/// <summary>
/// Constructor
/// </summary>
/// <param name="dest">Destination of the message</param>
/// <param name="src">Source of the message</param>
/// <param name="buf">Byte buffer of payload associated with the message</param>
public Message(Address dest, Address src, byte[] buf)
{
dest_addr = dest;
src_addr = src;
this.buf = buf;
headers = new PropertyCollection();
}
/// <remarks>
/// If the member already exists then the member will
/// not be added to the membership
/// </remarks>
/// <summary>
/// Adds a new member to this membership.
/// </summary>
/// <param name="new_member"></param>
public void add(Address new_member)
{
if(new_member != null && !members.Contains(new_member))
{
members.Add(new_member);
}
}
/// <summary>
/// Returns true, if this view contains a certain member
/// </summary>
/// <param name="mbr">The address of the member</param>
/// <returns>True, if this view contains a certain member</returns>
public bool containsMember( Address mbr )
{
if ( mbr == null || members == null )
{
return false;
}
return members.Contains(mbr);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="dest">Destination of the message</param>
/// <param name="src">Source of the message</param>
/// <param name="obj">Serialisable payload OR array of <c>Message</c>s</param>
public Message(Address dest, Address src, Object obj)
{
dest_addr = dest;
src_addr = src;
headers = new PropertyCollection();
if(obj!=null)
{
if(obj is Array)
setMessageArray((Array)obj);
else if(obj.GetType().IsSerializable)
setObject(obj);
else
throw new Exception("Message can only contain an Array of messages or a ISerializable object");
}
}
/// <summary>
/// Adds a member into the Digest.
/// </summary>
/// <param name="sender">Address of new member to add</param>
/// <param name="low_seqno">Lowest Sequence num received from this member</param>
/// <param name="high_seqno">Highest Sequence num received from this member</param>
public void add(Address sender, long low_seqno, long high_seqno)
{
if(index >= senders.Length)
{
if(Trace.trace)
Trace.error("Digest.add()", "index " + index +
" out of bounds, please create new Digest if you want more members !");
return;
}
if(sender == null)
{
if(Trace.trace)
Trace.error("Digest.add()", "sender is null, will not add it !");
return;
}
senders[index]=sender;
low_seqnos[index]=low_seqno;
high_seqnos[index]=high_seqno;
high_seqnos_seen[index]=-1;
index++;
}
/// <summary>
/// Sets the highest seen sequence number
/// </summary>
/// <param name="sender">Member to set the highest seen seq number for</param>
/// <param name="high_seqno_seen">New highest seen seq number</param>
public void setHighSeqnoSeenAt(Address sender, long high_seqno_seen)
{
int index=getIndex(sender);
if(index < 0)
return;
else
setHighSeqnoSeenAt(index, high_seqno_seen);
}
/**
* Similar to add(), but if the sender already exists, its seqnos will be modified (no new entry) as follows:
* <ol>
* <li>this.low_seqno=min(this.low_seqno, low_seqno)
* <li>this.high_seqno=max(this.high_seqno, high_seqno)
* <li>this.high_seqno_seen=max(this.high_seqno_seen, high_seqno_seen)
* </ol>
* If the sender doesn not exist, a new entry will be added (provided there is enough space)
*/
/// <remarks>
/// Similar to add(), but if the sender already exists, its seqnos will be modified (no new entry) as follows:
/// <list>
/// <item>this.low_seqno=min(this.low_seqno, low_seqno)</item>
/// <item>this.high_seqno=max(this.high_seqno, high_seqno)</item>
/// <item>this.high_seqno_seen=max(this.high_seqno_seen, high_seqno_seen)</item>
/// </list>
/// If the sender doesn not exist, a new entry will be added (provided there is enough space)
/// </remarks>
/// <summary>
/// Merge member into Digest. Also called from <c>merge(Digest)</c>.
/// </summary>
/// <param name="sender">Member to merge into Digest</param>
/// <param name="low_seqno">Lowest sequence number associated with this member</param>
/// <param name="high_seqno">Highest sequence number associated with this member</param>
/// <param name="high_seqno_seen">Highest sequence number seen associated with this member</param>
public void merge(Address sender, long low_seqno, long high_seqno, long high_seqno_seen)
{
int index;
long my_low_seqno, my_high_seqno, my_high_seqno_seen;
if(sender == null)
{
if(Trace.trace)
Trace.error("Digest.merge()", "sender == null");
return;
}
index=getIndex(sender);
if(index == -1)
{
add(sender, low_seqno, high_seqno, high_seqno_seen);
return;
}
my_low_seqno=lowSeqnoAt(index);
my_high_seqno=highSeqnoAt(index);
my_high_seqno_seen=highSeqnoSeenAt(index);
if(low_seqno < my_low_seqno)
setLowSeqnoAt(index, low_seqno);
if(high_seqno > my_high_seqno)
setHighSeqnoAt(index, high_seqno);
if(high_seqno_seen > my_high_seqno_seen)
setHighSeqnoSeenAt(index, high_seqno_seen);
}
/// <summary>
/// Increment the sender's high_seqno by 1
/// </summary>
/// <param name="sender">Member to increment</param>
public void incrementHighSeqno(Address sender)
{
if(sender == null) return;
for(int i=0; i < senders.Length; i++)
{
if(senders[i] != null && senders[i].Equals(sender))
{
high_seqnos[i]=high_seqnos[i]+1;
break;
}
}
}
/// <remarks>
/// Creates a ViewID with the coordinator address and the given Lamport timestamp.
