code: /**
   * Copyright (c) 2004-2005, Regents of the University of California
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * Neither the name of the University of California, Los Angeles nor the
   * names of its contributors may be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package avrora.sim.util;
  
  import avrora.core.Program;
  import avrora.sim.Simulator;
  import avrora.sim.State;
  
  /**
   * The <code>ProgramProfiler</code> class implements a probe that can be used to profile pieces of the program
   * or the whole program. It maintains a simple array of <code>long</code> that stores the cumulative cycles
   * consumed for each instruction in the program.
   *
   * @author Ben L. Titzer
   * @see Counter
   */
  public class ProgramTimeProfiler implements Simulator.Probe {
  
      /**
       * The <code>program</code> field stores a reference to the program being profiled.
       */
      public final Program program;
  
      /**
       * The <code>itime</code> field stores the cumulative number of cycles consumed  for each instruction in
       * the program. It is indexed by byte addresses. Thus <code>itime[addr]</code> corresponds to the time for
       * the instruction at <code>program.getInstr(addr)</code>.
       */
      public final long[] itime;
  
      protected long timeBegan;
  
      /**
       * The constructor for the program profiler constructs the required internal state to store the cycle
       * counts of each instruction.
       *
       * @param p the program to profile
       */
      public ProgramTimeProfiler(Program p) {
          int size = p.program_end;
          itime = new long[size];
          program = p;
      }
  
      /**
       * The <code>fireBefore()</code> method is called before the probed instruction executes. In the
       * implementation of the program profiler, it simply remembers the timestamp at the beginning of the
       * instruction.
       *
       * @param state   the state of the simulation
       * @param pc the address at which this instruction resides
       */
      public void fireBefore(State state, int pc) {
          timeBegan = state.getCycles();
      }
  
      /**
       * The <code>fireAfter()</code> method is called after the probed instruction executes. In the
       * implementation of the profiler, it counts the number of cycles consumed in executing this instruction
       * and adds it to the count for this instruction.
       *
       * @param state   the state of the simulation
       * @param pc the address at which this instruction resides
       */
      public void fireAfter(State state, int pc) {
          itime[pc] += state.getCycles() - timeBegan;
      }
  }
  