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/*

 * @test TestMaxMinHeapFreeRatioFlags

 * @key gc

 * @summary Verify that heap size changes according to max and min heap free ratios.

 * @library /test/lib

 * @modules java.base/jdk.internal.misc

 *          java.management

 * @run driver/timeout=240 TestMaxMinHeapFreeRatioFlags

 */

import java.util.LinkedList;

import java.util.Arrays;

import java.util.Collections;

import jdk.test.lib.process.OutputAnalyzer;

import jdk.test.lib.process.ProcessTools;

import jdk.test.lib.Utils;

import jdk.internal.misc.Unsafe;

public class TestMaxMinHeapFreeRatioFlags {

    public static final long M = 1024 * 1024;

    public static final long MAX_HEAP_SIZE = 200 * M;

    public static final long HEAP_SIZE = 10 * M;

    public static final long MAX_NEW_SIZE = 20 * M;

    public static final long NEW_SIZE = 5 * M;

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

        LinkedList<String> options = new LinkedList<>(

                Arrays.asList(Utils.getFilteredTestJavaOpts("-XX:[^ ]*HeapFreeRatio","-XX:\\+ExplicitGCInvokesConcurrent"))

        );

        negativeTest(20, false, 10, true, options);

        negativeTest(100, true, 0, false, options);

        negativeTest(101, false, 50, false, options);

        negativeTest(49, true, 102, true, options);

        negativeTest(-1, false, 50, false, options);

        negativeTest(50, true, -1, true, options);

        positiveTest(10, false, 90, false, true, options);

        positiveTest(10, true, 80, false, true, options);

        positiveTest(20, false, 70, true, true, options);

        positiveTest(25, true, 65, true, true, options);

        positiveTest(40, false, 50, false, true, options);

    }

    /**

     * Verify that heap size will be changed to conform

     * min and max heap free ratios.

     *

     * @param minRatio value of MinHeapFreeRatio option

     * @param useXminf used Xminf option instead of MinHeapFreeRatio

     * @param maxRatio value of MaxHeapFreeRatio option

     * @param useXmaxf used Xmaxf option instead of MaxHeapFreeRatio

     * @param options additional options for JVM

     */

    public static void positiveTest(int minRatio, boolean useXminf,

            int maxRatio, boolean useXmaxf, boolean shrinkHeapInSteps,

            LinkedList<String> options) throws Exception {

        LinkedList<String> vmOptions = new LinkedList<>(options);

        Collections.addAll(vmOptions,

                (useXminf ? "-Xminf" + minRatio / 100.0 : "-XX:MinHeapFreeRatio=" + minRatio),

                (useXmaxf ? "-Xmaxf" + maxRatio / 100.0 : "-XX:MaxHeapFreeRatio=" + maxRatio),

                "-Xmx" + MAX_HEAP_SIZE,

                "-Xms" + HEAP_SIZE,

                "--add-exports=java.base/jdk.internal.misc=ALL-UNNAMED",

                "-XX:NewSize=" + NEW_SIZE,

                "-XX:MaxNewSize=" + MAX_NEW_SIZE,

                "-XX:" + (shrinkHeapInSteps ? '+' : '-') + "ShrinkHeapInSteps",

                RatioVerifier.class.getName(),

                Integer.toString(minRatio),

                Integer.toString(maxRatio),

                Boolean.toString(shrinkHeapInSteps)

        );

        ProcessBuilder procBuilder = ProcessTools.createJavaProcessBuilder(vmOptions.toArray(new String[vmOptions.size()]));

        OutputAnalyzer analyzer = new OutputAnalyzer(procBuilder.start());

        analyzer.shouldHaveExitValue(0);

    }

    /**

     * Verify that VM will fail to start with specified ratios.

