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Edit File: runtest_mp.py
import faulthandler import json import os import queue import signal import subprocess import sys import tempfile import threading import time import traceback from typing import NamedTuple, NoReturn, Literal, Any, TextIO from test import support from test.support import os_helper from test.libregrtest.cmdline import Namespace from test.libregrtest.main import Regrtest from test.libregrtest.runtest import ( runtest, is_failed, TestResult, Interrupted, Timeout, ChildError, PROGRESS_MIN_TIME) from test.libregrtest.setup import setup_tests from test.libregrtest.utils import format_duration, print_warning if sys.platform == 'win32': import locale # Display the running tests if nothing happened last N seconds PROGRESS_UPDATE = 30.0 # seconds assert PROGRESS_UPDATE >= PROGRESS_MIN_TIME # Kill the main process after 5 minutes. It is supposed to write an update # every PROGRESS_UPDATE seconds. Tolerate 5 minutes for Python slowest # buildbot workers. MAIN_PROCESS_TIMEOUT = 5 * 60.0 assert MAIN_PROCESS_TIMEOUT >= PROGRESS_UPDATE # Time to wait until a worker completes: should be immediate JOIN_TIMEOUT = 30.0 # seconds USE_PROCESS_GROUP = (hasattr(os, "setsid") and hasattr(os, "killpg")) def must_stop(result: TestResult, ns: Namespace) -> bool: if isinstance(result, Interrupted): return True if ns.failfast and is_failed(result, ns): return True return False def parse_worker_args(worker_args) -> tuple[Namespace, str]: ns_dict, test_name = json.loads(worker_args) ns = Namespace(**ns_dict) return (ns, test_name) def run_test_in_subprocess(testname: str, ns: Namespace, stdout_fh: TextIO) -> subprocess.Popen: ns_dict = vars(ns) worker_args = (ns_dict, testname) worker_args = json.dumps(worker_args) if ns.python is not None: executable = ns.python else: executable = [sys.executable] cmd = [*executable, *support.args_from_interpreter_flags(), '-u', # Unbuffered stdout and stderr '-m', 'test.regrtest', '--worker-args', worker_args] # Running the child from the same working directory as regrtest's original # invocation ensures that TEMPDIR for the child is the same when # sysconfig.is_python_build() is true. See issue 15300. kw = dict( stdout=stdout_fh, # bpo-45410: Write stderr into stdout to keep messages order stderr=stdout_fh, text=True, close_fds=(os.name != 'nt'), cwd=os_helper.SAVEDCWD, ) if USE_PROCESS_GROUP: kw['start_new_session'] = True return subprocess.Popen(cmd, **kw) def run_tests_worker(ns: Namespace, test_name: str) -> NoReturn: setup_tests(ns) result = runtest(ns, test_name) print() # Force a newline (just in case) # Serialize TestResult as dict in JSON print(json.dumps(result, cls=EncodeTestResult), flush=True) sys.exit(0) # We do not use a generator so multiple threads can call next(). class MultiprocessIterator: """A thread-safe iterator over tests for multiprocess mode.""" def __init__(self, tests_iter): self.lock = threading.Lock() self.tests_iter = tests_iter def __iter__(self): return self def __next__(self): with self.lock: if self.tests_iter is None: raise StopIteration return next(self.tests_iter) def stop(self): with self.lock: self.tests_iter = None class MultiprocessResult(NamedTuple): result: TestResult # bpo-45410: stderr is written into stdout to keep messages order stdout: str error_msg: str ExcStr = str QueueOutput = tuple[Literal[False], MultiprocessResult] | tuple[Literal[True], ExcStr] class ExitThread(Exception): pass class TestWorkerProcess(threading.Thread): def __init__(self, worker_id: int, runner: "MultiprocessTestRunner") -> None: super().__init__() self.worker_id = worker_id self.pending = runner.pending self.output = runner.output self.ns = runner.ns self.timeout = runner.worker_timeout self.regrtest = runner.regrtest self.current_test_name = None self.start_time = None self._popen = None self._killed = False self._stopped = False def __repr__(self) -> str: info = [f'TestWorkerProcess #{self.worker_id}'] if self.is_alive(): info.append("running") else: info.append('stopped') test = self.current_test_name if test: info.append(f'test={test}') popen = self._popen if popen is not None: dt = time.monotonic() - self.start_time info.extend((f'pid={self._popen.pid}', f'time={format_duration(dt)}')) return '<%s>' % ' '.join(info) def _kill(self) -> None: popen = self._popen if popen is None: return if self._killed: return self._killed = True if USE_PROCESS_GROUP: what = f"{self} process group" else: what = f"{self}" print(f"Kill {what}", file=sys.stderr, flush=True) try: if USE_PROCESS_GROUP: os.killpg(popen.pid, signal.SIGKILL) else: popen.kill() except ProcessLookupError: # popen.kill(): the process completed, the TestWorkerProcess thread # read its exit status, but Popen.send_signal() read the returncode # just before Popen.wait() set returncode. pass except OSError as exc: print_warning(f"Failed to kill {what}: {exc!r}") def stop(self) -> None: # Method called from a different thread to stop this thread self._stopped = True self._kill() def mp_result_error( self, test_result: TestResult, stdout: str = '', err_msg=None ) -> MultiprocessResult: test_result.duration_sec = time.monotonic() - self.start_time return MultiprocessResult(test_result, stdout, err_msg) def _run_process(self, test_name: str, stdout_fh: TextIO) -> int: self.start_time = time.monotonic() self.current_test_name = test_name try: popen = run_test_in_subprocess(test_name, self.ns, stdout_fh) self._killed = False self._popen = popen except: self.current_test_name = None raise try: if self._stopped: # If kill() has been called before self._popen is set, # self._popen is still running. Call again kill() # to ensure that the process is killed. self._kill() raise ExitThread try: # gh-94026: stdout+stderr are written to tempfile retcode = popen.wait(timeout=self.timeout) assert retcode is not None return retcode except subprocess.TimeoutExpired: if self._stopped: # kill() has been called: communicate() fails on reading # closed stdout raise ExitThread # On timeout, kill the process self._kill() # None means TIMEOUT for the caller retcode = None # bpo-38207: Don't attempt to call communicate() again: on it # can hang until all child processes using stdout # pipes completes. except OSError: if self._stopped: # kill() has been called: communicate() fails # on reading closed stdout raise ExitThread raise except: self._kill() raise finally: self._wait_completed() self._popen = None self.current_test_name = None def _runtest(self, test_name: str) -> MultiprocessResult: if sys.platform == 'win32': # gh-95027: When stdout is not a TTY, Python uses the ANSI code # page for the sys.stdout encoding. If the main process runs in a # terminal, sys.stdout uses WindowsConsoleIO with UTF-8 encoding. encoding = locale.getencoding() else: encoding = sys.stdout.encoding # gh-94026: Write stdout+stderr to a tempfile as workaround for # non-blocking pipes on Emscripten with NodeJS. with tempfile.TemporaryFile('w+', encoding=encoding) as stdout_fh: # gh-93353: Check for leaked temporary files in the parent process, # since the deletion of temporary files can happen late during # Python finalization: too late for libregrtest. retcode = self._run_process(test_name, stdout_fh) stdout_fh.seek(0) stdout = stdout_fh.read().strip() if retcode is None: return self.mp_result_error(Timeout(test_name), stdout) err_msg = None if retcode != 0: err_msg = "Exit code %s" % retcode else: stdout, _, result = stdout.rpartition("\n") stdout = stdout.rstrip() if not result: err_msg = "Failed to parse worker stdout" else: try: # deserialize run_tests_worker() output result = json.loads(result, object_hook=decode_test_result) except Exception as exc: err_msg = "Failed to parse worker JSON: %s" % exc if err_msg is not None: return self.mp_result_error(ChildError(test_name), stdout, err_msg) return MultiprocessResult(result, stdout, err_msg) def run(self) -> None: while not self._stopped: try: try: test_name = next(self.pending) except StopIteration: break mp_result = self._runtest(test_name) self.output.put((False, mp_result)) if must_stop(mp_result.result, self.ns): break except ExitThread: break except BaseException: self.output.put((True, traceback.format_exc())) break def _wait_completed(self) -> None: popen = self._popen try: popen.wait(JOIN_TIMEOUT) except (subprocess.TimeoutExpired, OSError) as exc: print_warning(f"Failed to wait for {self} completion " f"(timeout={format_duration(JOIN_TIMEOUT)}): " f"{exc!r}") def wait_stopped(self, start_time: float) -> None: # bpo-38207: MultiprocessTestRunner.stop_workers() called self.stop() # which killed the process. Sometimes, killing the process from the # main thread does not interrupt popen.communicate() in # TestWorkerProcess thread. This loop with a timeout is a workaround # for that. # # Moreover, if this method fails to join the thread, it is likely # that Python will hang at exit while calling threading._shutdown() # which tries again to join the blocked thread. Regrtest.main() # uses EXIT_TIMEOUT to workaround this second bug. while True: # Write a message every second self.join(1.0) if not self.is_alive(): break dt = time.monotonic() - start_time self.regrtest.log(f"Waiting for {self} thread " f"for {format_duration(dt)}") if dt > JOIN_TIMEOUT: print_warning(f"Failed to join {self} in {format_duration(dt)}") break def get_running(workers: list[TestWorkerProcess]) -> list[TestWorkerProcess]: running = [] for worker in workers: current_test_name = worker.current_test_name if not current_test_name: continue dt = time.monotonic() - worker.start_time if dt >= PROGRESS_MIN_TIME: text = '%s (%s)' % (current_test_name, format_duration(dt)) running.append(text) return running class MultiprocessTestRunner: def __init__(self, regrtest: Regrtest) -> None: self.regrtest = regrtest self.log = self.regrtest.log self.ns = regrtest.ns self.output: queue.Queue[QueueOutput] = queue.Queue() self.pending = MultiprocessIterator(self.regrtest.tests) if self.ns.timeout is not None: # Rely on faulthandler to kill a worker process. This timouet is # when faulthandler fails to kill a worker process. Give a maximum # of 5 minutes to faulthandler to kill the worker. self.worker_timeout = min(self.ns.timeout * 1.5, self.ns.timeout + 5 * 60) else: self.worker_timeout = None self.workers = None def start_workers(self) -> None: self.workers = [TestWorkerProcess(index, self) for index in range(1, self.ns.use_mp + 1)] msg = f"Run tests in parallel using {len(self.workers)} child processes" if self.ns.timeout: msg += (" (timeout: %s, worker timeout: %s)" % (format_duration(self.ns.timeout), format_duration(self.worker_timeout))) self.log(msg) for worker in self.workers: worker.start() def stop_workers(self) -> None: start_time = time.monotonic() for worker in self.workers: worker.stop() for worker in self.workers: worker.wait_stopped(start_time) def _get_result(self) -> QueueOutput | None: use_faulthandler = (self.ns.timeout is not None) timeout = PROGRESS_UPDATE # bpo-46205: check the status of workers every iteration to avoid # waiting forever on an empty queue. while any(worker.is_alive() for worker in self.workers): if use_faulthandler: faulthandler.dump_traceback_later(MAIN_PROCESS_TIMEOUT, exit=True) # wait for a thread try: return self.output.get(timeout=timeout) except queue.Empty: pass # display progress running = get_running(self.workers) if running and not self.ns.pgo: self.log('running: %s' % ', '.join(running)) # all worker threads are done: consume pending results try: return self.output.get(timeout=0) except queue.Empty: return None def display_result(self, mp_result: MultiprocessResult) -> None: result = mp_result.result text = str(result) if mp_result.error_msg is not None: # CHILD_ERROR text += ' (%s)' % mp_result.error_msg elif (result.duration_sec >= PROGRESS_MIN_TIME and not self.ns.pgo): text += ' (%s)' % format_duration(result.duration_sec) running = get_running(self.workers) if running and not self.ns.pgo: text += ' -- running: %s' % ', '.join(running) self.regrtest.display_progress(self.test_index, text) def _process_result(self, item: QueueOutput) -> bool: """Returns True if test runner must stop.""" if item[0]: # Thread got an exception format_exc = item[1] print_warning(f"regrtest worker thread failed: {format_exc}") return True self.test_index += 1 mp_result = item[1] self.regrtest.accumulate_result(mp_result.result) self.display_result(mp_result) if mp_result.stdout: print(mp_result.stdout, flush=True) if must_stop(mp_result.result, self.ns): return True return False def run_tests(self) -> None: self.start_workers() self.test_index = 0 try: while True: item = self._get_result() if item is None: break stop = self._process_result(item) if stop: break except KeyboardInterrupt: print() self.regrtest.interrupted = True finally: if self.ns.timeout is not None: faulthandler.cancel_dump_traceback_later() # Always ensure that all worker processes are no longer # worker when we exit this function self.pending.stop() self.stop_workers() def run_tests_multiprocess(regrtest: Regrtest) -> None: MultiprocessTestRunner(regrtest).run_tests() class EncodeTestResult(json.JSONEncoder): """Encode a TestResult (sub)class object into a JSON dict.""" def default(self, o: Any) -> dict[str, Any]: if isinstance(o, TestResult): result = vars(o) result["__test_result__"] = o.__class__.__name__ return result return super().default(o) def decode_test_result(d: dict[str, Any]) -> TestResult | dict[str, Any]: """Decode a TestResult (sub)class object from a JSON dict.""" if "__test_result__" not in d: return d cls_name = d.pop("__test_result__") for cls in get_all_test_result_classes(): if cls.__name__ == cls_name: return cls(**d) def get_all_test_result_classes() -> set[type[TestResult]]: prev_count = 0 classes = {TestResult} while len(classes) > prev_count: prev_count = len(classes) to_add = [] for cls in classes: to_add.extend(cls.__subclasses__()) classes.update(to_add) return classes