/*

 * Copyright (c) 2014, 2016, 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

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * 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).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

/*

 * @test

 * @summary Stress test for malloc tracking

 * @key nmt jcmd stress

 * @library /test/lib

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

 *          java.management

 * @build sun.hotspot.WhiteBox

 * @run main ClassFileInstaller sun.hotspot.WhiteBox

 * @run main/othervm/timeout=600 -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:NativeMemoryTracking=detail MallocStressTest

 */

import java.util.concurrent.atomic.AtomicInteger;

import java.util.ArrayList;

import java.util.List;

import java.util.Random;

import jdk.test.lib.JDKToolFinder;

import jdk.test.lib.Platform;

import jdk.test.lib.process.ProcessTools;

import jdk.test.lib.process.OutputAnalyzer;

import sun.hotspot.WhiteBox;

public class MallocStressTest {

    private static int K = 1024;

    // The stress test runs in three phases:

    // 1. alloc: A lot of malloc with fewer free, which simulates a burst memory allocation

    //    that is usually seen during startup or class loading.

    // 2. pause: Pause the test to check accuracy of native memory tracking

    // 3. release: Release all malloc'd memory and check native memory tracking result.

    public enum TestPhase {

        alloc,

        pause,

        release

    };

    static TestPhase phase = TestPhase.alloc;

    // malloc'd memory

    static ArrayList<MallocMemory>  mallocd_memory = new ArrayList<MallocMemory>();

    static long                     mallocd_total  = 0;

    static WhiteBox                 whiteBox;

    static AtomicInteger            pause_count = new AtomicInteger();

    static boolean                  is_64_bit_system;

    private static boolean is_64_bit_system() { return is_64_bit_system; }

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

        is_64_bit_system = (Platform.is64bit());

        OutputAnalyzer output;

        whiteBox = WhiteBox.getWhiteBox();

        // Grab my own PID

        String pid = Long.toString(ProcessTools.getProcessId());

        ProcessBuilder pb = new ProcessBuilder();

        AllocThread[]   alloc_threads = new AllocThread[256];

        ReleaseThread[] release_threads = new ReleaseThread[64];

        int index;

        // Create many allocation threads

        for (index = 0; index < alloc_threads.length; index ++) {

            alloc_threads[index] = new AllocThread();

        }

        // Fewer release threads

        for (index = 0; index < release_threads.length; index ++) {

            release_threads[index] = new ReleaseThread();

        }

        if (is_64_bit_system()) {

            sleep_wait(2*60*1000);

        } else {

            sleep_wait(60*1000);

        }

        // pause the stress test

        phase = TestPhase.pause;

        while (pause_count.intValue() <  alloc_threads.length + release_threads.length) {

            sleep_wait(10);

        }

        long mallocd_total_in_KB = (mallocd_total + K / 2) / K;

        // Now check if the result from NMT matches the total memory allocated.

        String expected_test_summary = "Test (reserved=" + mallocd_total_in_KB +"KB, committed=" + mallocd_total_in_KB + "KB)";

        // Run 'jcmd <pid> VM.native_memory summary'

        pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "summary"});

        output = new OutputAnalyzer(pb.start());

        output.shouldContain(expected_test_summary);

        // Release all allocated memory

        phase = TestPhase.release;

        synchronized(mallocd_memory) {

            mallocd_memory.notifyAll();

        }

        // Join all threads

        for (index = 0; index < alloc_threads.length; index ++) {

            try {

                alloc_threads[index].join();

            } catch (InterruptedException e) {

            }

        }

        for (index = 0; index < release_threads.length; index ++) {

            try {

                release_threads[index].join();

            } catch (InterruptedException e) {

            }

        }

        // All test memory allocated should be released

        output = new OutputAnalyzer(pb.start());

        output.shouldNotContain("Test (reserved=");

        // Verify that tracking level has not been downgraded

        pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "statistics"});

        output = new OutputAnalyzer(pb.start());

        output.shouldNotContain("Tracking level has been downgraded due to lack of resources");

    }

    private static void sleep_wait(int n) {

        try {

            Thread.sleep(n);

        } catch (InterruptedException e) {

        }

    }

    static class MallocMemory {

        private long  addr;

        private int   size;

        MallocMemory(long addr, int size) {

            this.addr = addr;

            this.size = size;

        }

        long addr()  { return this.addr; }

        int  size()  { return this.size; }

    }

    static class AllocThread extends Thread {

        AllocThread() {

            this.setName("MallocThread");

            this.start();

        }

        // AllocThread only runs "Alloc" phase

        public void run() {

            Random random = new Random();

            while (MallocStressTest.phase == TestPhase.alloc) {

                int r = Math.abs(random.nextInt());

                // Only malloc small amount to avoid OOM

                int size = r % 32;

                if (is_64_bit_system()) {

                    r = r % 32 * K;

                } else {

                    r = r % 64;

                }

                if (size == 0) size = 1;

                long addr = MallocStressTest.whiteBox.NMTMallocWithPseudoStack(size, r);

                if (addr != 0) {

                    MallocMemory mem = new MallocMemory(addr, size);

                    synchronized(MallocStressTest.mallocd_memory) {

                        MallocStressTest.mallocd_memory.add(mem);

                        MallocStressTest.mallocd_total += size;

                    }

                } else {

                    System.out.println("Out of malloc memory");

                    break;

                }

            }

            MallocStressTest.pause_count.incrementAndGet();

        }

    }

    static class ReleaseThread extends Thread {

        private Random random = new Random();

        ReleaseThread() {

            this.setName("ReleaseThread");

            this.start();

        }

        public void run() {

            while(true) {

                switch(MallocStressTest.phase) {

                case alloc:

                    slow_release();

                    break;

                case pause:

                    enter_pause();

                    break;

                case release:

                    quick_release();

                    return;

                }

            }

        }

        private void enter_pause() {

            MallocStressTest.pause_count.incrementAndGet();

            while (MallocStressTest.phase != MallocStressTest.TestPhase.release) {

                try {

                    synchronized(MallocStressTest.mallocd_memory) {

                        MallocStressTest.mallocd_memory.wait(10);

                    }

                } catch (InterruptedException e) {

                }

            }

        }

        private void quick_release() {

            List<MallocMemory> free_list;

            while (true) {

                synchronized(MallocStressTest.mallocd_memory) {

                    if (MallocStressTest.mallocd_memory.isEmpty()) return;

                    int size =  Math.min(MallocStressTest.mallocd_memory.size(), 5000);

                    List<MallocMemory> subList = MallocStressTest.mallocd_memory.subList(0, size);

                    free_list = new ArrayList<MallocMemory>(subList);

                    subList.clear();

                }

                for (int index = 0; index < free_list.size(); index ++) {

                    MallocMemory mem = free_list.get(index);

                    MallocStressTest.whiteBox.NMTFree(mem.addr());

                }

            }

        }

        private void slow_release() {

            try {

                Thread.sleep(10);

            } catch (InterruptedException e) {

            }

            synchronized(MallocStressTest.mallocd_memory) {

                if (MallocStressTest.mallocd_memory.isEmpty()) return;

                int n = Math.abs(random.nextInt()) % MallocStressTest.mallocd_memory.size();

                MallocMemory mem = mallocd_memory.remove(n);

                MallocStressTest.whiteBox.NMTFree(mem.addr());

                MallocStressTest.mallocd_total -= mem.size();

            }

        }

    }

}