On 12/03/14 06:49, Martin Kletzander wrote:
> Currently, when there is an API that's blocking with locked domain and
> second API that's waiting in virDomainObjListFindByUUID() for the domain
> lock (with the domain list locked) no other API can be executed on any
> domain on the whole hypervisor because all would wait for the domain
> list to be locked. This patch adds new optional approach to this in
> which the domain is only ref'd (reference counter is incremented)
> instead of being locked and is locked *after* the list itself is
> unlocked. We might consider only ref'ing the domain in the future and
> leaving locking on particular APIs, but that's no tonight's fairy tale.
>
> Signed-off-by: Martin Kletzander <mkletzan@xxxxxxxxxx>
> ---
> src/conf/domain_conf.c | 27 ++++++++++++++++++++++++---
> src/conf/domain_conf.h | 2 ++
> src/libvirt_private.syms | 1 +
> 3 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 2d81c37..e5bb572 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -1068,8 +1068,10 @@ virDomainObjPtr virDomainObjListFindByID(virDomainObjListPtr doms,
> }
>
>
> -virDomainObjPtr virDomainObjListFindByUUID(virDomainObjListPtr doms,
> - const unsigned char *uuid)
> +static virDomainObjPtr
> +virDomainObjListFindByUUIDInternal(virDomainObjListPtr doms,
> + const unsigned char *uuid,
> + bool ref)
> {
> char uuidstr[VIR_UUID_STRING_BUFLEN];
> virDomainObjPtr obj;
> @@ -1078,12 +1080,31 @@ virDomainObjPtr virDomainObjListFindByUUID(virDomainObjListPtr doms,
> virUUIDFormat(uuid, uuidstr);
>
> obj = virHashLookup(doms->objs, uuidstr);
> + if (ref) {
> + virObjectRef(obj);
> + virObjectUnlock(doms);
> + }
> if (obj)
> virObjectLock(obj);
> - virObjectUnlock(doms);
> + if (!ref)
> + virObjectUnlock(doms);
> return obj;
> }
>
> +virDomainObjPtr
> +virDomainObjListFindByUUID(virDomainObjListPtr doms,
> + const unsigned char *uuid)
> +{
> + return virDomainObjListFindByUUIDInternal(doms, uuid, false);
> +}
> +
> +virDomainObjPtr
> +virDomainObjListFindByUUIDRef(virDomainObjListPtr doms,
> + const unsigned char *uuid)
> +{
> + return virDomainObjListFindByUUIDInternal(doms, uuid, false);
Umm both call the helper with @ref being false? That probably isn't right.
> +}
> +
> static int virDomainObjListSearchName(const void *payload,
> const void *name ATTRIBUTE_UNUSED,
> const void *data)
Peter
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