[libvirt] [PATCH 4/9] admin: Add support for connection close callbacks
Erik Skultety
eskultet at redhat.com
Tue Oct 13 13:38:17 UTC 2015
As we need a client disconnect handler, we need a mechanism to register
such handlers for a client.
---
include/libvirt/libvirt-admin.h | 19 ++++++
src/datatypes.c | 22 +++++++
src/datatypes.h | 14 +++-
src/libvirt-admin.c | 142 ++++++++++++++++++++++++++++++++++++++++
src/libvirt_admin_public.syms | 2 +
tools/virt-admin.c | 5 ++
6 files changed, 203 insertions(+), 1 deletion(-)
diff --git a/include/libvirt/libvirt-admin.h b/include/libvirt/libvirt-admin.h
index 72671c6..4539ac6 100644
--- a/include/libvirt/libvirt-admin.h
+++ b/include/libvirt/libvirt-admin.h
@@ -54,6 +54,25 @@ int virAdmConnectClose(virAdmConnectPtr conn);
int virAdmConnectRef(virAdmConnectPtr conn);
int virAdmConnectIsAlive(virAdmConnectPtr conn);
+/**
+ * virAdmConnectCloseFunc:
+ * @conn: virAdmConnect connection
+ * @reason: reason why the connection was closed (see virConnectCloseReason)
+ * @opaque: opaque client data
+ *
+ * A callback to be registered, in case a connection was closed.
+ */
+typedef void (*virAdmConnectCloseFunc)(virAdmConnectPtr conn,
+ int reason,
+ void *opaque);
+
+int virAdmConnectRegisterCloseCallback(virAdmConnectPtr conn,
+ virAdmConnectCloseFunc cb,
+ void *opaque,
+ virFreeCallback freecb);
+int virAdmConnectUnregisterCloseCallback(virAdmConnectPtr conn,
+ virAdmConnectCloseFunc cb);
+
# ifdef __cplusplus
}
# endif
diff --git a/src/datatypes.c b/src/datatypes.c
index 12bcfc1..9e374e4 100644
--- a/src/datatypes.c
+++ b/src/datatypes.c
@@ -60,8 +60,10 @@ static void virStorageVolDispose(void *obj);
static void virStoragePoolDispose(void *obj);
virClassPtr virAdmConnectClass;
+virClassPtr virAdmConnectCloseCallbackDataClass;
static void virAdmConnectDispose(void *obj);
+static void virAdmConnectCloseCallbackDataDispose(void *obj);
static int
virDataTypesOnceInit(void)
@@ -91,6 +93,7 @@ virDataTypesOnceInit(void)
DECLARE_CLASS(virStoragePool);
DECLARE_CLASS_LOCKABLE(virAdmConnect);
+ DECLARE_CLASS_LOCKABLE(virAdmConnectCloseCallbackData);
#undef DECLARE_CLASS_COMMON
#undef DECLARE_CLASS_LOCKABLE
@@ -822,6 +825,9 @@ virAdmConnectNew(void)
if (!(ret = virObjectLockableNew(virAdmConnectClass)))
return NULL;
+ if (!(ret->closeCallback = virObjectLockableNew(virAdmConnectCloseCallbackDataClass)))
+ return NULL;
+
return ret;
}
@@ -832,4 +838,20 @@ virAdmConnectDispose(void *obj)
if (conn->privateDataFreeFunc)
conn->privateDataFreeFunc(conn);
+
+ virObjectUnref(conn->closeCallback);
+}
+
+static void
+virAdmConnectCloseCallbackDataDispose(void *obj)
+{
+ virAdmConnectCloseCallbackDataPtr cb_data = obj;
+
+ virObjectLock(cb_data);
+
+ cb_data->callback = NULL;
+ if (cb_data->freeCallback)
+ cb_data->freeCallback(cb_data->opaque);
+
+ virObjectUnlock(cb_data);
}
diff --git a/src/datatypes.h b/src/datatypes.h
index be108fe..33df476 100644
--- a/src/datatypes.h
+++ b/src/datatypes.h
@@ -331,9 +331,11 @@ extern virClassPtr virAdmConnectClass;
typedef struct _virConnectCloseCallbackData virConnectCloseCallbackData;
typedef virConnectCloseCallbackData *virConnectCloseCallbackDataPtr;
+typedef struct _virAdmConnectCloseCallbackData virAdmConnectCloseCallbackData;
+typedef virAdmConnectCloseCallbackData *virAdmConnectCloseCallbackDataPtr;
/**
- * Internal structure holding data related to connection close callbacks.
