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 location string

 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.

 Post a message of type 'type' into the read messages queue.
 If 'msg' is defined it is also added as TString.
 This is used, for example, with kPROOF_FATAL to force the main thread
 to mark this socket as bad, avoiding race condition when a worker
 dies while in processing state.

 Return kTRUE if the remote server is a 'proofd'

 Get latest interrupt level and reset it; if the interrupt has to be
 propagated to lower stages forward will be kTRUE after the call

 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 to check its vitality.
 If external, the server waits for a reply from the server
 Returns kTRUE if OK or kFALSE in case of error.

 Remote touch functionality: contact the server to proof our vitality.
 No reply from server is expected.

 Interrupt the remote protocol instance. Used to propagate Ctrl-C.
 No reply from server is expected.

 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 or -5 if pipe broken (connection invalid).
 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.

 Init environment variables for XrdClient

 Try reconnection after failure

 Auxilliary

 Send interfaces

 Recv interfaces

 Interrupt the low level socket

 Set / Check async msg queue waiting status

 Standard options cannot be set

 Disable / Enable read timeout