Re: [libvirt] [PATCH] esx: Fix race condition in esxVI_EnsureSession
2011/5/16 Eric Blake <eblake(a)redhat.com>:
On 05/01/2011 01:57 PM, Matthias Bolte wrote:
> When the session has expired then multiple threads can race while
> reestablishing it.
>
> This race condition is not that critical as it requires a special usage
> pattern to be triggerd. It can only happen when an application doesn't
s/triggerd/triggered/
Fixed.
> do API calls for quite some time (the session expires after 30
min
> inactivity) and then multiple threads doing simultaneous API calls and
> end up doing simultaneous calls to esxVI_EnsureSession.
> ---
> src/esx/esx_vi.c | 47 +++++++++++++++++++++++++++++++++++------------
> src/esx/esx_vi.h | 4 +++-
> 2 files changed, 38 insertions(+), 13 deletions(-)
C code - I'm back in my element!
> +++ b/src/esx/esx_vi.h
> @@ -185,6 +185,7 @@ int esxVI_SharedCURL_Remove(esxVI_SharedCURL *shared, esxVI_CURL
*curl);
> */
>
> struct _esxVI_Context {
> + /* All members are used read-only after esxVI_Context_Connect ... */
> esxVI_CURL *curl;
> char *url;
> char *ipAddress;
> @@ -193,7 +194,8 @@ struct _esxVI_Context {
> esxVI_ServiceContent *service;
> esxVI_APIVersion apiVersion;
> esxVI_ProductVersion productVersion;
> - esxVI_UserSession *session;
> + esxVI_UserSession *session; /* ... except the session ... */
> + virMutexPtr sessionLock; /* ... that is protected by this mutex */
ACK, and thanks for those comments.
Thanks, pushed.
Matthias