Added some comments and try/except blocks

giambio/_core.py

@@ -63,23 +63,32 @@ class AsyncScheduler:
                 break
             if not self.tasks:
                 if self.paused:  # If there are no actively running tasks, we try to schedule the asleep ones
+                    try:
                         self.check_sleeping()
+                    except BaseException as error:
+                        self.current_task.exc = error
+                        self.reschedule_parent(self.current_task)
+                        raise  # Maybe find a better way to propagate errors?
             if self.selector.get_map():
+                try:
                     self.check_io()
+                except BaseException as error:
+                    self.current_task.exc = error
+                    self.reschedule_parent(self.current_task)
+                    raise  # Maybe find a better way to propagate errors?
             while self.tasks:    # While there are tasks to run
                 self.current_task = self.tasks.popleft()  # Sets the currently running task
+                try:
                     if self.current_task.status == "cancel":  # Deferred cancellation
                         self.current_task.cancelled = True
                         self.current_task.throw(CancelledError)
-                else:
+                    method, *args = self.current_task.run(self.current_task._notify)   # Run a single step with the calculation (and awake event-waiting tasks if any)
                     self.current_task.status = "run"
-                    try:
-                        method, *args = self.current_task.run(self.current_task._notify)   # Run a single step with the calculation
                     getattr(self, method)(*args)  # Sneaky method call, thanks to David Beazley for this ;)
                     if self.event_waiting:
                         self.check_events()
                 except CancelledError as cancelled:
-                        self.tasks.remove(cancelled.args[0])
+                    self.tasks.remove(cancelled.args[0])   # Remove the dead task
                 except StopIteration as e:   # Coroutine ends
                     self.current_task.result = e.args[0] if e.args else None
                     self.current_task.finished = True
@@ -189,6 +198,7 @@ class AsyncScheduler:
 
         if child.finished:
             self.tasks.append(self.current_task)
+        else:
            if child not in self.joined:
                 self.joined[child] = self.current_task
            else: