To facilitate use of the locking plugins from hypervisor drivers,
introduce a higher level API for locking virDomainObjPtr instances.
In includes APIs targetted to VM startup, and hotplug/unplug
* src/Makefile.am: Add domain lock API
* src/locking/domain_lock.c, src/locking/domain_lock.h: High
level API for domain locking
To allow hypervisor drivers to assume that a lock driver impl
will be guaranteed to exist, provide a 'nop' impl that is
compiled into the library
* src/Makefile.am: Add nop driver
* src/locking/lock_driver_nop.c, src/locking/lock_driver_nop.h:
Nop lock driver implementation
* src/locking/lock_manager.c: Enable direct access of 'nop'
driver, instead of dlopen()ing it.
Define the basic framework lock manager plugins. The
basic plugin API for 3rd parties to implemented is
defined in
src/locking/lock_driver.h
This allows dlopen()able modules for alternative locking
schemes, however, we do not install the header. This
requires lock plugins to be in-tree allowing changing of
the lock manager plugin API in future.
The libvirt code for loading & calling into plugins
is in
src/locking/lock_manager.{c,h}
* include/libvirt/virterror.h, src/util/virterror.c: Add
VIR_FROM_LOCKING
* src/locking/lock_driver.h: API for lock driver plugins
to implement
* src/locking/lock_manager.c, src/locking/lock_manager.h:
Internal API for managing locking
* src/Makefile.am: Add locking code