/// </remarks>
/// <summary>
/// Constructor
/// </summary>
/// <param name="coord_addr">The address of the member that issued this view</param>
/// <param name="id">The Lamport timestamp of the view</param>
public ViewId(Address coord_addr, long id)
{
this.coord_addr=coord_addr;
this.id=id;
}
/// <summary>
/// Called by the ProtocolSinkStack when messages are recevied.
/// </summary>
/// <param name="evt">Event that has been received.</param>
public void up(Event evt)
{
int type=evt.Type;
Message msg;
/*if the queue is not available, there is no point in
*processing the message at all*/
if(mq == null)
{
if(Trace.trace)
Trace.error("GroupChannel.up()", "message queue is null");
return;
}
switch(type)
{
case Event.MSG:
msg=(Message)evt.Arg;
if(!receive_local_msgs)
{ // discard local messages (sent by myself to me)
if(local_addr != null && msg.Source != null)
if(local_addr.Equals(msg.Source))
return;
}
break;
case Event.VIEW_CHANGE:
my_view=(View)evt.Arg;
if(!receive_views) // discard if client has not set receving views to on
return;
break;
case Event.SUSPECT:
if(!receive_suspects)
return;
break;
case Event.CONNECT_OK:
lock(connect_mutex)
{
Monitor.Pulse(connect_mutex);
}
break;
case Event.DISCONNECT_OK:
lock(disconnect_mutex)
{
Monitor.Pulse(disconnect_mutex);
}
break;
case Event.SET_LOCAL_ADDRESS:
local_addr=(Address)evt.Arg;
break;
case Event.EXIT:
handleExit(evt);
return; // no need to pass event up; already done in handleExit()
default:
break;
}
// If UpHandler is installed, pass all events to it and return (UpHandler is e.g. a building block)
if(up_handler != null)
{
up_handler.up(evt);
return;
}
if(type == Event.MSG || type == Event.VIEW_CHANGE || type == Event.SUSPECT ||
type == Event.EXIT) //type == Event.GET_APPLSTATE || type == Event.BLOCK
{
try
{
mq.Add(evt);
}
catch(Exception e)
{
if(Trace.trace)
Trace.error("GroupChannel.up()", "exception: " + e);
}
}
}
/// <summary>
/// Removes the specified member
/// </summary>
/// <param name="old_member">Member that has left the group</param>
public void remove(Address old_member)
{
if(old_member != null)
{
members.Remove(old_member);
}
}
/// <summary>
/// Returns true if the provided member belongs to this membership
/// </summary>
/// <param name="member">Member to check</param>
/// <returns>True if the provided member belongs to this membership, otherwise false</returns>
public bool contains(Address member)
{
if(member == null)
return false;
return members.Contains(member);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="creator">The creator of this view</param>
/// <param name="id">The lamport timestamp of this view</param>
/// <param name="members">Contains a list of all the members in the view, can be empty but not null.</param>
public View(Address creator, long id, ArrayList members)
: this(new ViewId(creator, id), members)
{
}
/// <summary>
/// Processes <c>Events</c> traveling up the stack
/// </summary>
/// <param name="evt">The Event to be processed</param>
public override void up(Event evt)
{
Message msg;
double r;
if (evt.Type == Event.SET_LOCAL_ADDRESS)
localAddress = (Address) evt.Arg;
if (evt.Type == Event.MSG)
{
msg = (Message) evt.Arg;
if (probUp > 0)
{
r = (double)((double)random.Next(100)/(double)100);
if (r < probUp)
{
if (excludeItself && msg.Source.Equals(localAddress))
{
if (Trace.trace) Trace.info("DISCARD.up()", "excluding itself");
}
else
{
if (Trace.trace) Trace.info("DISCARD.up()", "dropping message");
return;
}
}
}
}
passUp(evt);
}
/// <summary>
/// Constructor: used for deserialization
/// </summary>
/// <param name="info">Standard <c>SerializationInfo</c> object</param>
/// <param name="ctxt">Standard <c>StreamingContext</c> object</param>
public Message(SerializationInfo info, StreamingContext ctxt)
{
bool b_dest_addr = info.GetBoolean("b_dest_addr");
if (b_dest_addr)
dest_addr = (Address)info.GetValue("dest_addr",typeof(object));
