nmsgLib.h File Reference

Definitions for the network message routines. More...

Classes

struct nmsgHead_s

Network message header. More...

struct nmsgBuff_s

Prototype message buffer. More...

struct nmsgStats_s

Network statistics block. More...

Typedefs

typedef struct nmsgHead_s nmsgHead_t

Network message header.

typedef struct nmsgBuff_s nmsgBuff_t

Prototype message buffer.

typedef struct nmsgStats_s nmsgStats_t

Network statistics block.

typedef int nmsgConnCB_t (void *hndl, void **uParm)

Connect callback routine.

typedef int nmsgDiscCB_t (void *hndl, void **uParm)

Disconnect callback routine.

typedef int nmsgRcveCB_t (void *hndl, void **uParm, nmsgBuff_t *msg, char **dataP)

Receive message callback routine.

Enumerations

enum { NMSG_MAGIC = 0x6e4d7347 }

Magic word value definition. More...

enum {
  NMSG_SUCCESS = 0,
  NMSG_NOMEMORY = 1,
  NMSG_UNKNHOST = 2,
  NMSG_NOSEMCRE = 3,
  NMSG_NOTASKCR = 4,
  NMSG_NOTCONN = 5,
  NMSG_INVSEMA = 6,
  NMSG_DISCONN = 7,
  NMSG_TIMEDOUT = 8,
  NMSG_INVFDESC = 9,
  NMSG_INVHNDL = 10,
  NMSG_OPNTPERM = 11,
  NMSG_FILENFND = 12,
  NMSG_IOERROR = 13,
  NMSG_NOACCESS = 14,
  NMSG_NOSCHDEV = 15,
  NMSG_NOTADIR = 16,
  NMSG_NOTAFILE = 17,
  NMSG_XSFILDVC = 18,
  NMSG_XSFILOPN = 19,
  NMSG_NAMELONG = 20,
  NMSG_RDONLYFS = 21,
  NMSG_NETUNRCH = 22,
  NMSG_NETRESET = 23,
  NMSG_CONNABRT = 24,
  NMSG_CONNRSET = 25,
  NMSG_NOBUFSPC = 26,
  NMSG_SOCKCONN = 27,
  NMSG_SNOTCONN = 28,
  NMSG_SHUTDOWN = 29,
  NMSG_CONNTMO = 30,
  NMSG_CONNREF = 31,
  NMSG_NETDOWN = 32,
  NMSG_TOODEEP = 33,
  NMSG_HSTUNRCH = 34,
  NMSG_HOSTDOWN = 35,
  NMSG_UNSUPPRO = 36,
  NMSG_UNSUPPRF = 37,
  NMSG_PROTOTYP = 38,
  NMSG_UNSUPADF = 39,
  NMSG_NOSTREAM = 40,
  NMSG_ADDRUSED = 41,
  NMSG_ADDRUNAV = 42,
  NMSG_ALREADY = 43,
  NMSG_BADFNMBR = 44,
  NMSG_INPROGRS = 45,
  NMSG_OPRNINTR = 46,
  NMSG_INVDARG = 47,
  NMSG_NOTASOCK = 48,
  NMSG_OPNTSUPP = 49,
  NMSG_BADADDRS = 50,
  NMSG_PROTOERR = 51,
  NMSG_TRYAGAIN = 52,
  NMSG_MSGLONG = 53,
  NMSG_BRKNPIPE = 54,
  NMSG_UNKNERR = 55
}

Function return codes. More...

Functions

int nmsgCheck (void *hndl)

Check a network connection handle.

int nmsgClose (void *hndl, int force)

Terminate a message client or server.

int nmsgConnect (void **hndl, const char *node, int port)

Connect to a message server.

int nmsgConnectAsy (void **hndl, const char *node, int port, int prio, nmsgConnCB_t connRtn, nmsgDiscCB_t discRtn, void *uParm)

Connect asynchronously (robustly) to a message server.

const char * nmsgErrorMsg (int status)

Obtain the text of an error message.

void nmsgErrorReport (int status, const char *func)

Display an error message.

int nmsgListen (void **hndl, int port, int maxConn, int maxData, int prio, nmsgConnCB_t connRtn, nmsgDiscCB_t discRtn, nmsgRcveCB_t rcveRtn, void *uParm)

Establish a message server.

int nmsgRemoteIP (void *hndl, int *ip)

Get the IP address of the remote end.

int nmsgSend (void *hndl, nmsgBuff_t *msg)

Send a message and return immediately.

int nmsgSendW (void *hndl, nmsgBuff_t *msg, nmsgBuff_t **replyP, nmsgBuff_t *reply, int maxData)

Send a message and receive reply.

int nmsgStats (void *hndl, nmsgStats_t *stats)

Get connection statistics.

int nmsgWait (void *hndl, nmsgBuff_t **replyP, nmsgBuff_t *reply, int maxData)

Wait for a reply to a sent message.

