The util/threads.c/h code already has APIs for mutexes,
condition variables and thread locals. This commit adds
in code for actually creating threads.

* src/libvirt_private.syms: Export new symbols
* src/util/threads.h: Define APIs virThreadCreate, virThreadSelf,
  virThreadIsSelf and virThreadJoin
* src/util/threads-win32.c, src/util/threads-win32.h: Win32
  impl of threads
* src/util/threads-pthread.c, src/util/threads-pthread.h: POSIX
  impl of threads

* src/util/threads.c (includes) [WIN32]: On mingw, favor native
threading over pthreads-win32 library.
* src/util/thread.h [WIN32] Likewise.
Suggested by Daniel P. Berrange.

Gnulib can guarantee that pthread.h exists, but for now, it is a dummy
header with no support for most pthread_* functions.  Modify our
use of pthread to use function checks, rather than header checks,
to determine how much pthread support is present.

* bootstrap.conf (gnulib_modules): Add pthread.
* configure.ac: Drop all pthread.h checks.  Optimize function
checks.  Add check for pthread functions.
* src/Makefile.am (libvirt_lxc_LDADD): Ensure proper link.
* src/remote/remote_driver.c (remoteIOEventLoop): Depend on
pthread_sigmask, now that gnulib guarantees pthread.h.
* src/util/util.c (virFork): Likewise.
* src/util/threads.c (threads-pthread.c): Depend on
pthread_mutexattr_init, as a witness of full pthread support.
* src/util/threads.h (threads-pthread.h): Likewise.

This patch adds recursive locks necessary due to the processing of
network filter XML that can reference other network filters, including
references that cause looks. Loops in the XML are prevented but their
detection requires recursive locks.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

* global: patch created by running:
for f in $(git ls-files '*.[ch]') ; do
    cppi $f > $f.t && mv $f.t $f
done

* src/util/threads.h, src/util/threads-pthread.c,
  src/libvirt_private.syms: Add virCondWaitUntil()

* src/bridge.c, src/bridge.h, src/buf.c, src/buf.h, src/cgroup.c,
  src/cgroup.h, src/conf.c, src/conf.h, src/event.c, src/event.h,
  src/hash.c, src/hash.h, src/hostusb.c, src/hostusb.h,
  src/iptables.c, src/iptables.h, src/logging.c, src/logging.h,
  src/memory.c, src/memory.h, src/pci.c, src/pci.h, src/qparams.c,
  src/qparams.h, src/stats_linux.c, src/stats_linux.h,
  src/threads-pthread.c, src/threads-pthread.h, src/threads-win32.c,
  src/threads-win32.h, src/threads.c, src/threads.h, src/util.c,
  src/util.h, src/uuid.c, src/uuid.h, src/virterror.c,
  src/virterror_internal.h, src/xml.c, src/xml.h: Move all files
  into src/util/
* daemon/Makefile.am: Add -Isrc/util/ to build flags
* src/Makefile.am: Add -Isrc/util/ to build flags and update for
  moved files
* src/libvirt_private.syms: Export cgroup APIs since they're now
  in util rather than linking directly to drivers
* src/xen/xs_internal.c: Disable bogus virEventRemoveHandle call
  when built under PROXY
* proxy/Makefile.am: Update for changed file locations. Remove
  bogus build of event.c
* tools/Makefile.am, tests/Makefile.am: Add -Isrc/util/ to build flags