t_look - look at the current event on a transport endpoint
#include <xti.h> int t_look( int fd)
Parameters Before call After call fd x / This function returns the current event on the transport endpoint specified by fd. This function enables a transport provider to notify a transport user of an asynchronous event when the user is calling functions in synchronous mode. Certain events require immediate notification of the user and are indicated by a specific error, [TLOOK], on the current or next function to be executed. Details on events which cause functions to fail [TLOOK] may be found in
. This function also enables a transport user to poll a transport endpoint periodically for asynchronous events.
ALL - apart from T_UNINIT
On failure, t_errno is set to one of the following:
- [TBADF]
- The specified file descriptor does not refer to a transport endpoint.
- [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 error (t_errno).
- [TSYSERR]
- A system error has occurred during execution of this function.
Upon success, t_look() returns a value that indicates which of the allowable events has occurred, or returns zero if no event exists. One of the following events is returned:
- T_LISTEN
- Connection indication received.
- T_CONNECT
- Connect confirmation received.
- T_DATA
- Normal data received.
- T_EXDATA
- Expedited data received.
- T_DISCONNECT
- Disconnection received.
- T_UDERR
- Datagram error indication.
- T_ORDREL
- Orderly release indication.
- T_GODATA
- Flow control restrictions on normal data flow that led to a [TFLOW] error have been lifted. Normal data may be sent again.
- T_GOEXDATA
- Flow control restrictions on expedited data flow that led to a [TFLOW] error have been lifted. Expedited data may be sent again.
On failure, -1 is returned and t_errno is set to indicate the error.
t_open(), t_snd(), t_sndudata().
Additional functionality is provided through the Event Management (EM) interface.