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ZACTOR(3) CZMQ Manual ZACTOR(3)

NAME

zactor - Class for simple actor framework

SYNOPSIS

//  This is a stable class, and may not change except for emergencies. It
//  is provided in stable builds.
//  This class has draft methods, which may change over time. They are not
//  in stable releases, by default. Use --enable-drafts to enable.
// Actors get a pipe and arguments from caller
typedef void (zactor_fn) (
    zsock_t *pipe, void *args);
//  Create a new actor passing arbitrary arguments reference.
CZMQ_EXPORT zactor_t *
    zactor_new (zactor_fn task, void *args);
//  Destroy an actor.
CZMQ_EXPORT void
    zactor_destroy (zactor_t **self_p);
//  Send a zmsg message to the actor, take ownership of the message
//  and destroy when it has been sent.
CZMQ_EXPORT int
    zactor_send (zactor_t *self, zmsg_t **msg_p);
//  Receive a zmsg message from the actor. Returns NULL if the actor
//  was interrupted before the message could be received, or if there
//  was a timeout on the actor.
//  Caller owns return value and must destroy it when done.
CZMQ_EXPORT zmsg_t *
    zactor_recv (zactor_t *self);
//  Probe the supplied object, and report if it looks like a zactor_t.
CZMQ_EXPORT bool
    zactor_is (void *self);
//  Probe the supplied reference. If it looks like a zactor_t instance,
//  return the underlying libzmq actor handle; else if it looks like
//  a libzmq actor handle, return the supplied value.
CZMQ_EXPORT void *
    zactor_resolve (void *self);
//  Return the actor's zsock handle. Use this when you absolutely need
//  to work with the zsock instance rather than the actor.
CZMQ_EXPORT zsock_t *
    zactor_sock (zactor_t *self);
//  Self test of this class.
CZMQ_EXPORT void
    zactor_test (bool verbose);
#ifdef CZMQ_BUILD_DRAFT_API
// Function to be called on zactor_destroy. Default behavior is to send zmsg_t with string "$TERM" in a first frame.
//
// An example - to send $KTHXBAI string
//
//     if (zstr_send (self, "$KTHXBAI") == 0)
//         zsock_wait (self);
typedef void (zactor_destructor_fn) (
    zactor_t *self);
//  *** Draft method, for development use, may change without warning ***
//  Change default destructor by custom function. Actor MUST be able to handle new message instead of default $TERM.
CZMQ_EXPORT void
    zactor_set_destructor (zactor_t *self, zactor_destructor_fn destructor);
#endif // CZMQ_BUILD_DRAFT_API
Please add '@interface' section in './../src/zactor.c'.

DESCRIPTION

The zactor class provides a simple actor framework. It replaces the CZMQ zthread class, which had a complex API that did not fit the CLASS standard. A CZMQ actor is implemented as a thread plus a PAIR-PAIR pipe. The constructor and destructor are always synchronized, so the caller can be sure all resources are created, and destroyed, when these calls complete. (This solves a major problem with zthread, that a caller could not be sure when a child thread had finished.)

A zactor_t instance acts like a zsock_t and you can pass it to any CZMQ method that would take a zsock_t argument, including methods in zframe, zmsg, zstr, and zpoller. (zloop somehow escaped and needs catching.)

An actor function MUST call zsock_signal (pipe) when initialized and MUST listen to pipe and exit on $TERM command.

Please add @discuss section in ./../src/zactor.c.

EXAMPLE

From zactor_test method.

zactor_t *actor = zactor_new (echo_actor, "Hello, World");
assert (actor);
zstr_sendx (actor, "ECHO", "This is a string", NULL);
char *string = zstr_recv (actor);
assert (streq (string, "This is a string"));
freen (string);
zactor_destroy (&actor);
// custom destructor
// KTHXBAI_actor ends on "$KTHXBAI" string
zactor_t *KTHXBAI = zactor_new (KTHXBAI_actor, NULL);
assert (KTHXBAI);
// which is the one sent by KTHXBAI_destructor
zactor_set_destructor (KTHXBAI, KTHXBAI_destructor);
zactor_destroy (&KTHXBAI);
// custom destructor
// destructor using bsend/brecv
zactor_t *BSEND = zactor_new (BSEND_actor, NULL);
assert (BSEND);
zactor_set_destructor (BSEND, BSEND_destructor);
zactor_destroy (&BSEND);
#if defined (__WINDOWS__)
zsys_shutdown();
#endif

AUTHORS

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

RESOURCES

Main web site:

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

COPYRIGHT

Copyright (c) the 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
03/03/2019 CZMQ 4.2.0