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
XS_SEND(3) Crossroads I/O Manual XS_SEND(3)

xs_send - send a message part on a socket

int xs_send (void *socket, void *buf, size_t len, int flags );

The xs_send() function shall queue a message created from the buffer referenced by the buf and len arguments. The flags argument is a combination of the flags defined below:
XS_DONTWAIT
Specifies that the operation should be performed in non-blocking mode. If the message cannot be queued on the socket, the xs_send() function shall fail with errno set to EAGAIN.
XS_SNDMORE
Specifies that the message being sent is a multi-part message, and that further message parts are to follow. Refer to the section regarding multi-part messages below for a detailed description.
 
Note
 
 
A successful invocation of xs_send() does not indicate that the message has been transmitted to the network, only that it has been queued on the socket and Crossroads have assumed responsibility for the message.

A Crossroads message is composed of 1 or more message parts. Crossroads ensures atomic delivery of messages; peers shall receive either all message parts of a message or none at all. The total number of message parts is unlimited except by available memory.
An application that sends multipart messages must use the XS_SNDMORE flag when sending each message part except the final one.

The xs_send() function shall return number of bytes in the message if successful. Otherwise it shall return -1 and set errno to one of the values defined below.

EAGAIN
Non-blocking mode was requested and the message cannot be sent at the moment.
ENOTSUP
The xs_send() operation is not supported by this socket type.
EFSM
The xs_send() operation cannot be performed on this socket at the moment due to the socket not being in the appropriate state. This error may occur with socket types that switch between several states, such as XS_REP. See the messaging patterns section of xs_socket(3) for more information.
ETERM
The context associated with the specified socket was terminated.
ENOTSOCK
The provided socket was invalid.
EINTR
The operation was interrupted by delivery of a signal before the message was sent.

Sending a multi-part message.
/* Send a multi-part message consisting of three parts to socket */
rc = xs_send (socket, "ABC", 3, XS_SNDMORE);
assert (rc == 3);
rc = xs_send (socket, "DEFGH", 5, XS_SNDMORE);
assert (rc == 5);
/* Final part; no more parts to follow */
rc = xs_send (socket, "JK", 2, 0);
assert (rc == 2);

Applications that wish to use zero-copy messaging must use xs_sendmsg(3) instead of xs_send().
xs_recv(3) xs_socket(7) xs(7)

This man page was written by Martin Sustrik < sustrik@250bpm.com[1]>, Martin Lucina < martin@lucina.net[2]> and Pieter Hintjens < ph@imatix.com[3]>.

1.
sustrik@250bpm.com
mailto:sustrik@250bpm.com
2.
martin@lucina.net
mailto:martin@lucina.net
3.
ph@imatix.com
mailto:ph@imatix.com
12/20/2018 Crossroads I/O 1.2.0

Search for    or go to Top of page |  Section 3 |  Main Index

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