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/*
* Copyright 2008 biaoping.yin
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.frameworkset.spi.remote;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.frameworkset.spi.remote.annotations.GuardedBy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
* Title: RPCRequest.java
*
*
* Description:
*
*
* bboss workgroup
*
*
* Copyright (c) 2007
*
*
* @Date 2009-10-7 下午05:35:32
* @author biaoping.yin
* @version 1.0
*/
public class RPCRequest implements java.io.Serializable, ResponseCollector
{
private static final Logger log = LoggerFactory.getLogger(RPCRequest.class);
/** return only first response */
public static final int GET_FIRST = 1;
/** return all responses */
public static final int GET_ALL = 2;
/** return majority (of all non-faulty members) */
public static final int GET_MAJORITY = 3;
/** return majority (of all members, may block) */
public static final int GET_ABS_MAJORITY = 4;
/** return n responses (may block) */
public static final int GET_N = 5;
/** return no response (async call) */
public static final int GET_NONE = 6;
private long id;
/** to generate unique request IDs (see getRequestId()) */
private static long last_req_id = 1;
protected final int rsp_mode;
protected final int expected_mbrs;
private RPCAddress caller;
/** Map. Maps requests and responses */
@GuardedBy("lock")
private final Map requests = new HashMap();
/** bounded queue of suspected members */
@GuardedBy("lock")
private final List suspects = new ArrayList();
RPCMessage msg;
RPCIOHandler corr;
long timeout;
protected volatile boolean done = false;
/** list of members, changed by viewChange() */
@GuardedBy("lock")
private final List members = new ArrayList();
public RPCRequest(RPCMessage msg, RPCIOHandler corr, List mbrs, int rsp_mode, long timeout,
int expected_mbrs)
{
this.msg = msg;
this.rsp_mode = rsp_mode;
this.timeout = timeout;
this.id = getRequestId();
this.corr = corr;
this.expected_mbrs = expected_mbrs;
if (mbrs != null)
{
for (RPCAddress mbr : mbrs)
{
requests.put(mbr, new RPCResponse(mbr));
}
this.members.clear();
this.members.addAll(mbrs);
}
}
// public RPCRequest()
// {
// this.id = getRequestId();
// }
/** Generates a new unique request ID */
private static synchronized long getRequestId()
{
long result = System.currentTimeMillis();
if (result <= last_req_id)
{
result = last_req_id + 1;
}
last_req_id = result;
return result;
}
public long getId()
{
// TODO Auto-generated method stub
return id;
}
public void setResponseFilter(ResponseFilter filter)
{
rsp_filter = filter;
}
protected ResponseFilter rsp_filter = null;
public void receiveResponse(Object response_value, RPCAddress sender)
{
lock.lock();
try
{
if (done)
{
// if(log.isTraceEnabled())
// log.trace("command is done; cannot add response !");
}
// else if (suspects.contains(sender))
// {
// // if(log.isWarnEnabled())
// // log.warn("received response from suspected member " + sender
// // + "; discarding");
// }
else
{
// try
// {
// ClinentTransport transport = this.addresss.remove(sender);
// if(transport != null)
// transport.disconnect();
// }
// catch (Exception e)
// {
// log.error("transport.disconnect()", e);
// }
try
{
RPCResponse rsp = requests.get(sender);
if (rsp != null)
{
if (!rsp.wasReceived())
{
boolean responseReceived = (rsp_filter == null)
|| rsp_filter.isAcceptable(response_value, sender);
rsp.setValue(response_value);
rsp.setReceived(responseReceived);
if (log.isTraceEnabled())
log.trace(new StringBuilder("received response for request ").append(id)
.append(", sender=").append(sender).append(", val=").append(response_value).toString());
}
done = rsp_filter != null && !rsp_filter.needMoreResponses();
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
finally
{
completed.signalAll(); // wakes up execute()
lock.unlock();
}
}
/** keep suspects vector bounded */
private static final int MAX_SUSPECTS = 40;
// /**
// * Adds a member to the 'suspects' list. Removes oldest elements from
// * 'suspects' list to keep the list bounded ('max_suspects' number of
// * elements), Requires lock to be held
// */
// @GuardedBy("lock")
// private void addSuspect(RPCAddress suspected_mbr)
// {
// if (!suspects.contains(suspected_mbr))
// {
// suspects.add(suspected_mbr);
// while (suspects.size() >= MAX_SUSPECTS && !suspects.isEmpty())
