Data Structures
struct	EGsocket_t
	structure for socket More...
Files
file	eg_net.c
file	eg_net.ex.c
file	eg_net.h
Defines
#define	BOSS 1
#define	CLIENT 2
#define	EG_NET_ALLOW_NON_BLOCKING 0
	Set to one to enable non-blocking calls, zero to disable them. What happen in that case is that non-blocking calls behave as regular blocking calls.
#define	EG_NET_CONFIRM 0
	If set to one, check that the information send was properly received, this may slow down the code by a significant factor, and also may fix synchronization issues without enabling EG_NET_SYNCHRONIZE.
#define	EG_NET_DATA_QUEUE_SIZE 131072U
	minimum length of the data queue in any socket connection. By default it is set to 64Kb
#define	EG_NET_LISTEN_QUEUE_SIZE 16384U
	Minimum length of the incomming connection queue at the listening socket.
#define	EG_NET_MARKER '5'
#define	EG_NET_RECEIVE 1
#define	EG_NET_SEND 0
#define	EG_NET_SYNCHRONIZE 0
	If set to one, use synchronization among sender and receiver.
#define	EG_NET_TCPIP_OVERHEAD 128
	Overhead of a MAC/TCP/IP package over the data part of the packet, note that the MAC header is about 14 bytes long, that IP has an overhead of 20 bytes plus 4 bytes for options and padding. TCP other 20 bytes plus up to 44 bytes for options and padding, thus the overhead is between 58 and 102 bytes. Then to send x bytes across a TCP/IP connection, we actually send x bytes + [58-102] bytes. This overhead is the constant that we define bellow. For details on the structure of the MAC/IP/TCP headers, see the TCP/IP description. Note also that we shouldn't send packets of length above 572 bytes, thus the actual data length should be less than 470 bytes.
#define	EGnetClearSocket(__lskt)
	clear a socket structure and leave it ready to be freed
#define	EGnetInitSocket(skt) memset(skt,0,sizeof(EGsocket_t))
	Initialize a socket structure.
#define	EGnetSendInt(skt, n) EGnetSendUint(skt,(unsigned) n)
	send an int through a connected socket
#define	EGnetSendInt(skt, n) EGnetSendUint(skt,(unsigned) n)
#define	EGnetSendShort(skt, n) EGnetSendUshort(skt,(unsigned)n)
#define	EGnetSendShort(skt, n) EGnetSendUshort(skt,(unsigned)n)
	send a short through a connected socket
#define	EGnetSynchronize(skt, type, length)
	Assure that the data queue don't overflow by using syncronizations calls between both ends of the connections.
#define	KILL 3
Functions
int	EGnetConnect (EGsocket_t const skt, const char host_name, unsigned port)
	try to stablish a remote connection
int	EGnetDisconnect (EGsocket_t *const skt)
	close an established connection
int	EGnetListen (EGsocket_t *const skt, unsigned p)
	set a socket to wait for connections. Used as the server side of the connection
int	EGnetRecvChar (EGsocket_t const skt, char const c)
	recieve a char through a connected socket
int	EGnetRecvDouble (EGsocket_t const skt, double const d)
	recieve a double through a connected socket. The current implementation has some limits, it tries to represent the number where $0.5\leq\|x\|<1$ , unfortunatelly, $\|e\|\leq 128$ , and numbers that can't be represented in this form won't be transmitted in a right way.
int	EGnetRecvInt (EGsocket_t const skt, int n)
	recieve an int through a connected socket
int	EGnetRecvShort (EGsocket_t const skt, int n)
	recieve a short through a connected socket
int	EGnetRecvString (EGsocket_t const skt, char const str, size_t max_size)
	recieve a string through a connected socket, the string must have allocated memory and its maximum size be max_size (including the '\0' char)
int	EGnetRecvUint (EGsocket_t const skt, unsigned int n)
	recieve an unsigned int through a connected socket
int	EGnetRecvUshort (EGsocket_t const skt, unsigned n)
	recieve a unsigned short through a connected socket
int	EGnetSendChar (EGsocket_t *const skt, const int c)
	send a char through a connected socket
int	EGnetSendDouble (EGsocket_t *const skt, const double d)
	send a double through a connected socket. The current implementation has some limits, it tries to represent the number where $0.5\leq\|x\|<1$ , unfortunatelly, $\|e\|\leq 128$ , and numbers that can't be represented in this form won't be transmitted in a right way.
int	EGnetSendString (EGsocket_t const skt, const char const str)
	send a string through a connected socket, it will send up to the '\0' char at the end of the string (including it).
int	EGnetSendUint (EGsocket_t *const skt, unsigned int n)
	send an unsigned int through a connected socket
int	EGnetSendUshort (EGsocket_t *const skt, unsigned n)
	send a unsigned short through a connected socket
int	EGnetStartRead (EGsocket_t *const skt)
	accept an incomming connection from another program/host, if no connection is on the queue, the program will block until one is found.
int	EGnetStartReadNB (EGsocket_t *const skt)
	accept an incomming connection from another program/host. If no connection is on the queue (of incomming connections), the program will return EAGAIN, otherwise it return zero on success and non zero (1) in error.
int	EGnetStopRead (EGsocket_t *const skt)
	close an established connection with another program/host
int	main (int argc, char **argv)
static void	net_usage (char *program)
static int	parseargs (int argc, char **argv)
Variables
static char *	hname = 0
static int	mode = 0
static unsigned int	nchars = 0
static unsigned	port = 0

