[libvirt] [PATCH] snapshot: add virDomainSnapshotRef API

virDomainSnapshotPtr has a refcount member, but no one was able to use it. Furthermore, all of our other vir*Ptr objects have a *Ref method to match their *Free method. Thankfully, this is client-side only, so we can use this new function regardless of how old the server side is! (I have future patches to virsh that want to use it.) * include/libvirt/libvirt.h.in (virDomainSnapshotRef): Declare. * src/libvirt.c (virDomainSnapshotRef): Implement it. * src/libvirt_public.syms (LIBVIRT_0.9.13): Export it. --- include/libvirt/libvirt.h.in | 1 + src/libvirt.c | 33 +++++++++++++++++++++++++++++++++ src/libvirt_public.syms | 5 +++++ 3 files changed, 39 insertions(+) diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index da3ce29..fcb6695 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -3424,6 +3424,7 @@ typedef enum { int virDomainSnapshotDelete(virDomainSnapshotPtr snapshot, unsigned int flags); +int virDomainSnapshotRef(virDomainSnapshotPtr snapshot); int virDomainSnapshotFree(virDomainSnapshotPtr snapshot); /* diff --git a/src/libvirt.c b/src/libvirt.c index 6386ed4..00358d6 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -17487,6 +17487,39 @@ error: } /** + * virDomainSnapshotRef: + * @snapshot: the snapshot to hold a reference on + * + * Increment the reference count on the snapshot. For each + * additional call to this method, there shall be a corresponding + * call to virDomainSnapshotFree to release the reference count, once + * the caller no longer needs the reference to this object. + * + * This method is typically useful for applications where multiple + * threads are using a connection, and it is required that the + * connection and domain remain open until all threads have finished + * using the snapshot. ie, each new thread using a snapshot would + * increment the reference count. + * + * Returns 0 in case of success and -1 in case of failure. + */ +int +virDomainSnapshotRef(virDomainSnapshotPtr snapshot) +{ + if ((!VIR_IS_DOMAIN_SNAPSHOT(snapshot))) { + virLibDomainSnapshotError(VIR_ERR_INVALID_DOMAIN_SNAPSHOT, + __FUNCTION__); + virDispatchError(NULL); + return -1; + } + virMutexLock(&snapshot->domain->conn->lock); + VIR_DEBUG("snapshot=%p, refs=%d", snapshot, snapshot->refs); + snapshot->refs++; + virMutexUnlock(&snapshot->domain->conn->lock); + return 0; +} + +/** * virDomainSnapshotFree: * @snapshot: a domain snapshot object * diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms index 46c13fb..ba61595 100644 --- a/src/libvirt_public.syms +++ b/src/libvirt_public.syms @@ -534,4 +534,9 @@ LIBVIRT_0.9.11 { virDomainPMWakeup; } LIBVIRT_0.9.10; +LIBVIRT_0.9.13 { + global: + virDomainSnapshotRef; +} LIBVIRT_0.9.11; + # .... define new API here using predicted next version number .... -- 1.7.10.2