Detailed Description

Definitions for the network message routines.

Author:: Owen H Saxton

Id: nmsgLib.h,v 1.11 2011/03/28 18:39:27 saxton Exp

Typedef Documentation

typedef int nmsgConnCB_t(void *hndl, void **uParm)

Connect callback routine.

This routine, if supplied to the listen or asynchronous connection routine, is called whenever a network connection is established.

Parameters:

	hndl	The handle for the network connection.
	uParm	The address of a per-connection copy of the user parameter supplied in the call to the listen or connection routine.

Return values:

	0	Accept the connection.
	-1	Reject the connection (for listen callback only).

typedef int nmsgDiscCB_t(void *hndl, void **uParm)

Disconnect callback routine.

This routine, if supplied to the listen or asynchronous connection routine, is called whenever the network connection is broken.

Parameters:

	hndl	The handle for the network connection.
	uParm	The address of a per-connection copy of the user parameter supplied in the call to the listen or connection routine.

Returns:: The return value is ignored.

typedef int nmsgRcveCB_t(void *hndl, void **uParm, nmsgBuff_t *msg, char **dataP)

Receive message callback routine.

This routine is called whenever a message is received on the server (listener) side of a network connection. It processes the message and generates a reply. Normally the whole reply is placed in the area occupied by the incoming message, and can contain data up to the maximum length established in the original listen call. However, the data portion of the reply may alternatively be supplied in a piece of allocated memory and has no restriction on its size in this case.

Parameters:

	hndl	The handle for the network connection.
	uParm	The address of a per-connection copy of the user parameter supplied in the call to the listen routine.
	msg	The address of the received message.
	dataP	The address of a pointer to optionally receive the address of an alternate data area. This area must have been allocated via a call to malloc().

Returns:: The return value is ignored.

Enumeration Type Documentation

anonymous enum

Magic word value definition.

Enumerator:

NMSG_MAGIC

"nMsG"

anonymous enum

Function return codes.

Enumerator:

NMSG_SUCCESS	Success.
NMSG_NOMEMORY	Insufficient memory available.
NMSG_UNKNHOST	Unknown host name.
NMSG_NOSEMCRE	Cannot create semaphore.
NMSG_NOTASKCR	Cannot create task.
NMSG_NOTCONN	Not connected to server.
NMSG_INVSEMA	Invalid semaphore.
NMSG_DISCONN	Server connection was broken.
NMSG_TIMEDOUT	Timed out during connection.
NMSG_INVFDESC	Invalid file descriptor.
NMSG_INVHNDL	Invalid handle supplied.
NMSG_OPNTPERM	Operation not permitted.
NMSG_FILENFND	File not found.
NMSG_IOERROR	I/O error.
NMSG_NOACCESS	Access not permitted.
NMSG_NOSCHDEV	No such device.
NMSG_NOTADIR	Not a directory.
NMSG_NOTAFILE	Not a file.
NMSG_XSFILDVC	Too many files.
NMSG_XSFILOPN	Too many open files.
NMSG_NAMELONG	Name too long.
NMSG_RDONLYFS	Read-only file system.
NMSG_NETUNRCH	Network unreachable.
NMSG_NETRESET	Network has been reset.
NMSG_CONNABRT	Connection aborted.
NMSG_CONNRSET	Connection reset.
NMSG_NOBUFSPC	No buffer space available.
NMSG_SOCKCONN	Socket already connected.
NMSG_SNOTCONN	Socket not connected.
NMSG_SHUTDOWN	Socket shut down.
NMSG_CONNTMO	Connection timed out.
NMSG_CONNREF	Connection refused.
NMSG_NETDOWN	Network down.
NMSG_TOODEEP	Symbolic link level too deep.
NMSG_HSTUNRCH	Host unreachable.
NMSG_HOSTDOWN	Host down.
NMSG_UNSUPPRO	Unsupported protocol.
NMSG_UNSUPPRF	Unsupported protocol family.
NMSG_PROTOTYP	Wrong protocol type.
NMSG_UNSUPADF	Unsupported address family.
NMSG_NOSTREAM	No stream resources.
NMSG_ADDRUSED	Address in use.
NMSG_ADDRUNAV	Address unavailable.
NMSG_ALREADY	Operation already in progress.
NMSG_BADFNMBR	Invalid file number.
NMSG_INPROGRS	Operation in progress.
NMSG_OPRNINTR	Operation interrupted by signal.
NMSG_INVDARG	Invalid argument.
NMSG_NOTASOCK	Not a socket.
NMSG_OPNTSUPP	Operation not supported.
NMSG_BADADDRS	Invalid parameter address.
NMSG_PROTOERR	Protocol error.
NMSG_TRYAGAIN	Retry operation.
NMSG_MSGLONG	Message too long.
NMSG_BRKNPIPE	Broken pipe.
NMSG_UNKNERR	Unknown system error.

