ZMQ_CTX_SET(3) 0MQ Manual ZMQ_CTX_SET(3)NAMEzmq_ctx_set - set context options
SYNOPSIS
int zmq_ctx_set (void *context, int option_name, int option_value);
DESCRIPTION
The zmq_ctx_set() function shall set the option specified by the
option_name argument to the value of the option_value argument.
The zmq_ctx_set() function accepts the following options:
ZMQ_IO_THREADS: Set number of I/O threads
The ZMQ_IO_THREADS argument specifies the size of the 0MQ thread pool
to handle I/O operations. If your application is using only the inproc
transport for messaging you may set this to zero, otherwise set it to
at least one. This option only applies before creating any sockets on
the context.
Default value 1
ZMQ_THREAD_SCHED_POLICY: Set scheduling policy for I/O threads
The ZMQ_THREAD_SCHED_POLICY argument sets the scheduling policy for
internal context’s thread pool. This option is not available on
windows. Supported values for this option can be found in sched.h file,
or at http://man7.org/linux/man-pages/man2/sched_setscheduler.2.html.
This option only applies before creating any sockets on the context.
Default value -1
ZMQ_THREAD_PRIORITY: Set scheduling priority for I/O threads
The ZMQ_THREAD_PRIORITY argument sets scheduling priority for internal
context’s thread pool. This option is not available on windows.
Supported values for this option depend on chosen scheduling policy.
Details can be found in sched.h file, or at
http://man7.org/linux/man-pages/man2/sched_setscheduler.2.html. This
option only applies before creating any sockets on the context.
Default value -1
ZMQ_MAX_SOCKETS: Set maximum number of sockets
The ZMQ_MAX_SOCKETS argument sets the maximum number of sockets allowed
on the context. You can query the maximal allowed value with
zmq_ctx_get(3) using the ZMQ_SOCKET_LIMIT option.
Default value 1024
ZMQ_IPV6: Set IPv6 option
The ZMQ_IPV6 argument sets the IPv6 value for all sockets created in
the context from this point onwards. A value of 1 means IPv6 is
enabled, while 0 means the socket will use only IPv4. When IPv6 is
enabled, a socket will connect to, or accept connections from, both
IPv4 and IPv6 hosts.
Default value 0
RETURN VALUE
The zmq_ctx_set() function returns zero if successful. Otherwise it
returns -1 and sets errno to one of the values defined below.
ERRORS
EINVAL
The requested option option_name is unknown.
EXAMPLE
Setting a limit on the number of sockets.
void *context = zmq_ctx_new ();
zmq_ctx_set (context, ZMQ_MAX_SOCKETS, 256);
int max_sockets = zmq_ctx_get (context, ZMQ_MAX_SOCKETS);
assert (max_sockets == 256);
SEE ALSOzmq_ctx_get(3)zmq(7)AUTHORS
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0MQ 4.1.3 08/17/2015 ZMQ_CTX_SET(3)
