import contextlib import dataclasses import faulthandler import os.path import queue import signal import subprocess import sys import tempfile import threading import time import traceback from typing import Literal, TextIO from test import support from test.support import os_helper from .logger import Logger from .result import TestResult, State from .results import TestResults from .runtests import RunTests, JsonFile, JsonFileType from .single import PROGRESS_MIN_TIME from .utils import ( StrPath, StrJSON, TestName, MS_WINDOWS, format_duration, print_warning, count, plural) from .worker import create_worker_process, USE_PROCESS_GROUP if MS_WINDOWS: import locale import msvcrt # 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 # 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 @dataclasses.dataclass(slots=True, frozen=True) class MultiprocessResult: result: TestResult # bpo-45410: stderr is written into stdout to keep messages order worker_stdout: str | None = None err_msg: str | None = None ExcStr = str QueueOutput = tuple[Literal[False], MultiprocessResult] | tuple[Literal[True], ExcStr] class ExitThread(Exception): pass class WorkerError(Exception): def __init__(self, test_name: TestName, err_msg: str | None, stdout: str | None, state: str = State.MULTIPROCESSING_ERROR): result = TestResult(test_name, state=state) self.mp_result = MultiprocessResult(result, stdout, err_msg) super().__init__() class WorkerThread(threading.Thread): def __init__(self, worker_id: int, runner: "RunWorkers") -> None: super().__init__() self.worker_id = worker_id self.runtests = runner.runtests self.pending = runner.pending self.output = runner.output self.timeout = runner.worker_timeout self.log = runner.log self.test_name = None self.start_time = None self._popen = None self._killed = False self._stopped = False def __repr__(self) -> str: info = [f'WorkerThread #{self.worker_id}'] if self.is_alive(): info.append("running") else: info.append('stopped') test = self.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 WorkerThread 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 _run_process(self, runtests: RunTests, output_fd: int, tmp_dir: StrPath | None = None) -> int: popen = create_worker_process(runtests, output_fd, tmp_dir) self._popen = popen self._killed = False 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 def create_stdout(self, stack: contextlib.ExitStack) -> TextIO: """Create stdout temporay file (file descriptor).""" if MS_WINDOWS: # 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. stdout_file = tempfile.TemporaryFile('w+', encoding=encoding) stack.enter_context(stdout_file) return stdout_file def create_json_file(self, stack: contextlib.ExitStack) -> tuple[JsonFile, TextIO | None]: """Create JSON file.""" json_file_use_stdout = self.runtests.json_file_use_stdout() if json_file_use_stdout: json_file = JsonFile(None, JsonFileType.STDOUT) json_tmpfile = None else: json_tmpfile = tempfile.TemporaryFile('w+', encoding='utf8') stack.enter_context(json_tmpfile) json_fd = json_tmpfile.fileno() if MS_WINDOWS: json_handle = msvcrt.get_osfhandle(json_fd) json_file = JsonFile(json_handle, JsonFileType.WINDOWS_HANDLE) else: json_file = JsonFile(json_fd, JsonFileType.UNIX_FD) return (json_file, json_tmpfile) def create_worker_runtests(self, test_name: TestName, json_file: JsonFile) -> RunTests: """Create the worker RunTests.""" tests = (test_name,) if self.runtests.rerun: match_tests = self.runtests.get_match_tests(test_name) else: match_tests = None kwargs = {} if match_tests: kwargs['match_tests'] = match_tests return self.runtests.copy( tests=tests, json_file=json_file, **kwargs) def run_tmp_files(self, worker_runtests: RunTests, stdout_fd: int) -> (int, list[StrPath]): # 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. if not support.is_wasi: # Don't check for leaked temporary files and directories if Python is # run on WASI. WASI don't pass environment variables like TMPDIR to # worker processes. tmp_dir = tempfile.mkdtemp(prefix="test_python_") tmp_dir = os.path.abspath(tmp_dir) try: retcode = self._run_process(worker_runtests, stdout_fd, tmp_dir) finally: tmp_files = os.listdir(tmp_dir) os_helper.rmtree(tmp_dir) else: retcode = self._run_process(worker_runtests, stdout_fd) tmp_files = [] return (retcode, tmp_files) def read_stdout(self, stdout_file: TextIO) -> str: stdout_file.seek(0) try: return stdout_file.read().strip() except Exception as exc: # gh-101634: Catch UnicodeDecodeError if stdout cannot be # decoded from encoding raise WorkerError(self.test_name, f"Cannot read process stdout: {exc}", None) def read_json(self, json_file: JsonFile, json_tmpfile: TextIO | None, stdout: str) -> tuple[TestResult, str]: try: if json_tmpfile is not None: json_tmpfile.seek(0) worker_json: StrJSON = json_tmpfile.read() elif json_file.file_type == JsonFileType.STDOUT: stdout, _, worker_json = stdout.rpartition("\n") stdout = stdout.rstrip() else: with json_file.open(encoding='utf8') as json_fp: worker_json: StrJSON = json_fp.read() except Exception as exc: # gh-101634: Catch UnicodeDecodeError if stdout