/**
* Connectors just send and receive ConnectToMessages. They return all responses
* to the ConnectionOverlord that initiated the ConnectToMessage
* @return true if we have enough responses for this connector, and should
* stop listening for more
*/
virtual public bool HandleCtmResponse(Connector c, ISender return_path, ConnectToMessage resp) {
/**
* Time to start linking:
*/
Linker l = new Linker(_node, resp.Target.Address,
resp.Target.Transports,
resp.ConnectionType,
_node.Address.ToString());
_node.TaskQueue.Enqueue( l );
return true;
}
/**
* This is a method for use with the RpcManager. Remote
* nodes can call the "sys:ctm.ConnectTo" method to
* reach this method
*/
public IDictionary ConnectTo(IDictionary ht) {
ConnectToMessage ctm_req = new ConnectToMessage(ht);
//Console.Error.WriteLine("[{0}.ConnectTo({1})]", _n.Address, ctm_req);
NodeInfo target = ctm_req.Target;
string contype = ctm_req.ConnectionType;
Linker l = new Linker(_n, target.Address, target.Transports, contype, ctm_req.Token);
//Here we start the job:
_n.TaskQueue.Enqueue( l );
ConnectToMessage resp = GetCtmResponseTo(ctm_req);
//Console.Error.WriteLine("[{0}.ConnectTo()->{1}]", _n.Address, resp);
return resp.ToDictionary();
}
virtual protected void ConnectTo(Address target, string ConnectionType) {
ConnectionType mt = Connection.StringToMainType(ConnectionType);
/*
* This is an anonymous delegate which is called before
* the Connector starts. If it returns true, the Connector
* will finish immediately without sending an ConnectToMessage
*/
Linker l = new Linker(_node, target, null, ConnectionType,
_node.Address.ToString());
object link_task = l.Task;
Connector.AbortCheck abort = delegate(Connector c) {
bool stop = false;
stop = _node.ConnectionTable.Contains( mt, target );
if (!stop ) {
/*
* Make a linker to get the task. We won't use
* this linker.
* No need in sending a ConnectToMessage if we
* already have a linker going.
*/
stop = _node.TaskQueue.HasTask( link_task );
}
return stop;
};
if (abort(null)) {
return;
}
ConnectToMessage ctm = new ConnectToMessage(ConnectionType, _node.GetNodeInfo(8),
_node.Address.ToString());
ISender send = new AHSender(_node, target, AHPacket.AHOptions.Exact);
Connector con = new Connector(_node, send, ctm, this);
con.FinishEvent += ConnectorEndHandler;
con.AbortIf = abort;
_node.TaskQueue.Enqueue(con);
}
public LinkProtocolState(Linker l, TransportAddress ta, Edge e) {
_linker = l;
_node = l.LocalNode;
_contype = l.ConType;
_target_lock = null;
_lm_reply = new WriteOnce<LinkMessage>();
_x = new WriteOnce<Exception>();
_con = new WriteOnce<Connection>();
_ta = ta;
_is_finished = 0;
//Setup the edge:
_e = e;
_result = Result.None;
}
public RestartState(Linker l, TransportAddress ta)
: this(l, ta, _MAX_RESTARTS) {
}
public RestartState(Linker l, TransportAddress ta,
int remaining_attempts) {
_linker = l;
_ta = ta;
_restart_attempts = remaining_attempts;
_first_start = 1;
}
public LeafConnectionOverlord(Node local)
{
_compensate = 0;
_local = local;
_linker = null;
_sync = new object();
_rnd = new Random( _local.GetHashCode()
^ unchecked((int)DateTime.UtcNow.Ticks) );
_default_retry_interval = new TimeSpan(0,0,0,0,10000);
_current_retry_interval = new TimeSpan(0,0,0,0,10000);
//We initialize at at year 1 to start with:
_last_retry = DateTime.MinValue;
_last_non_leaf_connection_event = DateTime.MinValue;
_last_trim = DateTime.MinValue;
/*
* When a node is removed from the ConnectionTable,
* we should check to see if we need to work to get a
* replacement
*/
lock(_sync) {
local.ConnectionTable.DisconnectionEvent += this.CheckAndConnectHandler;
local.ConnectionTable.ConnectionEvent += this.CheckAndConnectHandler;
/**
* Every heartbeat we check to see if we need to act
*/
local.HeartBeatEvent += this.CheckAndConnectHandler;
}
}
/**
* When a Linker finishes, this method is called. This is
* to do memory management of the Linker objects
*/
protected void LinkerFinishHandler(object linker, EventArgs args)
{
//We need to remove this linker from our list:
lock( _sync ) {
_linker = null;
}
}
/**
* Linker objects call this when they are done, and we start
* again if we need to
*/
public void CheckAndConnectHandler(object linker, EventArgs args)
{
ConnectionEventArgs cea = args as ConnectionEventArgs;
DateTime now = DateTime.UtcNow;
Linker new_linker = null;
lock(_sync) {
if( cea != null ) {
//This is a connection event.
