(TLI/XTI)

t_sync(NET)

t_sync -- synchronize transport library

Syntax

TLI syntax

cc . . . -lnsl

#include <sys/tiuser.h>

int t_sync (fd)
int fd;

XTI syntax

cc . . . -lxti

#include <xti.h>

int t_sync (fd)
int fd;

Description

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 a raw file descriptor (obtained via open(S), dup(S), or as a result of a fork(S) and exec(S)) to an initialized 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 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 provider. t_sync returns the current state of the provider 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 provider's state after a t_sync is issued.

If the provider is undergoing a state transition when t_sync is called, the function fails.

Return values

t_sync returns the state of the transport provider on successful completion and -1 on failure, and t_errno is set to indicate the error. The state returned may be one of the following:

T_DATAXFER: data transfer
T_IDLE: idle
T_INCON: incoming connection pending
T_INREL: incoming orderly release (waiting for an orderly release request).
T_OUTCON: outgoing connection pending
T_OUTREL: outgoing orderly release (waiting for an orderly release indication)
T_UNBND: unbound

Diagnostics

On failure, t_errno may be set to one of the following:

[TBADF]: The specified file descriptor is a valid open file descriptor but does not refer to a transport endpoint.
[TSTATECHNG]: The transport provider is undergoing a state change.
[TSYSERR]: A system error occurred during execution of this function. One possibility is an I/O error and is indicated by EIO being set in errno.

Standards conformance

t_sync is conformant with:

AT&T SVID Issue 3 ;
X/Open CAE Specification, Networking Services, Issue 4, 1994. ;
and Intel386 Binary Compatibility Specification, Edition 2 (iBCSe2) .