Re: [libvirt] [PATCH 0/6] Complete cleanup of domain object usage

This should be the "last time" (famous last words) needing to alter this processing. I hope to get more than one pair of eyes looking at the series. I've looked at it long enough to feel comfortable with the changes, but I also know I probably have looked at it so long that I could have missed something! The first 3 patches set up the necessary infrastructure. Patches 4 & 5 are just something I found in libxl while doing this - they could be extracted and considered separately if need be; however, since I was thinking about @vm referencing - it just seemed to fit. Since I altered @vm it only seemed right to do the same for @conn. While it could be said that neither condition could happen - I figured better safe than sorry and I think it follows how this type of logic has been handled elsewhere in qemu. Patch 6 is where all the magic happens. I tried a few different ways to rework and split the Add/Remove processing, but either way I was left with rather ugly patches that required touching the same places, so I capitulated and combined them since there really is a delicate balance between those paths that have added a virObjectRef after the virDomainObjListAdd and those that just use virObjectUnlock on the returned ListAdd objects. Converting the latter to use Ref caused more "busy work" and equally large patches. The busy work was mosting around the processing required during ListAdd if something happened which resulted in ListRemove needing to be called. The "general change" is that instead of having ListAdd return an object with 2 refs and 1 lock it will now return an object with 3 refs and 1 lock. With that returned object, some drivers would perform an ObjectRef while others did not. For those that did not, they would use ObjectUnlock when done with the object so that when leaving whatever Create routine there was there would be at least 2 Refs on the object. The change here is to have them all be consistent. What follows is a "general description" of what was done for each. For bhyve, openvz, test, uml, and vmware (e.g. domain drivers that do not use virObjectRef on the returned virDomainObjListAdd object): Create/Add processing: -> Use EndAPI instead of ObjectUnlock -> Remove setting vm = NULL if the ListRemove was called to allow EndAPI processing to perform last Unref and Unlock NB: ListRemove would remove 2 refs and unlock, so it "worked", but would "consume" the returned object Undefine/Destroy processing: -> Alter ListRemove and ObjectLock to just be ListRemove allowing the EndAPI processing from a FindBy* to perform last Unref and Unlock For libxl, lxc, qemu, and vz (e.g. domain drivers that use virObjectRef on the returned virDomainObjListAdd object): Create/Add processing: -> Remove the ObjectRef -> Remove the ObjectLock when needing to call ListRemove to allow EndAPI processing to perform the last Unref and Unlock NB: ListRemove no longer Unlock's the returned object Undefine/Destroy processing: -> Alter ListRemove and ObjectLock to just be ListRemove allowing the EndAPI processing from a FindBy* to perform last Unref and Unlock NB: For the AutoDestroy type logic, no change is required since in the long run the object was left with the correct number of refs after create processing ran. The issue is more the direct mgmt of object during Add/Remove rather than mgmt of object once defined. John Ferlan (6): conf: Split FindBy{UUID|Name} into locked helpers conf: Use virDomainObjListFindBy*Locked for virDomainObjListAdd conf: Move and use virDomainObjListRemoveLocked libxl: Add refcnt for args->vm during migration libxl: Add refcnt for args->conn during migration conf: Clean up object referencing for Add and Remove src/bhyve/bhyve_driver.c | 21 ++---- src/conf/virdomainobjlist.c | 165 ++++++++++++++++++++++++++++---------------- src/libxl/libxl_driver.c | 64 ++++------------- src/libxl/libxl_migration.c | 41 ++++------- src/lxc/lxc_driver.c | 21 ++---- src/lxc/lxc_process.c | 17 +++-- src/openvz/openvz_conf.c | 2 +- src/openvz/openvz_driver.c | 20 ++---- src/qemu/qemu_domain.c | 17 +---- src/qemu/qemu_driver.c | 6 +- src/qemu/qemu_migration.c | 3 +- src/test/test_driver.c | 56 +++++---------- src/uml/uml_driver.c | 37 +++------- src/vmware/vmware_conf.c | 3 +- src/vmware/vmware_driver.c | 17 ++--- src/vz/vz_driver.c | 1 - src/vz/vz_sdk.c | 3 - 17 files changed, 192 insertions(+), 302 deletions(-)