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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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/*

 * @test TestPrintReferences

 * @bug 8136991 8186402 8186465 8188245

 * @summary Validate the reference processing logging

 * @key gc

 * @library /test/lib

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

 *          java.management

 */

import java.lang.ref.SoftReference;

import java.math.BigDecimal;

import java.util.ArrayList;

import jdk.test.lib.process.OutputAnalyzer;

import jdk.test.lib.process.ProcessTools;

import java.util.regex.Pattern;

import java.util.regex.Matcher;

public class TestPrintReferences {

  static String output;

  static final String doubleRegex = "[0-9]+[.,][0-9]+";

  static final String referenceProcessing = "Reference Processing";

  static final String softReference = "SoftReference";

  static final String weakReference = "WeakReference";

  static final String finalReference = "FinalReference";

  static final String phantomReference = "PhantomReference";

  static final String phase1 = "Phase1";

  static final String phase2 = "Phase2";

  static final String phase3 = "Phase3";

  static final String gcLogTimeRegex = ".* GC\\([0-9]+\\) ";

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

    test(true);

    test(false);

  }

  static String indent(int count) {

    return " {" + count + "}";

  }

  public static void test(boolean parallelRefProcEnabled) throws Exception {

    ProcessBuilder pb_enabled = ProcessTools.createJavaProcessBuilder("-Xlog:gc+phases+ref=debug",

                                                                      "-XX:+UseG1GC",

                                                                      "-Xmx32M",

                                                                      // Explicit thread setting is required to avoid using only 1 thread

                                                                      "-XX:" + (parallelRefProcEnabled ? "+" : "-") + "ParallelRefProcEnabled",

                                                                      "-XX:ParallelGCThreads=2",

                                                                      GCTest.class.getName());

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

    checkLogFormat(output, parallelRefProcEnabled);

    checkLogValue(output);

    output.shouldHaveExitValue(0);

  }

  // Find the first Reference Processing log and check its format.

  public static void checkLogFormat(OutputAnalyzer output, boolean parallelRefProcEnabled) {

    String countRegex = "[0-9]+";

    String timeRegex = doubleRegex + "ms";

    String totalRegex = gcLogTimeRegex + indent(4) + referenceProcessing + ": " + timeRegex + "\n";

    String balanceRegex = parallelRefProcEnabled ? gcLogTimeRegex + indent(8) + "Balance queues: " + timeRegex + "\n" : "";

    String softRefRegex = gcLogTimeRegex + indent(6) + softReference + ": " + timeRegex + "\n";

    String weakRefRegex = gcLogTimeRegex + indent(6) + weakReference + ": " + timeRegex + "\n";

    String finalRefRegex = gcLogTimeRegex + indent(6) + finalReference + ": " + timeRegex + "\n";

    String phantomRefRegex = gcLogTimeRegex + indent(6) + phantomReference + ": " + timeRegex + "\n";

    String refDetailRegex = gcLogTimeRegex + indent(8) + phase2 + ": " + timeRegex + "\n" +

                            gcLogTimeRegex + indent(8) + phase3 + ": " + timeRegex + "\n" +

                            gcLogTimeRegex + indent(8) + "Discovered: " + countRegex + "\n" +

                            gcLogTimeRegex + indent(8) + "Cleared: " + countRegex + "\n";

    String softRefDetailRegex = gcLogTimeRegex + indent(8) + phase1 + ": " + timeRegex + "\n" + refDetailRegex;

    output.shouldMatch(/* Total Reference processing time */

                       totalRegex +

                       /* SoftReference processing */

                       softRefRegex + balanceRegex + softRefDetailRegex +

                       /* WeakReference processing */

                       weakRefRegex + balanceRegex + refDetailRegex +

                       /* FinalReference processing */

                       finalRefRegex + balanceRegex + refDetailRegex +

                       /* PhantomReference processing */

                       );

  }

  // After getting time value, update 'output' for next use.

  public static BigDecimal getTimeValue(String name, int indentCount) {

    // Pattern of 'name', 'value' and some extra strings.

