Java Lease类代码示例

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Sends the first dirty for a received reference in order to get the
 * appropiate lease time from the server, and then schedules the dirty call
 * for lease renewal. If the first dirty message fails, a clean "strong"
 * message is sent for that remote object. If the first dirty call
 * succeeded, the reference becomes a "live" reference for the client DGC.
 * 
 * @param ref
 *            The reference received inside the stub
 * @return The <code>Endpoint / ObjID</code> pair contained inside the
 *         reference
 * @throws UnmarshalException
 *             If the first dirty call fails
 */
private final Pair<Endpoint, ObjID> activateReference(RemoteRef ref)
        throws UnmarshalException {
    // Get necessary data previously stored during RemoteRef
    // deserialization.
    Pair<Endpoint, ObjID> data = deserializedRemoteRefTable.get(ref);
    if (data == null) {
        throw new UnmarshalException(
                "Impossible to get a stub for this object.");
    }
    Lease lease = sendDirty(data.getFirst(),
            new ObjID[] { data.getSecond() });

    if (lease != null) {
        enqueueDirtyCall(data, lease.getValue());
        liveReferences.put(data, new Long(lease.getValue()));
        return data;
    } else {
        sendClean(data.getFirst(), new ObjID[] { data.getSecond() }, true);
        throw new UnmarshalException(
                "Impossible to get a stub for this object.");
    }
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Sends a dirty call to the DGC of the remote server, and returns the
 * <code>Lease</code> granted by that DGC.
 * 
 * @param ep
 *            The <code>Endpoint</code> where the dirty call will be sent.
 * @param obj
 *            An array containing the object identifiers that will be sent
 *            in the dirty call.
 * @return The <code>Lease</code> returned from the server DGC, or
 *         <code>null</code> if the call has failed.
 */
Lease sendDirty(Endpoint ep, ObjID[] obj) {
	synchronized(dgcObjID) { 
     Lease lease = new Lease(vmID, leaseValue);
     Object[] args = new Object[] { obj, ++sequenceNumber, lease };
     TransportManager tm = TransportManager.getTransportManager();
     Object response;
     try {
         response = tm.invoke(dgcObjID, ep, args, SEND_DIRTY_OP_NUM, true);
         if (response instanceof Lease) {
             if (vmID == null) {
                 vmID = ((Lease) response).getVMID();
             }
             return (Lease) response;
         }
         return null;
     } catch (Exception e) {
         return null;
     }
	}
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * ObjectInputFilter to filter DGC input objects.
 * The list of acceptable classes is very short and explicit.
 * The depth and array sizes are limited.
 *
 * @param filterInfo access to class, arrayLength, etc.
 * @return  {@link ObjectInputFilter.Status#ALLOWED} if allowed,
 *          {@link ObjectInputFilter.Status#REJECTED} if rejected,
 *          otherwise {@link ObjectInputFilter.Status#UNDECIDED}
 */
private static ObjectInputFilter.Status checkInput(ObjectInputFilter.FilterInfo filterInfo) {
    if (dgcFilter != null) {
        ObjectInputFilter.Status status = dgcFilter.checkInput(filterInfo);
        if (status != ObjectInputFilter.Status.UNDECIDED) {
            // The DGC filter can override the built-in white-list
            return status;
        }
    }

    if (filterInfo.depth() > DGC_MAX_DEPTH) {
        return ObjectInputFilter.Status.REJECTED;
    }
    Class<?> clazz = filterInfo.serialClass();
    if (clazz != null) {
        while (clazz.isArray()) {
            if (filterInfo.arrayLength() >= 0 && filterInfo.arrayLength() > DGC_MAX_ARRAY_SIZE) {
                return ObjectInputFilter.Status.REJECTED;
            }
            // Arrays are allowed depending on the component type
            clazz = clazz.getComponentType();
        }
        if (clazz.isPrimitive()) {
            // Arrays of primitives are allowed
            return ObjectInputFilter.Status.ALLOWED;
        }
        return (clazz == ObjID.class ||
                clazz == UID.class ||
                clazz == VMID.class ||
                clazz == Lease.class)
                ? ObjectInputFilter.Status.ALLOWED
                : ObjectInputFilter.Status.REJECTED;
    }
    // Not a class, not size limited
    return ObjectInputFilter.Status.UNDECIDED;
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * ObjectInputFilter to filter DGCClient return value (a Lease).
 * The list of acceptable classes is very short and explicit.
 * The depth and array sizes are limited.
 *
 * @param filterInfo access to class, arrayLength, etc.
 * @return  {@link ObjectInputFilter.Status#ALLOWED} if allowed,
 *          {@link ObjectInputFilter.Status#REJECTED} if rejected,
 *          otherwise {@link ObjectInputFilter.Status#UNDECIDED}
 */
private static ObjectInputFilter.Status leaseFilter(ObjectInputFilter.FilterInfo filterInfo) {

    if (filterInfo.depth() > DGCCLIENT_MAX_DEPTH) {
        return ObjectInputFilter.Status.REJECTED;
    }
    Class<?> clazz = filterInfo.serialClass();
    if (clazz != null) {
        while (clazz.isArray()) {
            if (filterInfo.arrayLength() >= 0 && filterInfo.arrayLength() > DGCCLIENT_MAX_ARRAY_SIZE) {
                return ObjectInputFilter.Status.REJECTED;
            }
            // Arrays are allowed depending on the component type
            clazz = clazz.getComponentType();
        }
        if (clazz.isPrimitive()) {
            // Arrays of primitives are allowed
            return ObjectInputFilter.Status.ALLOWED;
        }
        return (clazz == UID.class ||
                clazz == VMID.class ||
                clazz == Lease.class)
                ? ObjectInputFilter.Status.ALLOWED
                : ObjectInputFilter.Status.REJECTED;
    }
    // Not a class, not size limited
    return ObjectInputFilter.Status.UNDECIDED;
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Shedule the renewing call, taking into consideration that the following
 * lease was granted.
 *
 * @param lease the lease that was granted.
 */
public void schedule(Lease lease)
{
  long value = lease.getValue();

