Function set_trace_to_threads

pydevd_tracing.py:296–407

(tracing_func, thread_idents=None, create_dummy_thread=True)

def set_trace_to_threads(tracing_func, thread_idents=None, create_dummy_thread=True):
    if PYDEVD_USE_SYS_MONITORING:
        raise RuntimeError("Should not be called when using sys.monitoring.")
    assert tracing_func is not None

    ret = 0

    # Note: use sys._current_frames() keys to get the thread ids because it'll return
    # thread ids created in C/C++ where there's user code running, unlike the APIs
    # from the threading module which see only threads created through it (unless
    # a call for threading.current_thread() was previously done in that thread,
    # in which case a dummy thread would've been created for it).
    if thread_idents is None:
        thread_idents = set(sys._current_frames().keys())

        for t in threading.enumerate():
            # PY-44778: ignore pydevd threads and also add any thread that wasn't found on
            # sys._current_frames() as some existing threads may not appear in
            # sys._current_frames() but may be available through the `threading` module.
            if getattr(t, "pydev_do_not_trace", False):
                thread_idents.discard(t.ident)
            else:
                thread_idents.add(t.ident)

    curr_ident = thread.get_ident()
    curr_thread = threading._active.get(curr_ident)

    if curr_ident in thread_idents and len(thread_idents) != 1:
        # The current thread must be updated first (because we need to set
        # the reference to `curr_thread`).
        thread_idents = list(thread_idents)
        thread_idents.remove(curr_ident)
        thread_idents.insert(0, curr_ident)

    for thread_ident in thread_idents:
        # If that thread is not available in the threading module we also need to create a
        # dummy thread for it (otherwise it'll be invisible to the debugger).
        if create_dummy_thread:
            if thread_ident not in threading._active:

                class _DummyThread(threading._DummyThread):
                    def _set_ident(self):
                        # Note: Hack to set the thread ident that we want.
                        self._ident = thread_ident

                t = _DummyThread()
                # Reset to the base class (don't expose our own version of the class).
                t.__class__ = threading._DummyThread

                if thread_ident == curr_ident:
                    curr_thread = t

                with threading._active_limbo_lock:
                    # On Py2 it'll put in active getting the current indent, not using the
                    # ident that was set, so, we have to update it (should be harmless on Py3
                    # so, do it always).
                    threading._active[thread_ident] = t
                    threading._active[curr_ident] = curr_thread