# Posix\_mq 0.5.1 - fix notify(&block)

**URL:** <https://www.ruby-forum.com/t/posix-mq-0-5-1-fix-notify-block/188281>\
**Category:** Ruby\
**Created:** [May 9, 2010, 10:21am UTC](https://www.ruby-forum.com/t/posix-mq-0-5-1-fix-notify-block/188281 "2010-05-09T10:21:03Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ericw](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/97f17d/32.png) [@ericw](https://www.ruby-forum.com/u/ericw)\
**Post date:** [May 9, 2010, 10:21am UTC](https://www.ruby-forum.com/t/posix-mq-0-5-1-fix-notify-block/188281/1 "2010-05-09T10:21:03Z")

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POSIX message queues allow local processes to exchange data in the form  
of messages. This API is distinct from that provided by System V  
message queues, but provides similar functionality.

- [posix\_mq - POSIX message queues for Ruby](http://bogomips.org/ruby_posix_mq/)
- removed\_email\_address@domain.invalid
- git://git.bogomips.org/ruby\_posix\_mq.git

Changes:

Fix POSIX\_MQ#notify(&block) usage, this regression was  
introduced in 0.4.0 and our tests for it were broken, as well.

Not many people use POSIX\_MQ.notify(&block), however, as it’s only  
supported under Linux at the moment and “POSIX\_MQ.notify = signal” is  
more portable and efficient. Of course, it’s possible to use POSIX  
message queues without notifications at all in blocking mode. (and Linux  
and FreeBSD also allow POSIX\_MQ objects to be IO.select-ed).