The zero copy decoding strategy implemented for 4.2.0 can lead to a large
increase of main memory usage in some cases (I have seen one program go up to
40G from 10G after upgrading from 4.1.4). This commit adds a new option to
contexts, called ZMQ_ZERO_COPY_RECV, which allows one to switch to the old
decoding strategy.
Solution: add ZMQ_ZAP_ENFORCE_DOMAIN to hide backward incompatible
change and make it disabled by default.
In a future release that breaks API compatibility we can then switch
the default to enabled in order to achieve full RFC compatibility.
Fixes#2762
group being a `char *` is logically a text type, which needs an encoding.
Declare in the API that groups shall be UTF8-encoded,
matching the `zmq_msg_gets` API, which is the other user-facing `char *` API,
which has the same definition.
This allows bindings to provide text-type APIs,
which they cannot do if arbitrary bytes are allowed
Linux now supports Virtual Routing and Forwarding (VRF) as per:
https://www.kernel.org/doc/Documentation/networking/vrf.txt
In order for an application to bind or connect to a socket with an
address in a VRF, they need to first bind the socket to the VRF device:
setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, dev, strlen(dev)+1);
Note "dev" is the VRF device, eg. VRF "blue", rather than an interface
enslaved to the VRF.
Add a new socket option, ZMQ_BINDTODEVICE, to bind a socket to a device.
In general, if a socket is bound to a device, eg. an interface, only
packets received from that particular device are processed by the socket.
If device is a VRF device, then subsequent binds/connects to that socket
use addresses in the VRF routing table.
Solution:
* Document the new behaviour when generating 'ZMQ_POLLOUT' events
for ZMQ_ROUTER sockets with 'ZMQ_ROUTER_MANDATORY' set to `1`
* Add clarifications for 'ZMQ_ROUTER' socket when
'ZMQ_ROUTER_MANDATORY' is set to `1`
Problem: GSSAPI NAMETYPE options were not documented in man
pages for zmq_getsockopt() and zmq_setsockopt().
Solution: add new options to these manual pages.
Problem: the ZMQ_GSSAPI_PRINCIPAL socket option is described
as mandatory in the zmq_gssapi(7) manual page. In fact it
is optional.
Solution: Describe ZMQ_GSSAPI_PRINCIPAL as optional.
If unspecified, default credentials are used.
Solution: add a note pointing out that when new events are added the
ZMQ_EVENT_ALL mask will start returning them, so applications that
can't handle that transparently should not use it and instead pick
only the event types they want.
Creating a new event type and having monitors with ZMQ_EVENT_ALL
return them will not be considered a backward incompatible change
even though the flow of events will change.
