t_rcvconnect.3xti

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3XTI 代码 · 共 143 行

.TH t_rcvconnect 3xti
.SH Name
t_rcvconnect \- receive the confirmation from a connect request
.SH Syntax
.B #include <xti.h>
.br
.sp 1
.B int t_rcvconnect(\fIfd, call\fB)
.br
.B int \fIfd\fB;
.br
.B struct t_call \fI*call\fB;
.SH Arguments
.IP \fIfd\fR 10
Identifies the local transport endpoint where communications is
established.
.IP \fIcall\fR 10
Contains information associated with the newly established connection.
\fICall\fR points to a t_\fIcall\fR structure that contains the
following members:
.EX
struct netbuf \fIaddr\fP;
struct netbuf \fIopt\fP;
struct netbuf \fIudata\fP;
int \fIsequence\fR;
.EE
.IP 
The members of the \fIt_call\fR structure have the following meanings:
.RS 10
.IP \fIaddr\fR 12
Returns the protocol address associated with the responding transport endpoint. 
.IP \fIopt\fR 12
Presents any protocol-specific information associated with the transport endpoint. 
.IP \fIudata\fR 12
Points to any optional user data that may be returned by the destination transport 
user during connection establishment.
.IP \fIsequence\fR 12
Has no meaning for this function.
.RE
.SH Description
This function enables a calling transport user to determine the status
of a previously sent connect request. Is used in conjunction with
.PN t_connect() 
to establish a connection in asynchronous mode. The connection is established on 
successful completion of this function.
.NXR "t_rcvconnect system call"
.NXR "connect request" "determining status"
.PP
The \fImaxlen\fR field of each argument must be set before issuing this
function to indicate the maximum size of the buffer for each. However,
\fIcall\fR can be NULL, in which case no information is given to the user
on return from 
.PN t_rcvconnect(). 
By default,
.PN t_rcvconnect() 
executes in synchronous mode and waits for the
connection to be established before returning. On return, the
\fIaddr\fR, \fIopt\fR, and \fIudata\fR fields reflect values associated
with the connection.
.PP
.TS
tab(@);
lfHB lfHB lfHB
lfR  lfR  lfR .
_
.sp 6p
Parameters@Before Call@After Call
.sp 6p
_
.sp 6p
fd@x@/
call->addr.maxlen@x@/
call->addr.len@/@x
call->addr.buf@x@(x)
call->opt.maxlen@x@/
call->opt.len@/@x
call->opt.buf@x@(x)
call->udata.maxlen@x@/
call->udata.len@/@x
call->udata.buf@x@(?)
call->sequence@/@/
.sp 6p
_
.TE
.PP
.sp 12p
If O_NONBLOCK is set by means of 
.PN t_open() 
or
.PN fcntl()\fR,\fR 
.PN t_rcvconnect()
executes in asynchronous mode and reduces to a poll for existing connect confirmations. If none 
is available, 
.PN t_rcvconnect() 
fails and returns immediately without waiting for the connection to be established. The
.PN t_rcvconnect()
function must be reissued at a later time to
complete the connection establishment phase and retrieve the information
returned to \fIcall\fR. 
.SH Return Values
Upon successful completion, a value of 0 is returned. On failure, a
value of \-1 is returned, and \fBt_errno\fR is set to indicate the
error.
.SH Diagnostics
On failure, 
.PN t_errno() 
is set to one of the following:
.TP 20
[TBADF]
The specified file descriptor does not refer to a transport endpoint.
.TP 20 
[TBUFOVFLW]
The number of bytes allocated for an incoming argument is not sufficient
to store the value of that argument. The connect information to be
returned in \fIcall\fR is discarded. The provider's state, as seen
by the user, is changed to DATAXFER.
.TP 20
[TNODATA]
O_NONBLOCK was set, but a connect confirmation has not yet
arrived.
.TP 20
[TLOOK]
An asynchronous event has occurred on the transport connection and
requires immediate attention.
.TP 20
[TNOTSUPPORT]
This function is not supported by the underlying transport provider. 
.TP 20
[TOUTSTATE]
The function was issued in the wrong sequence on the transport endpoint
referenced by \fIfd\fR.
.TP 20
[TSYSERR]
A system error has occurred during execution of this function.
.SH See Also
t_accept(3xti),
t_alloc(3xti),
t_bind(3xti),
t_connect(3xti), 
t_listen(3xti), 
t_open(3xti),
t_optmgmt(3xti)