如何修復 Java 中的可調用重疊？

Question

我不確定標題是否詳細/正確，但我不知道如何在標題中描述它，所以我會盡力在這里描述它

我一直在嘗試在 Java 中使用 callable 進行並發，但結果不正確，似乎線程在運行時相互重疊……下面是調用函數

@Override
public String call() {
    String result = "yay";
    long startTime = System.currentTimeMillis();
    long endTime = startTime + timeOutMiliseconds * 1000;
    while (System.currentTimeMillis() < endTime) {
        int[] currentMapping = generateTpuMappingWithRange(ia, startRange, stopRange);
        System.out.println(" current - " + Arrays.toString(currentMapping) + " - " +  ID);
        result = Arrays.toString(currentMapping);
    }
    return result;
}

generateTpuMappingWithRange()函數只是生成另一個隨機整數數組，第一個索引從 startRange -> stopRange

（即 startRange = 0，stopRange = 2，然后 [0, 2, 1,] -> [1, 2, 1] 或 [2,2,1]）

構造函數

public MarkovTest(int ID, int startRange, int stopRange) {
    this.ID = ID;
    this.startRange = startRange;
    this.stopRange = stopRange;
    init();
}

這里是主要的

public static void main(String[] args) throws InterruptedException, ExecutionException {
    Callable<String> Array = new MarkovTest(1, 0, 1);
    Callable<String> Array2 = new MarkovTest(2, 2, 3);
    Callable<String> Array3 = new MarkovTest(3, 4, 5);

    List<Callable<String>> taskList = Arrays.asList(Array,Array2,Array3);

    List<Future<String>> future = executor.invokeAll(taskList);
    for(Future<String> result : future)
    {
        System.out.println(result.get());
    }
}

最后一個數字是ID變量是為了檢查它是否打印出正確的一個...但是這里有問題，在控制台中，這發生了...

 current - [0, 3, 5, 0, 5, 4, 3, 2, 1, 4, 6, 1, 3, 6] - 1
 current - [1, 3, 5, 0, 5, 4, 3, 2, 1, 4, 6, 1, 3, 6] - 3
 current - [0, 3, 5, 0, 5, 4, 2, 2, 0, 4, 6, 1, 3, 6] - 1
 current - [0, 3, 5, 0, 5, 4, 3, 2, 0, 4, 6, 1, 3, 6] - 2

第一行是正確的，ID 1 應該打印第一個索引在 0 到 1 范圍內的數組。但是 ID 3 和 2 在第一個索引中不應該有 0 或 1 ......這不會一直發生，但會出現在這里並且在數千個控制台輸出中

知道為什么會這樣嗎？ 因為這個我真的很緊張...T__T

編輯：添加了generateTpuMappingWithRange

private int[] generateTpuMappingWithRange(int[] iap, int startRange, int stopRange) {
    final Logger log = Logger.getLogger(MarkovTest.class);

    int maximumNoOfCoreIndex = 6;
    int minimumNoOfCoreIndex = 0;
    int firstIndex = 0;
    int[] result = iap;
    log.debug("OLD MAPPING = " + Arrays.toString(result));
    // generate random
    Random randomNum = new Random();
    // generate number from 0 -> 13 (because last number will always be 6)
    int randomIndex = randomNum.nextInt(iap.length - 1);
    // last one will always be 6 so dont need to include that
    int minusOrPlus = 0;
    minusOrPlus = randomNum.nextBoolean() ? 1 : -1;
    Task thisTask = this.model.getSwModel().getTasks().get(randomIndex);
    PuType thisTaskPuType = domains.get(thisTask);
    int[] newIndexValueRange = this.intervals.get(thisTaskPuType);

