| 1 | import bt2 |
| 2 | |
| 3 | # Run callable `func` in the context of a component's __init__ method. The |
| 4 | # callable is passed the Component being instantiated. |
| 5 | # |
| 6 | # The value returned by the callable is returned by run_in_component_init. |
| 7 | |
| 8 | def run_in_component_init(func): |
| 9 | class MySink(bt2._UserSinkComponent): |
| 10 | def __init__(self, params): |
| 11 | nonlocal res_bound |
| 12 | res_bound = func(self) |
| 13 | |
| 14 | def _consume(self): |
| 15 | pass |
| 16 | |
| 17 | g = bt2.Graph() |
| 18 | res_bound = None |
| 19 | g.add_component(MySink, 'comp') |
| 20 | |
| 21 | # We deliberately use a different variable for returning the result than |
| 22 | # the variable bound to the MySink.__init__ context and delete res_bound. |
| 23 | # The MySink.__init__ context stays alive until the end of the program, so |
| 24 | # if res_bound were to still point to our result, it would contribute an |
| 25 | # unexpected reference to the refcount of the result, from the point of view |
| 26 | # of the user of this function. It would then affect destruction tests, |
| 27 | # for example, which want to test what happens when the refcount of a Python |
| 28 | # object reaches 0. |
| 29 | |
| 30 | res = res_bound |
| 31 | del res_bound |
| 32 | return res |
| 33 | |
| 34 | # Create an empty trace class with default values. |
| 35 | |
| 36 | def get_default_trace_class(): |
| 37 | def f(comp_self): |
| 38 | return comp_self._create_trace_class() |
| 39 | |
| 40 | return run_in_component_init(f) |