Initial commit

Author: githubChenchi

__init__.py

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+# MicroPython uasyncio module
+# MIT license; Copyright (c) 2019 Damien P. George
+
+from .core import *
+
+__version__ = (3, 0, 0)
+
+_attrs = {
+    "wait_for": "funcs",
+    "wait_for_ms": "funcs",
+    "gather": "funcs",
+    "Event": "event",
+    "Lock": "lock",
+    "open_connection": "stream",
+    "start_server": "stream",
+    "StreamReader": "stream",
+    "StreamWriter": "stream",
+}
+
+# Lazy loader, effectively does:
+#   global attr
+#   from .mod import attr
+def __getattr__(attr):
+    mod = _attrs.get(attr, None)
+    if mod is None:
+        raise AttributeError(attr)
+    value = getattr(__import__(mod, None, None, True, 1), attr)
+    globals()[attr] = value
+    return value

core.py

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+# MicroPython uasyncio module
+# MIT license; Copyright (c) 2019 Damien P. George
+
+from utime import ticks_ms as ticks, ticks_diff, ticks_add
+import usys as sys
+import uselect as select
+
+# Import TaskQueue and Task, preferring built-in C code over Python code
+try:
+    from _uasyncio import TaskQueue, Task
+except:
+    from .task import TaskQueue, Task
+
+
+################################################################################
+# Exceptions
+
+
+class CancelledError(BaseException):
+    pass
+
+
+class TimeoutError(Exception):
+    pass
+
+
+# Used when calling Loop.call_exception_handler
+_exc_context = {"message": "Task exception wasn't retrieved", "exception": None, "future": None}
+
+
+################################################################################
+# Sleep functions
+
+# "Yield" once, then raise StopIteration
+class SingletonGenerator:
+    def __init__(self):
+        self.state = None
+        self.exc = StopIteration()
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.state is not None:
+            _task_queue.push_sorted(cur_task, self.state)
+            self.state = None
+            return None
+        else:
+            self.exc.__traceback__ = None
+            raise self.exc
+
+
+# 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()):
+    assert sgen.state is None
+    sgen.state = ticks_add(ticks(), max(0, t))
+    return sgen
+
+
+# Pause task execution for the given time (in seconds)
+def sleep(t):
+    return sleep_ms(int(t * 1000))
+
+
+################################################################################
+# Queue and poller for stream IO
+
+
+class IOQueue:
+    def __init__(self):
+        self.poller = select.poll()
+        self.map = {}  # maps id(stream) to [task_waiting_read, task_waiting_write, stream]
+
+    def _enqueue(self, s, idx):
+        if id(s) not in self.map:
+            entry = [None, None, s]
+            entry[idx] = cur_task
+            self.map[id(s)] = entry
+            self.poller.register(s, select.POLLIN if idx == 0 else select.POLLOUT)
+        else:
+            sm = self.map[id(s)]
+            assert sm[idx] is None
+            assert sm[1 - idx] is not None
+            sm[idx] = cur_task
+            self.poller.modify(s, select.POLLIN | select.POLLOUT)
+        # Link task to this IOQueue so it can be removed if needed
+        cur_task.data = self
+
+    def _dequeue(self, s):
+        del self.map[id(s)]
+        self.poller.unregister(s)
+
+    def queue_read(self, s):
+        self._enqueue(s, 0)
+
+    def queue_write(self, s):
+        self._enqueue(s, 1)
+
+    def remove(self, task):
+        while True:
+            del_s = None
+            for k in self.map:  # Iterate without allocating on the heap
+                q0, q1, s = self.map[k]
+                if q0 is task or q1 is task:
+                    del_s = s
+                    break
+            if del_s is not None:
+                self._dequeue(s)
+            else:
+                break
+
+    def wait_io_event(self, dt):
+        for s, ev in self.poller.ipoll(dt):
+            sm = self.map[id(s)]
+            # print('poll', s, sm, ev)
+            if ev & ~select.POLLOUT and sm[0] is not None:
+                # POLLIN or error
+                _task_queue.push_head(sm[0])
+                sm[0] = None
+            if ev & ~select.POLLIN and sm[1] is not None:
+                # POLLOUT or error
+                _task_queue.push_head(sm[1])
+                sm[1] = None
+            if sm[0] is None and sm[1] is None:
+                self._dequeue(s)
+            elif sm[0] is None:
+                self.poller.modify(s, select.POLLOUT)
+            else:
+                self.poller.modify(s, select.POLLIN)
+
+
+################################################################################
+# Main run loop
+
+# Ensure the awaitable is a task
+def _promote_to_task(aw):
+    return aw if isinstance(aw, Task) else create_task(aw)
+
+
+# Create and schedule a new task from a coroutine
+def create_task(coro):
+    if not hasattr(coro, "send"):
+        raise TypeError("coroutine expected")
+    t = Task(coro, globals())
+    _task_queue.push_head(t)
+    return t
+
+
+# Keep scheduling tasks until there are none left to schedule
+def run_until_complete(main_task=None):
+    global cur_task
+    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 _task_queue is ready to run
