Add reference counting on the virDomainObjPtr objects. With the
forthcoming asynchronous QEMU monitor, it will be neccessary to
release the lock on virDomainObjPtr while waiting for a monitor
command response. It is neccessary to ensure one thread can't
delete a virDomainObjPtr while another is waiting. By introducing
reference counting threads can make sure objects they are using
are not accidentally deleted while unlocked.
* src/conf/domain_conf.h, src/conf/domain_conf.c: Add
virDomainObjRef/Unref APIs, remove virDomainObjFree
* src/openvz/openvz_conf.c: replace call to virDomainObjFree
with virDomainObjUnref
The current virDomainObjListPtr object stores domain objects in
an array. This means that to find a particular objects requires
O(n) time, and more critically acquiring O(n) mutex locks.
The new impl replaces the array with a virHashTable, keyed off
UUID. Finding a object based on UUID is now O(1) time, and only
requires a single mutex lock. Finding by name/id is unchanged
in complexity.
In changing this, all code which iterates over the array had
to be updated to use a hash table iterator function callback.
Several of the functions which were identically duplicating
across all drivers were pulled into domain_conf.c
* src/conf/domain_conf.h, src/conf/domain_conf.c: Change
virDomainObjListPtr to use virHashTable. Add a initializer
method virDomainObjListInit, and rename virDomainObjListFree
to virDomainObjListDeinit, since its not actually freeing
the container, only its contents. Also add some convenient
methods virDomainObjListGetInactiveNames,
virDomainObjListGetActiveIDs and virDomainObjListNumOfDomains
which can be used to implement the correspondingly named
public API entry points in drivers
* src/libvirt_private.syms: Export new methods from domain_conf.h
* src/lxc/lxc_driver.c, src/opennebula/one_driver.c,
src/openvz/openvz_conf.c, src/openvz/openvz_driver.c,
src/qemu/qemu_driver.c, src/test/test_driver.c,
src/uml/uml_driver.c, src/vbox/vbox_tmpl.c: Update all code
to deal with hash tables instead of arrays for domains
Add the virStrncpy function, which takes a dst string, source string,
the number of bytes to copy and the number of bytes available in the
dest string. If the source string is too large to fit into the
destination string, including the \0 byte, then no data is copied and
the function returns NULL. Otherwise, this function copies n bytes
from source into dst, including the \0, and returns a pointer to the
dst string. This function is intended to replace all unsafe uses
of strncpy in the code base, since strncpy does *not* guarantee that
the buffer terminates with a \0.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