Function Documentation

int nmsgCheck ( void * hndl )

Check a network connection handle.

This routine checks whether a network handle is valid or not.

Parameters:

hndl

The handle for the connection.

Return values:

	1	The handle is valid.
	0	The handle is invalid.

References NMSG_MAGIC.

int nmsgClose	(	void *	hndl,
		int	force
	)

Terminate a message client or server.

This routine closes a network connection or stops a network server.

Parameters:

	hndl	The handle of the connection or server.
	force	For a client connection, if TRUE, the connection is closed even if another task is in the process of sending a message. If FALSE, the closing waits until any activity has ceased. Not used for a server.

Return values:

	NMSG_SUCCESS	Success.
	NMSG_INVHNDL	Invalid network handle.

References NMSG_INVHNDL, NMSG_MAGIC, and NMSG_SUCCESS.

int nmsgConnect	(	void **	hndl,
		const char *	node,
		int	port
	)

Connect to a message server.

This routine establishes a network connection to a message server.

Parameters:

	hndl	The address of a pointer to receive the identifying handle for the network connection.
	node	The address of the name of the node containing the message server.
	port	The port number on which to establish the connection.

Return values:

	NMSG_SUCCESS	The connection was established successfully.
	NMSG_NOMEMORY	Insuffucuent memory available.
	NMSG_UNKNHOST	Host is unknown.
	NMSG_NOSEMCRE	Unable to create sync. semaphore (VxWorks)
	NMSG_xxx	Various connection errors.

References NMSG_MAGIC, NMSG_NOMEMORY, NMSG_NOSEMCRE, NMSG_SUCCESS, and NMSG_UNKNHOST.

int nmsgConnectAsy	(	void **	hndl,
		const char *	node,
		int	port,
		int	prio,
		nmsgConnCB_t	connRtn,
		nmsgDiscCB_t	discRtn,
		void *	uParm
	)

Connect asynchronously (robustly) to a message server.

This routine establishes a robust network connection to a message server. The connection is done asynchronously, and the attempt is retried periodically if the initial attempt fails, or if the connection is broken.

Parameters:

	hndl	The address of a pointer to receive the identifying handle for the network connection.
	node	The address of the name of the node containing the message server.
	port	The port number on which to establish the connection.
	prio	The priority of the connection task, where applicable. If 0, the default value (100) is used.
	connRtn	The address of a routine to be called when the connection has been made.
	discRtn	The address of a routine to be called when the connection is broken.
	uParm	A parameter to be passed to the connect and disconnect callback routines.

Return values:

	NMSG_SUCCESS	The connection was established successfully.
	NMSG_NOMEMORY	Insuffucuent memory available.
	NMSG_UNKNHOST	Host is unknown.
	NMSG_NOSEMCRE	Unable to create sync. semaphore (VxWorks)
	NMSG_NOTASKCR	Unable to spawn connection task.

References NMSG_MAGIC, NMSG_NOMEMORY, NMSG_NOSEMCRE, NMSG_SUCCESS, and NMSG_UNKNHOST.

const char* nmsgErrorMsg ( int status )

Obtain the text of an error message.

This routine returns a pointer to the message corresponding to a given NMSG status code.

