Exemple #1
0
  /** Test if this module is working. */
  public static void selfTest() {

    System.out.print("Enter Condition2.selfTest\n");

    Lock lock = new Lock();
    Condition2 condition = new Condition2(lock);

    KThread t[] = new KThread[10];
    for (int i = 0; i < 10; i++) {
      t[i] = new KThread(new Condition2Test(lock, condition));
      t[i].setName("Thread" + i).fork();
    }

    KThread.yield();

    lock.acquire();

    System.out.print("condition.wake();\n");
    condition.wake();

    System.out.print("condition.wakeAll();\n");
    condition.wakeAll();

    lock.release();

    System.out.print("Leave Condition2.selfTest\n");

    t[9].join();
  }
Exemple #2
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  static void AdultItinerary() {
    System.out.println("--- called adult itinerary");

    /* This is where you should put your solutions. Make calls
     to the BoatGrader to show that it is synchronized. For
     example:
         bg.AdultRowToMolokai();
     indicates that an adult has rowed the boat across to Molokai
    */

    pilotLock.acquire();

    // While the boat is not at Oahu or there are more than 2 children on Oahu,
    // put the adult on Oahu thread to sleep (because we wouldn't send and adult in
    // these scenarios).
    while (boatLocation != 0 || numChildrenOnOahu >= 2) {
      System.out.println("--- can't send an adult to Molokai right now");
      adultReadyAtOahu.sleep();
    }

    System.out.println("--- sending an adult to Molokai");
    numAdultsOnOahu--; // an adult is rowing Oahu --> Molokai, so decrement
    bg.AdultRowToMolokai();
    numAdultsOnMolokai++; // adult has rowed over, so increment
    printState();
    boatLocation = 1; // boat is now at Molokai
    childReadyAtMolokai.wake(); // wake up child at Molokai since it's now their turn			

    pilotLock.release();
  }
Exemple #3
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  public static void begin(int adults, int children, BoatGrader b) {
    // Store the externally generated autograder in a class
    // variable to be accessible by children.
    bg = b;

    // Instantiate global variables here.
    numChildrenOnOahu = children; // all children start on Oahu
    numAdultsOnOahu = adults; // all adults start on Oahu
    numChildrenOnMolokai = 0;
    numAdultsOnMolokai = 0;
    pilotLock = new Lock(); // lock for traveling between islands
    adultReadyAtOahu = new Condition2(pilotLock);
    childReadyAtOahu = new Condition2(pilotLock);
    childReadyAtMolokai = new Condition2(pilotLock);
    gameEnd = new Lock(); // lock for whether or not to terminate
    end = new Condition(gameEnd);
    isDone = false;
    communicator = new Communicator();
    boatLocation = 0; // boat starts on Oahu
    hasChildPilot = false; // starts with no ppl in boat

    gameEnd.acquire();

    // Logic for child threads to run.
    Runnable childRunnable =
        new Runnable() {
          public void run() {
            ChildItinerary();
          }
        };

    // Logic for adult threads to run.
    Runnable adultRunnable =
        new Runnable() {
          public void run() {
            AdultItinerary();
          }
        };

    // Create threads here. See section 3.4 of the Nachos for Java
    // Walkthrough linked from the projects page.
    for (int i = 0; i < children; i++) {
      KThread child = new KThread(childRunnable);
      child.setName("Child");
      child.fork();
    }

    for (int i = 0; i < adults; i++) {
      KThread adult = new KThread(adultRunnable);
      adult.setName("Adult");
      adult.fork();
    }

    while (!isDone) {
      end.sleep();

      // If we've moved all adults and children from Oahu, then we're done!
      if (numChildrenOnOahu + numAdultsOnOahu == 0) {
        System.out.println("Game over! Whoo!");
        isDone = true;
        break;
      }
    }
  }
Exemple #4
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  static void ChildItinerary() {
    System.out.println("--- called child itinerary");

    pilotLock.acquire();

    Boolean readyToTerminate = false;
    int currentLocation = 0; // current location set to Oahu		

    while (!isDone) {
      if (currentLocation == 0) {
        // If we are currently on Oahu...
        while (boatLocation != 0 || numChildrenOnOahu == 1) {
          System.out.println(
              "--- child currently on Oahu, but the boat is not on Oahu ("
                  + boatLocation
                  + ") or we only have 1 child on Oahu ("
                  + numChildrenOnOahu
                  + ")");
          // ...but the boat is not in Oahu or we only have 1 child on Oahu, then sleep.
          childReadyAtOahu.sleep();
        }

        System.out.println("--- child currently on Oahu, ready to go");

        if (numAdultsOnOahu == 0 && numChildrenOnOahu == 2) {
          // ... we are ready to end the game!
          System.out.println("--- ready to end the game");
          readyToTerminate = true;
        }

        if (!hasChildPilot) {
          hasChildPilot = true;
          bg.ChildRowToMolokai();
          printState();
          currentLocation = 1; // this child are now now on Molokai		
        } else {
          numChildrenOnOahu -= 2; // 2 kids will go Oahu --> Molokai, so decrement
          bg.ChildRideToMolokai();
          numChildrenOnMolokai += 2; // 2 kids have arrived on Molokai, so increment	
          printState();
          currentLocation = 1; // this child are now now on Molokai
          boatLocation = 1; // boat is now at Molokai
          hasChildPilot = false;

          if (readyToTerminate) {
            gameEnd.acquire();
            end.wake();
            gameEnd.release();
            childReadyAtMolokai.sleep();
          } else {
            System.out.println("--- child ready on Molokai");
            childReadyAtMolokai.wake();
          }
        }
      } else {
        // Else, if we are currently on Molokai...
        while (boatLocation != 1 || hasChildPilot) {
          System.out.println(
              "--- child currently on Molokai, but either the boat is not on Molokai or there's already a child pilot");
          // ...but the boat is not at Molokai, then sleep.
          childReadyAtMolokai.sleep();
        }

        // ...then send a child back to Oahu.
        hasChildPilot = true;
        System.out.println("--- child currently on Molokai, send one back to Oahu");
        numChildrenOnMolokai--; // child is going from Molokai --> Oahu, so decrement
        bg.ChildRowToOahu();
        numChildrenOnOahu++; // child arrived at Oahu, so incrememt
        printState();
        boatLocation = 0; // boat is now at Oahu
        currentLocation = 0; // child is now at Oahu
        hasChildPilot = false;

        if (numChildrenOnOahu >= 2) {
          System.out.println("--- we now have 2 children on Oahu");
          childReadyAtOahu.wake(); // let Oahu now we're ready to go		
        } else {
          System.out.println("--- we don't enough children on Oahu so send an adult");
          adultReadyAtOahu.wake();
          childReadyAtOahu.sleep();
        }
      }
    }
  }