Detailed Description

This header contain the definitions to make basic client/server communications. The protocol used to comunicate is TCP/IP. and the type of communication is permanent (within each cycle connect/disconnect start_read/stop_read).

Version:: 0.9.1

History:

2005-08-30
- A different aproach is to always send back and forth the information (so that if debugging is enabled, we get confirmation that the data was sent right), the drawback is that the performance fall by a factor of two, but on the other hand, the previous fix had a degradation factor of 8 (in bytes per second)... so it seems that this approach is betteer and more stable, still waiting for further tests.
2005-08-29
- When sending lot's of information during a single connection, the internal send/receive data queue may overflow, to avoid this, we add a low level syncronization step every EG_NET_DATA_QUEUE_SIZE bits.
- Add EGnetClearSocket and EGnetInitSocket functions.
2005-06-14
- Take out the non-blocking versions (with a define) because it won't run on some machines, but according to the ISO definitions it should.... it's just the way it goes.
- Add flag to disable non-blocking calls.
2005-02-09
- Fix EGnetSendDouble, error comprises values < 0.5
2004-09-10
- Renan added some compatibility modifications to run this library on windows.
2004-01-14
- first implementation/

Define Documentation

#define BOSS 1

Examples:: eg_net.ex.c.

Definition at line 39 of file eg_net.ex.c.

Referenced by main().

#define CLIENT 2

Examples:: eg_net.ex.c.

Definition at line 40 of file eg_net.ex.c.

Referenced by main(), and parseargs().

#define EG_NET_ALLOW_NON_BLOCKING 0

Set to one to enable non-blocking calls, zero to disable them. What happen in that case is that non-blocking calls behave as regular blocking calls.

Definition at line 124 of file eg_net.h.

#define EG_NET_CONFIRM 0

If set to one, check that the information send was properly received, this may slow down the code by a significant factor, and also may fix synchronization issues without enabling EG_NET_SYNCHRONIZE.

Definition at line 73 of file eg_net.h.

#define EG_NET_DATA_QUEUE_SIZE 131072U

minimum length of the data queue in any socket connection. By default it is set to 64Kb

Definition at line 97 of file eg_net.h.

#define EG_NET_LISTEN_QUEUE_SIZE 16384U

Minimum length of the incomming connection queue at the listening socket.

Definition at line 102 of file eg_net.h.

#define EG_NET_MARKER '5'

Definition at line 333 of file eg_net.c.

#define EG_NET_RECEIVE 1

Definition at line 332 of file eg_net.c.

