bgeng777 commented on code in PR #27145: URL: https://github.com/apache/flink/pull/27145#discussion_r2464695059
########## flink-python/pyflink/fn_execution/datastream/process/async_function/operation.py: ########## @@ -0,0 +1,289 @@ +################################################################################ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +################################################################################ +import asyncio +import pickle +import threading +from typing import TypeVar, Generic, List, Iterable, Callable + +from pyflink.datastream import RuntimeContext, ResultFuture +from pyflink.datastream.functions import AsyncFunctionDescriptor +from pyflink.fn_execution.datastream.process.async_function.queue import \ + UnorderedStreamElementQueue, StreamElementQueue +from pyflink.fn_execution.datastream.process.operations import Operation +from pyflink.fn_execution.datastream.process.runtime_context import StreamingRuntimeContext + +IN = TypeVar('IN') +OUT = TypeVar('OUT') + + +class AtomicBoolean(object): + def __init__(self, initial_value=False): + self._value = initial_value + self._lock = threading.Lock() + + def get(self): + with self._lock: + return self._value + + def set(self, new_value): + with self._lock: + self._value = new_value + + def get_and_set(self, new_value): + with self._lock: + old_value = self._value + self._value = new_value + return old_value + + def compare_and_set(self, expected, new_value): + with self._lock: + if self._value == expected: + self._value = new_value + return True + return False + + +class ResultHandler(ResultFuture, Generic[IN, OUT]): + + def __init__(self, + classname: str, + timeout_func: Callable[[IN, ResultFuture[[OUT]]], None], + exception_handler: Callable[[Exception], None], + record: IN, + result_future: ResultFuture[OUT]): + self._classname = classname + self._timeout_func = timeout_func + self._exception_handler = exception_handler + self._record = record + self._result_future = result_future + self._timer = None + self._completed = AtomicBoolean(False) + + def register_timeout(self, timeout: int): + self._timer = threading.Timer(timeout, self._timer_triggered) + self._timer.start() + + def complete(self, result: List[OUT]): + # already completed (exceptionally or with previous complete call from ill-written + # AsyncFunction), so ignore additional result + if not self._completed.compare_and_set(False, True): + return + + if isinstance(result, Iterable): + self._process_results(result) + else: + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + if not isinstance(result, Iterable): + raise RuntimeError("The 'result_future' of AsyncFunction should be completed with " + "data of list type, please check the methods 'async_invoke' and " + "'timeout' of class '%s'." % self._classname) Review Comment: It looks like we can move 'RuntimeError' int the previous "else" instead of doing another `if not isinstance(result, Iterable)` again, Like ``` if not isinstance(result, Iterable): # complete with empty result, so that we remove timer and move ahead processing self._process_results([]) raise RuntimeError("The 'result_future' of AsyncFunction should be completed with " "data of list type, please check the methods 'async_invoke' and " "'timeout' of class '%s'." % self._classname) else: self._process_results(result) ``` ########## flink-python/pyflink/fn_execution/datastream/process/async_function/queue.py: ########## @@ -0,0 +1,345 @@ +################################################################################ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +################################################################################ +import collections +import threading +from abc import ABC +from typing import Generic, TypeVar, List + +from pyflink.datastream import ResultFuture +from pyflink.fn_execution.datastream.process.async_function import LONG_MIN_VALUE +from pyflink.fn_execution.datastream.process.input_handler import _emit_results + +OUT = TypeVar('OUT') + + +class StreamElementQueueEntry(ABC, ResultFuture, Generic[OUT]): + """ + An entry for the StreamElementQueue. The stream element queue entry stores the + StreamElement for which the stream element queue entry has been instantiated. Furthermore, it + allows to set the result of a completed entry through ResultFuture. + """ + + def is_done(self) -> bool: + """ + True if the stream element queue entry