    minimumNoOfCoreIndex = newIndexValueRange[0];
    maximumNoOfCoreIndex = newIndexValueRange[1];
    int newIndexValue = result[randomIndex] + minusOrPlus;
    // Split 0-1, 2-3, 4-5 for 3 markov chain.
    if (randomIndex == firstIndex) {
        if (newIndexValue > stopRange) {
            newIndexValue = startRange;
        } else if (newIndexValue < startRange) {
            newIndexValue = stopRange;
        }
    } else {
        if (newIndexValue > maximumNoOfCoreIndex) {
            newIndexValue = minimumNoOfCoreIndex;
        } else if (newIndexValue < minimumNoOfCoreIndex) {
            newIndexValue = maximumNoOfCoreIndex;
        }
    }
    // if the new index value generated from line above surpass our maximum no of
    // core, then it will return to number 0
    // This may resolve to infinite loop if THE SAME randomIndex appear again and
    // again and again and again, which hopefully wont be a thing for this
    // implementation

    result[randomIndex] = newIndexValue;
    log.debug("NEW MAPPING = " + Arrays.toString(result));
    log.debug(" location =" + randomIndex + " value =" + newIndexValue);
    return result;
}

這是代碼的完整版本，以防萬一。

init()方法基本上就是生成2個HashMap，主要用於確定每個索引的最大值和最小值。

public class MarkovTest implements Callable<String> {
static ExecutorService executor = Executors.newFixedThreadPool(3);

int startRange;
int stopRange;
long timeOutMiliseconds = 1000;
long maxIteration;
Amalthea model;
int[] ia;
int ID;
private final int nbCPUs;
private final int nbPUs;
private final HashMap<Task, PuType> domains = new HashMap<Task, PuType>();
private final HashMap<PuType, int[]> intervals = new HashMap<PuType, int[]>();   

public MarkovTest(int[] ia, Amalthea model, int ID, int startRange, int stopRange) {
    this.model = model;
    this.ia = ia;
    this.nbCPUs = CommonUtils.getNumberofCPUs(model);
    // this.nbGPUs = CommonUtils.getNumberofGPUs(this.model);
    this.nbPUs = CommonUtils.getNumberofPUs(model);
    this.ID = ID;
    this.startRange = startRange;
    this.stopRange = stopRange;
    init();
}

public static void main(String[] args) throws InterruptedException, ExecutionException {
    org.apache.log4j.BasicConfigurator.configure();
    Logger.getRootLogger().setLevel(Level.INFO);
    long startTime = System.currentTimeMillis();
    int[] ia = { 5, 2, 5, 3, 3, 1, 3, 5, 1, 0, 0, 6, 4, 6 };
    final Amalthea ama = AmaltheaLoader.loadFromFile(new File(SharedConsts.ECRTS_MODEL));

    Callable<String> Array = new MarkovTest(ia, ama, 1, 0, 1);
    Callable<String> Array2 = new MarkovTest(ia, ama, 2, 2, 3);
    Callable<String> Array3 = new MarkovTest(ia, ama, 3, 4, 5);

    List<Callable<String>> taskList = Arrays.asList(Array,Array2,Array3);

    List<Future<String>> future = executor.invokeAll(taskList);
    for(Future<String> result : future)
    {
        System.out.println(result.get());
    }
    long endTime = System.currentTimeMillis();
    long elapsedTime = endTime - startTime;
    System.out.println(" elapsed Time = " + elapsedTime);
    System.out.println("Done");
}

@Override
public String call() {
    String result = "yay";
    long startTime = System.currentTimeMillis();
    long endTime = startTime + timeOutMiliseconds * 1000;
    while (System.currentTimeMillis() < endTime) {
        int[] currentMapping = generateTpuMappingWithRange(ia, startRange, stopRange);
        System.out.println(" current - " + Arrays.toString(currentMapping) + " - " +  ID);
        result = Arrays.toString(currentMapping);
    }
    return result;
}

private int[] generateTpuMappingWithRange(int[] iap, int startRange, int stopRange) {
    final Logger log = Logger.getLogger(MarkovTest.class);

