[libvirt] [PATCH] python: Don't free must-not-free variables

Michal Privoznik mprivozn at redhat.com
Mon May 23 12:47:29 UTC 2011


py_str() function call PyString_AsString(). As written in documentation,
the caller must not free the returned value, because it points to some
internal structures.
---
 python/libvirt-override.c |   15 ++++++---------
 1 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/python/libvirt-override.c b/python/libvirt-override.c
index a151e78..7998723 100644
--- a/python/libvirt-override.c
+++ b/python/libvirt-override.c
@@ -35,6 +35,8 @@ extern void initcygvirtmod(void);
 #define VIR_PY_INT_FAIL (libvirt_intWrap(-1))
 #define VIR_PY_INT_SUCCESS (libvirt_intWrap(0))
 
+/* We don't want to free() returned value, as written in doc
+ * to PyString_AsString. */
 static char *py_str(PyObject *obj)
 {
     PyObject *str = PyObject_Str(obj);
@@ -2660,7 +2662,6 @@ libvirt_virEventAddHandleFunc  (int fd,
         char *name = py_str(python_cb);
         printf("%s: %s is not callable\n", __FUNCTION__,
                name ? name : "libvirt.eventInvokeHandleCallback");
-        free(name);
 #endif
         goto cleanup;
     }
@@ -2805,7 +2806,6 @@ libvirt_virEventAddTimeoutFunc(int timeout,
         char *name = py_str(python_cb);
         printf("%s: %s is not callable\n", __FUNCTION__,
                name ? name : "libvirt.eventInvokeTimeoutCallback");
-        free(name);
 #endif
         goto cleanup;
     }
@@ -2919,17 +2919,11 @@ libvirt_virEventRegisterImpl(ATTRIBUTE_UNUSED PyObject * self,
 {
     /* Unref the previously-registered impl (if any) */
     Py_XDECREF(addHandleObj);
-    free(addHandleName);
     Py_XDECREF(updateHandleObj);
-    free(updateHandleName);
     Py_XDECREF(removeHandleObj);
-    free(removeHandleName);
     Py_XDECREF(addTimeoutObj);
-    free(addTimeoutName);
     Py_XDECREF(updateTimeoutObj);
-    free(updateTimeoutName);
     Py_XDECREF(removeTimeoutObj);
-    free(removeTimeoutName);
 
     /* Parse and check arguments */
     if (!PyArg_ParseTuple(args, (char *) "OOOOOO:virEventRegisterImpl",
@@ -2944,7 +2938,10 @@ libvirt_virEventRegisterImpl(ATTRIBUTE_UNUSED PyObject * self,
         !PyCallable_Check(removeTimeoutObj))
         return VIR_PY_INT_FAIL;
 
-    /* Get argument string representations (for error reporting) */
+    /* Get argument string representations (for error reporting).
+     * py_str calls PyString_AsString() which returns pointer to:
+     * 'internal buffer of string, not a copy.' and 'It must not be
+     * deallocated' (pyhton c-api documentation) */
     addHandleName = py_str(addHandleObj);
     updateHandleName = py_str(updateHandleObj);
     removeHandleName = py_str(removeHandleObj);
-- 
1.7.5.rc3




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