Parameters:

status

The NMSG status code.

Returns:: The address of the corresponding message text.

References NMSG_ADDRUNAV, NMSG_ADDRUSED, NMSG_ALREADY, NMSG_BADADDRS, NMSG_BADFNMBR, NMSG_BRKNPIPE, NMSG_CONNABRT, NMSG_CONNREF, NMSG_CONNRSET, NMSG_CONNTMO, NMSG_DISCONN, NMSG_FILENFND, NMSG_HOSTDOWN, NMSG_HSTUNRCH, NMSG_INPROGRS, NMSG_INVDARG, NMSG_INVHNDL, NMSG_INVSEMA, NMSG_IOERROR, NMSG_MSGLONG, NMSG_NAMELONG, NMSG_NETDOWN, NMSG_NETRESET, NMSG_NETUNRCH, NMSG_NOACCESS, NMSG_NOBUFSPC, NMSG_NOMEMORY, NMSG_NOSCHDEV, NMSG_NOSEMCRE, NMSG_NOSTREAM, NMSG_NOTADIR, NMSG_NOTAFILE, NMSG_NOTASKCR, NMSG_NOTASOCK, NMSG_NOTCONN, NMSG_OPNTPERM, NMSG_OPNTSUPP, NMSG_OPRNINTR, NMSG_PROTOERR, NMSG_PROTOTYP, NMSG_RDONLYFS, NMSG_SHUTDOWN, NMSG_SNOTCONN, NMSG_SOCKCONN, NMSG_SUCCESS, NMSG_TIMEDOUT, NMSG_TOODEEP, NMSG_TRYAGAIN, NMSG_UNKNERR, NMSG_UNKNHOST, NMSG_UNSUPADF, NMSG_UNSUPPRF, NMSG_UNSUPPRO, NMSG_XSFILDVC, and NMSG_XSFILOPN.

Referenced by nmsgErrorReport().

void nmsgErrorReport	(	int	status,
		const char *	func
	)

Display an error message.

This routine outputs to stderr the message corresponding to a given NMSG status code.

Parameters:

	status	The NMSG status code.
	func	The function name to be displayed at the start of the message.

References nmsgErrorMsg().

int nmsgListen	(	void **	hndl,
		int	port,
		int	maxConn,
		int	maxData,
		int	prio,
		nmsgConnCB_t	connRtn,
		nmsgDiscCB_t	discRtn,
		nmsgRcveCB_t	rcveRtn,
		void *	uParm
	)

Establish a message server.

This routine establishes a network message server (listener).

Parameters:

	hndl	The address of a pointer to receive the identifying handle for the network listener.
	port	The port number on which to establish the server.
	maxConn	The maximum number of concurrent connections that the server will allow.
	maxData	The maximum number of data bytes that can be transferred in a single message.
	prio	The priority of the listener (server) and receiver tasks, where applicable. If 0, the default value (100) is used.
	connRtn	The address of a routine to be called when a new connection has been made. The connection will be rejected if this routine returns ERROR status.
	discRtn	The address of a routine to be called when a connection is broken.
	rcveRtn	The address of a routine to be called whenever a message is received.
	uParm	A parameter to be passed to the connect, disconnect and receive callback routines.

Return values:

	NMSG_SUCCESS	The connection was established successfully.
	NMSG_NOMEMORY	Insuffucuent memory available.
	NMSG_NOTASKCR	Unable to spawn listener task.
	NMSG_xxx	Various system errors.

References NMSG_MAGIC, NMSG_NOMEMORY, and NMSG_SUCCESS.

int nmsgRemoteIP	(	void *	hndl,
		int *	ip
	)

Get the IP address of the remote end.

This routine returns the IP address of the remote end of a connection. It can be used on either end of a connection.

Parameters:

	hndl	The handle for the connection.
	ip	The addressof an integer to receive the IP address.

Return values:

	NMSG_SUCCESS	Success.
	NMSG_INVHNDL	Invalid network handle.

References NMSG_INVHNDL, NMSG_MAGIC, and NMSG_SUCCESS.

int nmsgSend	(	void *	hndl,
		nmsgBuff_t *	msg
	)

Send a message and return immediately.

This routine sends a message on a network connection and returns without waiting for a reply.

