X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/84402e8e2ee2a2d0bef25fdceb0a263ed8b471f6..6fbcdfade89b3812c24152c86f8aa3be510df7f2:/examples/deprecated/java/dht/chord/Node.java

diff --git a/examples/deprecated/java/dht/chord/Node.java b/examples/deprecated/java/dht/chord/Node.java
deleted file mode 100644
index f3bb660612..0000000000
--- a/examples/deprecated/java/dht/chord/Node.java
+++ /dev/null
@@ -1,394 +0,0 @@
-/* Copyright (c) 2006-2020. The SimGrid Team. All rights reserved.          */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-package dht.chord;
-
-import org.simgrid.msg.Msg;
-import org.simgrid.msg.Comm;
-import org.simgrid.msg.Host;
-import org.simgrid.msg.Task;
-import org.simgrid.msg.Process;
-import org.simgrid.msg.MsgException;
-import org.simgrid.msg.TimeoutException;
-public class Node extends Process {
-  protected int id;
-  protected String mailbox;
-  protected int predId;
-  protected String predMailbox;
-  protected int nextFingerToFix;
-  protected Comm commReceive;
-  ///Last time I changed a finger or my predecessor
-  protected double lastChangeDate;
-  private int[] fingers;
-
-  public Node(Host host, String name, String[] args) {
-    super(host,name,args);
-  }
-
-  @Override
-  public void main(String[] args) throws MsgException {
-    if (args.length != 2 && args.length != 4) {
-      Msg.info("You need to provide 2 or 4 arguments.");
-      return;
-    }
-    double initTime = Msg.getClock();
-    int i;
-    boolean joinSuccess;
-    double deadline;
-
-    double nextStabilizeDate = initTime + Common.PERIODIC_STABILIZE_DELAY;
-    double nextFixFingersDate = initTime + Common.PERIODIC_FIX_FINGERS_DELAY;
-    double nextCheckPredecessorDate = initTime + Common.PERIODIC_CHECK_PREDECESSOR_DELAY;
-    double nextLookupDate = initTime + Common.PERIODIC_LOOKUP_DELAY;
-
-    mailbox = args[0];
-    id = Integer.parseInt(args[0]);
-
-    fingers = new int[Common.NB_BITS];
-    for (i = 0; i < Common.NB_BITS; i++) {
-      fingers[i] = -1;
-      setFinger(i,this.id);
-    }
-
-    //First node
-    if (args.length == 2) {
-      deadline = Integer.parseInt(args[1]);
-      create();
-      joinSuccess = true;
-    } else {
-      int knownId = Integer.parseInt(args[1]);
-      deadline = Integer.parseInt(args[3]);
-      Msg.debug("Hey! Let's join the system with the id " + id + ".");
-
-      joinSuccess = join(knownId);
-    }
-
-    if (!joinSuccess) {
-      Msg.info("I couldn't join the ring");
-      return;
-    }
-
-    double currentClock = Msg.getClock();
-    while (currentClock < (initTime + deadline) && currentClock < Common.MAX_SIMULATION_TIME) {
-      if (commReceive == null) {
-        commReceive = Task.irecv(this.mailbox);
-      }
-      try {
-        if (!commReceive.test()) {
-          if (currentClock >= nextStabilizeDate) {
-            stabilize();
-            nextStabilizeDate = Msg.getClock() + Common.PERIODIC_STABILIZE_DELAY;
-          } else if (currentClock >= nextFixFingersDate) {
-            fixFingers();
-            nextFixFingersDate = Msg.getClock() + Common.PERIODIC_FIX_FINGERS_DELAY;
-          } else if (currentClock >= nextCheckPredecessorDate) {
-            this.checkPredecessor();
-            nextCheckPredecessorDate = Msg.getClock() + Common.PERIODIC_CHECK_PREDECESSOR_DELAY;
-          } else if (currentClock >= nextLookupDate) {
-            this.randomLookup();
-            nextLookupDate = Msg.getClock() + Common.PERIODIC_LOOKUP_DELAY;
-          } else {
-            waitFor(5);
-          }
-          currentClock = Msg.getClock();
-        } else {
-          handleTask(commReceive.getTask());
-          currentClock = Msg.getClock();
-          commReceive = null;
-        }
-      }
-      catch (Exception e) {
-        currentClock = Msg.getClock();
-        commReceive = null;
-      }
-    }
-    leave();
-    if (commReceive != null) {
-      commReceive = null;
-    }
-  }
-
-  private void handleTask(Task task) {
-    if (task instanceof FindSuccessorTask) {
-      FindSuccessorTask fTask = (FindSuccessorTask)task;
-      Msg.debug("Receiving a 'Find Successor' request from " + fTask.getIssuerHostName() + " for id " + 
-                fTask.getRequestId());
-      // is my successor the successor?
