t_sync(3N)

NAME

t_sync − synchronize transport library

SYNOPSIS

cc [ flag ... ] file ... −lnsl [ library ... ]

#include <xti.h>

int t_sync(int fd);

DESCRIPTION

This routine is part of the XTI interfaces which evolved from the TLI interfaces. XTI represents the future evolution of these interfaces. However, TLI interfaces are supported for compatibility. When using a TLI routine that has the same name as an XTI routine, a different header file, tiuser.h , must be used. Refer to the section, TLI COMPATIBILITY , for a description of differences between the two interfaces.

For the transport endpoint specified by fd, t_sync() synchronizes the data structures managed by the transport library with information from the underlying transport provider. In doing so, it can convert an uninitialized file descriptor (obtained using open(2), dup(2), or as a result of a fork(2) and exec(2)) to an initialize transport endpoint, assuming that file descriptor referenced a transport provider. This function also allows two cooperating processes to synchronize their interaction with a transport provider.

For example, if a process issues a fork() for a new process and issues an exec(), the new process must issue a t_sync() to build the private library data structure associated with a transport endpoint and to synchronize the data structure with the relevant provider information.

It is important to remember that the transport provider treats all users of a transport endpoint as a single user. If multiple processes are using the same endpoint, they should coordinate their activities so as not to violate the state of the transport endpoint. t_sync() returns the current state of the transport endpoint to the user, thereby enabling the user to verify the state before taking further action. This coordination is only valid among cooperating processes; it is possible that a process or an incoming event could change the endpoint’s state after a t_sync() is issued.

If the transport endpoint is undergoing a state transition when t_sync() is called, the function will fail.

VALID STATES

Legitimate states (see t_getstate(3N)) for a call to this routine are every one except T_UNINIT .

RETURN VALUES

t_sync() returns:

State of The Transport Provider On success.

−1 On failure.

On failure, t_errno is set to indicate the error, and possibly errno is set.

The state returned may be one of the following:

T_UNBND unbound

T_IDLE idle

T_OUTCON outgoing connection pending

T_INCON incoming connection pending

T_DATAXFER data transfer

T_OUTREL outgoing orderly release (waiting for an orderly release indication)

T_INREL incoming orderly release (waiting for an orderly release request)

ERRORS

On failure, t_errno is set to one of the following:

TBADF The specified file descriptor does not refer to a transport endpoint. This error may be returned when the fd has been previously closed or when an erroneous number may have been passed to the call.

TPROTO This error indicates that a communication problem has been detected between XTI and the transport provider for which there is no other suitable XTI t_errno value.

TSTATECHNG The transport endpoint is undergoing a state change.

TSYSERR A system error has occurred during execution of this function, errno will be set to the specific error.

TLI COMPATIBILITY

The XTI and TLI interface definitions have common names but use different header files. This, and other semantic differences between the two interfaces are described in the subsections below.

Interface Header

The XTI interfaces use the header file, xti.h . TLI interfaces should not use this header. They should use the header:

#include <tiuser.h>

Error Description Values

The t_errno value that can be set by the XTI interface and cannot be set by the TLI interface is:

TPROTO

For more information refer to the Transport Interfaces Programming Guide.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
MT-Level	MT-Safe

Museum

Related Articles