bool b_src_addr = info.GetBoolean("b_src_addr");
if (b_src_addr)
src_addr = (Address)info.GetValue("src_addr",typeof(object));
int bufferLength = info.GetInt32("bufferLength");
if (bufferLength > 0)
{
buf = new byte[bufferLength];
for(int i = 0; i< bufferLength;i++)
{
buf[i] = info.GetByte(i.ToString());
}
}
String strHeaders = info.GetString("strHeaders");
headers = new PropertyCollection();
if (String.Compare(strHeaders,"NULL")!=0)
{
String[] headerArray = strHeaders.Split(':');
for(int j = 0;j<headerArray.Length;j++)
{
headers.Add(headerArray[j],info.GetValue(headerArray[j],typeof(object)));
}
}
}
public void suspect(Address suspected_mbr)
{
}
public void channelReconnected(Address addr)
{
if (!closing)
txtMsgsReceived.AppendText("-=-=-=-=-" + "Channel is Reconnected!" + "-=-=-=-=-" + "\n");
}
/// <summary>
/// Checks if a member is in the Digest
/// </summary>
/// <param name="sender">Member to check</param>
/// <returns>True if the message is in the Digest</returns>
public bool contains(Address sender)
{
return getIndex(sender) != -1;
}
/// <remarks>
/// Creates a ViewID with the coordinator address and a Lamport timestamp of 0.
/// </remarks>
/// <summary>
/// Constructor
/// </summary>
/// <param name="coord_addr">The address of the member that issued this view</param>
public ViewId(Address coord_addr)
{
this.coord_addr=coord_addr;
}
/// <summary>
/// Gets the position of the member in the Digest
/// </summary>
/// <param name="sender">Member to check</param>
/// <returns>Position of member</returns>
public int getIndex(Address sender)
{
int ret=-1;
if(sender == null)
return ret;
for(int i=0; i < senders.Length; i++)
if(sender.Equals(senders[i]))
return i;
return ret;
}
/// <summary>
/// Processes <c>Events</c> traveling up the stack
/// </summary>
/// <param name="evt">The Event to be processed</param>
public override void up(Event evt)
{
switch(evt.Type)
{
case Event.SET_LOCAL_ADDRESS:
localAddress = (Address) evt.Arg;
localStamp = new VectorTimeStamp(localAddress);
delayQueue = new ArrayList();
break;
case Event.VIEW_CHANGE:
ArrayList newViewMembers = ((View) evt.Arg).getMembers();
localStamp.merge((ArrayList) newViewMembers.Clone());
localStamp.reset();
break;
case Event.MSG:
Message msg = (Message)evt.Arg;
Header hdr = msg.getHeader(getName());
//Check that the correct header is available
if(hdr == null || !(hdr is CausalHeader))
{
if(Trace.trace)
Trace.error("Causal.up()","No Causal Header Found!");
passUp(evt);
return;
}
CausalHeader cHdr = (CausalHeader)hdr;
//Pass message up if it is causually next
String diag = "";
bool next = localStamp.causallyNext(cHdr.VectorTime, out diag);
//passUp(new Event(Event.MSG, new Message(null,localAddress,diag)));
if(Trace.trace)
Trace.info("CAUSAL.up()", diag + "Causally Next = " + next);
if(next)
{
if(Trace.trace)
Trace.info("CAUSAL.up()","Message received in sequence.");
passUp(evt);
localStamp.max(cHdr.VectorTime);
}
else //Else add to the delayed queue
{
if(Trace.trace)
Trace.warn("CAUSAL.up()","Message received out of sequence.");
cHdr.VectorTime.AssosicatedMessage = msg;
addToQueue(cHdr.VectorTime);
}
//Check the delayed queue removing all items that can be passed up
TransportableVectorTimeStamp queuedVector = null;
while ((delayQueue.Count > 0) &&
localStamp.causallyNext((queuedVector = (TransportableVectorTimeStamp)delayQueue[0]), out diag))
{
delayQueue.Remove(queuedVector);
passUp(new Event(Event.MSG, queuedVector.AssosicatedMessage));
localStamp.max(queuedVector);
}
return;
}
passUp(evt);
}
/// <summary>
/// Gets the highest seen sequence number
/// </summary>
/// <param name="sender">Member that the highest seen sequence number is required for</param>
/// <returns>Highest seen sequence number</returns>
public long highSeqnoSeenAt(Address sender)
{
long ret=-1;
int index;
if(sender == null) return ret;
index=getIndex(sender);
if(index == -1)
return ret;
else
return high_seqnos_seen[index];
}
