t_sync() — Synchronize transport library
Standards
| Standards / Extensions | C or C++ | Dependencies |
|---|---|---|
| XPG4.2 | both |
Format
#define _XOPEN_SOURCE_EXTENDED 1
#include <xti.h>
int t_sync(int fd);General description
Synchronizes the data structures managed by the transport library with information from the underlying transport provider, for the transport endpoint specified by fd, In doing so, it can convert an uninitialized file descriptor (obtained using open(), dup(), or as a result of a fork() and exec() ) to an initialized transport 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 - except for T_UNINIT
Returned value
- T_DATAXFER
- Data transfer.
- T_IDLE
- Idle.
- T_INCON
- Incoming connection pending.
- T_OUTCON
- Outgoing connection pending.
- T_UNBND
- Unbound.
- Error Code
- Description
- 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.
- 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).
- TSTATECHNG
- The transport endpoint is undergoing a state change.
- TSYSERR
- A system error has occurred during execution of this function.