[libvirt] [PATCH v4 2/7] virConnectRegisterCloseCallback: Cleanup 'opaque' if there is no connectRegisterCloseCallback
The commit 'close callback: move it to driver' (88f09b75eb99) moved
the responsibility for the close callback to the driver. But if the
driver doesn't support the connectRegisterCloseCallback API this
function does nothing, even no unsupported error report. This behavior
may lead to problems, for example memory leaks, as the caller cannot
differentiate whether the close callback was 'really' registered or
not.
Therefore call directly @freecb if the connectRegisterCloseCallback
API is not supported by the driver used by the connection and update
the documentation.
Signed-off-by: Marc Hartmayer <mhartmay(a)linux.ibm.com>
---
src/libvirt-host.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/src/libvirt-host.c b/src/libvirt-host.c
index 221a1b7a4353..94383ed449a9 100644
--- a/src/libvirt-host.c
+++ b/src/libvirt-host.c
@@ -1398,7 +1398,7 @@ virConnectIsAlive(virConnectPtr conn)
* @conn: pointer to connection object
* @cb: callback to invoke upon close
* @opaque: user data to pass to @cb
- * @freecb: callback to free @opaque
+ * @freecb: callback to free @opaque when not used anymore
*
* Registers a callback to be invoked when the connection
* is closed. This callback is invoked when there is any
@@ -1412,7 +1412,9 @@ virConnectIsAlive(virConnectPtr conn)
*
* The @freecb must not invoke any other libvirt public
* APIs, since it is not called from a re-entrant safe
- * context.
+ * context. Only if virConnectRegisterCloseCallback is
+ * successful, @freecb will be called, otherwise the
+ * caller is responsible to free @opaque.
*
* Returns 0 on success, -1 on error
*/
@@ -1428,9 +1430,13 @@ virConnectRegisterCloseCallback(virConnectPtr conn,
virCheckConnectReturn(conn, -1);
virCheckNonNullArgGoto(cb, error);
- if (conn->driver->connectRegisterCloseCallback &&
- conn->driver->connectRegisterCloseCallback(conn, cb, opaque, freecb) <
0)
- goto error;
+ if (conn->driver->connectRegisterCloseCallback) {
+ if (conn->driver->connectRegisterCloseCallback(conn, cb, opaque, freecb)
< 0)
+ goto error;
+ } else {
+ if (freecb)
+ freecb(opaque);
+ }
return 0;
--
2.21.0