if( cea.Connection.MainType != ConnectionType.Leaf ) {
_last_non_leaf_connection_event = now;
}
}
//Check in order of cheapness, so we can avoid hard work...
bool time_to_start = (now - _last_retry >= _current_retry_interval );
if ( (_linker == null) && time_to_start &&
IsActive && NeedConnection ) {
//Now we double the retry interval. When we get a connection
//We reset it back to the default value:
_last_retry = now;
_current_retry_interval += _current_retry_interval;
_current_retry_interval = (_MAX_RETRY_INTERVAL < _current_retry_interval) ?
_MAX_RETRY_INTERVAL : _current_retry_interval;
//Get a random address to connect to:
//Make a copy:
object[] tas = _local.RemoteTAs.ToArray();
/*
* Make a randomized list of TransportAddress objects to connect to:
* This is a very nice algorithm. It is optimal in that it produces
* a permutation of a list using N swaps and log(N!) bits
* of entropy.
*/
for(int j = 0; j < tas.Length; j++) {
//Swap the j^th position with this position:
int i = _rnd.Next(j, tas.Length);
if( i != j ) {
object temp_ta = tas[i];
tas[i] = tas[j];
tas[j] = temp_ta;
}
}
/**
* Make a Link to a remote node
*/
_linker = new Linker(_local, null, tas, "leaf", _local.Address.ToString());
new_linker = _linker;
}
else if (cea != null) {
/*
* This is the case that there was a non-leaf connection
* or disconnection, BUT it is not yet time to start OR
* there is current linker running OR we are not active OR
* we don't need a connection
*
* In this case, we set the retry interval back to the default
* value. This is because we only do the exponential back
* off when there we can't seem to get connected when we try.
* Clearly we are getting edges here, so there is no need
* for the back-off.
*/
//Reset the connection interval to the default value:
_current_retry_interval = _default_retry_interval;
//We are not seeking another connection
//log.Info("LeafConnectionOverlord : not seeking connection");
}
//Check to see if it is time to trim.
}//Drop the lock
Trim();
/**
* If there is a new linker, start it after we drop the lock
*/
if( new_linker != null ) {
new_linker.FinishEvent += this.LinkerFinishHandler;
new_linker.Start();
}
}
public RestartState(Linker l, TransportAddress ta,
int remaining_attempts) {
_linker = l;
_ta = ta;
_restart_attempts = remaining_attempts;
//Compute the interval:
Random rand = new Random();
int restart_sec = rand.Next(_MS_RESTART_TIME);
_interval = new TimeSpan(0,0,0,0,restart_sec);
}
/**
* Initiates connection setup.
