uasyncio Revert name of task queue instance.

uasyncio_iostream/README.md

@@ -1,15 +1,15 @@
 # Changes to usayncio
 
 This archive contains suggestions for changes to new `uasyncio`. Item 3 below
-added 2 Dec.
+added 2 Dec, task queue name reverted to `_queue` as this can now be private.
 
  1. Implement as a Python package.
  2. Implement synchronisation primitives as package modules to conserve RAM.
  3. `Primitive` class has methods common to most synchronisation primitives.
+ Avoids the need for primitives to access the task queue directly.
  4. Add `.priority` method to `Stream` class. Enables I/O to be handled at high
  priority on a per-device basis.
  5. Rename task queue class `TQueue` to avoid name clash with Queue primitive.
- 6. Rename task queue instance to `tqueue` as it might be used by primitives.
 
 ## Minor changes
 
@@ -22,7 +22,7 @@ added 2 Dec.
 # CPython-compatible synchronisation primitives
 
 These aim to work efficiently with the new version. All are separate modules to
-conserve RAM.
+conserve RAM. Items 1-4 use classes based on `uasyncio.Primitive`.
 
  1. `Event`: just moved to separate module.
  2. `Lock`: Kevin Köck's solution.

uasyncio_iostream/uasyncio/__init__.py

@@ -17,11 +17,11 @@ class Primitive:
     def run_next(self):
         awt = self.waiting.next
         if awt:  # Schedule next task waiting on primitive
-            tqueue.push_head(self.waiting.pop_head())
+            _queue.push_head(self.waiting.pop_head())
         return awt
     def run_all(self):
         while self.waiting.next:  # Schedule all tasks waiting on primitive
-            tqueue.push_head(self.waiting.pop_head())
+            _queue.push_head(self.waiting.pop_head())
     def save_current(self):  # Postpone currently running task
         self.waiting.push_head(cur_task)
         # Set calling task's data to this event that it waits on, to double-link it
@@ -128,15 +128,15 @@ class Task:
         if hasattr(self.data, 'waiting'):
             self.data.waiting.remove(self)
         else:
-            tqueue.remove(self)
+            _queue.remove(self)
-        tqueue.push_error(self, CancelledError)
+        _queue.push_error(self, CancelledError)
         return True
 
 # Create and schedule a new task from a coroutine
 def create_task(coro):
     assert not isinstance(coro, type_genf), 'Coroutine arg expected.'  # upy issue #3241
     t = Task(coro)
-    tqueue.push_head(t)
+    _queue.push_head(t)
     return t
 
 # "Yield" once, then raise StopIteration
@@ -157,7 +157,7 @@ class SingletonGenerator:
 # Pause task execution for the given time (integer in milliseconds, uPy extension)
 # Use a SingletonGenerator to do it without allocating on the heap
 def sleep_ms(t, sgen=SingletonGenerator()):
-    tqueue.push_sorted(cur_task, ticks_add(ticks(), t))
+    _queue.push_sorted(cur_task, ticks_add(ticks(), t))
     sgen.state = 1
     return sgen
 
@@ -188,7 +188,7 @@ async def wait_for(aw, timeout):
         # Ignore CancelledError from aw, it's probably due to timeout
         pass
     finally:
-        tqueue.remove(cancel_task)
+        _queue.remove(cancel_task)
     if cancel_task.coro is None:
         # Cancel task ran to completion, ie there was a timeout
         raise TimeoutError
@@ -265,15 +265,15 @@ class IOQueue:
             #print('poll', s, sm, ev, err)
             if ev & select.POLLIN or (err and sm[0] is not None):
                 if fast:
-                    tqueue.push_priority(sm[0])
+                    _queue.push_priority(sm[0])
                 else:
-                    tqueue.push_head(sm[0])
+                    _queue.push_head(sm[0])
                 sm[0] = None
             if ev & select.POLLOUT or (err and sm[1] is not None):
                 if fast:
-                    tqueue.push_priority(sm[1])
+                    _queue.push_priority(sm[1])
                 else:
-                    tqueue.push_head(sm[1])
+                    _queue.push_head(sm[1])
                 sm[1] = None
             if sm[0] is None and sm[1] is None:
                 self._dequeue(s)
@@ -391,7 +391,7 @@ async def start_server(cb, host, port, backlog=5):
 # Main run loop
 
 # Queue of Task instances
-tqueue = TQueue()
+_queue = TQueue()
 
 # Task queue and poller for stream IO
 _io_queue = IOQueue()
@@ -402,15 +402,15 @@ def run_until_complete(main_task=None):
     excs_all = (CancelledError, Exception) # To prevent heap allocation in loop
     excs_stop = (CancelledError, StopIteration) # To prevent heap allocation in loop
     while True:
-        # Wait until the head of tqueue is ready to run
+        # Wait until the head of _queue is ready to run
         dt = 1
         while dt > 0:
             dt = -1
-            if tqueue.next:
+            if _queue.next:
-                # A task waiting on tqueue
+                # A task waiting on _queue
-                if isinstance(tqueue.next.data, int):
+                if isinstance(_queue.next.data, int):
                     # "data" is time to schedule task at
-                    dt = max(0, ticks_diff(tqueue.next.data, ticks()))
+                    dt = max(0, ticks_diff(_queue.next.data, ticks()))
                 else:
                     # "data" is an exception to throw into the task
                     dt = 0
@@ -421,7 +421,7 @@ def run_until_complete(main_task=None):
             _io_queue.wait_io_event(dt)
 
         # Get next task to run and continue it
-        t = tqueue.pop_head()
+        t = _queue.pop_head()
         cur_task = t
         try:
             # Continue running the coroutine, it's responsible for rescheduling itself
@@ -439,7 +439,7 @@ def run_until_complete(main_task=None):
             waiting = False
             if hasattr(t, 'waiting'):
                 while t.waiting.next:
-                    tqueue.push_head(t.waiting.pop_head())
+                    _queue.push_head(t.waiting.pop_head())
                     waiting = True
                 t.waiting = None # Free waiting queue head
             _io_queue.remove(t) # Remove task from the IO queue (if it's on it)