    int maximumNoOfCoreIndex = 6;
    int minimumNoOfCoreIndex = 0;
    int firstIndex = 0;
    int[] result = iap;
    log.debug("OLD MAPPING = " + Arrays.toString(result));
    // generate random
    Random randomNum = new Random();
    // generate number from 0 -> 13 (because last number will always be 6)
    int randomIndex = randomNum.nextInt(iap.length - 1);
    // last one will always be 6 so dont need to include that
    int minusOrPlus = 0;
    minusOrPlus = randomNum.nextBoolean() ? 1 : -1;
    Task thisTask = this.model.getSwModel().getTasks().get(randomIndex);
    PuType thisTaskPuType = domains.get(thisTask);
    int[] newIndexValueRange = this.intervals.get(thisTaskPuType);

    minimumNoOfCoreIndex = newIndexValueRange[0];
    maximumNoOfCoreIndex = newIndexValueRange[1];
    int newIndexValue = result[randomIndex] + minusOrPlus;
    // Split 0-4, 5-10, 11-13 for 3 markov chain.
    if (randomIndex == firstIndex) {
        if (newIndexValue > stopRange) {
            newIndexValue = startRange;
        } else if (newIndexValue < startRange) {
            newIndexValue = stopRange;
        }
    } else {
        if (newIndexValue > maximumNoOfCoreIndex) {
            newIndexValue = minimumNoOfCoreIndex;
        } else if (newIndexValue < minimumNoOfCoreIndex) {
            newIndexValue = maximumNoOfCoreIndex;
        }
    }
    // if the new index value generated from line above surpass our maximum no of
    // core, then it will return to number 0
    // This may resolve to infinite loop if THE SAME randomIndex appear again and
    // again and again and again, which hopefully wont be a thing for this
    // implementation

    result[randomIndex] = newIndexValue;
    log.debug("NEW MAPPING = " + Arrays.toString(result));
    log.debug(" location =" + randomIndex + " value =" + newIndexValue);
    return result;
}

private void init() {
    final Logger log = Logger.getLogger(CallableForMarkov.class);
    for (final Task t : this.model.getSwModel().getTasks()) {
        boolean cpu = false;
        boolean gpu = false;
        boolean defaultVal = false;
        for (final CallGraphItem geb : t.getCallGraph().getItems()) {
            if (geb instanceof Group) {
                final Group cs = (Group) geb;
                for (final CallGraphItem csi : cs.getItems()) {
                    if (csi instanceof RunnableCall) {
                        final RunnableCall trc = (RunnableCall) csi;
                        for (final CallGraphItem ri : trc.getRunnable().getRunnableItems()) {
                            if (ri instanceof Ticks) {
                                final Ticks ticks = (Ticks) ri;
                                if (null != ticks.getDefault() && ticks.getDefault().getAverage() > 0) {
                                    defaultVal = true;
                                }
                                for (final Entry<ProcessingUnitDefinition, IDiscreteValueDeviation> e : ticks
                                        .getExtended().entrySet()) {
                                    if (!gpu && e.getKey().getPuType().equals(PuType.GPU)) {
                                        gpu = true;
                                    } else if (!cpu && e.getKey().getPuType().equals(PuType.CPU)) {
                                        cpu = true;
                                    }
                                }
                            }
                        }
                        // TODO check if there are runnables with different tick vals
                    }
                }
            }
        }
        if (cpu && !gpu) {
            /* task can be mapped only to CPUs */
            log.debug(t.getName() + " can be mapped to 0 --" + (this.nbCPUs - 1));
            this.domains.put(t, PuType.CPU);
            if (!this.intervals.containsKey(PuType.CPU)) {
                this.intervals.put(PuType.CPU, new int[] { 0, this.nbCPUs - 1 });
            }
        } else if (gpu && !cpu) {
            /* task can be mapped only to GPUs */
            log.debug(t.getName() + " can be mapped to " + this.nbCPUs + "--" + (this.nbPUs - 1));
            this.domains.put(t, PuType.GPU);
            if (!this.intervals.containsKey(PuType.GPU)) {
                this.intervals.put(PuType.GPU, new int[] { this.nbCPUs, this.nbPUs - 1 });
            }
        } else if (defaultVal || (gpu && cpu)) {
            /* task can be mapped anywhere */
            log.debug(t.getName() + " can be mapped to 0 --" + (this.nbPUs - 1));
            this.domains.put(t, PuType._UNDEFINED_);
            if (!this.intervals.containsKey(PuType._UNDEFINED_)) {
                this.intervals.put(PuType._UNDEFINED_, new int[] { 0, this.nbPUs - 1 });
            }
        } else {
            /* Task can be mapped nowhere */
            log.fatal(t.getName() + " can be mapped nowhere");
        }
    }
}