* @param sender the ISender for the Connector to use
* @param contype the type of connection we want to make
* @param token the token used for connection messages
* @param responses the maximum number of ctm response messages to listen
*/
protected void ConnectTo(ISender sender, string contype, string token, int responses)
{
ConnectionType mt = Connection.StringToMainType(contype);
/*
* This is an anonymous delegate which is called before
* the Connector starts. If it returns true, the Connector
* will finish immediately without sending an ConnectToMessage
*/
Connector.AbortCheck abort = null;
ForwardingSender fs = sender as ForwardingSender;
if( fs != null ) {
//In general, we only know the exact node we are trying
//to reach when we are using a ForwardingSender
Address target = fs.Destination;
Linker l = new Linker(_node, target, null, contype, token);
object linker_task = l.Task; //This is what we check for
abort = delegate(Connector c) {
bool stop = _node.ConnectionTable.Contains( mt, target );
if (!stop ) {
/*
* Make a linker to get the task. We won't use
* this linker.
* No need in sending a ConnectToMessage if we
* already have a linker going.
*/
stop = _node.TaskQueue.HasTask( linker_task );
}
return stop;
};
if ( abort(null) ) {
return;
}
}
//Send the 4 neighbors closest to this node:
ArrayList nearest = _node.ConnectionTable.GetNearestTo( (AHAddress)_node.Address, 4);
NodeInfo[] near_ni = new NodeInfo[nearest.Count];
int i = 0;
foreach(Connection cons in nearest) {
//We don't use the TAs, just the addresses
near_ni[i] = NodeInfo.CreateInstance(cons.Address);
i++;
}
ConnectToMessage ctm = new ConnectToMessage(contype, _node.GetNodeInfo(8), near_ni, token);
Connector con = new Connector(_node, sender, ctm, this);
con.AbortIf = abort;
//Keep a reference to it does not go out of scope
lock( _sync ) {
_connectors[con] = responses;
}
con.FinishEvent += new EventHandler(this.ConnectorEndHandler);
//Start up this Task:
_node.TaskQueue.Enqueue(con);
}
/**
* When we get ConnectToMessage responses the connector tells us.
*/
override public bool HandleCtmResponse(Connector c, ISender ret_path,
ConnectToMessage ctm_resp)
{
/**
* Time to start linking:
*/
Linker l = new Linker(_node, ctm_resp.Target.Address,
ctm_resp.Target.Transports,
ctm_resp.ConnectionType,
ctm_resp.Token);
_node.TaskQueue.Enqueue( l );
/**
* Check this guys neighbors:
*/
/* POB: I don't think this is needed because we also do the
* same thing in the ConnectorEndHandler, so why do this twice?
* In fact, it seems better to wait for all the responses before
* looking for the closest one
*
* commenting this out:
*
ConnectionList structs =
_node.ConnectionTable.GetConnections(ConnectionType.Structured);
ConnectToNearer(structs, ctm_resp.Target.Address, ctm_resp.Neighbors);
*/
//See if we want more:
bool got_enough = true;
object des_o = _connectors[c];
if( des_o != null ) {
got_enough = (c.ReceivedCTMs.Count >= (int)des_o);
}
return got_enough;
}
/**
* Connectors just send and receive ConnectToMessages. They return all responses
* to the ConnectionOverlord that initiated the ConnectToMessage
* @return true if we have enough responses for this connector, and should
* stop listening for more
*/
virtual public bool HandleCtmResponse(Connector c, ISender return_path, ConnectToMessage resp) {
/**
* Time to start linking:
*/
ICollection transports = resp.Target.Transports;
if(TAAuth != null) {
ArrayList trans = new ArrayList();
foreach(TransportAddress ta in resp.Target.Transports) {
if(TAAuth.Authorize(ta) != TAAuthorizer.Decision.Deny) {
trans.Add(ta);
}
}
transports = trans;
}
Linker l = new Linker(_node, resp.Target.Address, transports,
resp.ConnectionType, resp.Token);
l.FinishEvent += LinkerEndHandler;
_node.TaskQueue.Enqueue( l );
return true;
}