+        dt = 1
+        while dt > 0:
+            dt = -1
+            t = _task_queue.peek()
+            if t:
+                # A task waiting on _task_queue; "ph_key" is time to schedule task at
+                dt = max(0, ticks_diff(t.ph_key, ticks()))
+            elif not _io_queue.map:
+                # No tasks can be woken so finished running
+                return
+            # print('(poll {})'.format(dt), len(_io_queue.map))
+            _io_queue.wait_io_event(dt)
+
+        # Get next task to run and continue it
+        t = _task_queue.pop_head()
+        cur_task = t
+        try:
+            # Continue running the coroutine, it's responsible for rescheduling itself
+            exc = t.data
+            if not exc:
+                t.coro.send(None)
+            else:
+                t.data = None
+                t.coro.throw(exc)
+        except excs_all as er:
+            # Check the task is not on any event queue
+            assert t.data is None
+            # This task is done, check if it's the main task and then loop should stop
+            if t is main_task:
+                if isinstance(er, StopIteration):
+                    return er.value
+                raise er
+            # Schedule any other tasks waiting on the completion of this task
+            waiting = False
+            if hasattr(t, "waiting"):
+                while t.waiting.peek():
+                    _task_queue.push_head(t.waiting.pop_head())
+                    waiting = True
+                t.waiting = None  # Free waiting queue head
+            if not waiting and not isinstance(er, excs_stop):
+                # An exception ended this detached task, so queue it for later
+                # execution to handle the uncaught exception if no other task retrieves
+                # the exception in the meantime (this is handled by Task.throw).
+                _task_queue.push_head(t)
+            # Indicate task is done by setting coro to the task object itself
+            t.coro = t
+            # Save return value of coro to pass up to caller
+            t.data = er
+
+
+# Create a new task from a coroutine and run it until it finishes
+def run(coro):
+    return run_until_complete(create_task(coro))
+
+
+################################################################################
+# Event loop wrapper
+
+
+async def _stopper():
+    pass
+
+
+_stop_task = None
+
+
+class Loop:
+    _exc_handler = None
+
+    @staticmethod
+    def create_task(coro):
+        return create_task(coro)
+
+    @staticmethod
+    def run_forever():
+        global _stop_task
+        _stop_task = Task(_stopper(), globals())
+        run_until_complete(_stop_task)
+        # TODO should keep running until .stop() is called, even if there're no tasks left
+
+    @staticmethod
+    def run_until_complete(aw):
+        return run_until_complete(_promote_to_task(aw))
+
+    @staticmethod
+    def stop():
+        global _stop_task
+        if _stop_task is not None:
+            _task_queue.push_head(_stop_task)
+            # If stop() is called again, do nothing
+            _stop_task = None
+
+    @staticmethod
+    def close():
+        pass
+
+    @staticmethod
+    def set_exception_handler(handler):
+        Loop._exc_handler = handler
+
+    @staticmethod
+    def get_exception_handler():
+        return Loop._exc_handler
+
+    @staticmethod
+    def default_exception_handler(loop, context):
+        print(context["message"])
+        print("future:", context["future"], "coro=", context["future"].coro)
+        sys.print_exception(context["exception"])
+
+    @staticmethod
+    def call_exception_handler(context):
+        (Loop._exc_handler or Loop.default_exception_handler)(Loop, context)
+
+
+# The runq_len and waitq_len arguments are for legacy uasyncio compatibility
+def get_event_loop(runq_len=0, waitq_len=0):
+    return Loop
+
+
+def new_event_loop():
+    global _task_queue, _io_queue
+    # TaskQueue of Task instances
+    _task_queue = TaskQueue()
+    # Task queue and poller for stream IO
+    _io_queue = IOQueue()
+    return Loop
+
+
+# Initialise default event loop
+new_event_loop()

event.py

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+# MicroPython uasyncio module
+# MIT license; Copyright (c) 2019-2020 Damien P. George
+
+from . import core
+
+# Event class for primitive events that can be waited on, set, and cleared
+class Event:
+    def __init__(self):
+        self.state = False  # False=unset; True=set
+        self.waiting = core.TaskQueue()  # Queue of Tasks waiting on completion of this event
+
+    def is_set(self):
+        return self.state
+
+    def set(self):
+        # Event becomes set, schedule any tasks waiting on it
+        while self.waiting.peek():
+            core._task_queue.push_head(self.waiting.pop_head())
+        self.state = True
+
+    def clear(self):
+        self.state = False
+
+    async def wait(self):
+        if not self.state:
+            # Event not set, put the calling task on the event's waiting queue
+            self.waiting.push_head(core.cur_task)
+            # Set calling task's data to the event's queue so it can be removed if needed
+            core.cur_task.data = self.waiting
+            yield
+        return True