has been completed; otherwise false. + """ + pass + + def emit_result(self, output_processor) -> int: + """ + Emits the results associated with this queue entry. + + :return: The number of popped input elements. + """ + pass + + def complete_exceptionally(self, error: Exception): + """ + Exceptions should be handled in the ResultHandler. + """ + raise Exception("This result future should only be used to set completed results.") + + +class StreamRecordQueueEntry(StreamElementQueueEntry): + """ + StreamElementQueueEntry implementation for StreamRecord. This class also acts as + the ResultFuture implementation which is given to the AsyncFunction. The async + function completes this class with a collection of results. + """ + + def __init__(self, windowed_value, timestamp, watermark, record): + self._windowed_value = windowed_value + self._record = record + self._timestamp = timestamp + self._watermark = watermark + self._completed_results = None + self._on_complete_handler = None + + def is_done(self) -> bool: + return self._completed_results is not None + + def emit_result(self, output_processor): + output_processor.process_outputs( + self._windowed_value, + _emit_results(self._timestamp, self._watermark, self._completed_results, False)) + return 1 + + def on_complete(self, handler): + self._on_complete_handler = handler + + def complete(self, result: List[OUT]): + self._completed_results = result + if self._on_complete_handler is not None: + self._on_complete_handler(self) + + +class WatermarkQueueEntry(StreamElementQueueEntry): + """ + StreamElementQueueEntry implementation for Watermark. + """ + + def __init__(self, watermark): + self._watermark = watermark + + def is_done(self) -> bool: + return True + + def emit_result(self, output_processor): + # watermark will be passed together with the record + return 0 + + def complete(self, result: List[OUT]): + raise Exception("Cannot complete a watermark.") + + +class StreamElementQueue(ABC, Generic[OUT]): + + def put(self, windowed_value, timestamp, watermark, record) -> ResultFuture[OUT]: + """ + Put the given record in the queue. This operation blocks until the queue has + capacity left. + + This method returns a handle to the inserted element that allows to set the result of the + computation. + + :param windowed_value: The windowed value for the record to be inserted. + :param timestamp: The timestamp of the record to be inserted. + :param watermark: The watermark of the record to be inserted. + :param record: The actual record to be inserted. + :return: A handle to the element. + """ + pass + + def advance_watermark(self, watermark): + """ + Tries to put the given watermark in the queue. This operation succeeds if the queue has + capacity left and fails if the queue is full. + + :param watermark: The watermark to be inserted. + """ + pass + + def emit_completed_element(self, output_processor): + """ + Emits one completed element from the head of this queue into the given output. + + Will not emit any element if no element has been completed. + """ + pass + + def has_completed_elements(self) -> bool: + """ + Checks if there is at least one completed head element. + """ + pass + + def wait_for_completed_elements(self): + """ + Waits until there is completed elements. + """ + pass + + def wait_for_in_flight_elements_processed(self): + """ + Waits until any inflight elements have been processed. + """ + pass + + def is_empty(self) -> bool: + """ + True if the queue is empty; otherwise false. + """ + pass + + def size(self) -> int: + """ + Return the size of the queue. + """ + pass + + +class UnorderedStreamElementQueue(StreamElementQueue): + + class Segment(object): + + def __init__(self, capacity): + self._incomplete_elements = set() + self._complete_elements = collections.deque(maxlen=capacity) Review Comment: maybe what we mean here is "completed" (i.e. something is finished) instead of "complete"(i.e. entire) ########## flink-python/pyflink/fn_execution/datastream/process/async_function/operation.py: ########## @@ -0,0 +1,289 @@ +################################################################################ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +################################################################################ +import asyncio +import pickle +import threading +from typing import TypeVar, Generic, List, Iterable, Callable + +from pyflink.datastream import RuntimeContext, ResultFuture +from pyflink.datastream.functions import AsyncFunctionDescriptor +from pyflink.fn_execution.datastream.process.async_function.queue import \ + UnorderedStreamElementQueue, StreamElementQueue +from pyflink.fn_execution.datastream.process.operations import Operation +from pyflink.fn_execution.datastream.process.runtime_context import StreamingRuntimeContext + +IN = TypeVar('IN') +OUT = TypeVar('OUT') + + +class AtomicBoolean(object): + def __init__(self, initial_value=False): + self._value = initial_value + self._lock = threading.Lock() + + def get(self): + with self._lock: + return self._value + + def set(self, new_value): + with self._lock: + self._value = new_value + + def get_and_set(self, new_value): + with self._lock: + old_value = self._value + self._value = new_value + return old_value + + def compare_and_set(self, expected, new_value): + with self._lock: + if self._value == expected: + self._value = new_value + return True + return False + + +class ResultHandler(ResultFuture, Generic[IN, OUT]): + + def __init__(self, + classname: str, + timeout_func: Callable[[IN, ResultFuture[[OUT]]], None], + exception_handler: Callable[[Exception], None], + record: IN, + result_future: ResultFuture[OUT]): + self._classname = classname + self._timeout_func = timeout_func + self._exception_handler = exception_handler + self._record = record + self._result_future = result_future + self._timer = None + self._completed = AtomicBoolean(False) + + def register_timeout(self, timeout: int): + self._timer = threading.Timer(timeout, self._timer_triggered) + self._timer.start() + + def complete(self, result: List[OUT]): + # already completed (exceptionally or with previous complete call from ill-written + # AsyncFunction), so ignore additional result + if not self._completed.compare_and_set(False, True): + return + + if isinstance(result, Iterable): + self._process_results(result) + else: + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + if not isinstance(result, Iterable): + raise RuntimeError("The 'result_future' of AsyncFunction should be completed with " + "data of list type, please check the methods 'async_invoke' and " + "'timeout' of class '%s'." % self._classname) + + def complete_exceptionally(self, error: Exception): + # already completed, so ignore exception + if not self._completed.compare_and_set(False, True): + return + + self._exception_handler( + Exception("Could not complete the element:" + str(self._record), error)) + + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + def _process_results(self, result: List[OUT]): + if self._timer is not None: + self._timer.cancel() + self._timer = None + + self._result_future.complete(result) + + def _timer_triggered(self): + if not self._completed.get(): + self._timeout_func(self._record, self) + + +class Emitter(threading.Thread): + + def __init__(self, + exception_handler: Callable[[Exception], None], + output_processor, + queue: StreamElementQueue): + super().__init__() + self._exception_handler = exception_handler + self._output_processor = output_processor + self._queue = queue + self._running = True + + def run(self): + while self._running: + try: + if self._queue.has_completed_elements(): + self._queue.emit_completed_element(self._output_processor) + else: + self._queue.wait_for_completed_elements() + except Exception as e: + self._running = False + self._exception_handler(e) + + def stop(self): + self._running = False + + +class AsyncFunctionRunner(threading.Thread): + def __init__(self, exception_handler: Callable[[Exception], None]): + super().__init__() + self._exception_handler = exception_handler + self._loop = None + + def run(self): + self._loop = asyncio.new_event_loop() + asyncio.set_event_loop(self._loop) + self._loop.run_forever() + + def stop(self): + if self._loop is not None: + self._loop.stop() Review Comment: Should we do `self._loop.close()` to free underlying resources? ```suggestion self._loop.stop() self._loop.close() ``` ########## flink-python/pyflink/fn_execution/datastream/process/async_function/operation.py: ########## @@ -0,0 +1,289 @@ +################################################################################ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +################################################################################ +import asyncio +import pickle +import threading +from typing import TypeVar, Generic, List, Iterable, Callable + +from