Class: ZMQ::Context
Overview
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 when allocation succeeds. It’s necessary for passing to the #Socket constructor when allocating new sockets. All sockets live within a context.
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. If you must use threads, then make sure to execute a full memory barrier (e.g. mutex) as you pass a socket from one thread to the next.
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.
context = ZMQ::Context.create
if context
socket = context.socket(ZMQ::REQ)
if socket
...
else
STDERR.puts "Socket allocation failed"
end
else
STDERR.puts "Context allocation failed"
end
Instance Attribute Summary collapse
-
#context ⇒ Object
readonly
Returns the value of attribute context.
-
#pointer ⇒ Object
readonly
Returns the value of attribute pointer.
Class Method Summary collapse
Instance Method Summary collapse
-
#initialize(io_threads = 1) ⇒ Context
constructor
Use the factory method Context#create to make contexts.
-
#socket(type) ⇒ Object
Short-cut to allocate a socket for a specific context.
-
#terminate ⇒ Object
Call to release the context and any remaining data associated with past sockets.
Methods included from Util
errno, error_string, nonblocking_flag, resultcode_ok?, version
Constructor Details
#initialize(io_threads = 1) ⇒ Context
Use the factory method Context#create to make contexts.
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# File 'lib/ffi-rzmq/context.rb', line 54 def initialize io_threads = 1 @sockets = [] @context = LibZMQ.zmq_init io_threads @pointer = @context error_check 'zmq_init', (@context.nil? || @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 46 def context @context end |
#pointer ⇒ Object (readonly)
Returns the value of attribute pointer.
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# File 'lib/ffi-rzmq/context.rb', line 46 def pointer @pointer end |
Class Method Details
.create(io_threads = 1) ⇒ Object
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# File 'lib/ffi-rzmq/context.rb', line 48 def self.create io_threads = 1 new(io_threads) rescue nil 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::DEALER
#ZMQ::ROUTER
Returns a #ZMQ::Socket when the allocation succeeds, nil if it fails.
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# File 'lib/ffi-rzmq/context.rb', line 98 def socket type sock = nil begin sock = Socket.new @context, type rescue ContextError => e sock = nil end 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 return -1 to indicate the operation failed.
Returns 0 for success, -1 for failure.
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# File 'lib/ffi-rzmq/context.rb', line 70 def terminate unless @context.nil? || @context.null? remove_finalizer rc = LibZMQ.zmq_term @context @context = nil @sockets = nil rc else 0 end end |