'\" te
.\"  Copyright 1989 AT&T
.\" Copyright (C) 1999, Sun Microsystems, Inc. All Rights Reserved
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.TH RPC_CONTROL 3NSL "Feb 24, 1999"
.SH NAME
rpc_control \- library routine for manipulating global RPC attributes for
client and server applications
.SH SYNOPSIS
.LP
.nf
\fBbool_t\fR \fBrpc_control\fR(\fBint\fR \fIop\fR, \fBvoid *\fR\fIinfo\fR);
.fi

.SH DESCRIPTION
.sp
.LP
This \fBRPC\fR library routine allows applications to set and modify global
\fBRPC\fR attributes that apply to clients as well as servers.  At present, it
supports only server side operations. This function allows applications to set
and modify global attributes that apply to client as well as server functions.
\fIop\fR indicates the type of operation, and \fIinfo\fR is a pointer to the
operation specific information. The supported values of \fIop\fR and their
argument types, and what they do are:
.sp
.in +2
.nf
RPC_SVC_MTMODE_SET       int *	set multithread mode
RPC_SVC_MTMODE_GET       int *	get multithread mode
RPC_SVC_THRMAX_SET       int *	set maximum number of threads
RPC_SVC_THRMAX_GET       int *	get maximum number of threads
RPC_SVC_THRTOTAL_GET     int *	get number of active threads
RPC_SVC_THRCREATES_GET   int *	get number of threads created
RPC_SVC_THRERRORS_GET    int *	get number of thread create errors
RPC_SVC_USE_POLLFD       int *	set number of file descriptors to unlimited
RPC_SVC_CONNMAXREC_SET   int *  set non-blocking max rec size
RPC_SVC_CONNMAXREC_GET   int *  get non-blocking max rec size
.fi
.in -2

.sp
.LP
There are three multithread (MT) modes.  These are:
.sp
.in +2
.nf
RPC_SVC_MT_NONE	Single threaded mode	(default)
RPC_SVC_MT_AUTO	Automatic MT mode
RPC_SVC_MT_USER	User MT mode
.fi
.in -2

.sp
.LP
Unless the application sets the Automatic or User MT modes, it will stay in the
default (single threaded) mode.  See the \fINetwork Interfaces Programmer's
Guide\fR for the meanings of these modes and programming examples.  Once a mode
is set, it cannot be changed.
.sp
.LP
By default, the maximum number of threads that the server will create at any
time is 16.  This allows the service developer to put a bound on thread
resources consumed by a server.  If a server needs to process more than 16
client requests concurrently, the maximum number of threads must be set to the
desired number.  This parameter may be set at any time by the server.
.sp
.LP
Set and get operations will succeed even in modes where the operations don't
apply.  For example, you can set the maximum number of threads in any mode,
even though it makes sense only for the Automatic MT mode. All of the get
operations except \fBRPC_SVC_MTMODE_GET\fR apply only to the Automatic MT mode,
so values returned in other modes may be undefined.
.sp
.LP
By default, \fBRPC\fR servers are limited to a maximum of 1024 file descriptors
or connections due to limitations in the historical interfaces
\fBsvc_fdset\fR(3NSL) and \fBsvc_getreqset\fR(3NSL). Applications written to
use the preferred interfaces of \fBsvc_pollfd\fR(3NSL) and
\fBsvc_getreq_poll\fR(3NSL) can use an unlimited number of file descriptors.
Setting \fBinfo\fR to point to a non-zero integer and  \fIop\fR to
\fBRPC_SVC_USE_POLLFD\fR removes the limitation.
.sp
.LP
Connection oriented \fBRPC\fR transports read \fBRPC\fR requests in blocking
mode by default. Thus, they may be adversely affected by network delays and
broken clients. \fBRPC_SVC_CONNMAXREC_SET\fR enables non-blocking mode and
establishes the maximum record size (in bytes) for \fBRPC\fR requests;
\fBRPC\fR responses are not affected. Buffer space is allocated as needed up to
the specified maximum, starting at the maximum or \fBRPC_MAXDATASIZE\fR,
whichever is smaller.
.sp
.LP
The value established by \fBRPC_SVC_CONNMAXREC_SET\fR is used when a connection
is created, and it remains in effect for that connection until it is closed. To
change the value for existing connections on a per-connection basis, see
\fBsvc_control\fR(3NSL).
.sp
.LP
\fBRPC_SVC_CONNMAXREC_GET\fR retrieves the current maximum record size. A zero
value means that no maximum is in effect, and that the connections are in
blocking mode.
.sp
.LP
\fIinfo\fR is a pointer to an argument of type \fBint\fR. Non-connection RPC
transports ignore \fBRPC_SVC_CONNMAXREC_SET\fR and
\fBRPC_SVC_CONNMAXREC_GET\fR.
.SH RETURN VALUES
.sp
.LP
This routine returns \fBTRUE\fR if the operation was successful and
returns\fBFALSE\fR otherwise.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
MT-Level	MT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBrpcbind\fR(1M), \fBrpc\fR(3NSL), \fBrpc_svc_calls\fR(3NSL),
\fBattributes\fR(5)
.sp
.LP
\fINetwork Interfaces Programmer's Guide\fR