[PATCH 2/2] trace-cruncher: Add attach()

["Yordan Karadzhov (VMware)" <y.karadz@gmail.com>]

Here we add mechanisms that will make possible to reattach object to
the ftracepy module. This means that the object will be properly
destroyed when the module exits.

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
 src/ftracepy-utils.c                           | 18 ++++++++++++++----
 src/ftracepy-utils.h                           |  2 ++
 src/ftracepy.c                                 |  5 +++++
 .../tests/1_unit/test_01_ftracepy_unit.py      | 13 +++++++++++++
 4 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/src/ftracepy-utils.c b/src/ftracepy-utils.c
index bf811ae..d4fa59e 100644
--- a/src/ftracepy-utils.c
+++ b/src/ftracepy-utils.c
@@ -507,24 +507,34 @@ static void set_destroy_flag(PyObject *py_obj, bool val)
 	obj_head->destroy = val;
 }
 
-PyObject *PyFtrace_detach(PyObject *self, PyObject *args, PyObject *kwargs)
+static PyObject *set_destroy(PyObject *args, PyObject *kwargs, bool destroy)
 {
 	static char *kwlist[] = {"object", NULL};
-	PyObject *py_obj = NULL;
+	PyObject *py_obj;
 
 	if (!PyArg_ParseTupleAndKeywords(args,
 					 kwargs,
 					 "O",
 					 kwlist,
 					 &py_obj)) {
-		return false;
+		return NULL;
 	}
 
-	set_destroy_flag(py_obj, false);
+	set_destroy_flag(py_obj, destroy);
 
 	Py_RETURN_NONE;
 }
 
+PyObject *PyFtrace_detach(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+	return set_destroy(args, kwargs, false);
+}
+
+PyObject *PyFtrace_attach(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+	return set_destroy(args, kwargs, true);
+}
+
 static char aname_pool[] =
 	"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
diff --git a/src/ftracepy-utils.h b/src/ftracepy-utils.h
index c1eec21..be1b37c 100644
--- a/src/ftracepy-utils.h
+++ b/src/ftracepy-utils.h
@@ -83,6 +83,8 @@ PyObject *PyFtrace_dir(PyObject *self);
 
 PyObject *PyFtrace_detach(PyObject *self, PyObject *args, PyObject *kwargs);
 
+PyObject *PyFtrace_attach(PyObject *self, PyObject *args, PyObject *kwargs);
+
 PyObject *PyFtrace_create_instance(PyObject *self, PyObject *args,
 						   PyObject *kwargs);
 
diff --git a/src/ftracepy.c b/src/ftracepy.c
index e48adb6..763a7d2 100644
--- a/src/ftracepy.c
+++ b/src/ftracepy.c
@@ -150,6 +150,11 @@ static PyMethodDef ftracepy_methods[] = {
 	 METH_VARARGS | METH_KEYWORDS,
 	 "Detach object from the \'ftracepy\' module."
 	},
+	{"attach",
+	 (PyCFunction) PyFtrace_attach,
+	 METH_VARARGS | METH_KEYWORDS,
+	 "Attach object to the \'ftracepy\' module."
+	},
 	{"create_instance",
 	 (PyCFunction) PyFtrace_create_instance,
 	 METH_VARARGS | METH_KEYWORDS,
diff --git a/tracecruncher/tests/1_unit/test_01_ftracepy_unit.py b/tracecruncher/tests/1_unit/test_01_ftracepy_unit.py
index a7010e2..d3e3960 100644
--- a/tracecruncher/tests/1_unit/test_01_ftracepy_unit.py
+++ b/tracecruncher/tests/1_unit/test_01_ftracepy_unit.py
@@ -48,6 +48,19 @@ class InstanceTestCase(unittest.TestCase):
             inst_2 = ft.find_instance(another_instance_name)
         self.assertTrue(err in str(context.exception))
 
+    def test_1_detach(self):
+        inst = ft.create_instance(instance_name)
+        ft.detach(inst)
+
+    def test_2_attach(self):
+        inst = ft.find_instance(instance_name)
+        ft.attach(inst)
+
+    def test_3_attach(self):
+        tracefs_dir = ft.dir();
+        instance_dir = tracefs_dir + '/instances/' + instance_name
+        self.assertFalse(os.path.isdir(instance_dir))
+
 
 class PyTepTestCase(unittest.TestCase):
     def test_init_local(self):
-- 
2.30.2