@@ -128,7 +128,7 @@ class BaseRunner(metaclass=abc.ABCMeta):

         self._max_tasks = ntasks

-        self._pending_pids = {}

+        self._pending_tasks = {}  # mapping from concurrent.futures.Future → point id

         # if we instantiate our own executor, then we are also responsible

         # for calling 'shutdown'

@@ -170,7 +170,7 @@ class BaseRunner(metaclass=abc.ABCMeta):

         return self.log is not None

     def _ask(self, n):

-        pending_ids = self._pending_pids.values()

+        pending_ids = self._pending_tasks.values()

         pids_gen = (pid for pid in self._to_retry.keys() if pid not in pending_ids)

         pids = list(itertools.islice(pids_gen, n))

@@ -210,7 +210,7 @@ class BaseRunner(metaclass=abc.ABCMeta):

     def _process_futures(self, done_futs):

         for fut in done_futs:

-            pid = self._pending_pids.pop(fut)

+            pid = self._pending_tasks.pop(fut)

             try:

                 y = fut.result()

                 t = time.time() - fut.start_time  # total execution time

@@ -234,7 +234,7 @@ class BaseRunner(metaclass=abc.ABCMeta):

         # Launch tasks to replace the ones that completed

         # on the last iteration, making sure to fill workers

         # that have started since the last iteration.

-        n_new_tasks = max(0, self._get_max_tasks() - len(self._pending_pids))

+        n_new_tasks = max(0, self._get_max_tasks() - len(self._pending_tasks))

         if self.do_log:

             self.log.append(("ask", n_new_tasks))

@@ -246,17 +246,17 @@ class BaseRunner(metaclass=abc.ABCMeta):

             point = self._id_to_point[pid]

             fut = self._submit(point)

             fut.start_time = start_time

-            self._pending_pids[fut] = pid

+            self._pending_tasks[fut] = pid

         # Collect and results and add them to the learner

-        futures = list(self._pending_pids.keys())

+        futures = list(self._pending_tasks.keys())

         return futures

     def _remove_unfinished(self):

         # remove points with 'None' values from the learner

         self.learner.remove_unfinished()

         # cancel any outstanding tasks

-        remaining = list(self._pending_pids.keys())

+        remaining = list(self._pending_tasks.keys())

         for fut in remaining:

             fut.cancel()

         return remaining

@@ -302,7 +302,7 @@ class BaseRunner(metaclass=abc.ABCMeta):

     @property

     def pending_points(self):

         return [

-            (fut, self._id_to_point[pid]) for fut, pid in self._pending_pids.items()

+            (fut, self._id_to_point[pid]) for fut, pid in self._pending_tasks.items()

         ]