/*
 *  This file is part of the Jikes RVM project (http://jikesrvm.org).
 *
 *  This file is licensed to You under the Common Public License (CPL);
 *  You may not use this file except in compliance with the License. You
 *  may obtain a copy of the License at
 *
 *      http://www.opensource.org/licenses/cpl1.0.php
 *
 *  See the COPYRIGHT.txt file distributed with this work for information
 *  regarding copyright ownership.
 */
package org.mmtk.utility.sanitychecker;

import org.mmtk.plan.Plan;
import org.mmtk.plan.Trace;
import org.mmtk.plan.Simple;
import org.mmtk.policy.Space;
import org.mmtk.utility.Constants;
import org.mmtk.utility.Log;

import org.mmtk.vm.VM;

import org.vmmagic.pragma.*;
import org.vmmagic.unboxed.*;

/**
 * This class performs sanity checks for Simple collectors.
 */
@Uninterruptible public final class SanityChecker implements Constants {

  /* Counters */
  public static long referenceCount;
  public static long rootReferenceCount;
  public static long danglingReferenceCount;
  public static long nullReferenceCount;
  public static long liveObjectCount;

  public static final int DEAD = -2;
  public static final int ALIVE = -1;
  public static final int UNSURE = 0;

  public static final int LOG_SANITY_DATA_SIZE = 21;
  /* Trace */
  public Trace trace;
  private final SanityDataTable sanityTable;
  private boolean preGCSanity;

  /****************************************************************************
   * Constants
   */
  public SanityChecker() {
    sanityTable = new SanityDataTable(Plan.sanitySpace, LOG_SANITY_DATA_SIZE);
    trace = new Trace(Plan.sanitySpace);
  }

  /**
   * @return The current sanity data table.
   */
  public SanityDataTable getSanityTable() {
    return sanityTable;
  }

  /**
   * @return True if this is pre-gc sanity, false if post-gc
   */
  public boolean preGCSanity() {
    return preGCSanity;
  }

  /**
   * Perform any sanity checking collection phases.
   *
   * @param phaseId The id to proces
   * @return True if the phase was handled.
   */
  @NoInline
  public boolean collectionPhase(int phaseId) {
    if (phaseId == Simple.SANITY_SET_PREGC) {
      preGCSanity = true;
      return true;
    }

    if (phaseId == Simple.SANITY_SET_POSTGC) {
      preGCSanity = false;
      return true;
    }

    if (phaseId == Simple.SANITY_PREPARE) {
      Log.writeln("");
      Log.write("============================== GC Sanity Checking ");
      Log.writeln("==============================");
      Log.writeln("Performing Sanity Checks...");

      // Reset counters
      referenceCount = 0;
      nullReferenceCount = 0;
      liveObjectCount = 0;
      danglingReferenceCount = 0;
      rootReferenceCount = 0;

      // Clear data space
      sanityTable.acquireTable();

      trace.prepareNonBlocking();
      return true;
    }

    if (phaseId == Simple.SANITY_ROOTS) {
      VM.scanning.resetThreadCounter();
      return true;
    }

    if (phaseId == Simple.SANITY_RELEASE) {
      trace.release();
      sanityTable.releaseTable();

      Log.writeln("roots\tobjects\trefs\tnull");
      Log.write(rootReferenceCount);Log.write("\t");
      Log.write(liveObjectCount);Log.write("\t");
      Log.write(referenceCount);Log.write("\t");
      Log.writeln(nullReferenceCount);

      Log.write("========================================");
      Log.writeln("========================================");

      return true;
    }

    return false;
  }

  /**
   * Print out object information (used for warning and error messages)
   *
   * @param object The object to dump info for.
   */
  public static void dumpObjectInformation(ObjectReference object) {
    Log.write(object);
    Log.write(" [");
    Log.write(Space.getSpaceForObject(object).getName());
    Log.write("] ");
    Log.writeln(VM.objectModel.getTypeDescriptor(object));
  }
}