On Wed, Dec 03, 2014 at 10:00:52AM +0100, Peter Krempa wrote:
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.
DUH! Dumb me, thanks for catching that... Martin
+} + static int virDomainObjListSearchName(const void *payload, const void *name ATTRIBUTE_UNUSED, const void *data)Peter
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