Fix: bt2: autodisc: remove thread error while inserting status in map

If something fails in `bt_bt2_auto_discover_source_components`, we
append an error cause and we go to the error label.  This function
returns a bt_value map containing the return status code and the auto-discovery results, if it was successful.
So we then run into:

	if (result) {
		insert_entry_status = bt_value_map_insert_signed_integer_entry(result, "status", status);
		if (insert_entry_status != BT_VALUE_MAP_INSERT_ENTRY_STATUS_OK) {
			BT_VALUE_PUT_REF_AND_RESET(result);
			PyErr_NoMemory();
		}
	}

However, since there is an error on the current thread, we fail this
precondition:

    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:64 Babeltrace 2 library precondition not satisfied.
    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:66 ------------------------------------------------------------------------
    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:67 Condition ID: `pre:value-map-insert-signed-integer-entry:no-error`.
    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:69 Function: bt_value_map_insert_signed_integer_entry().
    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:70 ------------------------------------------------------------------------
    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:71 Error is:
    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:73 API function called while current thread has an error: function=bt_value_map_insert_signed_integer_entry
    06-30 11:27:11.697 3948806 3948806 F LIB/ASSERT-COND bt_lib_assert_cond_failed@assert-cond.c:76 Aborting...

Change the function to temporarily remove the current thread error,
while inserting the status in the map.  In the unlikely event where the
insertion fail because of a memory error, then we just release the error
and it gets lost.

Change-Id: I1b54fb7c8cb0f719fee867e7385dd6a3949cbde4
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/8512
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>

diff --git a/src/bindings/python/bt2/bt2/native_bt_autodisc.i.h b/src/bindings/python/bt2/bt2/native_bt_autodisc.i.h
index 43e9dc82e534f6e244c6b04c89b1c6f48e14f840..d6a4d24bbe1ae0d3f089ee6639ac8ca081111d43 100644 (file)
--- a/src/bindings/python/bt2/bt2/native_bt_autodisc.i.h
+++ b/src/bindings/python/bt2/bt2/native_bt_autodisc.i.h
@@ -43,6 +43,7 @@ bt_value *bt_bt2_auto_discover_source_components(const bt_value *inputs,
        bt_value *components_list = NULL;
        bt_value *component_info = NULL;
        bt_value_map_insert_entry_status insert_entry_status;
        bt_value *components_list = NULL;
        bt_value *component_info = NULL;
        bt_value_map_insert_entry_status insert_entry_status;

+       const bt_error *error = NULL;

 
        BT_ASSERT(bt_value_get_type(inputs) == BT_VALUE_TYPE_ARRAY);
        for (i = 0; i < bt_value_array_get_length(inputs); i++) {
 
        BT_ASSERT(bt_value_get_type(inputs) == BT_VALUE_TYPE_ARRAY);
        for (i = 0; i < bt_value_array_get_length(inputs); i++) {


@@ -178,11 +179,23 @@ error:
 
 end:
        if (result) {
 
 end:
        if (result) {

+               /*
+                * If an error happened, we must clear the error temporarily
+                * while we insert the status in the map.
+                */
+               error = bt_current_thread_take_error();

                insert_entry_status = bt_value_map_insert_signed_integer_entry(result, "status", status);
                insert_entry_status = bt_value_map_insert_signed_integer_entry(result, "status", status);

-               if (insert_entry_status != BT_VALUE_MAP_INSERT_ENTRY_STATUS_OK) {
+               if (insert_entry_status == BT_VALUE_MAP_INSERT_ENTRY_STATUS_OK) {
+                       if (error) {
+                               bt_current_thread_move_error(error);
+                               error = NULL;
+                       }
+               } else {

                        BT_VALUE_PUT_REF_AND_RESET(result);
                        PyErr_NoMemory();
                }
                        BT_VALUE_PUT_REF_AND_RESET(result);
                        PyErr_NoMemory();
                }

+
+

        }
 
        auto_source_discovery_fini(&auto_disc);
        }
 
        auto_source_discovery_fini(&auto_disc);


@@ -190,5 +203,9 @@ end:
        bt_value_put_ref(components_list);
        bt_value_put_ref(component_info);
 
        bt_value_put_ref(components_list);
        bt_value_put_ref(component_info);
 

+       if (error) {
+               bt_error_release(error);
+       }
+

        return result;
 }
        return result;
 }

diff --git a/tests/bindings/python/bt2/test_trace_collection_message_iterator.py b/tests/bindings/python/bt2/test_trace_collection_message_iterator.py
index c9a6ebd73eda11c15715555e7871328bd755fa2a..954b149c33645fc47c625b60a7681f1c130f08b1 100644 (file)
--- a/tests/bindings/python/bt2/test_trace_collection_message_iterator.py
+++ b/tests/bindings/python/bt2/test_trace_collection_message_iterator.py
@@ -26,6 +26,10 @@ _AUTO_SOURCE_DISCOVERY_PARAMS_LOG_LEVEL_PATH = os.path.join(
     _BT_TESTS_DATADIR, "auto-source-discovery", "params-log-level"
 )
 
     _BT_TESTS_DATADIR, "auto-source-discovery", "params-log-level"
 )
 

+_METADATA_SYNTAX_ERROR_TRACE_PATH = os.path.join(
+    _BT_CTF_TRACES_PATH, "fail", "metadata-syntax-error"
+)
+

 
 class _SomeSource(
     bt2._UserSourceComponent, message_iterator_class=bt2._UserMessageIterator
 
 class _SomeSource(
     bt2._UserSourceComponent, message_iterator_class=bt2._UserMessageIterator


@@ -709,5 +713,15 @@ class TestAutoDiscoverSourceComponentSpecsParamsObjLogLevel(
         self.assertEqual(msgs[1].stream.name, "TestSourceB: deore")
 
 
         self.assertEqual(msgs[1].stream.name, "TestSourceB: deore")
 
 

+class TestAutoDiscoverFailures(unittest.TestCase):
+    def test_metadata_syntax_error(self):
+        with self.assertRaisesRegex(
+            bt2._Error,
+            'At line 3 in metadata stream: syntax error, unexpected CTF_RSBRAC: token="]"',
+        ):
+            specs = [bt2.AutoSourceComponentSpec(_METADATA_SYNTAX_ERROR_TRACE_PATH)]
+            bt2.TraceCollectionMessageIterator(specs)
+
+

 if __name__ == "__main__":
     unittest.main()
 if __name__ == "__main__":
     unittest.main()