pyflink.datastream import RuntimeContext, ResultFuture +from pyflink.datastream.functions import AsyncFunctionDescriptor +from pyflink.fn_execution.datastream.process.async_function.queue import \ + UnorderedStreamElementQueue, StreamElementQueue +from pyflink.fn_execution.datastream.process.operations import Operation +from pyflink.fn_execution.datastream.process.runtime_context import StreamingRuntimeContext + +IN = TypeVar('IN') +OUT = TypeVar('OUT') + + +class AtomicBoolean(object): + def __init__(self, initial_value=False): + self._value = initial_value + self._lock = threading.Lock() + + def get(self): + with self._lock: + return self._value + + def set(self, new_value): + with self._lock: + self._value = new_value + + def get_and_set(self, new_value): + with self._lock: + old_value = self._value + self._value = new_value + return old_value + + def compare_and_set(self, expected, new_value): + with self._lock: + if self._value == expected: + self._value = new_value + return True + return False + + +class ResultHandler(ResultFuture, Generic[IN, OUT]): + + def __init__(self, + classname: str, + timeout_func: Callable[[IN, ResultFuture[[OUT]]], None], + exception_handler: Callable[[Exception], None], + record: IN, + result_future: ResultFuture[OUT]): + self._classname = classname + self._timeout_func = timeout_func + self._exception_handler = exception_handler + self._record = record + self._result_future = result_future + self._timer = None + self._completed = AtomicBoolean(False) + + def register_timeout(self, timeout: int): + self._timer = threading.Timer(timeout, self._timer_triggered) + self._timer.start() + + def complete(self, result: List[OUT]): + # already completed (exceptionally or with previous complete call from ill-written + # AsyncFunction), so ignore additional result + if not self._completed.compare_and_set(False, True): + return + + if isinstance(result, Iterable): + self._process_results(result) + else: + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + if not isinstance(result, Iterable): + raise RuntimeError("The 'result_future' of AsyncFunction should be completed with " + "data of list type, please check the methods 'async_invoke' and " + "'timeout' of class '%s'." % self._classname) + + def complete_exceptionally(self, error: Exception): + # already completed, so ignore exception + if not self._completed.compare_and_set(False, True): + return + + self._exception_handler( + Exception("Could not complete the element:" + str(self._record), error)) + + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + def _process_results(self, result: List[OUT]): + if self._timer is not None: + self._timer.cancel() + self._timer = None + + self._result_future.complete(result) + + def _timer_triggered(self): + if not self._completed.get(): + self._timeout_func(self._record, self) + + +class Emitter(threading.Thread): + + def __init__(self, + exception_handler: Callable[[Exception], None], + output_processor, + queue: StreamElementQueue): + super().__init__() + self._exception_handler = exception_handler + self._output_processor = output_processor + self._queue = queue + self._running = True + + def run(self): + while self._running: + try: + if self._queue.has_completed_elements(): + self._queue.emit_completed_element(self._output_processor) + else: + self._queue.wait_for_completed_elements() + except Exception as e: + self._running = False + self._exception_handler(e) + + def stop(self): + self._running = False + + +class AsyncFunctionRunner(threading.Thread): + def __init__(self, exception_handler: Callable[[Exception], None]): + super().__init__() + self._exception_handler = exception_handler + self._loop = None + + def run(self): + self._loop = asyncio.new_event_loop() + asyncio.set_event_loop(self._loop) + self._loop.run_forever() + + def stop(self): + if self._loop is not None: + self._loop.stop() + self._loop = None + + async def exception_handler_wrapper(self, async_function, *arg): + try: + await async_function(*arg) + except Exception as e: + self._exception_handler(e) + + def run_async(self, async_function, *arg): + wrapped_function = self.exception_handler_wrapper(async_function, *arg) + asyncio.run_coroutine_threadsafe(wrapped_function, self._loop) Review Comment: I want to make sure I understand the error handling here correctly so I try to summarize the error handling process with a simple case: 1. there are 3 records that should be processed by `AsyncOperation`'s`process_element`. 