#define EG_NET_SEND 0

Definition at line 331 of file eg_net.c.

#define EG_NET_SYNCHRONIZE 0

If set to one, use synchronization among sender and receiver.

Definition at line 77 of file eg_net.h.

#define EG_NET_TCPIP_OVERHEAD 128

Overhead of a MAC/TCP/IP package over the data part of the packet, note that the MAC header is about 14 bytes long, that IP has an overhead of 20 bytes plus 4 bytes for options and padding. TCP other 20 bytes plus up to 44 bytes for options and padding, thus the overhead is between 58 and 102 bytes. Then to send x bytes across a TCP/IP connection, we actually send x bytes + [58-102] bytes. This overhead is the constant that we define bellow. For details on the structure of the MAC/IP/TCP headers, see the TCP/IP description. Note also that we shouldn't send packets of length above 572 bytes, thus the actual data length should be less than 470 bytes.

Definition at line 91 of file eg_net.h.

#define EGnetClearSocket ( __lskt )

Value:

({\
  EGsocket_t*const _EGskt = (EGsocket_t*)(__lskt);\
  if(_EGskt->s_fd) close(_EGskt->s_fd);\
  if(_EGskt->f_fd) close(_EGskt->f_fd);\
  memset(_EGskt,0,sizeof(EGsocket_t));\
  0;})

clear a socket structure and leave it ready to be freed

Definition at line 132 of file eg_net.h.

#define EGnetInitSocket ( skt ) memset(skt,0,sizeof(EGsocket_t))

Initialize a socket structure.

Examples:: eg_net.ex.c.

Definition at line 128 of file eg_net.h.

Referenced by main().

#define EGnetSendInt	(	skt,
		n
	)		EGnetSendUint(skt,(unsigned) n)

send an int through a connected socket

Definition at line 212 of file eg_net.h.

#define EGnetSendInt	(	skt,
		n
	)		EGnetSendUint(skt,(unsigned) n)

Examples:: eg_net.ex.c.

Definition at line 530 of file eg_net.c.

Referenced by main().

#define EGnetSendShort	(	skt,
		n
	)		EGnetSendUshort(skt,(unsigned)n)

Examples:: eg_net.ex.c.

Definition at line 466 of file eg_net.c.

Referenced by main().

#define EGnetSendShort	(	skt,
		n
	)		EGnetSendUshort(skt,(unsigned)n)

send a short through a connected socket

Definition at line 193 of file eg_net.h.

#define EGnetSynchronize	(	skt,
		type,
		length
	)

Assure that the data queue don't overflow by using syncronizations calls between both ends of the connections.

Parameters:

	skt	socket where we are working.
	type	either EG_NET_SEND or EG_NET RECEIVE.
	length	bytes being transfered.

Definition at line 381 of file eg_net.c.

#define KILL 3

Examples:: eg_net.ex.c.

Definition at line 41 of file eg_net.ex.c.

Referenced by main().

Function Documentation

int EGnetConnect	(	EGsocket_t *const	skt,
		const char *	host_name,
		unsigned	port
	)

try to stablish a remote connection

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetDisconnect ( EGsocket_t *const skt )

close an established connection

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetListen	(	EGsocket_t *const	skt,
		unsigned	p
	)

set a socket to wait for connections. Used as the server side of the connection

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetRecvChar	(	EGsocket_t *const	skt,
		char *const	c
	)

recieve a char through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetRecvDouble	(	EGsocket_t *const	skt,
		double *const	d
	)

recieve a double through a connected socket. The current implementation has some limits, it tries to represent the number $ d = 2^ex $ where $0.5\leq|x|<1$ , unfortunatelly, $|e|\leq 128$ , and numbers that can't be represented in this form won't be transmitted in a right way.