+ * Internal structures holding data related to connection close callbacks.
*/
struct _virConnectCloseCallbackData {
virObjectLockable parent;
@@ -344,6 +346,15 @@ struct _virConnectCloseCallbackData {
virFreeCallback freeCallback;
};
+struct _virAdmConnectCloseCallbackData {
+ virObjectLockable parent;
+
+ virAdmConnectPtr conn;
+ virAdmConnectCloseFunc callback;
+ void *opaque;
+ virFreeCallback freeCallback;
+};
+
/**
* _virConnect:
*
@@ -400,6 +411,7 @@ struct _virAdmConnect {
void *privateData;
virFreeCallback privateDataFreeFunc;
+ virAdmConnectCloseCallbackDataPtr closeCallback;
};
diff --git a/src/libvirt-admin.c b/src/libvirt-admin.c
index e12e2b8..9ad124e 100644
--- a/src/libvirt-admin.c
+++ b/src/libvirt-admin.c
@@ -64,9 +64,31 @@ remoteAdminPrivDispose(void *opaque)
remoteAdminPrivPtr priv = opaque;
virObjectUnref(priv->program);
+ virNetClientClose(priv->client);
virObjectUnref(priv->client);
}
+static void
+remoteAdminClientCloseFunc(virNetClientPtr client ATTRIBUTE_UNUSED,
+ int reason,
+ void *opaque)
+{
+ virAdmConnectCloseCallbackDataPtr cbdata = opaque;
+
+ virObjectLock(cbdata);
+
+ if (cbdata->callback) {
+ VIR_DEBUG("Triggering connection close callback %p reason=%d, opaque=%p",
+ cbdata->callback, reason, cbdata->opaque);
+ cbdata->callback(cbdata->conn, reason, cbdata->opaque);
+
+ if (cbdata->freeCallback)
+ cbdata->freeCallback(cbdata->opaque);
+ cbdata->callback = NULL;
+ cbdata->freeCallback = NULL;
+ }
+ virObjectUnlock(cbdata);
+}
static int
callFull(virAdmConnectPtr conn ATTRIBUTE_UNUSED,
@@ -137,6 +159,11 @@ remoteAdminConnectOpen(virAdmConnectPtr conn, unsigned int flags)
args.flags = flags;
+ virObjectRef(conn->closeCallback);
+ virNetClientSetCloseCallback(priv->client, remoteAdminClientCloseFunc,
+ conn->closeCallback,
+ virObjectFreeCallback);
+
if (call(conn, 0, ADMIN_PROC_CONNECT_OPEN,
(xdrproc_t)xdr_admin_connect_open_args, (char *)&args,
(xdrproc_t)xdr_void, (char *)NULL) == -1) {
@@ -164,6 +191,9 @@ remoteAdminConnectClose(virAdmConnectPtr conn)
goto done;
}
+ virNetClientSetCloseCallback(priv->client, NULL, conn->closeCallback,
+ virObjectFreeCallback);
+
rv = 0;
done:
@@ -462,3 +492,115 @@ virAdmConnectIsAlive(virAdmConnectPtr conn)
else
return 0;
}
+
+/**
+ * virAdmConnectRegisterCloseCallback:
+ * @conn: connection to admin server
+ * @cb: callback to be invoked upon connection close
+ * @opaque: user data to pass to @cb
+ * @freecb: callback to free @opaque
+ *
+ * Registers a callback to be invoked when the connection
+ * is closed. This callback is invoked when there is any
+ * condition that causes the socket connection to the
+ * hypervisor to be closed.
+ *
+ * The @freecb must not invoke any other libvirt public
+ * APIs, since it is not called from a re-entrant safe
+ * context.
