class TXSocket: public TSocket, public XrdClientAbsUnsolMsgHandler

 Interface to ErrorHandler (protected).

 Constructor
 Open the connection to a remote XrdProofd instance and start a PROOF
 session.
 The mode 'm' indicates the role of this connection:
     'a'      Administrator; used by an XPD to contact the head XPD
     'i'      Internal; used by a TXProofServ to call back its creator
              (see XrdProofUnixConn)
     'C'      PROOF manager: open connection only (do not start a session)
     'M'      Client creating a top master
     'A'      Client attaching to top master
     'm'      Top master creating a submaster
     's'      Master creating a slave
 The buffer 'logbuf' is a null terminated string to be sent over at
 login.

 TXSocket copy ctor.

 TXSocket assignment operator.

 Destructor

 Set session ID to 'id'. If id < 0, disable also the asynchronous handler.

 Disconnect a session. Use opt= "S" or "s" to
 shutdown remote session.
 Default is opt = "".

 Close connection. Available options are (case insensitive)
   'P'   force closing of the underlying physical connection
   'S'   shutdown remote session, is any
 A session ID can be given using #...# signature, e.g. "#1#".
 Default is opt = "".

 We are here if an unsolicited response comes from a logical conn
 The response comes in the form of an XrdClientMessage *, that must NOT be
 destroyed after processing. It is destroyed by the first sender.
 Remember that we are in a separate thread, since unsolicited
 responses are asynchronous by nature.

 Get read descriptor of the global pipe used for monitoring of the
 XPD sockets

 Write a byte to the global pipe to signal new availibility of
 new messages

 Read a byte to the global pipe to synchronize message pickup

 Remove any reference to socket 's' from the global pipe and
 ready-socket queue

 Return kTRUE if the remote server is a 'proofd'

 Get highest interrupt level in the queue

 Flush the asynchronous queue.
 Typically called when a kHardInterrupt is received.
 Returns number of bytes in flushed buffers.

 This method sends a request for creation of (or attachment to) a remote
 server application.

 Send a raw buffer of specified length.
 Use opt = kDontBlock to ask xproofd to push the message into the proofsrv.
 (by default is appended to a queue waiting for a request from proofsrv).
 Returns the number of bytes sent or -1 in case of error.

 Ping functionality: contact the server and get an acknowledgement.
 If external, the server waits for a reply from the server
 Use opt = kDontBlock to ask xproofd to push the message into the proofsrv.
 (by default is appended to a queue waiting for a request from proofsrv).
 Returns the number of bytes sent or -1 in case of error.

 Wait and pick-up next buffer from the asynchronous queue

 Pop-up a buffer of at least size bytes from the spare list
 If none is found either one is reallocated or a new one
 created

 Release read buffer giving back to the spare list

 Receive a raw buffer of specified length bytes.

 Send urgent message (interrupt) to remote server
 Returns 0 or -1 in case of error.

 Send a TMessage object. Returns the number of bytes in the TMessage
 that were sent and -1 in case of error.

 Receive a TMessage object. The user must delete the TMessage object.
 Returns length of message in bytes (can be 0 if other side of connection
 is closed) or -1 in case of error. In those case mess == 0.

 Send message to intermediate coordinator.
 If any output is due, this is returned as an obj string to be
 deleted by the caller

 Send urgent message to counterpart; 'type' specifies the type of
 the message (see TXSocket::EUrgentMsgType), and 'int1', 'int2'
 two containers for additional information.

 Dump content of the ready socket list

 Init environment variables for XrdClient

 Auxilliary

 Send interfaces

 Recv interfaces

 Interrupt the low level socket

 Standard options cannot be set

 Disable / Enable read timeout