Parameters:

	hndl	The handle for the connection.
	msg	The address of message to be sent. It must be formatted using the nmsgBuff_t structure type.

Return values:

	NMSG_SUCCESS	Success.
	NMSG_INVHNDL	Invalid network handle.
	NMSG_NOTCONN	Not connected to server.
	NMSG_INVSEMA	Invalid semaphore.
	NMSG_DISCONN	Server connection was broken.

References nmsgHead_s::func, nmsgBuff_s::head, nmsgHead_s::leng, nmsgHead_s::magic, NMSG_INVHNDL, NMSG_INVSEMA, NMSG_MAGIC, NMSG_NOTCONN, NMSG_SUCCESS, nmsgHead_s::parm, and nmsgHead_s::stat.

int nmsgSendW	(	void *	hndl,
		nmsgBuff_t *	msg,
		nmsgBuff_t **	replyP,
		nmsgBuff_t *	reply,
		int	maxData
	)

Send a message and receive reply.

This routine sends a message on a network connection and waits for a reply.

Parameters:

	hndl	The handle for the connection.
	msg	The address of message to be sent. It must be formatted using the nmsgBuff_t structure type.
	replyP	The address of a pointer to receive the address of the reply. If a reply area is supplied and it is big enough, this will be the address of this area. Otherwise a sufficiently large reply area is allocated and its address returned here. In this latter case, the memory must be relinquished using free() after it is no longer needed.
	reply	The address of an area to receive the reply to the message, or NULL if no area is to be used.
	maxData	The maximum number of data bytes that can be put into the supplied reply area.

Return values:

	NMSG_SUCCESS	Success.
	NMSG_INVHNDL	Invalid network handle.
	NMSG_NOTCONN	Not connected to server.
	NMSG_INVSEMA	Invalid semaphore.
	NMSG_DISCONN	Server connection was broken.

References nmsgHead_s::func, nmsgBuff_s::head, nmsgHead_s::leng, nmsgHead_s::magic, NMSG_DISCONN, NMSG_INVHNDL, NMSG_INVSEMA, NMSG_MAGIC, NMSG_NOTCONN, NMSG_SUCCESS, nmsgHead_s::parm, and nmsgHead_s::stat.

int nmsgStats	(	void *	hndl,
		nmsgStats_t *	stats
	)

Get connection statistics.

This routine returns a block of connection statistics containing the number of connects, disconnects, messages sent/received, bytes sent and bytes received.

Parameters:

	hndl	The handle for the connection.
	stats	The address of an area to receive the statistics block.

Return values:

	NMSG_SUCCESS	Success.
	NMSG_INVHNDL	Invalid network handle.

References nmsgStats_s::nByteR, nmsgStats_s::nByteS, nmsgStats_s::nConn, nmsgStats_s::nDisc, nmsgStats_s::nMsg, NMSG_INVHNDL, NMSG_MAGIC, and NMSG_SUCCESS.

int nmsgWait	(	void *	hndl,
		nmsgBuff_t **	replyP,
		nmsgBuff_t *	reply,
		int	maxData
	)

Wait for a reply to a sent message.

This routine waits for a reply to a previously sent message.

Parameters:

	hndl	The handle for the connection.
	replyP	The address of a pointer to receive the address of the reply. If a reply area is supplied and it is big enough, this will be the address of this area. Otherwise a sufficiently large reply area is allocated and its address returned here. In this latter case, the memory must be relinquished using free() after it is no longer needed.
	reply	The address of an area to receive the reply to the message, or NULL if no area is to be used.
	maxData	The maximum number of data bytes that can be put into the supplied reply area.

Return values:

	NMSG_SUCCESS	Success.
	NMSG_INVHNDL	Invalid network handle.
	NMSG_NOTCONN	Not connected to server.
	NMSG_INVSEMA	Invalid semaphore.
	NMSG_DISCONN	Server connection was broken.

References NMSG_DISCONN, NMSG_INVHNDL, NMSG_INVSEMA, NMSG_MAGIC, NMSG_NOTCONN, and NMSG_SUCCESS.


