context manager and subsystem work

appdaemon/context_manager.py

@@ -4,25 +4,40 @@ import logging
 import signal
 from concurrent.futures import ThreadPoolExecutor
 from contextlib import ExitStack, contextmanager
+from threading import Event, Lock
 from time import sleep
 from typing import Any, Callable
 
 logger = logging.getLogger()
 
 
-class CustomContextManager:
+def handler(signum, frame):
+    print('Signal handler called with signal', signum)
+    raise OSError("Couldn't open device!")
+
+
+class AppDaemonRunContext:
     _stack: ExitStack
     loop: asyncio.AbstractEventLoop
     executor: ThreadPoolExecutor
+    stop_event: Event
+    shutdown_lock: Lock
 
     def __init__(self):
         self._stack = ExitStack()
+        self.stop_event = Event()
+        self.shutdown_lock = Lock()
 
     def __enter__(self):
         self.loop = self._stack.enter_context(self.asyncio_context())
         logger.debug("Entered asyncio context")
-        self.loop.add_signal_handler(signal.SIGINT, self.handle_signal)
+
-        self.loop.add_signal_handler(signal.SIGTERM, self.handle_signal)
+        signals = (signal.SIGHUP, signal.SIGTERM, signal.SIGINT)
+        for s in signals:
+            self.loop.add_signal_handler(s, lambda s=s: self.loop.create_task(self.shutdown(s)))
+
+        # self.loop.add_signal_handler(signal.SIGINT, self.handle_signal, signal.SIGINT)
+        # self.loop.add_signal_handler(signal.SIGTERM, self.handle_signal)
         # self.executor = self._stack.enter_context(ThreadPoolExecutor(max_workers=5))
         self.executor = self._stack.enter_context(self.thread_context())
         logger.debug("Entered threadpool context")
@@ -32,30 +47,53 @@ class CustomContextManager:
         self._stack.__exit__(exc_type, exc_value, traceback)
         logger.debug("Exited context")
 
+    async def shutdown(self, signal):
+        """Cleanup tasks tied to the service's shutdown.
+        
+        https://www.roguelynn.com/words/asyncio-graceful-shutdowns/
+        """
+        logger.info(f"Received exit signal {signal.name}...")
+        if not self.stop_event.is_set():
+            logger.debug('Setting stop event')
+            self.stop_event.set()
+        
+            tasks = [
+                t for t in asyncio.all_tasks()
+                if t is not asyncio.current_task()
+            ]
+
+            for task in tasks:
+                # logger.debug(f"Waiting on task to finish: {task.get_coro().__qualname__}")
+                logger.debug(f"Cancelling {task.get_name()}: {task.get_coro().__qualname__}")
+                task.cancel()
+
+            logger.debug('Waiting for tasks to finish...')
+            try:
+                await asyncio.gather(*tasks, return_exceptions=True)
+            except asyncio.CancelledError as e:
+                logger.debug(f'Cancelled: {e}')
+            logger.debug("Stopping event loop in context shutdown")
+            self.loop.stop()
+        else:
+            logger.warning('Already started shutdown')
+
     @contextmanager
     def asyncio_context(self):
         try:
-            loop = asyncio.new_event_loop()
+            loop = asyncio.get_event_loop()
-            asyncio.set_event_loop(loop)
             yield loop
         finally:
             loop.close()
-            logger.info("Closed the event loop.")
+            if loop.is_closed():
+                logger.debug("Closed the event loop.")
 
     @contextmanager
     def thread_context(self):
         with ThreadPoolExecutor(max_workers=5) as executor:
             yield executor
+        if executor._shutdown:
             logger.debug('Shut down the ThreadPoolExecutor')
 
-    def handle_signal(self, signum=None, frame=None):
-        logger.info(f'Handle signal: {signum}, {frame}')
-        # match signum:
-        #     case signal.SIGINT:
-        #         pass
-        #     case signal.SIGTERM:
-        #         pass
-
     async def run_in_executor(
         self,
         func: Callable,
@@ -97,14 +135,17 @@ if __name__ == "__main__":
         await asyncio.sleep(delay)
         logger.info(f'{id_} Done async')
 
-    with CustomContextManager() as cm:
+    with AppDaemonRunContext() as cm:
         for _ in range(3):
             logger.info('Submitting random dummy_functions')
-            cm.executor.submit(dummy_function, random.random() * 3.0)
+            cm.executor.submit(dummy_function, random.random() * 10.0)
             cm.loop.create_task(async_dummy_function(random.random() * 5.0))
         