2. `self._async_function_runner.run_async` is called for element1 in main thread. 3. `self._async_function_runner.run_async` is called for element2 in main thread but the task has not been submitted to the`loop` thread(i.e. line 172 has not been executed). 4. the`loop` thread executes the processing of element1, then exception happens, `AsyncOperation` marks exception. 5. `AsyncOperation` in main threads submits the element2 to `loop` thread. 6. `AsyncOperation` in main thread finds exception when processing element3 and raises. After some population, the main thread calls `AsyncOperation`'s close() and stops the `loop` thread. According to the doc of async io: <img width="2078" height="672" alt="image" src="https://github.com/user-attachments/assets/287947cc-8a32-4ac2-bddf-785c17811f37"; /> if the `loop` thread has not process element2's task, then the thread just stops and no extra processing for element2. If the `loop` thread is processing element2, the `loop` thread will finish the processing. But as AsyncOperation has been closed, is it possible that the `loop` thread runs into some bad cases(e.g. if the async function uses some freed resources setup in advance)? ########## flink-python/pyflink/fn_execution/datastream/process/async_function/operation.py: ########## @@ -0,0 +1,289 @@ +################################################################################ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +################################################################################ +import asyncio +import pickle +import threading +from typing import TypeVar, Generic, List, Iterable, Callable + +from pyflink.datastream import RuntimeContext, ResultFuture +from pyflink.datastream.functions import AsyncFunctionDescriptor +from pyflink.fn_execution.datastream.process.async_function.queue import \ + UnorderedStreamElementQueue, StreamElementQueue +from pyflink.fn_execution.datastream.process.operations import Operation +from pyflink.fn_execution.datastream.process.runtime_context import StreamingRuntimeContext + +IN = TypeVar('IN') +OUT = TypeVar('OUT') + + +class AtomicBoolean(object): + def __init__(self, initial_value=False): + self._value = initial_value + self._lock = threading.Lock() + + def get(self): + with self._lock: + return self._value + + def set(self, new_value): + with self._lock: + self._value = new_value + + def get_and_set(self, new_value): + with self._lock: + old_value = self._value + self._value = new_value + return old_value + + def compare_and_set(self, expected, new_value): + with self._lock: + if self._value == expected: + self._value = new_value + return True + return False + + +class ResultHandler(ResultFuture, Generic[IN, OUT]): + + def __init__(self, + classname: str, + timeout_func: Callable[[IN, ResultFuture[[OUT]]], None], + exception_handler: Callable[[Exception], None], + record: IN, + result_future: ResultFuture[OUT]): + self._classname = classname + self._timeout_func = timeout_func + self._exception_handler = exception_handler + self._record = record + self._result_future = result_future + self._timer = None + self._completed = AtomicBoolean(False) + + def register_timeout(self, timeout: int): + self._timer = threading.Timer(timeout, self._timer_triggered) + self._timer.start() + + def complete(self, result: List[OUT]): + # already completed (exceptionally or with previous complete call from ill-written + # AsyncFunction), so ignore additional result + if not self._completed.compare_and_set(False, True): + return + + if isinstance(result, Iterable): + self._process_results(result) + else: + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + if not isinstance(result, Iterable): + raise RuntimeError("The 'result_future' of AsyncFunction should be completed with " + "data of list type, please check the methods 'async_invoke' and " + "'timeout' of class '%s'." % self._classname) + + def complete_exceptionally(self, error: Exception): + # already completed, so ignore exception + if not self._completed.compare_and_set(False, True): + return + + self._exception_handler( + Exception("Could not complete the element:" + str(self._record), error)) + + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + def _process_results(self, result: List[OUT]): + if self._timer is not None: + self._timer.cancel() + self._timer = None + + self._result_future.complete(result) + + def _timer_triggered(self): + if not self._completed.get(): + self._timeout_func(self._record, self) + + +class Emitter(threading.Thread): + + def __init__(self, + exception_handler: Callable[[Exception], None], + output_processor, + queue: StreamElementQueue): + super().