-      if (isInInterval(fTask.getRequestId(), this.id + 1, fingers[0])) {
-        Msg.debug("Send the request to " + fTask.getAnswerTo() + " with answer " + fingers[0]);
-        FindSuccessorAnswerTask answer = new FindSuccessorAnswerTask(getHost().getName(), mailbox, fingers[0]);
-        answer.dsend(fTask.getAnswerTo());
-      } else {
-        // otherwise, forward the request to the closest preceding finger in my table
-        int closest = closestPrecedingNode(fTask.getRequestId());
-        Msg.debug("Forward the request to " + closest);
-        fTask.dsend(Integer.toString(closest));
-      }
-    } else if (task instanceof GetPredecessorTask) {
-      GetPredecessorTask gTask = (GetPredecessorTask)(task);
-      Msg.debug("Receiving a 'Get Predecessor' request from " + gTask.getIssuerHostName());
-      GetPredecessorAnswerTask answer = new GetPredecessorAnswerTask(getHost().getName(), mailbox, predId);
-      answer.dsend(gTask.getAnswerTo());
-    } else if (task instanceof NotifyTask) {
-      NotifyTask nTask = (NotifyTask)task;
-      notify(nTask.getRequestId());
-    } else {
-      Msg.debug("Ignoring unexpected task of type:" + task);
-    }
-  }
-
-  private void leave() {
-    Msg.debug("Well Guys! I Think it's time for me to quit ;)");
-    // TODO: Notify my successor and predecessor.
-  }
-
-  /** @brief Initializes the current node as the first one of the system  */
-  private void create() {
-    Msg.debug("Create a new Chord ring...");
-    setPredecessor(-1);
-  }
-
-  // Makes the current node join the ring, knowing the id of a node already in the ring 
-  private boolean join(int knownId) {
-    Msg.info("Joining the ring with id " + this.id + " knowing node " + knownId);
-    setPredecessor(-1);
-    int successorId = remoteFindSuccessor(knownId, this.id);
-    if (successorId == -1) {
-      Msg.info("Cannot join the ring.");
-    } else {
-      setFinger(0, successorId);
-    }
-    return successorId != -1;
-  }
-
-  private void setPredecessor(int predecessorId) {
-    if (predecessorId != predId) {
-      predId = predecessorId;
-      if (predecessorId != -1) {
-        predMailbox = Integer.toString(predId);
-      }
-      lastChangeDate = Msg.getClock();
-    }
-  }
-
-  /**
-   * @brief Asks another node its predecessor.
-   * @param askTo the node to ask to
-   * @return the id of its predecessor node, or -1 if the request failed(or if the node does not know its predecessor)
-   */
-  private int remoteGetPredecessor(int askTo) {
-    int predecessorId = -1;
-    boolean stop = false;
-    Msg.debug("Sending a 'Get Predecessor' request to " + askTo);
-    String mailboxTo = Integer.toString(askTo);
-    GetPredecessorTask sendTask = new GetPredecessorTask(getHost().getName(), this.mailbox);
-    try {
-      sendTask.send(mailboxTo, Common.TIMEOUT);
-      do {
-        if (commReceive == null) {
-          commReceive = Task.irecv(this.mailbox);
-        }
-        commReceive.waitCompletion(Common.TIMEOUT);
-        Task taskReceived = commReceive.getTask();
-        if (taskReceived instanceof GetPredecessorAnswerTask) {
-          predecessorId = ((GetPredecessorAnswerTask) taskReceived).getAnswerId();
-          stop = true;
-        } else {
-          handleTask(taskReceived);
-        }
-        commReceive = null;
-      } while (!stop);
-    }
-    catch (MsgException e) {
-      Msg.debug("Failed to send the Get Predecessor request");
-    }
-    commReceive = null;
-
-    return predecessorId;
-  }
-
-  /**
-   * @brief Makes the current node find the successor node of an id.
-   * @param node the current node
-   * @param id the id to find
-   * @return the id of the successor node, or -1 if the request failed
-   */
-  private int findSuccessor(int id) {
-    if (isInInterval(id, this.id + 1, fingers[0])) {
-      return fingers[0];
-    }
-
-    int closest = this.closestPrecedingNode(id);
-    return remoteFindSuccessor(closest, id);
-  }
-
-  // Asks another node the successor node of an id.
-  private int remoteFindSuccessor(int askTo, int id) {
-    int successor = -1;
-    boolean stop = false;
-    String askToMailbox = Integer.toString(askTo);
-    Task sendTask = new FindSuccessorTask(getHost().getName(), this.mailbox, id);
-    Msg.debug("Sending a 'Find Successor' request to " + askToMailbox + " for id " + id);
-    try {
-      sendTask.send(askToMailbox, Common.TIMEOUT);
-      do {
-        if (commReceive == null) {
-          commReceive = Task.irecv(this.mailbox);
-        }
-        commReceive.waitCompletion(Common.TIMEOUT);
-        Task task = commReceive.getTask();
-        if (task instanceof FindSuccessorAnswerTask) {
-          //TODO: Check if this this our answer.
