t_sync(3xti)
Name
t_sync − synchronize transport library
Syntax
#include <xti.h>
int t_sync(fd)
int fd;
Arguments
fdIdentifies the local transport endpoint.
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, t_sync() can convert an uninitialized file descriptor to an initialized transport endpoint, by updating and allocating the necessary library data structures. The file descriptor, which is assumed to have referenced a transport endpoint, has to be obtained by means of an open(), dup(), or be the result of a fork and exec(). The 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 activates so as not to violate the state of the transport endpoint. The t_sync() function 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 valid only 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.
| Parameters | Before Call | After Call |
| fd | x | / |
Return Values
Upon successful completion, t_sync returns the state of the transport endpoint. On failure, a value of −1 is returned, and t_errno is set to indicate the error. The state returned is one of the following:
T_IDLEIdle
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)
Diagnostics
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.