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 * Copyright (c) 2024, Red Hat Inc.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 2 along with this work; if not, write to the Free Software Foundation,
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/*
 * @test
 * @bug 8332122
 * @summary Test to verify correctness of peak malloc tracking
 * @key randomness
 * @library /test/lib
 * @modules java.base/jdk.internal.misc
 *          java.management
 * @build jdk.test.whitebox.WhiteBox
 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:NativeMemoryTracking=summary -Xms32m -Xmx32m -Xint PeakMallocTest
 *
 */

// Note we run the test with -Xint to keep compilers from running and reduce malloc noise.

import jdk.test.lib.process.OutputAnalyzer;

import jdk.test.whitebox.WhiteBox;

public class PeakMallocTest {

    private static WhiteBox wb = WhiteBox.getWhiteBox();
    private static final double FUDGE_FACTOR = 0.2;

    public static void main(String[] args) throws Exception {

        // Measure early malloc total and peak
        OutputAnalyzer output = NMTTestUtils.startJcmdVMNativeMemory("scale=1");
        long earlyTotal = getMallocTotal(output);
        long earlyPeak = getMallocPeak(output);
        System.out.println("Early malloc total: " + earlyTotal);
        System.out.println("Early malloc peak: " + earlyPeak);

        // Allocate a large amount of memory and then free
        long allocSize = Math.max(8 * earlyPeak, 250 * 1024 * 1024); // MAX(earlyPeak * 8, 250MB)
        long addr = wb.NMTMalloc(allocSize);
        System.out.println("Allocation size: " + allocSize);
        wb.NMTFree(addr);

        // Measure again
        output = NMTTestUtils.startJcmdVMNativeMemory("scale=1");
        long currTotal = getMallocTotal(output);
        long currPeak = getMallocPeak(output);
        System.out.println("Current malloc total: " + currTotal);
        System.out.println("Current malloc peak: " + currPeak);

        // Verify total global malloc is similar with a fudge factor
        double mallocLowerBound = earlyTotal * (1 - FUDGE_FACTOR);
        double mallocUpperBound = earlyTotal * (1 + FUDGE_FACTOR);
        if (currTotal < mallocLowerBound || currTotal > mallocUpperBound) {
            throw new Exception("Global malloc measurement is incorrect. " +
                    "Expected range: [" + mallocLowerBound + " - " + mallocUpperBound + "]. " +
                    "Actual malloc total: " + currTotal);
        }

        // Verify global malloc peak reflects large allocation with a fudge factor
        long peakDiff = currPeak - earlyPeak;
        double peakLowerBound = allocSize * (1 - FUDGE_FACTOR);
        double peakUpperBound = allocSize * (1 + FUDGE_FACTOR);
        if (peakDiff < peakLowerBound || peakDiff > peakUpperBound) {
            throw new Exception("Global malloc peak measurement is incorrect. " +
                    "Expected peak diff range: [" + peakLowerBound + " - " + peakUpperBound + "]. " +
                    "Actual peak diff: " + peakDiff);
        }
    }

    private static long getMallocPeak(OutputAnalyzer output) {
        // First match should correspond to global malloc peak
        String global = output.firstMatch("peak=\\d*");
        return Long.parseLong(global.substring(global.indexOf("=") + 1));
    }

    private static long getMallocTotal(OutputAnalyzer output) {
        // First match should correspond to global malloc total
        String global = output.firstMatch("malloc: \\d*");
        return Long.parseLong(global.substring(global.indexOf(" ") + 1));
    }
}