-          FindSuccessorAnswerTask fTask = (FindSuccessorAnswerTask) task;
-          stop = true;
-          successor = fTask.getAnswerId();
-        } else {
-          handleTask(task);
-        }
-        commReceive = null;
-      } while (!stop);
-    }
-    catch (TimeoutException e) {
-      Msg.debug("Failed to send the 'Find Successor' request");
-    }
-    catch (MsgException e) {
-      Msg.debug("Failed to receive Find Successor");
-    }
-    commReceive = null;
-
-    return successor;
-  }
-
-  // This function is called periodically. It checks the immediate successor of the current node.
-  private void stabilize() {
-    Msg.debug("Stabilizing node");
-    int candidateId;
-    int successorId = fingers[0];
-    if (successorId != this.id){
-      candidateId = remoteGetPredecessor(successorId);
-    } else {
-      candidateId = predId;
-    }
-    //This node is a candidate to become my new successor
-    if (candidateId != -1 && isInInterval(candidateId, this.id + 1, successorId - 1)) {
-      setFinger(0, candidateId);
-    }
-    if (successorId != this.id) {
-      remoteNotify(successorId, this.id);
-    }
-  }
-
-  /**
-   * @brief Notifies the current node that its predecessor may have changed.
-   * @param candidate_id the possible new predecessor
-   */
-  private void notify(int predecessorCandidateId) {
-    if (predId == -1 || isInInterval(predecessorCandidateId, predId + 1, this.id - 1 )) {
-      setPredecessor(predecessorCandidateId);
-    }
-  }
-
-  /**
-   * @brief Notifies a remote node that its predecessor may have changed.
-   * @param notify_id id of the node to notify
-   * @param candidate_id the possible new predecessor
-   */
-  private void remoteNotify(int notifyId, int predecessorCandidateId) {
-    Msg.debug("Sending a 'Notify' request to " + notifyId);
-    Task sentTask = new NotifyTask(getHost().getName(), this.mailbox, predecessorCandidateId);
-    sentTask.dsend(Integer.toString(notifyId));
-  }
-
-  // This function is called periodically.
-  // It refreshes the finger table of the current node.
-  private void fixFingers() {
-    Msg.debug("Fixing fingers");
-    int successorId = findSuccessor(id + (1 << nextFingerToFix));
-    if (successorId != -1) {
-      if (successorId != fingers[nextFingerToFix]) {
-        setFinger(nextFingerToFix, successorId);
-      }
-      nextFingerToFix = (nextFingerToFix + 1) % Common.NB_BITS;
-    }
-  }
-
-  // This function is called periodically.
-  // It checks whether the predecessor has failed
-  private void checkPredecessor() {
-    //TODO
-  }
-
-  // Performs a find successor request to a random id.
-  private void randomLookup() {
-    int dest = 1337;
-    findSuccessor(dest);
-  }
-
-  /**
-   * @brief Returns the closest preceding finger of an id with respect to the finger table of the current node.
-   * @param id the id to find
-   * @return the closest preceding finger of that id
-   */
-  private int closestPrecedingNode(int id) {
-    for (int i = Common.NB_BITS - 1; i >= 0; i--) {
-      if (isInInterval(fingers[i], this.id + 1, id - 1)) {
-        return fingers[i];
-      }
-    }
-    return this.id;
-  }
-
-  /**
-   * @brief Returns whether an id belongs to the interval [start, end].
-   *
-   * The parameters are noramlized to make sure they are between 0 and nb_keys - 1).
-   * 1 belongs to [62, 3]
-   * 1 does not belong to [3, 62]
-   * 63 belongs to [62, 3]
-   * 63 does not belong to [3, 62]
-   * 24 belongs to [21, 29]
-   * 24 does not belong to [29, 21]
-   *
-   * @param id id to check
-   * @param start lower bound
-   * @param end upper bound
-   * @return a non-zero value if id in in [start, end]
-   */
-  private static boolean isInInterval(int id, int start, int end) {
-    int normId = normalize(id);
-    int normStart = normalize(start);
-    int normEnd = normalize(end);
-
-    // make sure end >= start and id >= start
-    if (normEnd < normStart) {
-      normEnd += Common.NB_KEYS;
-    }
-    if (normId < normStart) {
-      normId += Common.NB_KEYS;
-    }
-    return (normId <= normEnd);
-  }
-
-  /**
-   * @brief Turns an id into an equivalent id in [0, nb_keys).
-   * @param id an id
-   * @return the corresponding normalized id
-   */
-  private static int normalize(int id) {
-    return id & (Common.NB_KEYS - 1);
-  }
-
-  /**
-   * @brief Sets a finger of the current node.
-   * @param finger_index index of the finger to set (0 to nb_bits - 1)
-   * @param id the id to set for this finger
-   */
-  private void setFinger(int fingerIndex, int id) {
-    if (id != fingers[fingerIndex]) {
-      fingers[fingerIndex] = id;
-      lastChangeDate = Msg.getClock();
-    }
-  }
-}