zactor(3)
=========

NAME
----
zactor - simple actor framework

SYNOPSIS
--------
----
//  This is a stable class, and may not change except for emergencies. It
//  is provided in stable builds.
// 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);

----

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"));
free (string);
zactor_destroy (&actor);
----