// suspects.remove(0); // keeps queue bounded
// }
// }
// public void suspect(RPCAddress suspected_member)
// {
//
// if (suspected_member == null)
// return;
//
// lock.lock();
// try
// {
// addSuspect(suspected_member);
// RPCResponse rsp = requests.get(suspected_member);
// if (rsp != null)
// {
// rsp.setSuspected(true);
// rsp.setValue(null);
// completed.signalAll();
// }
// }
// finally
// {
// lock.unlock();
// }
//
// }
// public void viewChange(View new_view)
// {
//
// // TODO Auto-generated method stub
//
// }
private final Lock lock = new ReentrantLock();
/** Is set as soon as the request has received all required responses */
private final Condition completed = lock.newCondition();
public RPCResponseList getResults()
{
lock.lock();
try
{
// List rsps = requests.values();
return new RPCResponseList(requests);
}
finally
{
// this.closeShortConnection();
lock.unlock();
}
}
public void setCaller(RPCAddress local_addr)
{
this.caller = local_addr;
// TODO Auto-generated method stub
}
public boolean execute() throws Exception
{
this.corr.sendRequest(this.id, members, this.msg, this);
lock.lock();
try
{
done = false;
boolean retval = collectResponses(timeout);
// if(retval == false && log.isTraceEnabled())
// log.trace("call did not execute correctly, request is " +
// this.toString());
return retval;
}
finally
{
done = true;
lock.unlock();
}
}
// /**
// * 关闭短连接
// */
// private void closeShortConnection()
// {
// Collection ss = this.addresss.values();
// if(ss != null)
// {
// for(Iterator ts = ss.iterator();ts.hasNext();)
// {
// ClinentTransport t = ts.next();
// t.disconnect();
// }
// }
//
// }
@GuardedBy("lock")
private boolean collectResponses(long timeout) throws Exception
{
if (timeout <= 0)
{
while (true)
{ /* Wait for responses: */
// adjustMembership(); // may not be necessary, just to make
// sure...
if (responsesComplete())
{
if (corr != null)
{
corr.done(id);
}
// if(log.isTraceEnabled() && rsp_mode != GET_NONE) {
// log.trace("received all responses: " + toString());
// }
return true;
}
try
{
completed.await();
// System.out.println("");
}
catch (Exception e)
{
}
}
}
else
{
long start_time = System.currentTimeMillis();
long timeout_time = start_time + timeout;
while (timeout > 0)
{ /* Wait for responses: */
if (responsesComplete())
{
if (corr != null)
corr.done(id);
// if(log.isTraceEnabled() && rsp_mode != GET_NONE) {
// log.trace("received all responses: " + toString());
// }
return true;
}
timeout = timeout_time - System.currentTimeMillis();
if (timeout > 0)
{
try
{
completed.await(timeout, TimeUnit.MILLISECONDS);
// System.out.println("");
}
catch (Exception e)
{
}
}
}
if (corr != null)
{
corr.done(id);
}
// if(log.isTraceEnabled())
// log.trace("timed out waiting for responses");
return false;
}
}
@GuardedBy("lock")
private boolean responsesComplete()
{
int num_received = 0, num_not_received = 0, num_suspected = 0;
final int num_total = requests.size();
if (done)
return true;
for (RPCResponse rsp : requests.values())
{
if (rsp.wasReceived())
{
num_received++;
}
else
{
if (rsp.wasSuspected())
{
num_suspected++;
}
else
{
num_not_received++;
}
}
}
switch (rsp_mode)
{
case GET_FIRST:
if (num_received > 0)
return true;
if (num_suspected >= num_total)
// e.g. 2 members, and both suspected
return true;
break;
case GET_ALL:
return num_received + num_suspected >= num_total;
case GET_MAJORITY:
int majority = determineMajority(num_total);
if (num_received + num_suspected >= majority)
return true;
break;
case GET_ABS_MAJORITY:
majority = determineMajority(num_total);
if (num_received >= majority)
return true;
break;
case GET_N:
if (expected_mbrs >= num_total)
{
return responsesComplete();
}
return num_received >= expected_mbrs || num_received + num_not_received < expected_mbrs
&& num_received + num_suspected >= expected_mbrs;
case GET_NONE:
return true;
default:
// if(log.isErrorEnabled()) log.error("rsp_mode " + rsp_mode +
// " unknown !");
break;
}
return false;
}
private static int determineMajority(int i)
{
return i < 2 ? i : (i / 2) + 1;
}
// private transient Map addresss= new
// HashMap();
// public void registConnection(ClinentTransport transport)
// {
// addresss.put(transport.getRpcaddress(), transport);
// // TODO Auto-generated method stub
//
// }
public String toString()
{
return msg.toString();
}
}
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