GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  ZCTX (3)

.ds Aq ’

NAME

zctx - working with 0MQ contexts (deprecated)

CONTENTS

SYNOPSIS

//  Create new context, returns context object, replaces zmq_init
CZMQ_EXPORT zctx_t *
    zctx_new (void);

// Destroy context and all sockets in it, replaces zmq_term CZMQ_EXPORT void zctx_destroy (zctx_t **self_p);

// Create new shadow context, returns context object CZMQ_EXPORT zctx_t * zctx_shadow (zctx_t *self); // Raise default I/O threads from 1, for crazy heavy applications // The rule of thumb is one I/O thread per gigabyte of traffic in // or out. Call this method before creating any sockets on the context, // or calling zctx_shadow, or the setting will have no effect. CZMQ_EXPORT void zctx_set_iothreads (zctx_t *self, int iothreads);

// Set msecs to flush sockets when closing them, see the ZMQ_LINGER // man page section for more details. By default, set to zero, so // any in-transit messages are discarded when you destroy a socket or // a context. CZMQ_EXPORT void zctx_set_linger (zctx_t *self, int linger);

// Set initial high-water mark for inter-thread pipe sockets. Note that // this setting is separate from the default for normal sockets. You // should change the default for pipe sockets *with care*. Too low values // will cause blocked threads, and an infinite setting can cause memory // exhaustion. The default, no matter the underlying ZeroMQ version, is // 1,000. CZMQ_EXPORT void zctx_set_pipehwm (zctx_t *self, int pipehwm);

// Set initial send HWM for all new normal sockets created in context. // You can set this per-socket after the socket is created. // The default, no matter the underlying ZeroMQ version, is 1,000. CZMQ_EXPORT void zctx_set_sndhwm (zctx_t *self, int sndhwm);

// Set initial receive HWM for all new normal sockets created in context. // You can set this per-socket after the socket is created. // The default, no matter the underlying ZeroMQ version, is 1,000. CZMQ_EXPORT void zctx_set_rcvhwm (zctx_t *self, int rcvhwm);

// Return low-level 0MQ context object, will be NULL before first socket // is created. Use with care. CZMQ_EXPORT void * zctx_underlying (zctx_t *self);

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

DESCRIPTION

The zctx class wraps 0MQ contexts. It manages open sockets in the context and automatically closes these before terminating the context. It provides a simple way to set the linger timeout on sockets, and configure contexts for number of I/O threads. Sets-up signal (interrupt) handling for the process.

The zctx class has these main features:

o

o Tracks all open sockets and automatically closes them before calling zmq_term(). This avoids an infinite wait on open sockets.

o

o Automatically configures sockets with a ZMQ_LINGER timeout you can define, and which defaults to zero. The default behavior of zctx is therefore like 0MQ/2.0, immediate termination with loss of any pending messages. You can set any linger timeout you like by calling the zctx_set_linger() method.

o

o Moves the iothreads configuration to a separate method, so that default usage is 1 I/O thread. Lets you configure this value.

o

o Sets up signal (SIGINT and SIGTERM) handling so that blocking calls such as zmq_recv() and zmq_poll() will return when the user presses Ctrl-C.

Note

this class is deprecated in favor of zsock, which does not expose contexts in the API at all. All zsock instances use the same global context.

EXAMPLE

From zctx_test method.

//  Create and destroy a context without using it
zctx_t *ctx = zctx_new ();
assert (ctx);
zctx_destroy (&ctx);
assert (ctx == NULL);

// Create a context with many busy sockets, destroy it ctx = zctx_new (); assert (ctx); zctx_set_iothreads (ctx, 1); zctx_set_linger (ctx, 5); // 5 msecs void *s1 = zctx__socket_new (ctx, ZMQ_PAIR); assert (s1); void *s2 = zctx__socket_new (ctx, ZMQ_XREQ); assert (s2); void *s3 = zctx__socket_new (ctx, ZMQ_REQ); assert (s3); void *s4 = zctx__socket_new (ctx, ZMQ_REP); assert (s4); void *s5 = zctx__socket_new (ctx, ZMQ_PUB); assert (s5); void *s6 = zctx__socket_new (ctx, ZMQ_SUB); assert (s6); int rc = zsocket_connect (s1, "tcp://127.0.0.1:5555"); assert (rc == 0); rc = zsocket_connect (s2, "tcp://127.0.0.1:5555"); assert (rc == 0); rc = zsocket_connect (s3, "tcp://127.0.0.1:5555"); assert (rc == 0); rc = zsocket_connect (s4, "tcp://127.0.0.1:5555"); assert (rc == 0); rc = zsocket_connect (s5, "tcp://127.0.0.1:5555"); assert (rc == 0); rc = zsocket_connect (s6, "tcp://127.0.0.1:5555"); assert (rc == 0); assert (zctx_underlying (ctx)); zctx_destroy (&ctx);

AUTHORS

The czmq manual was written by the authors in the AUTHORS file.

RESOURCES

Main web site: \m[blue] \m[]

Report bugs to the email <\m[blue]zeromq-dev@lists.zeromq.org\m[][1]>

COPYRIGHT

Copyright (c) 1991-2012 iMatix Corporation -- http://www.imatix.com Copyright other contributors as noted in the AUTHORS file. This file is part of CZMQ, the high-level C binding for 0MQ: http://czmq.zeromq.org This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. LICENSE included with the czmq distribution.

NOTES

1. zeromq-dev@lists.zeromq.org  mailto:zeromq-dev@lists.zeromq.org
Search for    or go to Top of page |  Section 3 |  Main Index


CZMQ 3&.0&.1 ZCTX (3) 06/01/2015

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.