFlag, main, max);
        output = new OutputAnalyzer(pb.start());
        output.shouldHaveExitValue(0);
        output.reportDiagnosticSummary();
        report("------ end Test " + test);
    }
}