NAME

t_sync() − synchronize transport library

SYNOPSIS

#include <xti.h> (for X/OPEN Transport Interface - XTI)

or

#include <tiuser.h> (for Transport Layer Interface - TLI)

int t_sync (fd)
int fd;

DESCRIPTION

For the transport endpoint specified by fd, the t_sync() function 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 via open(), dup() or as a result of a fork() and exec()) to an initialized endpoint, assuming that the file descriptor referenced a transport endpoint, by updating and allocating the necessary library data structures.  This function also allows two cooperating processes to synchronize their interaction with a transport provider. 

For example, if a process forks 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.  The function 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

 All - apart from T_UNINIT

RETURN VALUE

t_sync returns the state of the transport connection endpoint on successful completion and -1 on failure, and t_errno is set to indicate the error.  The state returned is 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 an erroneous number may have been passed to the call. 

­[TSTATECHNG] The transport endpoint is undergoing a state change. 

­[TSYSERR] A system error has occurred during execution of this function. 

­[TPROTO] (XTI only) 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). 

SEE ALSO

t_open(3), t_getstate(3), dup(2), exec(2), fork(2), open(2). 

STANDARDS CONFORMANCE

t_sync(): SVID2, XPG3, XPG4

Hewlett-Packard Company  —  HP-UX Release 10.20:  July 1996