+ *
+ * Returns 0 on success, -1 on error
+ */
+int virAdmConnectRegisterCloseCallback(virAdmConnectPtr conn,
+ virAdmConnectCloseFunc cb,
+ void *opaque,
+ virFreeCallback freecb)
+{
+ VIR_DEBUG("conn=%p", conn);
+
+ virResetLastError();
+
+ virCheckAdmConnectReturn(conn, -1);
+
+ virObjectRef(conn);
+
+ virObjectLock(conn);
+ virObjectLock(conn->closeCallback);
+
+ virCheckNonNullArgGoto(cb, error);
+
+ if (conn->closeCallback->callback) {
+ virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+ _("A close callback is already registered"));
+ goto error;
+ }
+
+ conn->closeCallback->conn = conn;
+ conn->closeCallback->callback = cb;
+ conn->closeCallback->opaque = opaque;
+ conn->closeCallback->freeCallback = freecb;
+
+ virObjectUnlock(conn->closeCallback);
+ virObjectUnlock(conn);
+
+ return 0;
+
+ error:
+ virObjectUnlock(conn->closeCallback);
+ virObjectUnlock(conn);
+ virDispatchError(NULL);
+ virObjectUnref(conn);
+ return -1;
+
+}
+
+/**
+ * virAdmConnectUnregisterCloseCallback:
+ * @conn: pointer to connection object
+ * @cb: pointer to the current registered callback
+ *
+ * Unregisters the callback previously set with the
+ * virAdmConnectRegisterCloseCallback method. The callback
+ * will no longer receive notifications when the connection
+ * closes. If a virFreeCallback was provided at time of
+ * registration, it will be invoked.
+ *
+ * Returns 0 on success, -1 on error
+ */
+int virAdmConnectUnregisterCloseCallback(virAdmConnectPtr conn,
+ virAdmConnectCloseFunc cb)
+{
+ VIR_DEBUG("conn=%p", conn);
+
+ virResetLastError();
+
+ virCheckAdmConnectReturn(conn, -1);
+
+ virObjectLock(conn);
+ virObjectLock(conn->closeCallback);
+
+ virCheckNonNullArgGoto(cb, error);
+
+ if (conn->closeCallback->callback != cb) {
+ virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+ _("A different callback was requested"));
+ goto error;
+ }
+
+ conn->closeCallback->callback = NULL;
+ if (conn->closeCallback->freeCallback)
+ conn->closeCallback->freeCallback(conn->closeCallback->opaque);
+ conn->closeCallback->freeCallback = NULL;
+
+ virObjectUnlock(conn->closeCallback);
+ virObjectUnlock(conn);
+ virObjectUnref(conn);
+
+ return 0;
+
+ error:
+ virObjectUnlock(conn->closeCallback);
+ virObjectUnlock(conn);
+ virDispatchError(NULL);
+ return -1;
+}
diff --git a/src/libvirt_admin_public.syms b/src/libvirt_admin_public.syms
index 16cfd42..5b9ba51 100644
--- a/src/libvirt_admin_public.syms
+++ b/src/libvirt_admin_public.syms
@@ -16,4 +16,6 @@ LIBVIRT_ADMIN_1.3.0 {
virAdmConnectClose;
virAdmConnectRef;
virAdmConnectIsAlive;
+ virAdmConnectRegisterCloseCallback;
+ virAdmConnectUnregisterCloseCallback;
};
diff --git a/tools/virt-admin.c b/tools/virt-admin.c
index 4964e3d..679ae99 100644
--- a/tools/virt-admin.c
+++ b/tools/virt-admin.c
@@ -91,6 +91,10 @@ vshAdmConnect(vshControl *ctl, unsigned int flags)
vshError(ctl, "%s", _("Failed to connect to the admin server"));
return NULL;
} else {
+ if (virAdmConnectRegisterCloseCallback(priv->conn, NULL, NULL,
+ NULL) < 0)
+ vshError(ctl, "%s", _("Unable to register disconnect callback"));
+
if (priv->wantReconnect)
vshPrint(ctl, "%s\n", _("Reconnected to the admin server"));
else
@@ -108,6 +112,7 @@ vshAdmDisconnectInternal(vshControl *ctl, virAdmConnectPtr *conn)
if (!*conn)
return ret;
+ virAdmConnectUnregisterCloseCallback(*conn, NULL);
ret = virAdmConnectClose(*conn);
if (ret < 0)
vshError(ctl, "%s", _("Failed to disconnect from the admin server"));
--
2.4.3
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