[libvirt] [PATCH v2] ServerClient: Flush cached data

[Daniel P. Berrange]

On Tue, Nov 01, 2011 at 03:46:06PM +0100, Jiri Denemark wrote:
> From: Michal Privoznik <mprivozn at redhat.com>
> 
> If daemon is using SASL it reads client data into a cache. This cache is
> big (usually 65KB) and can thus contain 2 or more messages. However,
> on socket event we can dispatch only one message. So if we read two
> messages at once, the second will not be dispatched as the socket event
> goes away with filling the cache.
> Moreover, when dispatching the cache we need to remember to take care
> of client max requests limit.
> ---
>  src/rpc/virnetserverclient.c |   29 ++++++++++++++++++++++++++++-
>  1 files changed, 28 insertions(+), 1 deletions(-)
> 
> diff --git a/src/rpc/virnetserverclient.c b/src/rpc/virnetserverclient.c
> index 1256f0f..2f5ae8f 100644
> --- a/src/rpc/virnetserverclient.c
> +++ b/src/rpc/virnetserverclient.c
> @@ -72,6 +72,8 @@ struct _virNetServerClient
>  #if HAVE_SASL
>      virNetSASLSessionPtr sasl;
>  #endif
> +    int sockTimer; /* Timer to be fired upon cached data,
> +                    * so we jump out from poll() immediately */
>  
>      /* Count of messages in the 'tx' queue,
>       * and the server worker pool queue
> @@ -103,6 +105,7 @@ struct _virNetServerClient
>  
>  static void virNetServerClientDispatchEvent(virNetSocketPtr sock, int events, void *opaque);
>  static void virNetServerClientUpdateEvent(virNetServerClientPtr client);
> +static void virNetServerClientDispatchRead(virNetServerClientPtr client);
>  
>  static void virNetServerClientLock(virNetServerClientPtr client)
>  {
> @@ -204,6 +207,9 @@ static void virNetServerClientUpdateEvent(virNetServerClientPtr client)
>      mode = virNetServerClientCalculateHandleMode(client);
>  
>      virNetSocketUpdateIOCallback(client->sock, mode);
> +
> +    if (client->rx && virNetSocketHasCachedData(client->sock))
> +        virEventUpdateTimeout(client->sockTimer, 0);
>  }
>  
>  
> @@ -293,6 +299,19 @@ virNetServerClientCheckAccess(virNetServerClientPtr client)
>      return 0;
>  }
>  
> +static void virNetServerClientSockTimerFunc(int timer,
> +                                            void *opaque)
> +{
> +    virNetServerClientPtr client = opaque;
> +    virNetServerClientLock(client);
> +    virEventUpdateTimeout(timer, -1);
> +    /* Although client->rx != NULL when this timer is enabled, it might have
> +     * changed since the client was unlocked in the meantime. */
> +    if (client->rx)
> +        virNetServerClientDispatchRead(client);
> +    virNetServerClientUnlock(client);
> +}
> +
>  
>  virNetServerClientPtr virNetServerClientNew(virNetSocketPtr sock,
>                                              int auth,
> @@ -319,6 +338,11 @@ virNetServerClientPtr virNetServerClientNew(virNetSocketPtr sock,
>      client->tlsCtxt = tls;
>      client->nrequests_max = nrequests_max;
>  
> +    client->sockTimer = virEventAddTimeout(-1, virNetServerClientSockTimerFunc,
> +                                           client, NULL);
> +    if (client->sockTimer < 0)
> +        goto error;
> +
>      if (tls)
>          virNetTLSContextRef(tls);
>  
> @@ -557,6 +581,8 @@ void virNetServerClientFree(virNetServerClientPtr client)
>  #if HAVE_SASL
>      virNetSASLSessionFree(client->sasl);
>  #endif
> +    if (client->sockTimer > 0)
> +        virEventRemoveTimeout(client->sockTimer);
>      virNetTLSSessionFree(client->tls);
>      virNetTLSContextFree(client->tlsCtxt);
>      virNetSocketFree(client->sock);
> @@ -990,7 +1016,8 @@ virNetServerClientDispatchEvent(virNetSocketPtr sock, int events, void *opaque)
>          } else {
>              if (events & VIR_EVENT_HANDLE_WRITABLE)
>                  virNetServerClientDispatchWrite(client);
> -            if (events & VIR_EVENT_HANDLE_READABLE)
> +            if (events & VIR_EVENT_HANDLE_READABLE &&
> +                client->rx)
>                  virNetServerClientDispatchRead(client);
>          }
>      }

ACK this looks good


Daniel
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