ZMQ_INPROC(7) 0MQ Manual ZMQ_INPROC(7)NAME
zmq_inproc - 0MQ local in-process (inter-thread) communication transport
SYNOPSIS
The in-process transport passes messages via memory directly between threads sharing a single 0MQ context.
Note
No I/O threads are involved in passing messages using the inproc transport. Therefore, if you are using a 0MQ context for in-process
messaging only you can initialise the context with zero I/O threads. See zmq_init(3) for details.
ADDRESSING
A 0MQ address string consists of two parts as follows: transport://endpoint. The transport part specifies the underlying transport protocol
to use, and for the in-process transport shall be set to inproc. The meaning of the endpoint part for the in-process transport is defined
below.
Assigning a local address to a socket
When assigning a local address to a socket using zmq_bind() with the inproc transport, the endpoint shall be interpreted as an arbitrary
string identifying the name to create. The name must be unique within the 0MQ context associated with the socket and may be up to 256
characters in length. No other restrictions are placed on the format of the name.
Connecting a socket
When connecting a socket to a peer address using zmq_connect() with the inproc transport, the endpoint shall be interpreted as an arbitrary
string identifying the name to connect to. The name must have been previously created by assigning it to at least one socket within the
same 0MQ context as the socket being connected.
WIRE FORMAT
Not applicable.
EXAMPLES
Assigning a local address to a socket.
/* Assign the in-process name "#1" */
rc = zmq_bind(socket, "inproc://#1");
assert (rc == 0);
/* Assign the in-process name "my-endpoint" */
rc = zmq_bind(socket, "inproc://my-endpoint");
assert (rc == 0);
Connecting a socket.
/* Connect to the in-process name "#1" */
rc = zmq_connect(socket, "inproc://#1");
assert (rc == 0);
/* Connect to the in-process name "my-endpoint" */
rc = zmq_connect(socket, "inproc://my-endpoint");
assert (rc == 0);
SEE ALSO zmq_bind(3)zmq_connect(3)zmq_ipc(7)zmq_tcp(7)zmq_pgm(7)zmq(7)AUTHORS
This manual page was written by the 0MQ community.
0MQ 2.2.0 04/04/2012 ZMQ_INPROC(7)
Check Out this Related Man Page
ZMQ_TCP(7) 0MQ Manual ZMQ_TCP(7)NAME
zmq_tcp - 0MQ unicast transport using TCP
SYNOPSIS
TCP is an ubiquitous, reliable, unicast transport. When connecting distributed applications over a network with 0MQ, using the TCP
transport will likely be your first choice.
ADDRESSING
A 0MQ address string consists of two parts as follows: transport://endpoint. The transport part specifies the underlying transport protocol
to use, and for the TCP transport shall be set to tcp. The meaning of the endpoint part for the TCP transport is defined below.
Assigning a local address to a socket
When assigning a local address to a socket using zmq_bind() with the tcp transport, the endpoint shall be interpreted as an interface
followed by a colon and the TCP port number to use.
An interface may be specified by either of the following:
o The wild-card *, meaning all available interfaces.
o The primary IPv4 address assigned to the interface, in its numeric representation.
o The interface name as defined by the operating system.
Note
Interface names are not standardised in any way and should be assumed to be arbitrary and platform dependent. On Win32 platforms no
short interface names exist, thus only the primary IPv4 address may be used to specify an interface.
Connecting a socket
When connecting a socket to a peer address using zmq_connect() with the tcp transport, the endpoint shall be interpreted as a peer address
followed by a colon and the TCP port number to use.
A peer address may be specified by either of the following:
o The DNS name of the peer.
o The IPv4 address of the peer, in its numeric representation.
WIRE FORMAT
0MQ messages are transmitted over TCP in frames consisting of an encoded payload length, followed by a flags field and the message body.
The payload length is defined as the combined length in octets of the message body and the flags field.
For frames with a payload length not exceeding 254 octets, the payload length shall be encoded as a single octet. The minimum valid payload
length of a frame is 1 octet, thus a payload length of 0 octets is invalid and such frames SHOULD be ignored.
For frames with a payload length exceeding 254 octets, the payload length shall be encoded as a single octet with the value 255 followed by
the payload length represented as a 64-bit unsigned integer in network byte order.
The flags field consists of a single octet containing various control flags:
Bit 0 (MORE): More message parts to follow. A value of 0 indicates that there are no more message parts to follow; or that the message
being sent is not a multi-part message. A value of 1 indicates that the message being sent is a multi-part message and more message parts
are to follow.
Bits 1-7: Reserved. Bits 1-7 are reserved for future expansion and MUST be set to zero.
The following ABNF grammar represents a single frame:
frame = (length flags data)
length = OCTET / (escape 8OCTET)
flags = OCTET
escape = %xFF
data = *OCTET
The following diagram illustrates the layout of a frame with a payload length not exceeding 254 octets:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload length| Flags | Message body ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message body ...
+-+-+-+-+-+-+- ...
The following diagram illustrates the layout of a frame with a payload length exceeding 254 octets:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0xff | Payload length ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload length ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload length| Flags | Message body ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message body ...
+-+-+-+-+-+-+-+ ...
EXAMPLES
Assigning a local address to a socket.
/* TCP port 5555 on all available interfaces */
rc = zmq_bind(socket, "tcp://*:5555");
assert (rc == 0);
/* TCP port 5555 on the local loop-back interface on all platforms */
rc = zmq_bind(socket, "tcp://127.0.0.1:5555");
assert (rc == 0);
/* TCP port 5555 on the first Ethernet network interface on Linux */
rc = zmq_bind(socket, "tcp://eth0:5555");
assert (rc == 0);
Connecting a socket.
/* Connecting using an IP address */
rc = zmq_connect(socket, "tcp://192.168.1.1:5555");
assert (rc == 0);
/* Connecting using a DNS name */
rc = zmq_connect(socket, "tcp://server1:5555");
assert (rc == 0);
SEE ALSO zmq_bind(3)zmq_connect(3)zmq_pgm(7)zmq_ipc(7)zmq_inproc(7)zmq(7)AUTHORS
This manual page was written by the 0MQ community.
0MQ 2.2.0 04/04/2012 ZMQ_TCP(7)