[PATCH v6 00/10] libxl: event API

[Ian Jackson <ian.jackson@eu.citrix.com>]

This series is the latest revision of my event handling API.  It
includes changes in response to a number of comments made.  It also
includes a few new consequential patches and unrelated
fixes/improvements, as usual.

The most significant difference is the new "libxl__egc" type which is
used instead of libxl__gc by event-generating functions.  This
prevents accidental violation of the callback reentrancy rules.

I'm still working on this series.  At the moment I'm working on
providing asynchronous calls for long-running operations; this
requires more support machinery which is still not finalised.

Of the resulting patches in this series,

These should perhaps go in soon:
 01/10 libxl: make LIBXL_INIT_GC a statement, not an initialiser
 03/10 libxl: move a lot more includes into libxl_internal.h
 04/10 libxl: Provide more formal libxl__ctx_lock and _unlock
 05/10 libxl: Fix leaks on context init failure
 09/10 libxl: introduce libxl_fd_set_nonblock, rationalise _cloexec

This one has now been tested and can go in IMO:
 02/10 xenstore: New function xs_path_is_subpath

These are the meat:
 07/10 libxl: New API for providing OS events to libxl
 08/10 libxl: New event generation API
 10/10 libxl: Permit multithreaded event waiting

And this one has become rendered obsolete.  If we are to retain the
new libxl__egc structure, I will drop it.  Otherwise it may still be
needed, and it's disruptive, which is why I haven't dropped it from my
series yet:
 06/10 DROP: libxl: rename libxl__free_all