zmonitor_v2(3)
==============

NAME
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zmonitor_v2 - socket event monitor (deprecated)

SYNOPSIS
--------
----
//  This code needs backporting to work with ZMQ v3.2
#if (ZMQ_VERSION_MAJOR == 4)

//  Create a new socket monitor
CZMQ_EXPORT zmonitor_t *
    zmonitor_new (zctx_t *ctx, void *socket, int events);

//  Destroy a socket monitor
CZMQ_EXPORT void
    zmonitor_destroy (zmonitor_t **self_p);

//  Receive a status message from the monitor; if no message arrives within
//  500 msec, or the call was interrupted, returns NULL.
CZMQ_EXPORT zmsg_t *
    zmonitor_recv (zmonitor_t *self);

//  Get the ZeroMQ socket, for polling 
CZMQ_EXPORT void *
    zmonitor_socket (zmonitor_t *self);

//  Enable verbose tracing of commands and activity
CZMQ_EXPORT void
    zmonitor_set_verbose (zmonitor_t *self, bool verbose);
#endif          //  ZeroMQ 4.0 or later

// Self test of this class
CZMQ_EXPORT void
    zmonitor_v2_test (bool verbose);
----

DESCRIPTION
-----------

The zmonitor class provides an API for obtaining socket events such as
connected, listen, disconnected, etc. Socket events are only available
for sockets connecting or bound to ipc:// and tcp:// endpoints.
This class wraps the ZMQ socket monitor API, see zmq_socket_monitor for
details. Currently this class requires libzmq v4.0 or later and is empty
on older versions of libzmq.

This class is deprecated in CZMQ v3; it works together with zctx, zsocket,
and other deprecated V2 classes. New applications should use the V3 zmonitor
interface, based on zactor, together with the zsock class for sockets.

EXAMPLE
-------
.From zmonitor_v2_test method
----
zctx_t *ctx = zctx_new ();
assert (ctx);
bool result;

void *sink = zsocket_new (ctx, ZMQ_PULL);
assert (sink);
zmonitor_t *sinkmon = zmonitor_new (ctx,
                                    sink, ZMQ_EVENT_LISTENING | ZMQ_EVENT_ACCEPTED);
assert (sinkmon);
zmonitor_set_verbose (sinkmon, verbose);

//  Check sink is now listening
int port_nbr = zsocket_bind (sink, "tcp://127.0.0.1:*");
assert (port_nbr != -1);
result = s_check_event (sinkmon, ZMQ_EVENT_LISTENING);
assert (result);

void *source = zsocket_new (ctx, ZMQ_PUSH);
assert (source);
zmonitor_t *sourcemon = zmonitor_new (ctx,
                                      source, ZMQ_EVENT_CONNECTED | ZMQ_EVENT_DISCONNECTED);
assert (sourcemon);
zmonitor_set_verbose (sourcemon, verbose);
zsocket_connect (source, "tcp://127.0.0.1:%d", port_nbr);

//  Check source connected to sink
result = s_check_event (sourcemon, ZMQ_EVENT_CONNECTED);
assert (result);

//  Check sink accepted connection
result = s_check_event (sinkmon, ZMQ_EVENT_ACCEPTED);
assert (result);

zmonitor_destroy (&sinkmon);
zmonitor_destroy (&sourcemon);
zctx_destroy (&ctx);
----