Java ExecutorCompletionService.poll方法代碼示例

import java.util.concurrent.ExecutorCompletionService; //導入方法依賴的package包/類
private void waitForCompletion(ExecutorCompletionService<Boolean> completer, int numtasks) throws ExecutionException {
    int remainingTasks = numtasks;
    while (remainingTasks > 0) {
        try {
            Future<Boolean> completed = completer.poll(4, TimeUnit.SECONDS);
            if (completed == null) {
                System.err.println("Completer timed out");
                throw new RuntimeException(new TimeoutException());
            }
            else {
                completed.get();
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        remainingTasks--;
    }
}
 

import java.util.concurrent.ExecutorCompletionService; //導入方法依賴的package包/類
private Response handleN(long start, long deadline,
        ExecutorCompletionService<Response> completionService, List<Destination> destinations,
        ResultMerger merger, BaseMessage message, Consistency c) {
  List<Response> responses = new ArrayList<>();
  int wantedResults = (Integer) c.getParameters().get("n");
  int sucessfulSoFar = 0;
  while (start <= deadline) {
    Response r = null;
    try {
      Future<Response> future = completionService.poll(deadline - start, TimeUnit.MILLISECONDS);
      r = future.get();
      if (r != null){
        responses.add(r);
        sucessfulSoFar++;
      }
      if (sucessfulSoFar >= wantedResults) {
        break;
      }
    } catch (InterruptedException | ExecutionException e) {
      continue;
    }
    start = System.currentTimeMillis();
  } 
  return merger.merge(responses, message);
}
 

import java.util.concurrent.ExecutorCompletionService; //導入方法依賴的package包/類
private void execute(String[] args) throws IOException {
    if (args.length != 3) {
        usage();
        System.exit(1);
    }
    if (args[0].contains("-h")) {
        usage();
        System.exit(0);
    }
    int numThreads = Integer.parseInt(args[0]);
    ArrayBlockingQueue<Path> queue = new ArrayBlockingQueue<>(1000);
    rootDir = Paths.get(args[1]);
    QueueFiller filler = new QueueFiller(rootDir, queue, numThreads);
    new Thread(filler).start();
    outputDir = Paths.get(args[2]);
    Files.createDirectories(outputDir);
    ExecutorService executorService = Executors.newFixedThreadPool(numThreads);
    ExecutorCompletionService<Integer> executorCompletionService = new ExecutorCompletionService<Integer>(executorService);

    for (int i = 0; i < numThreads; i++) {
        executorCompletionService.submit(new FileRunner(queue,
                Files.newBufferedWriter(outputDir.resolve("mimes-"+i+".txt"))));
    }

    int completed = 0;
    while (completed < numThreads) {
        try {
            Future<Integer> future = executorCompletionService.poll(1, TimeUnit.SECONDS);
            if (future != null) {
                completed++;
            }
        } catch (InterruptedException e) {

        }
    }
    executorService.shutdown();
    executorService.shutdownNow();
    System.exit(0);
}
 

import java.util.concurrent.ExecutorCompletionService; //導入方法依賴的package包/類
private Response handleAll(long start, long deadline,
        ExecutorCompletionService<Response> completionService, List<Destination> destinations,
        ResultMerger merger, BaseMessage message) {
  List<Response> responses = new ArrayList<>();
  while (start <= deadline) {
    Response r = null;
    try {
      Future<Response> future = completionService.poll(deadline - start, TimeUnit.MILLISECONDS);
      r = future.get();
      if (r != null) {
        responses.add(r);
      }
    } catch (InterruptedException | ExecutionException e) {
      return new Response().withProperty("exception", "coordinator timeout");
    }
    if (r == null) {
      return new Response().withProperty("exception", "coordinator timeout");
    }
    if (r.containsKey("exception")) {
      return r;
    }
    if (responses.size() == destinations.size()) {
      break;
    }
    start = System.currentTimeMillis();
  }
  if (responses.size() == destinations.size()) {
    return merger.merge(responses, message);
  } else {
    return new Response().withProperty("exception", "coordinator timeout");
  }
}
 

import java.util.concurrent.ExecutorCompletionService; //導入方法依賴的package包/類
private void execute(String[] args) throws IOException {
    if (args.length != 3) {
        usage();
        System.exit(1);
    }
    if (args[0].contains("-h")) {
        usage();
        System.exit(0);
    }
    int numThreads = Integer.parseInt(args[0]);
    BufferedReader r = Files.newBufferedReader(Paths.get(args[1]));
    ArrayBlockingQueue<DigestURLPair> queue = new ArrayBlockingQueue<DigestURLPair>(1000);
    QueueFiller filler = new QueueFiller(r, queue, numThreads);
    new Thread(filler).start();
    rootDir = Paths.get(args[2]);
    System.out.println("creating thread pool");
    ExecutorService executorService = Executors.newFixedThreadPool(numThreads);
    ExecutorCompletionService<Integer> executorCompletionService = new ExecutorCompletionService<Integer>(executorService);
    System.out.println("about to start");

    for (int i = 0; i < numThreads; i++) {
        System.out.println("submitted "+i);
        executorCompletionService.submit(new WGetter(queue));
    }

    int completed = 0;
    while (completed < numThreads) {
        try {
            Future<Integer> future = executorCompletionService.poll(1, TimeUnit.SECONDS);
            if (future != null) {
                completed++;
            }
        } catch (InterruptedException e) {