Classes
struct	nmsgHead_s
	Network message header. More...
struct	nmsgBuff_s
	Prototype message buffer. More...
struct	nmsgStats_s
	Network statistics block. More...
Typedefs
typedef struct nmsgHead_s	nmsgHead_t
	Network message header.
typedef struct nmsgBuff_s	nmsgBuff_t
	Prototype message buffer.
typedef struct nmsgStats_s	nmsgStats_t
	Network statistics block.
typedef int	nmsgConnCB_t (void hndl, void *uParm)
	Connect callback routine.
typedef int	nmsgDiscCB_t (void hndl, void *uParm)
	Disconnect callback routine.
typedef int	nmsgRcveCB_t (void hndl, void uParm, nmsgBuff_t msg, char **dataP)
	Receive message callback routine.
Enumerations
enum	{ NMSG_MAGIC = 0x6e4d7347 }
	Magic word value definition. More...
enum	{ NMSG_SUCCESS = 0, NMSG_NOMEMORY = 1, NMSG_UNKNHOST = 2, NMSG_NOSEMCRE = 3, NMSG_NOTASKCR = 4, NMSG_NOTCONN = 5, NMSG_INVSEMA = 6, NMSG_DISCONN = 7, NMSG_TIMEDOUT = 8, NMSG_INVFDESC = 9, NMSG_INVHNDL = 10, NMSG_OPNTPERM = 11, NMSG_FILENFND = 12, NMSG_IOERROR = 13, NMSG_NOACCESS = 14, NMSG_NOSCHDEV = 15, NMSG_NOTADIR = 16, NMSG_NOTAFILE = 17, NMSG_XSFILDVC = 18, NMSG_XSFILOPN = 19, NMSG_NAMELONG = 20, NMSG_RDONLYFS = 21, NMSG_NETUNRCH = 22, NMSG_NETRESET = 23, NMSG_CONNABRT = 24, NMSG_CONNRSET = 25, NMSG_NOBUFSPC = 26, NMSG_SOCKCONN = 27, NMSG_SNOTCONN = 28, NMSG_SHUTDOWN = 29, NMSG_CONNTMO = 30, NMSG_CONNREF = 31, NMSG_NETDOWN = 32, NMSG_TOODEEP = 33, NMSG_HSTUNRCH = 34, NMSG_HOSTDOWN = 35, NMSG_UNSUPPRO = 36, NMSG_UNSUPPRF = 37, NMSG_PROTOTYP = 38, NMSG_UNSUPADF = 39, NMSG_NOSTREAM = 40, NMSG_ADDRUSED = 41, NMSG_ADDRUNAV = 42, NMSG_ALREADY = 43, NMSG_BADFNMBR = 44, NMSG_INPROGRS = 45, NMSG_OPRNINTR = 46, NMSG_INVDARG = 47, NMSG_NOTASOCK = 48, NMSG_OPNTSUPP = 49, NMSG_BADADDRS = 50, NMSG_PROTOERR = 51, NMSG_TRYAGAIN = 52, NMSG_MSGLONG = 53, NMSG_BRKNPIPE = 54, NMSG_UNKNERR = 55 }
	Function return codes. More...
Functions
int	nmsgCheck (void *hndl)
	Check a network connection handle.
int	nmsgClose (void *hndl, int force)
	Terminate a message client or server.
int	nmsgConnect (void *hndl, const char node, int port)
	Connect to a message server.
int	nmsgConnectAsy (void *hndl, const char node, int port, int prio, nmsgConnCB_t connRtn, nmsgDiscCB_t discRtn, void *uParm)
	Connect asynchronously (robustly) to a message server.
const char *	nmsgErrorMsg (int status)
	Obtain the text of an error message.
void	nmsgErrorReport (int status, const char *func)
	Display an error message.
int	nmsgListen (void *hndl, int port, int maxConn, int maxData, int prio, nmsgConnCB_t connRtn, nmsgDiscCB_t discRtn, nmsgRcveCB_t rcveRtn, void uParm)
	Establish a message server.
int	nmsgRemoteIP (void hndl, int ip)
	Get the IP address of the remote end.
int	nmsgSend (void hndl, nmsgBuff_t msg)
	Send a message and return immediately.
int	nmsgSendW (void hndl, nmsgBuff_t msg, nmsgBuff_t *replyP, nmsgBuff_t reply, int maxData)
	Send a message and receive reply.
int	nmsgStats (void hndl, nmsgStats_t stats)
	Get connection statistics.
int	nmsgWait (void hndl, nmsgBuff_t replyP, nmsgBuff_t reply, int maxData)
	Wait for a reply to a sent message.