    String patternString = gcLogTimeRegex + indent(indentCount) + name + ": " + "(" + doubleRegex + ")";

    Matcher m = Pattern.compile(patternString).matcher(output);

     if (!m.find()) {

      throw new RuntimeException("Could not find time log for " + patternString);

     }

    String match = m.group();

    String value = m.group(1);

    double result = Double.parseDouble(value);

    int index = output.indexOf(match);

    if (index != -1) {

      output = output.substring(index, output.length());

    }

    // Convert to BigDecimal to control the precision of floating point arithmetic.

    return BigDecimal.valueOf(result);

  }

  // Reference log is printing 1 decimal place of elapsed time.

  // So sum of each sub-phases could be slightly larger than the enclosing phase in some cases.

  // e.g. If there are 3 sub-phases:

  //      Actual value:  SoftReference(5.55) = phase1(1.85) + phase2(1.85) + phase3(1.85)

  //      Log value:     SoftReference(5.6) = phase1(1.9) + phase2(1.9) + phase3(1.9)

  //      When checked:  5.6 < 5.7 (sum of phase1~3)

  // Because of this we need method to verify that our measurements and calculations are valid.

  public static boolean greaterThanOrApproximatelyEqual(BigDecimal phaseTime, BigDecimal sumOfSubPhasesTime, BigDecimal tolerance) {

    if (phaseTime.compareTo(sumOfSubPhasesTime) >= 0) {

      // phaseTime is greater than or equal.

      return true;

    }

    BigDecimal diff = sumOfSubPhasesTime.subtract(phaseTime);

    if (diff.compareTo(tolerance) <= 0) {

      // Difference is within tolerance, so approximately equal.

      return true;

    }

    // sumOfSubPhasesTime is greater than phaseTime and not within tolerance.

    return false;

  }

  public static BigDecimal checkPhaseTime(String refType) {

    BigDecimal phaseTime = getTimeValue(refType, 2);

    BigDecimal sumOfSubPhasesTime = BigDecimal.valueOf(0.0);

    if (softReference.equals(refType)) {

      sumOfSubPhasesTime = sumOfSubPhasesTime.add(getTimeValue(phase1, 4));

    }

    sumOfSubPhasesTime = sumOfSubPhasesTime.add(getTimeValue(phase2, 4));

    sumOfSubPhasesTime = sumOfSubPhasesTime.add(getTimeValue(phase3, 4));

    // If there are 3 sub-phases, we should allow 0.1 tolerance.

    final BigDecimal toleranceFor3SubPhases = BigDecimal.valueOf(0.1);

    if (!greaterThanOrApproximatelyEqual(phaseTime, sumOfSubPhasesTime, toleranceFor3SubPhases)) {

      throw new RuntimeException(refType +" time(" + phaseTime +

                                 "ms) is less than the sum(" + sumOfSubPhasesTime + "ms) of each phases");

    }

    return phaseTime;

  }

  // Find the first concurrent Reference Processing log and compare phase time vs. sum of sub-phases.

  public static void checkLogValue(OutputAnalyzer out) {

    output = out.getStdout();

    BigDecimal refProcTime = getTimeValue(referenceProcessing, 0);

    BigDecimal sumOfSubPhasesTime = checkPhaseTime(softReference);

    sumOfSubPhasesTime = sumOfSubPhasesTime.add(checkPhaseTime(weakReference));

    sumOfSubPhasesTime = sumOfSubPhasesTime.add(checkPhaseTime(finalReference));

    sumOfSubPhasesTime = sumOfSubPhasesTime.add(checkPhaseTime(phantomReference));

    // If there are 4 sub-phases, we should allow 0.2 tolerance.

    final BigDecimal toleranceFor4SubPhases = BigDecimal.valueOf(0.2);

    if (!greaterThanOrApproximatelyEqual(refProcTime, sumOfSubPhasesTime, toleranceFor4SubPhases)) {

      throw new RuntimeException("Reference Processing time(" + refProcTime + "ms) is less than the sum("

                                 + sumOfSubPhasesTime + "ms) of each phases");

    }

  }

  static class GCTest {

    static final int SIZE = 512 * 1024;

    static Object[] dummy = new Object[SIZE];

    public static void main(String [] args) {

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

        dummy[i] = new SoftReference<>(new Object());

      }

    }

  }

}