Posix_mq 0.4.0

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.

Changes:

Small bugfixes and small API changes to avoid potential
issues/misuse are the focus of this release.

For non-blocking operation, the GVL is no longer bounced. This
reduces synchronization/scheduling overhead when used in
non-blocking applications.

Small cleanups and documentation improvements, too.

  • make POSIX_MQ#dup and POSIX_MQ#clone no-op
  • do not release GVL for non-blocking operations
  • do not release GVL when unlinking/opening
  • POSIX_MQ#<< does not release GVL when non-blocking
  • avoid shadow warnings
  • README: add mailing list archives info
  • POSIX_MQ#to_io works under FreeBSD, too
  • fix potential race with notify(&block)
  • add TODO item for using netlink under Linux
  • remove non-portable #warning CPP directive
  • ensure POSIX_MQ#name is clobber-proof