diff options
Diffstat (limited to 'doc/zmq_proxy_steerable.3')
| -rw-r--r-- | doc/zmq_proxy_steerable.3 | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/doc/zmq_proxy_steerable.3 b/doc/zmq_proxy_steerable.3 new file mode 100644 index 0000000..51a48e6 --- /dev/null +++ b/doc/zmq_proxy_steerable.3 @@ -0,0 +1,112 @@ +'\" t +.\" Title: zmq_proxy_steerable +.\" Author: [see the "AUTHORS" section] +.\" Generator: DocBook XSL Stylesheets v1.76.1 <http://docbook.sf.net/> +.\" Date: 10/14/2014 +.\" Manual: 0MQ Manual +.\" Source: 0MQ 4.0.5 +.\" Language: English +.\" +.TH "ZMQ_PROXY_STEERABLE" "3" "10/14/2014" "0MQ 4\&.0\&.5" "0MQ Manual" +.\" ----------------------------------------------------------------- +.\" * Define some portability stuff +.\" ----------------------------------------------------------------- +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" http://bugs.debian.org/507673 +.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.SH "NAME" +zmq_proxy_steerable \- start built\-in 0MQ proxy with PAUSE/RESUME/TERMINATE control flow +.SH "SYNOPSIS" +.sp +\fBint zmq_proxy_steerable (const void \fR\fB\fI*frontend\fR\fR\fB, const void \fR\fB\fI*backend\fR\fR\fB, const void \fR\fB\fI*capture\fR\fR\fB, const void \fR\fB\fI*control\fR\fR\fB);\fR +.SH "DESCRIPTION" +.sp +The \fIzmq_proxy_steerable()\fR function starts the built\-in 0MQ proxy in the current application thread, as \fIzmq_proxy()\fR do\&. Please, refer to this function for the general description and usage\&. We describe here only the additional control flow provided by the socket passed as the fourth argument "control"\&. +.sp +If the control socket is not NULL, the proxy supports control flow\&. If \fIPAUSE\fR is received on this socket, the proxy suspends its activities\&. If \fIRESUME\fR is received, it goes on\&. If \fITERMINATE\fR is received, it terminates smoothly\&. At start, the proxy runs normally as if zmq_proxy was used\&. +.sp +If the control socket is NULL, the function behave exactly as if zmq_proxy had been called\&. +.sp +Refer to \fBzmq_socket\fR(3) for a description of the available socket types\&. Refer to \fBzmq_proxy\fR(3) for a description of the zmq_proxy\&. +.SH "EXAMPLE USAGE" +.sp +cf zmq_proxy +.SH "RETURN VALUE" +.sp +The \fIzmq_proxy_steerable()\fR function returns 0 if TERMINATE is sent to its control socket\&. Otherwise, it returns \-1 and \fIerrno\fR set to \fBETERM\fR (the 0MQ \fIcontext\fR associated with either of the specified sockets was terminated)\&. +.SH "EXAMPLE" +.PP +\fBCreating a shared queue proxy\fR. +.sp +.if n \{\ +.RS 4 +.\} +.nf +// Create frontend, backend and control sockets +void *frontend = zmq_socket (context, ZMQ_ROUTER); +assert (backend); +void *backend = zmq_socket (context, ZMQ_DEALER); +assert (frontend); +void *control = zmq_socket (context, ZMQ_SUB); +assert (control); + +// Bind sockets to TCP ports +assert (zmq_bind (frontend, "tcp://*:5555") == 0); +assert (zmq_bind (backend, "tcp://*:5556") == 0); +assert (zmq_connect (control, "tcp://*:5557") == 0); + +// Subscribe to the control socket since we have chosen SUB here +assert (zmq_setsockopt (control, ZMQ_SUBSCRIBE, "", 0)); + +// Start the queue proxy, which runs until ETERM or "TERMINATE" +// received on the control socket +zmq_proxy_steerable (frontend, backend, NULL, control); +.fi +.if n \{\ +.RE +.\} +.PP +\fBSet up a controller in another node, process or whatever\fR. +.sp +.if n \{\ +.RS 4 +.\} +.nf +void *control = zmq_socket (context, ZMQ_PUB); +assert (control); +assert (zmq_bind (control, "tcp://*:5557") == 0); + +// pause the proxy +assert (zmq_send (control, "PAUSE", 5, 0) == 0); + +// resume the proxy +assert (zmq_send (control, "RESUME", 6, 0) == 0); + +// terminate the proxy +assert (zmq_send (control, "TERMINATE", 9, 0) == 0); +\-\-\- + + +SEE ALSO +.fi +.if n \{\ +.RE +.\} +.sp +\fBzmq_proxy\fR(3) \fBzmq_bind\fR(3) \fBzmq_connect\fR(3) \fBzmq_socket\fR(3) \fBzmq\fR(7) +.SH "AUTHORS" +.sp +This page was written by the 0MQ community\&. To make a change please read the 0MQ Contribution Policy at \m[blue]\fBhttp://www\&.zeromq\&.org/docs:contributing\fR\m[]\&. |