TSYNC(3N-SVR4)     RISC/os Reference Manual      TSYNC(3N-SVR4)



NAME
     t_sync - synchronize transport library

SYNOPSIS
     #include <tiuser.h>

     int tsync (int fd);

DESCRIPTION
     For the transport endpoint specified by fd, tsync synchron-
     izes 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(2), dup(2), or as a result of a fork(2) and exec(2)] 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 tsync 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.  tsync returns the current state of
     the provider to the user, thereby enabling the user to ver-
     ify the state before taking further action.  This coordina-
     tion is only valid among cooperating processes; it is possi-
     ble that a process or an incoming event could change the
     provider's state after a tsync is issued.

     If the provider is undergoing a state transition when tsync
     is called, the function will fail.

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

     [TBADF]            The specified file descriptor does not
                        refer to a transport endpoint.

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

     [TSYSERR]          A system error has occurred during execu-
                        tion of this function.

SEE ALSO
     dup(2), exec(2), fork(2), open(2).



                        Printed 11/19/92                   Page 1

TSYNC(3N-SVR4)     RISC/os Reference Manual      TSYNC(3N-SVR4)



DIAGNOSTICS
     tsync returns the state of the transport provider on suc-
     cessful completion and -1 on failure and t_errno is set to
     indicate the error.  The state returned may be 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)


































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