     *

     * @param minRatio value of MinHeapFreeRatio option

     * @param useXminf used Xminf option instead of MinHeapFreeRatio

     * @param maxRatio value of MaxHeapFreeRatio option

     * @param useXmaxf used Xmaxf option instead of MaxHeapFreeRatio

     * @param options additional options for JVM

     */

    public static void negativeTest(int minRatio, boolean useXminf,

            int maxRatio, boolean useXmaxf,

            LinkedList<String> options) throws Exception {

        LinkedList<String> vmOptions = new LinkedList<>(options);

        Collections.addAll(vmOptions,

                (useXminf ? "-Xminf" + minRatio / 100.0 : "-XX:MinHeapFreeRatio=" + minRatio),

                (useXmaxf ? "-Xmaxf" + maxRatio / 100.0 : "-XX:MaxHeapFreeRatio=" + maxRatio),

                "--add-exports=java.base/jdk.internal.misc=ALL-UNNAMED",

                "-version"

        );

        ProcessBuilder procBuilder = ProcessTools.createJavaProcessBuilder(vmOptions.toArray(new String[vmOptions.size()]));

        OutputAnalyzer analyzer = new OutputAnalyzer(procBuilder.start());

        analyzer.shouldHaveExitValue(1);

        analyzer.shouldContain("Error: Could not create the Java Virtual Machine.");

    }

    /**

     * RatioVerifier will be executed in the tested VM.

     * It will check that real heap usage after collection lies between MinHeapFreeRatio and MaxHeapFreeRatio.

     */

    public static class RatioVerifier {

        private static final Unsafe unsafe = Unsafe.getUnsafe();

        // Size of byte array that will be allocated

        public static final int CHUNK_SIZE = 1024;

        // Length of byte array, that will be added to "garbage" list.

        public static final int ARRAY_LENGTH = CHUNK_SIZE - Unsafe.ARRAY_BYTE_BASE_OFFSET;

        // Amount of tries to force heap shrinking/expansion using GC

        public static final int GC_TRIES = 10;

        // Value that will be added/substracted from expected min/max heap free ratio

        // during memory allocation to make sure that specified limit will be exceeded.

        public static final double OVERLOAD = 0.05;

        // Acceptable heap free ratio limit exceedance: verification will fail if

        // actual ratio is lower than expected min heap free ratio - VARIANCE or

        // higher than expected max heap free ratio + VARIANCE.

        public static final double VARIANCE = 0.025;

        public static LinkedList<Object> garbage = new LinkedList<>();

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

            if (args.length != 3) {

                throw new IllegalArgumentException("Expected 3 args: <minRatio> <maxRatio> <shrinkHeapInSteps>");

            }

                return;

            }

            double minRatio = Integer.valueOf(args[0]) / 100.0;

            double maxRatio = Integer.valueOf(args[1]) / 100.0;

            boolean shrinkHeapInSteps = Boolean.valueOf(args[2]);

            long maxHeapSize = getMax();

            int gcTries = (shrinkHeapInSteps ? GC_TRIES : 1);

            // Initial checks. This also links up everything in these helper methods,

            // in case it brings more garbage.

            forceGC(gcTries);

            verifyRatio(minRatio, maxRatio);

            // commit 0.5 of total heap size to have enough space

            // to both shink and expand

            while (getCommitted() < maxHeapSize / 2) {

                garbage.add(new byte[ARRAY_LENGTH]);

            }

            forceGC(gcTries);

            // Verify that current heap free ratio lies between specified limits

            verifyRatio(minRatio, maxRatio);

            // Estimate how much memory we have to allocate to force expansion

            long memoryToFill = (long) (getCommitted() * (1 - minRatio + OVERLOAD))

                    - getUsed();

            long previouslyCommitted = getCommitted();

            while (memoryToFill > 0) {

                garbage.add(new byte[CHUNK_SIZE]);

                memoryToFill -= CHUNK_SIZE;

            }

            forceGC(gcTries);

            // Verify that after memory allocation heap free ratio is still conforming specified limits

            verifyRatio(minRatio, maxRatio);

