corosync/man/cpg_join.3.in

.\"/*
.\" * Copyright (c) 2006 Red Hat, Inc.
.\" *
.\" * All rights reserved.
.\" *
.\" * Author: Patrick Caulfield <pcaulfie@redhat.com>
.\" *
.\" * This software licensed under BSD license, the text of which follows:
.\" *
.\" * Redistribution and use in source and binary forms, with or without
.\" * modification, are permitted provided that the following conditions are met:
.\" *
.\" * - Redistributions of source code must retain the above copyright notice,
.\" *   this list of conditions and the following disclaimer.
.\" * - Redistributions in binary form must reproduce the above copyright notice,
.\" *   this list of conditions and the following disclaimer in the documentation
.\" *   and/or other materials provided with the distribution.
.\" * - Neither the name of the MontaVista Software, Inc. nor the names of its
.\" *   contributors may be used to endorse or promote products derived from this
.\" *   software without specific prior written permission.
.\" *
.\" * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
.\" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
.\" * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
.\" * THE POSSIBILITY OF SUCH DAMAGE.
.\" */
.TH CPG_JOIN 3 2004-08-31 "corosync Man Page" "Corosync Cluster Engine Programmer's Manual"
.SH NAME
cpg_join \- Joins one or more groups in the CPG library
.SH SYNOPSIS
.B #include <corosync/cpg.h>
.sp
.BI "int cpg_join(cpg_handle_t " handle ", struct cpg_name *" group ");
.SH DESCRIPTION
The
.B cpg_join
function is used to join one group.  When a group is joined, the
.B cpg_mcast_joined(3)
is called internally to multicast to the groups joined in the argument
.I handle.
The process will also get notifications of other processes joining
and leaving the group.
Messages that are sent to any of the groups joined to the parameter
.I handle
will be delivered by
.B cpg_dispatch(3).
.PP
This function may be only be called once for each handle. When a group has been joined
the process will start to receive callbacks relating to messages sent from members
of the group or notifications of processes joining or leaving the group.
.PP
Note that more than one process on each node can join a CPG group and
each will receive its own copy of any messages sent using
.I cpg_mcast_joined()
and its own confchg callback.
.PP

The argument
.I group
is used to specify the group to join.


The
.I groups
argument is of the type struct cpg_name which is defined by the structure:

.IP
.RS
.ne 18
.nf
.ta 4n 30n 33n
struct cpg_name {
        int length;
        char value[128];
};
.ta
.fi
.RE
.IP
.PP
.PP
.SH RETURN VALUE
This call returns the CS_OK value if successful, CS_ERR_INVALID_PARAM if the
handle is already joined to a group.
.PP
.SH ERRORS
Not all errors are documented.
.SH "SEE ALSO"
.BR cpg_overview (3),
.BR cpg_initialize (3),
.BR cpg_finalize (3),
.BR cpg_fd_get (3),
.BR cpg_dispatch (3),
.BR cpg_join (3),
.BR cpg_leave (3),
.BR cpg_mcast_joined (3),
.BR cpg_membership_get (3)
.BR cpg_zcb_alloc (3)
.BR cpg_zcb_free (3)
.BR cpg_zcb_mcast_joined (3)
.BR cpg_context_get (3)
.BR cpg_context_set (3)
.BR cpg_local_get (3)

.PP