+        try:
             logger.info('Running until complete')
             cm.loop.run_until_complete(asyncio.gather(*asyncio.all_tasks(cm.loop)))
+        except asyncio.CancelledError:
+            logger.error('Cancelled')
     
     if cm.loop.is_closed():
         logger.debug('Loop is closed')

appdaemon/subsystem.py

@@ -0,0 +1,146 @@
+import asyncio
+import logging
+from dataclasses import dataclass, field
+from logging import Logger, getLogger
+from threading import Event, RLock
+from typing import Callable, Coroutine
+
+from appdaemon.models import AppDaemonConfig
+from context_manager import AppDaemonRunContext
+
+
+@dataclass
+class ADSubsystem:
+    AD: "AppDaemon"
+    stop: Event
+    lock: RLock = field(default_factory=RLock)
+    logger: Logger = field(init=False)
+
+    def __post_init__(self) -> None:
+        name = f'_{self.__class__.__name__.lower()}'
+        self.logger = getLogger(f'AppDaemon.{name}')
+        self.AD.starts.append(self.start)
+
+    @property
+    def stopping(self) -> bool:
+        return self.stop.is_set()
+
+    def start(self):
+        raise NotImplementedError('Need to implement start for subsystem')
+
+
+@dataclass
+class Utility(ADSubsystem):
+    loop_rate: float = 1.0
+
+    def start(self):
+        self.AD.create_task(self.loop(), 'Utility loop')
+
+    async def loop(self):
+        while not self.stopping:
+            self.logger.info('Looping...')
+            await asyncio.sleep(self.loop_rate)
+        self.logger.debug('Stopped utility loop')
+
+
+@dataclass
+class Plugin(ADSubsystem):
+    state: dict[str, int] = field(default_factory=dict)
+    update_rate: float = 10.0
+
+    def __post_init__(self) -> None:
+        super().__post_init__()
+        self.state['update_count'] = 0
+
+    def start(self):
+        self.AD.create_task(self.periodic_self_udpate(), 'Periodic plugin update')
+
+    async def periodic_self_udpate(self):
+        while not self.stopping:
+            with self.lock:
+                self.state['update_count'] += 1
+                self.logger.info(f'Updated self: {self.state["update_count"]}')
+            await asyncio.sleep(self.update_rate)
+        self.logger.debug('Stopped plugin updates')
+
+
+@dataclass
+class AppDaemon:
+    cfg: AppDaemonConfig
+    context: AppDaemonRunContext
+    utility: Utility = field(init=False)
+    plugins: dict[str, Plugin] = field(default_factory=dict)
+    starts: list[Callable] = field(default_factory=list)
+
+    def __post_init__(self) -> None:
+        self.utility = Utility(self, self.context.stop_event)
+        self.plugins['dummy'] = Plugin(self, self.context.stop_event)
+
+    def create_task(self, coro: Coroutine, name: str | None = None):
+        return self.context.loop.create_task(coro, name=name)
+
+    def start(self):
+        for start in self.starts:
+            start()
+
+
+@dataclass
+class ADMain:
+    config_file: str
+    cfg: AppDaemonConfig = field(init=False)
+
+    def __post_init__(self) -> None:
+        raw_cfg = read_config_file(self.config_file)
+        self.cfg = AppDaemonConfig(
+            config_file=self.config_file,
+            **raw_cfg['appdaemon']
+        )
+
+    def run(self):
+        with AppDaemonRunContext() as cm:
+            ad = AppDaemon(self.cfg, cm)
+            ad.start()
+            cm.loop.run_forever()
+
+
+if __name__ == '__main__':
+    import logging.config
+
+    from appdaemon.utils import read_config_file
+    from rich.console import Console
+    from rich.highlighter import NullHighlighter
+
+    console = Console()
+    logging.config.dictConfig(
+        {
+            'version': 1,
+            'disable_existing_loggers': False,
+            'formatters': {'basic': {'style': '{', 'format': '{message}'}},
+            'handlers': {
+                'rich': {
+                    '()': 'rich.logging.RichHandler',
+                    'formatter': 'basic',
+                    'console': console,
+                    'highlighter': NullHighlighter(),
+                    'markup': True
+                }
+            },
+            'root': {'level': 'DEBUG', 'handlers': ['rich']},
+        }
+    )
+
+    main = ADMain('/conf/ad-test/conf/appdaemon.yaml')
+    main.run()
+
+    # config_file = '/conf/ad-test/conf/appdaemon.yaml'
+    # raw_cfg = read_config_file(config_file)
+
+    # cfg = AppDaemonConfig(
+    #     config_file=config_file,
+    #     **raw_cfg['appdaemon']
+    # )
+
+    # with AppDaemonRunContext() as cm:
+    #     ad = AppDaemon(cfg, cm)
+    #     # ad.start()
+    #     # cm.loop.run_forever()