HP-UX Reference (11i v2 04/09) - 3 Library Functions N-Z (vol 7)

t
t_sync(3) t_sync(3)
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 syn-
chronize 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.
Thread-Safeness
The
t_sync() function is safe to be called by multithreaded applications, and it is thread-safe for both
POSIX Threads and DCE User Threads. It has a cancellation point. It is neither async-cancel safe nor
async-signal safe. Finally, it is not fork-safe.
Valid States
All - apart from
T_UNINIT.
RETURN VALUE
t_sync returns the state of the transport connection endpoint on successful completion and −1on
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
HP-UX 11i Version 2: September 2004 − 1 − Hewlett-Packard Company Section 3−−1095