class ZMQ::ManagedMessage
A subclass of #Message that includes finalizers for deallocating native memory when this object is garbage collected. Note that on certain Ruby runtimes the use of finalizers can add 10s of microseconds of overhead for each message. The convenience comes at a price.
The constructor optionally takes a string as an argument. It will copy this string to native memory in preparation for transmission. So, don't pass a string unless you intend to send it. Internally it calls copy_in_string.
Call close to release buffers when you have not passed this on to Socket#send. That method calls close on your behalf.
When you are done using a received message object, just let it go out of scope to release the memory. During the next garbage collection run it will call the equivalent of #LibZMQ.zmq_msg_close to release all buffers. Obviously, this automatic collection of message objects comes at the price of a larger memory footprint (for the finalizer proc object) and lower performance. If you wanted blistering performance, Ruby isn't there just yet.
As noted above, for sent objects the underlying library will call close for you.
Private Class Methods
Message finalizer Note that there is no error checking for the call to zmq_msg_close. This is intentional. Since this code runs as a finalizer, there is no way to catch a raised exception anywhere near where the error actually occurred in the code, so we just ignore deallocation failures here.
# File lib/ffi-rzmq/message.rb, line 283 def self.close ptr Proc.new do # release the data buffer LibZMQ.zmq_msg_close ptr end end
Public Instance Methods
Manually release the message struct and its associated data buffer.
# File lib/ffi-rzmq/message.rb, line 261 def close rc = super() remove_finalizer rc end
Makes a copy of len
bytes from the ruby string
bytes
. Library handles deallocation of the native memory
buffer.
# File lib/ffi-rzmq/message.rb, line 249 def copy_in_bytes bytes, len rc = super(bytes, len) # make sure we have a way to deallocate this memory if the object goes # out of scope define_finalizer rc end
Private Instance Methods
# File lib/ffi-rzmq/message.rb, line 270 def define_finalizer ObjectSpace.define_finalizer(self, self.class.close(@pointer)) end
# File lib/ffi-rzmq/message.rb, line 274 def remove_finalizer ObjectSpace.undefine_finalizer self end