11:05 a.m.
virConnectSetKeepAlive public API can be used by a client connecting to
remote server to start using keepalive protocol. The API is handled
directly by remote driver and not transmitted over the wire to the
server.
---
Notes:
Version 3 ACKed.
Version 4:
- explicitly document the semantics of interval <= 0 and count = 0
Version 3:
- remove virConnectAllowKeepAlive
- rename virConnectStartKeepAlive as virConnectSetKeepAlive
- add a note to virEventRegisterImpl that running the event loop
is mandatory once registered
Version 2:
- no change
include/libvirt/libvirt.h.in | 4 +++
src/driver.h | 5 +++
src/libvirt.c | 57 ++++++++++++++++++++++++++++++++++++++++++
src/libvirt_internal.h | 10 ++++++-
src/libvirt_public.syms | 1 +
src/util/event.c | 6 ++--
6 files changed, 78 insertions(+), 5 deletions(-)
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 7102bce..8ce4335 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -3275,6 +3275,10 @@ typedef struct _virTypedParameter virMemoryParameter;
*/
typedef virMemoryParameter *virMemoryParameterPtr;
+int virConnectSetKeepAlive(virConnectPtr conn,
+ int interval,
+ unsigned int count);
+
#ifdef __cplusplus
}
#endif
diff --git a/src/driver.h b/src/driver.h
index b899d0e..c1223c1 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -735,6 +735,10 @@ typedef int
(*virDrvDomainBlockPull)(virDomainPtr dom, const char *path,
unsigned long bandwidth, unsigned int flags);
+typedef int
+ (*virDrvSetKeepAlive)(virConnectPtr conn,
+ int interval,
+ unsigned int count);
/**
* _virDriver:
@@ -893,6 +897,7 @@ struct _virDriver {
virDrvDomainGetBlockJobInfo domainGetBlockJobInfo;
virDrvDomainBlockJobSetSpeed domainBlockJobSetSpeed;
virDrvDomainBlockPull domainBlockPull;
+ virDrvSetKeepAlive setKeepAlive;
};
typedef int
diff --git a/src/libvirt.c b/src/libvirt.c
index a6bcee6..0c33da1 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -16964,3 +16964,60 @@ error:
virDispatchError(dom->conn);
return -1;
}
+
+/**
+ * virConnectSetKeepAlive:
+ * @conn: pointer to a hypervisor connection
+ * @interval: number of seconds of inactivity before a keepalive message is sent
+ * @count: number of messages that can be sent in a row
+ *
+ * Start sending keepalive messages after interval second of inactivity and
+ * consider the connection to be broken when no response is received after
+ * count keepalive messages sent in a row. In other words, sending count + 1
+ * keepalive message results in closing the connection. When interval is <= 0,
+ * no keepalive messages will be sent. When count is 0, the connection will be
+ * automatically closed after interval seconds of inactivity without sending
+ * any keepalive messages.
+ *
+ * Note: client has to implement and run event loop to be able to use keepalive
+ * messages. Failure to do so may result in connections being closed
+ * unexpectedly.
+ *
+ * Returns -1 on error, 0 on success, 1 when remote party doesn't support
+ * keepalive messages.
+ */
+int virConnectSetKeepAlive(virConnectPtr conn,
+ int interval,
+ unsigned int count)
+{
+ int ret = -1;
+
+ VIR_DEBUG("conn=%p, interval=%d, count=%u", conn, interval, count);
+
+ virResetLastError();
+
+ if (!VIR_IS_CONNECT(conn)) {
+ virLibConnError(VIR_ERR_INVALID_CONN, __FUNCTION__);
+ virDispatchError(NULL);
+ return -1;
+ }
+
+ if (interval <= 0) {
+ virLibConnError(VIR_ERR_INVALID_ARG,
+ _("negative or zero interval make no sense"));
+ goto error;
+ }
+
+ if (conn->driver->setKeepAlive) {
+ ret = conn->driver->setKeepAlive(conn, interval, count);
+ if (ret < 0)
+ goto error;
+ return ret;
+ }
+
+ virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+ virDispatchError(conn);
+ return -1;
+}
diff --git a/src/libvirt_internal.h b/src/libvirt_internal.h
index 6e44341..dbbf7e0 100644
--- a/src/libvirt_internal.h
+++ b/src/libvirt_internal.h
@@ -39,8 +39,8 @@ int virStateActive(void);
*
* The remote driver passes features through to the real driver at the
* remote end unmodified, except if you query a VIR_DRV_FEATURE_REMOTE*
- * feature.
- *
+ * feature. Queries for VIR_DRV_FEATURE_PROGRAM* features are answered
+ * directly by the RPC layer and not by the real driver.
*/
enum {
/* Driver supports V1-style virDomainMigrate, ie. domainMigratePrepare/
@@ -79,6 +79,12 @@ enum {
* to domain configuration, i.e., starting from Begin3 and not Perform3.
*/
VIR_DRV_FEATURE_MIGRATE_CHANGE_PROTECTION = 7,
+
+ /*
+ * Remote party supports keepalive program (i.e., sending keepalive
+ * messages).
+ */
+ VIR_DRV_FEATURE_PROGRAM_KEEPALIVE = 8,
};
diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
index 9762fc4..468e28a 100644
--- a/src/libvirt_public.syms
+++ b/src/libvirt_public.syms
@@ -491,6 +491,7 @@ LIBVIRT_0.9.5 {
LIBVIRT_0.9.7 {
global:
+ virConnectSetKeepAlive;
virDomainReset;
virDomainSnapshotGetParent;
virDomainSnapshotListChildrenNames;
diff --git a/src/util/event.c b/src/util/event.c
index bd781ec..495a1f3 100644
--- a/src/util/event.c
+++ b/src/util/event.c
@@ -193,9 +193,9 @@ void virEventRegisterImpl(virEventAddHandleFunc addHandle,
* not have a need to integrate with an external event
* loop impl.
*
- * Once registered, the application can invoke
- * virEventRunDefaultImpl in a loop to process
- * events
+ * Once registered, the application has to invoke virEventRunDefaultImpl in
+ * a loop to process events. Failure to do so may result in connections being
+ * closed unexpectedly as a result of keepalive timeout.
*
* Returns 0 on success, -1 on failure.
*/
--
1.7.7.1