            // Verify that heap was actually expanded

            if (previouslyCommitted >= getCommitted()) {

                throw new RuntimeException("Heap was not expanded.");

            }

            // Estimate how much memory we have to free to force shrinking

            long memoryToFree = getUsed()

                    - (long) (getCommitted() * (1 - maxRatio - OVERLOAD));

            previouslyCommitted = getCommitted();

            while (memoryToFree > 0 && garbage.size() > 0) {

                garbage.remove(garbage.size() - 1);

                memoryToFree -= CHUNK_SIZE;

            }

            forceGC(gcTries);

            // Verify that heap free ratio is still conforming specified limits

            verifyRatio(minRatio, maxRatio);

            // Verify that heap was actually shrinked

            if (previouslyCommitted <= getCommitted()) {

                throw new RuntimeException("Heap was not shrinked.");

            }

        }

        public static void forceGC(int gcTries) {

            for (int i = 0; i < gcTries; i++) {

                System.gc();

                try {

                    Thread.sleep(10);

                } catch (InterruptedException ie) {

                }

            }

        }

        /**

         * Verify that heap free ratio is conforming specified limits.

         * Actual heap free ratio may be very close to one of specified limits,

         * but exceed for more then VARIANCE.

         * Verification will also pass if actual ratio is not conforming limits,

         * but it is not possible to shrink/expand heap.

         */

        public static void verifyRatio(double minRatio, double maxRatio) {

            double ratio = getHeapFreeRatio();

            System.out.println(minRatio + " " + ratio + " " + maxRatio);

            if (minRatio - ratio > VARIANCE

                    && getCommitted() < getMax()) {

                throw new RuntimeException("Current heap free ratio is lower than "

                        + "MinHeapFreeRatio (" + ratio + " vs " + minRatio + ").");

            }

            if (ratio - maxRatio > VARIANCE

                    && getUsed() > getInit()) {

                throw new RuntimeException("Current heap free ratio is higher than "

                        + "MaxHeapFreeRatio (" + ratio + " vs " + maxRatio + ").");

            }

        }

        /*

         * Obtain information about heap size.

         *

         * For G1 information summed up for all type of regions,

         * because tested options affect overall heap sizing.

         *

         * For all other GCs return information only for old gen.

         */

        public static long getMax() {

            return HeapRegionUsageTool.getOldUsage().getMax();

        }

        public static long getInit() {

            if (GCTypes.OldGCType.getOldGCType() == GCTypes.OldGCType.G1) {

                return HeapRegionUsageTool.getEdenUsage().getInit()

                        + HeapRegionUsageTool.getSurvivorUsage().getInit()

                        + HeapRegionUsageTool.getOldUsage().getInit();

            } else {

                return HeapRegionUsageTool.getOldUsage().getInit();

            }

        }

        public static long getUsed() {

            if (GCTypes.OldGCType.getOldGCType() == GCTypes.OldGCType.G1) {

                return HeapRegionUsageTool.getEdenUsage().getUsed()

                        + HeapRegionUsageTool.getSurvivorUsage().getUsed()

                        + HeapRegionUsageTool.getOldUsage().getUsed();

            } else {

                return HeapRegionUsageTool.getOldUsage().getUsed();

            }

        }

        public static long getCommitted() {

            if (GCTypes.OldGCType.getOldGCType() == GCTypes.OldGCType.G1) {

                return HeapRegionUsageTool.getEdenUsage().getCommitted()

                        + HeapRegionUsageTool.getSurvivorUsage().getCommitted()

                        + HeapRegionUsageTool.getOldUsage().getCommitted();

            } else {

                return HeapRegionUsageTool.getOldUsage().getCommitted();

            }

        }

        public static long getFree() {

            return getCommitted() - getUsed();

        }

        public static double getHeapFreeRatio() {

            return getFree() / (double) getCommitted();

        }

    }

}