}

Answer 1

看看我在代碼摘錄中的內聯注釋：

public static void main(String[] args) throws InterruptedException, ExecutionException {
    org.apache.log4j.BasicConfigurator.configure();
    Logger.getRootLogger().setLevel(Level.INFO);
    long startTime = System.currentTimeMillis();   

    //-----> You have created an instance of ia
    int[] ia = { 5, 2, 5, 3, 3, 1, 3, 5, 1, 0, 0, 6, 4, 6 };
    final Amalthea ama = AmaltheaLoader.loadFromFile(new File(SharedConsts.ECRTS_MODEL));  

//-----> You have passed the _same_ instance to all of the constructor calls
    Callable<String> Array = new MarkovTest(ia, ama, 1, 0, 1);
    Callable<String> Array2 = new MarkovTest(ia, ama, 2, 2, 3);
    Callable<String> Array3 = new MarkovTest(ia, ama, 3, 4, 5);  
    ...    

 //---->lets move a bit down to the method that's called within the Callable  

private int[] generateTpuMappingWithRange(int[] iap, int startRange, int stopRange) {  
   ...    
  int firstIndex = 0;
   ...  
   int randomIndex = random.nextInt(iap.length - 1);  
   ...  
 //---> this part should make sure what you are stating, that "ID 1 should print array with first index in range 0 to 1." and this is correct
   if (randomIndex == firstIndex) {

        if (newIndexValue > stopRange) {
            newIndexValue = startRange;
        } else if (newIndexValue < startRange) {
            newIndexValue = stopRange;
        }

    }  else {
        if (newIndexValue > maximumNoOfCoreIndex) {
            newIndexValue = minimumNoOfCoreIndex;
        } else if (newIndexValue < minimumNoOfCoreIndex) {
            newIndexValue = maximumNoOfCoreIndex;
        }
    }
       ...

但是，正如我在上面的代碼中提到的，您已將相同的ia實例傳遞給所有構造函數調用。

這意味着所有 3 個MarkovTest實例都將在同一個ia ，單獨修改它，因此您為數組的第一個元素設置的規則不起作用。

例如，當一個MarkovTest與ID=2得到了一個randomIndex == firstIndex ，所以它修改ia的第一索引相應，然后它打印ia與更新的和正確的新的第一值。

之后，一個ID=1的MarkovTest運行，它得到randomIndex != firstIndex ，所以它在randomIndex處修改ia的值，然后打印ia ，帶有先前更新但現在不正確的第一個值，以及未觸及的值以及在randomIndex正確更新的新值。

這個循環重復直到System.currentTimeMillis() < endTime對於每個MarkovTest 。

解決方案：

有幾種解決方案，當您將相同的實例傳遞給所有 3 個MarkovTest ，您可以直接在類中初始化ia ，而無需該構造函數參數。

如果您堅持使用構造函數參數，那么您可以：

int[] ia_copy;  

public MarkovTest(int[] ia, Amalthea model, int ID, int startRange, int stopRange) {
    this.model = model;  

    //----> create a copy like this:
    ia_copy=new int[ia.length];
    System.arraycopy( ia, 0, ia_copy, 0, ia.length );  

    this.nbCPUs = CommonUtils.getNumberofCPUs(model);
    // this.nbGPUs = CommonUtils.getNumberofGPUs(this.model);
    this.nbPUs = CommonUtils.getNumberofPUs(model);
    this.ID = ID;
    this.startRange = startRange;
    this.stopRange = stopRange;
    init();
}

只是不要忘記更改所有引用，尤其是在：

@Override
public String call() {
...
while (System.currentTimeMillis() < endTime) {  
//----> ia to ia_copy 
        int[] currentMapping = generateTpuMappingWithRange(ia_copy , startRange, stopRange);  
...