Class: ZMQ::Context

Inherits:
Object
  • Object
show all
Includes:
Util
Defined in:
lib/ffi-rzmq/context.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Util

#errno, #error_string, minimum_api?, version

Constructor Details

#initialize(io_threads = 1) ⇒ Context

Recommended to use the default for io_threads since most programs will not saturate I/O.

The rule of thumb is to make io_threads equal to the number gigabits per second that the application will produce.

The io_threads number specifies the size of the thread pool allocated by 0mq for processing incoming/outgoing messages.

Returns a context object. It’s necessary for passing to the #Socket constructor when allocating new sockets. All sockets live within a context. Sockets in one context may not be accessed from another context; doing so raises an exception.

Also, Sockets should only be accessed from the thread where they were first created. Do not pass sockets between threads; pass in the context and allocate a new socket per thread.

To connect sockets between contexts, use inproc or ipc transport and set up a 0mq socket between them. This is also the recommended technique for allowing sockets to communicate between threads.

Will raise a #ContextError when the native library context cannot be be allocated.



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# File 'lib/ffi-rzmq/context.rb', line 40

def initialize io_threads = 1
  @sockets = []
  @context = LibZMQ.zmq_init io_threads
  @pointer = @context
  error_check ZMQ_INIT_STR, @context.null? ? 1 : 0

  define_finalizer
end

Instance Attribute Details

#context ⇒ Object (readonly)

Returns the value of attribute context.



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# File 'lib/ffi-rzmq/context.rb', line 12

def context
  @context
end

#pointer ⇒ Object (readonly)

Returns the value of attribute pointer.



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# File 'lib/ffi-rzmq/context.rb', line 12

def pointer
  @pointer
end

Instance Method Details

#socket(type) ⇒ Object

Short-cut to allocate a socket for a specific context.

Takes several type values:

#ZMQ::REQ
#ZMQ::REP
#ZMQ::PUB
#ZMQ::SUB
#ZMQ::PAIR
#ZMQ::PULL
#ZMQ::PUSH
#ZMQ::XREQ
#ZMQ::XREP

Returns a #ZMQ::Socket.

May raise a #ContextError or #SocketError.



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# File 'lib/ffi-rzmq/context.rb', line 87

def socket type
  sock = Socket.new @context, type
  error_check ZMQ_SOCKET_STR, sock.nil? ? 1 : 0
  sock
end

#terminate ⇒ Object

Call to release the context and any remaining data associated with past sockets. This will close any sockets that remain open; further calls to those sockets will raise failure exceptions.

Returns nil.

Will raise a #ContextError when the call fails. Failures occur when the context has somehow become null (indicates a libzmq bug).



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# File 'lib/ffi-rzmq/context.rb', line 59

def terminate
  unless @context.nil? || @context.null?
    result_code = LibZMQ.zmq_term @context
    error_check ZMQ_TERM_STR, result_code
    @context = nil
    @sockets = nil
    remove_finalizer
  end
  nil
end