        }
    }
    executorService.shutdown();
    executorService.shutdownNow();
    System.exit(0);


}
 

import java.util.concurrent.ExecutorCompletionService; //導入方法依賴的package包/類
public void execute(String[] args) throws Exception {

        if (args[0].equals("-h") || args[0].equals("--help")) {
            usage();
            System.exit(1);
        }


        int numThreads = Integer.parseInt(args[0]);
        Path indexDir = Paths.get(args[1]);
        String pClass = args[2];
        //load index files into memory...there should only be 300 for now
        File[] gzs = indexDir.toFile().listFiles();
        numThreads = (gzs.length < numThreads) ? gzs.length : numThreads;

        ArrayBlockingQueue<Path> paths = new ArrayBlockingQueue<>(gzs.length+numThreads);
        Arrays.sort(gzs);
        for (File f : gzs) {
            paths.add(f.toPath());
        }
        for (int i = 0; i < numThreads; i++) {
            paths.add(CCIndexReaderWrapper.POISON);
        }

        ExecutorService executorService = Executors.newFixedThreadPool(numThreads);
        ExecutorCompletionService<Integer> completionService = new ExecutorCompletionService<Integer>(executorService);

        String[] newArgs = Arrays.copyOfRange(args, 3, args.length);
        List<IndexRecordProcessor> procs = new ArrayList<>();

        for (int i = 0; i < numThreads; i++) {
            IndexRecordProcessor p = (IndexRecordProcessor) Class.forName(PACKAGE_NAME+"."+pClass).newInstance();
            p.init(newArgs);
            procs.add(p);
            completionService.submit(new CCIndexReaderWrapper(paths, p));
        }
        int completed = 0;
        while (completed < numThreads) {
            Future<Integer> result = completionService.poll(1, TimeUnit.SECONDS);
            if (result != null) {
                completed++;
            } else {
                System.out.println("In completion loop: "+completed);
            }
        }
        executorService.shutdown();
        executorService.shutdownNow();
        System.exit(1);
    }
 

import java.util.concurrent.ExecutorCompletionService; //導入方法依賴的package包/類
/**
 * Get all aggregate values for all aggregators.  This is the multi-threaded
 * version.
 * @param list The sorted list copy of values to aggregate.
 * @param comparator A <code>Comparator</code> over T objects.
 * @param parallelism The degree of parallelism.
 * @return A <code>List</code> of <code>AggregateValues</code>.
 */
private <T> List<AggregateValue<T>> getAggregateValues(List<T> list,
   Comparator<? super T> comparator, int parallelism)
{
   List<PositionedAggregatorList<T>> listOfPals = new ArrayList<PositionedAggregatorList<T>>(parallelism);
   // Initialize it with null elements, so that when "set" is called later,
   // Java won't complain about the size being zero.
   for (int p = 0; p < parallelism; p++)
      listOfPals.add(null);

   // Lazy-initialize the ExecutorCompletionService.
   ExecutorCompletionService<PositionedAggregatorList<T>> service = initializeService();
   int size = list.size();
   // Submit AggregateRunners that are specific to this task.
   for (int p = 0; p < parallelism; p++)
   {
      int startIndex = (size * p) / parallelism;
      int endIndex = (size * (p + 1)) / parallelism - 1;
      service.submit(new AggregateRunner<T>(myAggregators, list, p, comparator, startIndex, endIndex, amIUsingSuperAggregation, myProperties));
   }

   // Wait until all Threads have created their PositionedAggregatorList.
   // If an Exception is thrown, it will be caught in the form of an
   // ExecutionException, and wrapped in an UnsupportedOperationException.
   int numPALs = 0;
   while (numPALs < parallelism)
   {
      try
      {
         Future<PositionedAggregatorList<T>> future = service.poll(1, TimeUnit.SECONDS);
         if (future != null)
         {
            // Something completed and is available.  Add it to the list of
            // PALs in its proper position.
            PositionedAggregatorList<T> pal = future.get();

            listOfPals.set(pal.getPosition(), pal);
            numPALs++;
         }
      }
      catch(InterruptedException ignored) {}
      catch(ExecutionException e)
      {
         throw new UnsupportedOperationException(e.getClass().getName() +
            " caught while aggregating.", e);
      }
   }

   return Aggregations.mergeLists(listOfPals, comparator, amIUsingSuperAggregation, myProperties);
}