2013/9/17 Victor Stinner <victor.stin...@gmail.com>: > Issue tracking the implementation: > http://bugs.python.org/issue18874
If you want to test the implementation, you can try the following repository: http://hg.python.org/features/tracemalloc Or try the patch attached on the issue #18874 on the Python default version. Compile Python and use "-X tracemalloc" command line option to enable the module at startup. Then you can play with tracemalloc.DisplayTopTask.display() and tracemalloc.TakeSnapshot.take_snapshot(). To create Python snapshots easily, modify Lib/test/regrtest.py to use the following block: take = tracemalloc.TakeSnapshot() # tracemalloc.set_traceback_limit(15); take.with_traces = True take.filename_template = "/tmp/tracemalloc-$pid-$counter.pickle" take.start(10) And then start: ./python -X tracemalloc -m test "take.with_traces = True" is slower but required if you want to use cumulative views, show the traceback, or group traces by address. Use a lower traceback limit if the test suite is too slow. When you get a snapshot file, you can analyze it using: ./python -m tracemalloc /tmp/tracemalloc-1564-0001.pickle Add --help to see all options. I like the --traceback option. > ``get_filters()`` function: > > Get the filters on Python memory allocations as list of ``Filter`` > instances. I hesitate to add a Filters class which would contain a list of filters. The logic to check if list of filters matchs is non-trivial. You have to split inclusive and exclusive filters and take care of empty list of inclusive/exclusive filters. See the code of Snapshot.apply_filters() for example. > ``get_object_trace(obj)`` function: > > Get the trace of a Python object *obj* as a ``Trace`` instance. > > The function only returns the trace of the memory block directly > holding to object. The ``size`` attribute of the trace is smaller > than the total size of the object if the object is composed of more > than one memory block. > > Return ``None`` if the ``tracemalloc`` module did not trace the > allocation of the object. > > See also ``gc.get_referrers()`` and ``sys.getsizeof()`` functions. The function can be see of a lie because it does not count all bytes of a object (as explained in the doc above). The function should maybe be renamed to "get_trace(address)" to avoid the confusion. > DisplayTop class > ---------------- Oh, I forgot to document the new "previous_top_stats" attribute. It is used to compare two snapshots. > DisplayTopTask class > -------------------- > > ``start(delay: int)`` method: > > Start a task using the ``start_timer()`` function calling the > ``display()`` method every *delay* seconds. I should probably repeat here that only one timer can used at the same time. So only one DisplayTopTask or one TakeSnapshot instance can be used at the same time. It's a design choice to keep start_timer() simple, there is no need for a complex scheduler for such simple debug tool. You *can* run the two tasks at the same time by writing your own function: def mytask(top_task, snapshot_task): top_task.display() snapshot_task.take_snapshot() tracemalloc.start_timer(10, mytask, top_task, snapshot_task) > Snapshot class > -------------- > > ``create(\*, with_traces=False, with_stats=True, > user_data_callback=None)`` classmethod: It's the only function using keyword-only parameters. I don't know it's a good practice and should be used on other methods, or if it should be avoided? > *user_data_callback* is an optional callable object. Its result > should be serializable by the ``pickle`` module, or > ``Snapshot.write()`` would fail. If *user_data_callback* is set, it > is called and the result is stored in the ``Snapshot.user_data`` > attribute. Otherwise, ``Snapshot.user_data`` is set to ``None``. The idea is to attach arbitrary data to a snapshot. Examples: * size of Python caches: cache of linecache and re modules * size of the internal Unicode intern dict * gc.get_stats() * gc.get_count() * len(gc.get_objects()) * ("tracemalloc_size" should maybe moved to the user_data) I hesitate to use a dictionary for user_data. The problem is to decice how to display such data in DisplayTop. For example, gc.get_count() is a number whereas tracemalloc_size is size is bytes (should be formatted using kB, MB, etc. suffixes). What do you think? Victor _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