__init__() + self._exception_handler = exception_handler + self._output_processor = output_processor + self._queue = queue + self._running = True + + def run(self): + while self._running: + try: + if self._queue.has_completed_elements(): + self._queue.emit_completed_element(self._output_processor) + else: + self._queue.wait_for_completed_elements() + except Exception as e: + self._running = False + self._exception_handler(e) + + def stop(self): + self._running = False + + +class AsyncFunctionRunner(threading.Thread): + def __init__(self, exception_handler: Callable[[Exception], None]): + super().__init__() + self._exception_handler = exception_handler + self._loop = None + + def run(self): + self._loop = asyncio.new_event_loop() + asyncio.set_event_loop(self._loop) + self._loop.run_forever() + + def stop(self): + if self._loop is not None: + self._loop.stop() + self._loop = None + + async def exception_handler_wrapper(self, async_function, *arg): + try: + await async_function(*arg) + except Exception as e: + self._exception_handler(e) + + def run_async(self, async_function, *arg): + wrapped_function = self.exception_handler_wrapper(async_function, *arg) + asyncio.run_coroutine_threadsafe(wrapped_function, self._loop) + + +class AsyncOperation(Operation): + def __init__(self, serialized_fn, operator_state_backend): + super(AsyncOperation, self).__init__(serialized_fn, operator_state_backend) + ( + self.class_name, + self.open_func, + self.close_func, + self.async_invoke_func, + self.timeout_func, + self._timeout, + capacity, + output_mode + ) = extract_async_function( + user_defined_function_proto=serialized_fn, + runtime_context=StreamingRuntimeContext.of( + serialized_fn.runtime_context, self.base_metric_group + ) + ) + self._retry_enabled = False + if output_mode == AsyncFunctionDescriptor.OutputMode.UNORDERED: + self._queue = UnorderedStreamElementQueue(capacity, self._raise_exception_if_exists) + else: + raise NotImplementedError() + self._emitter = None + self._async_function_runner = None + self._exception = None + + def set_output_processor(self, output_processor): + self._output_processor = output_processor + + def open(self): + self.open_func() + self._emitter = Emitter(self._mark_exception, self._output_processor, self._queue) + self._emitter.daemon = True + self._emitter.start() + + self._async_function_runner = AsyncFunctionRunner(self._mark_exception) + self._async_function_runner.daemon = True + self._async_function_runner.start() + + def close(self): + self.close_func() + if self._emitter is not None: + self._emitter.stop() + self._emitter = None + + if self._async_function_runner is not None: + self._async_function_runner.stop() + self._async_function_runner = None Review Comment: do we need `self._exception = None` here? In other words, when failover happens, will we reuse `AsyncOperation` object or just create a new one? ########## flink-python/pyflink/fn_execution/datastream/process/async_function/operation.py: ########## @@ -0,0 +1,289 @@ +################################################################################ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +################################################################################ +import asyncio +import pickle +import threading +from typing import TypeVar, Generic, List, Iterable, Callable + +from pyflink.datastream import RuntimeContext, ResultFuture +from pyflink.datastream.functions import AsyncFunctionDescriptor +from pyflink.fn_execution.datastream.process.async_function.queue import \ + UnorderedStreamElementQueue, StreamElementQueue +from pyflink.fn_execution.datastream.process.operations import Operation +from pyflink.fn_execution.datastream.process.runtime_context import StreamingRuntimeContext + +IN = TypeVar('IN') +OUT = TypeVar('OUT') + + +class AtomicBoolean(object): + def __init__(self, initial_value=False): + self._value = initial_value + self._lock = threading.Lock() + + def get(self): + with self._lock: + return self._value + + def set(self, new_value): + with self._lock: + self._value = new_value + + def get_and_set(self, new_value): + with self._lock: + old_value = self._value + self._value = new_value + return old_value + + def compare_and_set(self, expected, new_value): + with self._lock: + if self._value == expected: + self._value = new_value + return True + return False + + +class ResultHandler(ResultFuture, Generic[IN, OUT]): + + def __init__(self, + classname: str, + timeout_func: Callable[[IN, ResultFuture[[OUT]]], None], + exception_handler: Callable[[Exception], None], + record: IN, + result_future: ResultFuture[OUT]): + self._classname = classname + self._timeout_func = timeout_func + self._exception_handler = exception_handler + self._record = record + self._result_future = result_future + self._timer = None + self._completed = AtomicBoolean(False) + + def register_timeout(self, timeout: int): + self._timer = threading.Timer(timeout, self._timer_triggered) + self._timer.start() + + def complete(self, result: List[OUT]): + # already completed (exceptionally or with previous complete call from ill-written + # AsyncFunction), so ignore additional result + if not self._completed.compare_and_set(False, True): + return + + if isinstance(result, Iterable): + self._process_results(result) + else: + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + if not isinstance(result, Iterable): + raise RuntimeError("The 'result_future' of AsyncFunction should be completed with " + "data of list type, please check the methods 'async_invoke' and " + "'timeout' of class '%s'." % self._classname) + + def complete_exceptionally(self, error: Exception): + # already completed, so ignore exception + if not self._completed.compare_and_set(False, True): + return + + self._exception_handler( + Exception("Could not complete the element:" + str(self._record), error)) + + # complete with empty result, so that we remove timer and move ahead processing + self._process_results([]) + + def _process_results(self, result: List[OUT]): + if self._timer is not None: + self._timer.cancel() + self._timer = None + + self._result_future.complete(result) + + def _timer_triggered(self): + if not self._completed.get(): + self._timeout_func(self._record, self) + + +class Emitter(threading.Thread): + + def __init__(self, + exception_handler: Callable[[Exception], None], + output_processor, + queue: StreamElementQueue): + super().__init__() + self._exception_handler = exception_handler + self._output_processor = output_processor + self._queue = queue + self._running = True + + def run(self): + while self._running: + try: + if self._queue.has_completed_elements(): + self._queue.emit_completed_element(self._output_processor) + else: + self._queue.wait_for_completed_elements() + except Exception as e: + self._running = False + self._exception_handler(e) + + def stop(self): + self._running = False + + +class AsyncFunctionRunner(threading.Thread): + def __init__(self, exception_handler: Callable[[Exception], None]): + super().__init__() + self._exception_handler = exception_handler + self._loop = None + + def run(self): + self._loop = asyncio.new_event_loop() + asyncio.set_event_loop(self._loop) + self._loop.run_forever() + + def stop(self): + if self._loop is not None: + self._loop.stop() + self._loop = None + + async def exception_handler_wrapper(self, async_function, *arg): + try: + await async_function(*arg) + except Exception as e: + self._exception_handler(e) + + def run_async(self, async_function, *arg): + wrapped_function = self.exception_handler_wrapper(async_function, *arg) + asyncio.run_coroutine_threadsafe(wrapped_function, self._loop) + + +class AsyncOperation(Operation): + def __init__(self, serialized_fn, operator_state_backend): + super(AsyncOperation, self).__init__(serialized_fn, operator_state_backend) + ( + self.class_name, + self.open_func, + self.close_func, + self.async_invoke_func, + self.timeout_func, + self._timeout, + capacity, + output_mode + ) = extract_async_function( + user_defined_function_proto=serialized_fn, + runtime_context=StreamingRuntimeContext.of( + serialized_fn.runtime_context, self.base_metric_group + ) + ) + self._retry_enabled = False + if output_mode == AsyncFunctionDescriptor.OutputMode.UNORDERED: + self._queue = UnorderedStreamElementQueue(capacity, self._raise_exception_if_exists) + else: + raise NotImplementedError() Review Comment: ```suggestion raise NotImplementedError("ORDERED mode is supported.") ``` -- This is an automated message from the Apache Git Service. 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