void completed(InetAddress remote, String cfname) {
   logger.debug("Repair completed for {} on {}", remote, cfname);
   RepairJob job = activeJobs.get(cfname);
   if (job.completedSynchronizationJob(remote)) {
     activeJobs.remove(cfname);
     if (activeJobs.isEmpty()) completed.signalAll();
   }
 }
    // we don't care about the return value but care about it throwing exception
    public void runMayThrow() throws Exception {
      if (endpoints.isEmpty()) {
        differencingDone.signalAll();
        logger.info(
            "No neighbors to repair with for "
                + tablename
                + " on "
                + range
                + ": "
                + getName()
                + " completed.");
        return;
      }

      // Checking all nodes are live
      for (InetAddress endpoint : endpoints) {
        if (!FailureDetector.instance.isAlive(endpoint)) {
          differencingDone.signalAll();
          logger.info(
              "Could not proceed on repair because a neighbor ("
                  + endpoint
                  + ") is dead: "
                  + getName()
                  + " failed.");
          return;
        }
      }

      AntiEntropyService.instance.sessions.put(getName(), this);
      Gossiper.instance.register(this);
      FailureDetector.instance.registerFailureDetectionEventListener(this);
      try {
        // Create and queue a RepairJob for each column family
        for (String cfname : cfnames) {
          RepairJob job = new RepairJob(cfname);
          jobs.offer(job);
          activeJobs.put(cfname, job);
        }

        jobs.peek().sendTreeRequests();

        // block whatever thread started this session until all requests have been returned:
        // if this thread dies, the session will still complete in the background
        completed.await();
        if (exception != null) throw exception;
      } catch (InterruptedException e) {
        throw new RuntimeException(
            "Interrupted while waiting for repair: repair will continue in the background.");
      } finally {
        FailureDetector.instance.unregisterFailureDetectionEventListener(this);
        Gossiper.instance.unregister(this);
        AntiEntropyService.instance.sessions.remove(getName());
      }
    }
 void failedNode(InetAddress remote) {
   String errorMsg =
       String.format("Problem during repair session %s, endpoint %s died", sessionName, remote);
   logger.error(errorMsg);
   exception = new IOException(errorMsg);
   // If a node failed, we stop everything (though there could still be some activity in the
   // background)
   jobs.clear();
   activeJobs.clear();
   differencingDone.signalAll();
   completed.signalAll();
 }
    void completed(Differencer differencer) {
      logger.debug(
          String.format(
              "[repair #%s] Repair completed between %s and %s on %s",
              getName(), differencer.r1.endpoint, differencer.r2.endpoint, differencer.cfname));
      RepairJob job = activeJobs.get(differencer.cfname);
      if (job == null) {
        assert terminated;
        return;
      }

      if (job.completedSynchronization(differencer)) {
        activeJobs.remove(differencer.cfname);
        String remaining =
            activeJobs.size() == 0
                ? ""
                : String.format(
                    " (%d remaining column family to sync for this session)", activeJobs.size());
        logger.info(
            String.format(
                "[repair #%s] %s is fully synced%s", getName(), differencer.cfname, remaining));
        if (activeJobs.isEmpty()) completed.signalAll();
      }
    }
 /** clear all RepairJobs and terminate this session. */
 public void forceShutdown() {
   differencingDone.signalAll();
   completed.signalAll();
 }
    // we don't care about the return value but care about it throwing exception
    public void runMayThrow() throws Exception {
      logger.info(
          String.format(
              "[repair #%s] new session: will sync %s on range %s for %s.%s",
              getName(), repairedNodes(), range, tablename, Arrays.toString(cfnames)));

      if (endpoints.isEmpty()) {
        differencingDone.signalAll();
        logger.info(
            String.format(
                "[repair #%s] No neighbors to repair with on range %s: session completed",
                getName(), range));
        return;
      }

      // Checking all nodes are live
      for (InetAddress endpoint : endpoints) {
        if (!FailureDetector.instance.isAlive(endpoint)) {
          differencingDone.signalAll();
          logger.info(
              String.format(
                  "[repair #%s] Cannot proceed on repair because a neighbor (%s) is dead: session failed",
                  getName(), endpoint));
          return;
        }

        if (Gossiper.instance.getVersion(endpoint) < MessagingService.VERSION_11 && isSequential) {
          logger.info(
              String.format(
                  "[repair #%s] Cannot repair using snapshots as node %s is pre-1.1",
                  getName(), endpoint));
          return;
        }
      }

      AntiEntropyService.instance.sessions.put(getName(), this);
      Gossiper.instance.register(this);
      FailureDetector.instance.registerFailureDetectionEventListener(this);
      try {
        // Create and queue a RepairJob for each column family
        for (String cfname : cfnames) {
          RepairJob job = new RepairJob(cfname);
          jobs.offer(job);
          activeJobs.put(cfname, job);
        }

        jobs.peek().sendTreeRequests();

        // block whatever thread started this session until all requests have been returned:
        // if this thread dies, the session will still complete in the background
        completed.await();
        if (exception == null) {
          logger.info(String.format("[repair #%s] session completed successfully", getName()));
        } else {
          logger.error(
              String.format("[repair #%s] session completed with the following error", getName()),
              exception);
          throw exception;
        }
      } catch (InterruptedException e) {
        throw new RuntimeException("Interrupted while waiting for repair.");
      } finally {
        // mark this session as terminated
        terminate();
        FailureDetector.instance.unregisterFailureDetectionEventListener(this);
        Gossiper.instance.unregister(this);
        AntiEntropyService.instance.sessions.remove(getName());
      }
    }