public int GetAvailablePort()
{
int portsCount = 0;
lock (this._availablePortsList)
{
portsCount = this._availablePortsList.Count;
}
if (portsCount > 0)
{
int portToReturn = 0;
portToReturn = this.DequeueNextAvailablePort();
if (portsCount <= AVAILABLE_PORTS_QUEUE_MIN_SIZE)
{
this.SchedulePortsSearchingTask();
}
return(portToReturn);
}
else
{
this._LastAssignedPortNumber = CommunicationsUtilities.GetFreeTCPPortOnPortsRange(this._portsRangeLowerLimit, this._portsRangeUpperLimit);
return(this._LastAssignedPortNumber);
}
}
private int DequeueNextAvailablePort()
{
bool gotPort = false;
int currentPortFromqueue = 0;
while (!gotPort)
{
if (this._availablePortsList.Count > 0)
{
currentPortFromqueue = System.Convert.ToInt32(this._availablePortsList.GetByIndex(0));
lock (this._availablePortsList)
{
this._availablePortsList.RemoveAt(0);
}
System.Net.Sockets.TcpListener listener = null;
string host = System.Net.Dns.GetHostName();
System.Net.IPAddress local_IPAddress = CommunicationsLibrary.Utilities.CommunicationsUtilities.GetActiveIPAddress();
listener = new System.Net.Sockets.TcpListener(local_IPAddress, currentPortFromqueue);
try
{
listener.Start();
listener.Stop();
this._LastAssignedPortNumber = currentPortFromqueue;
listener = null;
gotPort = true;
}
catch (System.Net.Sockets.SocketException ex)
{
switch (ex.ErrorCode)
{
case 10048: //the port is opened by another process
try
{
listener.Stop();
}
catch (Exception)
{
}
break;
case 10055: //there is no more space to allocate another port in the system, no more resources available
string msg = "Error finding an open port : " + ex.Message;
throw (new Exception(msg));
}
}
catch (Exception)
{
try
{
listener.Stop();
}
catch (Exception)
{
}
}
}
else
{
this._LastAssignedPortNumber = CommunicationsUtilities.GetFreeTCPPortOnPortsRange(this._portsRangeLowerLimit, this._portsRangeUpperLimit);
}
}
return(this._LastAssignedPortNumber);
}
