perf python: Add support for 'struct perf_counts_values' to return counter data

Add support for the perf_counts_values struct to enable the python
bindings to read and return the counter data.

Committer notes:

Use T_ULONG instead of Py_T_ULONG, as all the other PyMemberDef arrays,
fixing the build with older python3 versions.

Use { .name = NULL, } to finish the new PyMemberDef
pyrf_counts_values_members array, again as the other arrays to please
some clang versions, ditto for PyGetSetDef.

Signed-off-by: Gautam Menghani <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Howard Chu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Madhavan Srinivasan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ian Rogers <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Gautam Menghani

tools/perf/util/python.c

@@ -626,6 +626,92 @@ static int pyrf_thread_map__setup_types(void)
 	return PyType_Ready(&pyrf_thread_map__type);
 }
 
+struct pyrf_counts_values {
+	PyObject_HEAD
+
+	struct perf_counts_values values;
+};
+
+static const char pyrf_counts_values__doc[] = PyDoc_STR("perf counts values object.");
+
+static void pyrf_counts_values__delete(struct pyrf_counts_values *pcounts_values)
+{
+	Py_TYPE(pcounts_values)->tp_free((PyObject *)pcounts_values);
+}
+
+#define counts_values_member_def(member, ptype, help) \
+	{ #member, ptype, \
+	  offsetof(struct pyrf_counts_values, values.member), \
+	  0, help }
+
+static PyMemberDef pyrf_counts_values_members[] = {
+	counts_values_member_def(val, T_ULONG, "Value of event"),
+	counts_values_member_def(ena, T_ULONG, "Time for which enabled"),
+	counts_values_member_def(run, T_ULONG, "Time for which running"),
+	counts_values_member_def(id, T_ULONG, "Unique ID for an event"),
+	counts_values_member_def(lost, T_ULONG, "Num of lost samples"),
+	{ .name = NULL, },
+};
+
+static PyObject *pyrf_counts_values_get_values(struct pyrf_counts_values *self, void *closure)
+{
+	PyObject *vals = PyList_New(5);
+
+	if (!vals)
+		return NULL;
+	for (int i = 0; i < 5; i++)
+		PyList_SetItem(vals, i, PyLong_FromLong(self->values.values[i]));
+
+	return vals;
+}
+
+static int pyrf_counts_values_set_values(struct pyrf_counts_values *self, PyObject *list,
+					 void *closure)
+{
+	Py_ssize_t size;
+	PyObject *item = NULL;
+
+	if (!PyList_Check(list)) {
+		PyErr_SetString(PyExc_TypeError, "Value assigned must be a list");
+		return -1;
+	}
+
+	size = PyList_Size(list);
+	for (Py_ssize_t i = 0; i < size; i++) {
+		item = PyList_GetItem(list, i);
+		if (!PyLong_Check(item)) {
+			PyErr_SetString(PyExc_TypeError, "List members should be numbers");
+			return -1;
+		}
+		self->values.values[i] = PyLong_AsLong(item);
+	}
+
+	return 0;
+}
+
+static PyGetSetDef pyrf_counts_values_getset[] = {
+	{"values", (getter)pyrf_counts_values_get_values, (setter)pyrf_counts_values_set_values,
+		"Name field", NULL},
+	{ .name = NULL, },
+};
+
+static PyTypeObject pyrf_counts_values__type = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	.tp_name	= "perf.counts_values",
+	.tp_basicsize	= sizeof(struct pyrf_counts_values),
+	.tp_dealloc	= (destructor)pyrf_counts_values__delete,
+	.tp_flags	= Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE,
+	.tp_doc		= pyrf_counts_values__doc,
+	.tp_members	= pyrf_counts_values_members,
+	.tp_getset	= pyrf_counts_values_getset,
+};
+
+static int pyrf_counts_values__setup_types(void)
+{
+	pyrf_counts_values__type.tp_new = PyType_GenericNew;
+	return PyType_Ready(&pyrf_counts_values__type);
+}
+
 struct pyrf_evsel {
 	PyObject_HEAD
 
@@ -1475,7 +1561,8 @@ PyMODINIT_FUNC PyInit_perf(void)
 	    pyrf_evlist__setup_types() < 0 ||
 	    pyrf_evsel__setup_types() < 0 ||
 	    pyrf_thread_map__setup_types() < 0 ||
-	    pyrf_cpu_map__setup_types() < 0)
+	    pyrf_cpu_map__setup_types() < 0 ||
+	    pyrf_counts_values__setup_types() < 0)
 		return module;
 
 	/* The page_size is placed in util object. */
@@ -1520,6 +1607,9 @@ PyMODINIT_FUNC PyInit_perf(void)
 	Py_INCREF(&pyrf_cpu_map__type);
 	PyModule_AddObject(module, "cpu_map", (PyObject*)&pyrf_cpu_map__type);
 
+	Py_INCREF(&pyrf_counts_values__type);
+	PyModule_AddObject(module, "counts_values", (PyObject *)&pyrf_counts_values__type);
+
 	dict = PyModule_GetDict(module);
 	if (dict == NULL)
 		goto error;