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetRecvInt	(	EGsocket_t *const	skt,
		int *	n
	)

recieve an int through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetRecvShort	(	EGsocket_t *const	skt,
		int *	n
	)

recieve a short through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetRecvString	(	EGsocket_t *const	skt,
		char *const const	exstr,
		size_t	max_size
	)

recieve a string through a connected socket, the string must have allocated memory and its maximum size be max_size (including the '\0' char)

int EGnetRecvUint	(	EGsocket_t *const	skt,
		unsigned int *	n
	)

recieve an unsigned int through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetRecvUshort	(	EGsocket_t *const	skt,
		unsigned *	n
	)

recieve a unsigned short through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetSendChar	(	EGsocket_t *const	skt,
		const int	c
	)

send a char through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetSendDouble	(	EGsocket_t *const	skt,
		const double	exd
	)

send a double through a connected socket. The current implementation has some limits, it tries to represent the number $ d = 2^ex $ where $0.5\leq|x|<1$ , unfortunatelly, $|e|\leq 128$ , and numbers that can't be represented in this form won't be transmitted in a right way.

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetSendString	(	EGsocket_t *const	skt,
		const char *const const	exstr
	)

send a string through a connected socket, it will send up to the '\0' char at the end of the string (including it).

int EGnetSendUint	(	EGsocket_t *const	skt,
		unsigned int	n
	)

send an unsigned int through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetSendUshort	(	EGsocket_t *const	skt,
		unsigned	n
	)

send a unsigned short through a connected socket

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetStartRead ( EGsocket_t *const skt )

accept an incomming connection from another program/host, if no connection is on the queue, the program will block until one is found.

Examples:: eg_net.ex.c.

Referenced by main().

int EGnetStartReadNB ( EGsocket_t *const skt )

accept an incomming connection from another program/host. If no connection is on the queue (of incomming connections), the program will return EAGAIN, otherwise it return zero on success and non zero (1) in error.

int EGnetStopRead ( EGsocket_t *const skt )

close an established connection with another program/host

Examples:: eg_net.ex.c.

Referenced by main().

int main	(	int	argc,
		char **	argv
	)

Definition at line 110 of file eg_net.ex.c.

References BOSS, CHECKRVAL, CLIENT, EGlib_info(), EGlib_version(), EGnetConnect(), EGnetDisconnect(), EGnetInitSocket, EGnetListen(), EGnetRecvChar(), EGnetRecvDouble(), EGnetRecvInt(), EGnetRecvShort(), EGnetRecvUint(), EGnetRecvUshort(), EGnetSendChar(), EGnetSendDouble(), EGnetSendInt, EGnetSendShort, EGnetSendUint(), EGnetSendUshort(), EGnetStartRead(), EGnetStopRead(), EGrand(), EGrandInit(), EGsetLimits(), EGsigSet, hname, KILL, MESSAGE, mode, nchars, parseargs(), port, and TEST.

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static void net_usage ( char * program ) [static]

Examples:: eg_net.ex.c.

Definition at line 27 of file eg_net.ex.c.

Referenced by parseargs().

static int parseargs	(	int	argc,
		char **	argv
	)			`[static]`

Examples:: eg_net.ex.c.

Definition at line 46 of file eg_net.ex.c.

References CLIENT, hname, MESSAGE, mode, nchars, net_usage(), and port.

Referenced by main().

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Variable Documentation

char* hname = 0 [static]

Examples:: eg_net.ex.c.

Definition at line 44 of file eg_net.ex.c.

Referenced by main(), and parseargs().

int mode = 0 [static]

Examples:: eg_net.ex.c, and eg_slk.ex.c.

Definition at line 45 of file eg_net.ex.c.

Referenced by main(), and parseargs().

unsigned int nchars = 0 [static]

Examples:: eg_net.ex.c.

Definition at line 42 of file eg_net.ex.c.

Referenced by main(), and parseargs().

unsigned port = 0 [static]

Examples:: eg_net.ex.c.

Definition at line 43 of file eg_net.ex.c.

Referenced by main(), and parseargs().

EGnet

Data Structures

Files

Defines

Functions

Variables

Detailed Description

Define Documentation

Function Documentation

Variable Documentation