  // Shedule a 10 % earlier because some time is needed for the message
  // to reach the server.
  long reduced = (value * 90)/100;
  if (reduced == 0)
    reduced = value;

  timer.schedule(new LeaseTimerTask(), reduced);
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Renew the lease.
 */
public void renew()
{
  Object renewIt = null;
  // Iterate throw the list of associated references. If all are
  // discarded, there is no need to renew.
  synchronized (ref)
  {
    Iterator iter = ref.iterator();
    WeakReference w;
    while (iter.hasNext() && renewIt == null)
      {
        w = (WeakReference) iter.next();
        renewIt = w.get();
        if (renewIt == null)
          // Discard the weak reference if its target has been garbage
          // collected.
          iter.remove();
      }
  }

  if (renewIt!=null)
    {
      Lease lease = notifyDGC( (UnicastRef) renewIt);

      // Schedule the next renewing session.
      if (lease!=null)
        schedule(lease);
    }
    {
      // All references collected - discard this entry.
    }
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Notify DGC that we still hold this reference.
 *
 * @param renewIt the reference we still have (must not be null).
 */
public Lease notifyDGC(UnicastRef renewIt)
{
  try
    {
      return renewIt.notifyDGC(lease);
    }
  catch (Exception e)
    {
      // Failed to notify.
      // TODO Take some relevant action in the case if we failed
      // to notify the remote object owner.
      return null;
    }
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Shedule the renewing call, taking into consideration that the following
 * lease was granted.
 * 
 * @param lease the lease that was granted.
 */
public void schedule(Lease lease)
{
  long value = lease.getValue();
  
  // Shedule a 10 % earlier because some time is needed for the message
  // to reach the server.
  long reduced = (value * 90)/100;
  if (reduced == 0)
    reduced = value;
  
  timer.schedule(new LeaseTimerTask(), reduced);
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Renew the lease.
 */
public void renew()
{
  Object renewIt = null;
  // Iterate throw the list of associated references. If all are
  // discarded, there is no need to renew.
  synchronized (ref)
  {
    Iterator iter = ref.iterator();
    WeakReference w;
    while (iter.hasNext() && renewIt == null)
      {
        w = (WeakReference) iter.next();
        renewIt = w.get();
        if (renewIt == null)
          // Discard the weak reference if its target has been garbage
          // collected.
          iter.remove();
      }
  }
  
  if (renewIt!=null)
    {
      Lease lease = notifyDGC( (UnicastRef) renewIt);
      
      // Schedule the next renewing session.
      if (lease!=null)
        schedule(lease);
    }
    {
      // All references collected - discard this entry.
    }
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
/**
 * Notify DGC that we still hold this reference.
 * 
 * @param renewIt the reference we still have (must not be null).
 */
public Lease notifyDGC(UnicastRef renewIt)
{
  try
    {
      return renewIt.notifyDGC(lease);
    }
  catch (Exception e)
    {
      // Failed to notify.
      // TODO Take some relevant action in the case if we failed
      // to notify the remote object owner.
      return null;
    }
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
void dgcDirty() {
    ObjID[] ids;

    synchronized (tablesLock) {
        ids = (ObjID[]) renewTable.keySet().toArray(
                new ObjID[renewTable.size()]);
    }

    try {
        Lease lease = dgcStub.dirty(ids, getSeqNumber(),
                new Lease(vmid, DGCImpl.maxDuration));
        failedDirtyCallsNum = 0;
        failureStartTime = 0;
        latestLeaseDuration = lease.getValue();
        renewTime = System.currentTimeMillis()
                + latestLeaseDuration / 2;
    } catch (RemoteException re) {
        // dirty call failed
        long curTime = System.currentTimeMillis();
        ++failedDirtyCallsNum;

        if (failedDirtyCallsNum == 1) {
            failureStartTime = curTime;
            latestLeaseDuration = (latestLeaseDuration > 0)
                    ? latestLeaseDuration : DGCImpl.maxDuration;
            failedRenewBaseDuration = latestLeaseDuration >> 5;
        }
        renewTime = curTime +
            failedRenewBaseDuration * ((failedDirtyCallsNum - 1) << 1);

        if (renewTime > failureStartTime + latestLeaseDuration) {
            renewTime = Long.MAX_VALUE;
        }
    }
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
public void testGetValueAndGetVMID() {
	VMID vmid = new VMID();
	long duration = (long) Math.random() * Long.MAX_VALUE;

	Lease lease = new Lease(vmid, duration);

	assertEquals(duration, lease.getValue());
	assertEquals(vmid, lease.getVMID());
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
public void testLease001() {
    long duration = 0;
    assertNotNull(msgNotNull, new Lease(id, duration));
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
public void testLease002() {
    id = new VMID();
    long duration = 0;
    assertNotNull(msgNotNull, new Lease(id, duration));
}
 

import java.rmi.dgc.Lease; //导入依赖的package包/类
public void testLease003() {
    long duration = Long.MAX_VALUE;
    assertNotNull(msgNotNull, new Lease(id, duration));
}