cannot be # decoded from encoding err_msg = f"Failed to read worker process JSON: {exc}" raise WorkerError(self.test_name, err_msg, stdout, state=State.MULTIPROCESSING_ERROR) if not worker_json: raise WorkerError(self.test_name, "empty JSON", stdout) try: result = TestResult.from_json(worker_json) except Exception as exc: # gh-101634: Catch UnicodeDecodeError if stdout cannot be # decoded from encoding err_msg = f"Failed to parse worker process JSON: {exc}" raise WorkerError(self.test_name, err_msg, stdout, state=State.MULTIPROCESSING_ERROR) return (result, stdout) def _runtest(self, test_name: TestName) -> MultiprocessResult: with contextlib.ExitStack() as stack: stdout_file = self.create_stdout(stack) json_file, json_tmpfile = self.create_json_file(stack) worker_runtests = self.create_worker_runtests(test_name, json_file) retcode, tmp_files = self.run_tmp_files(worker_runtests, stdout_file.fileno()) stdout = self.read_stdout(stdout_file) if retcode is None: raise WorkerError(self.test_name, None, stdout, state=State.TIMEOUT) if retcode != 0: raise WorkerError(self.test_name, f"Exit code {retcode}", stdout) result, stdout = self.read_json(json_file, json_tmpfile, stdout) if tmp_files: msg = (f'\n\n' f'Warning -- {test_name} leaked temporary files ' f'({len(tmp_files)}): {", ".join(sorted(tmp_files))}') stdout += msg result.set_env_changed() return MultiprocessResult(result, stdout) def run(self) -> None: fail_fast = self.runtests.fail_fast fail_env_changed = self.runtests.fail_env_changed while not self._stopped: try: try: test_name = next(self.pending) except StopIteration: break self.start_time = time.monotonic() self.test_name = test_name try: mp_result = self._runtest(test_name) except WorkerError as exc: mp_result = exc.mp_result finally: self.test_name = None mp_result.result.duration = time.monotonic() - self.start_time self.output.put((False, mp_result)) if mp_result.result.must_stop(fail_fast, fail_env_changed): 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: RunWorkers.stop_workers() called self.stop() # which killed the process. Sometimes, killing the process from the # main thread does not interrupt popen.communicate() in # WorkerThread 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.log(f"Waiting for {self} thread 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[WorkerThread]) -> list[str]: running = [] for worker in workers: test_name = worker.test_name if not test_name: continue dt = time.monotonic() - worker.start_time if dt >= PROGRESS_MIN_TIME: text = f'{test_name} ({format_duration(dt)})' running.append(text) if not running: return None return f"running ({len(running)}): {', '.join(running)}" class RunWorkers: def __init__(self, num_workers: int, runtests: RunTests, logger: Logger, results: TestResult) -> None: self.num_workers = num_workers self.runtests = runtests self.log = logger.log self.display_progress = logger.display_progress self.results: TestResults = results self.output: queue.Queue[QueueOutput] = queue.Queue() tests_iter = runtests.iter_tests() self.pending = MultiprocessIterator(tests_iter) self.timeout = runtests.timeout if self.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.timeout * 1.5, self.timeout + 5 * 60) else: self.worker_timeout = None self.workers = None jobs = self.runtests.get_jobs() if jobs is not None: # Don't spawn more threads than the number of jobs: # these worker threads would never get anything to do. self.num_workers = min(self.num_workers, jobs) def start_workers(self) -> None: self.workers = [WorkerThread(index, self) for index in range(1, self.num_workers + 1)] jobs = self.runtests.get_jobs() if jobs is not None: tests = count(jobs, 'test') else: tests = 'tests' nworkers = len(self.workers) processes = plural(nworkers, "process", "processes") msg = (f"Run {tests} in parallel using " f"{nworkers} worker {processes}") if self.timeout: msg += (" (timeout: %s, worker timeout: %s)" % (format_duration(self.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: pgo = self.runtests.pgo use_faulthandler = (self.timeout is not None) # 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=PROGRESS_UPDATE) except queue.Empty: pass if not pgo: # display progress running = get_running(self.workers) if running: self.log(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 pgo = self.runtests.pgo text = str(result) if mp_result.err_msg: # MULTIPROCESSING_ERROR text += ' (%s)' % mp_result.err_msg elif (result.duration >= PROGRESS_MIN_TIME and not pgo): text += ' (%s)' % format_duration(result.duration) if not pgo: running = get_running(self.workers) if running: text += f' -- {running}' self.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}") result = TestResult("", state=State.MULTIPROCESSING_ERROR) self.results.accumulate_result(result, self.runtests) return result self.test_index += 1 mp_result = item[1] result = mp_result.result self.results.accumulate_result(result, self.runtests) self.display_result(mp_result) if mp_result.worker_stdout: print(mp_result.worker_stdout, flush=True) return result def run(self) -> None: fail_fast = self.runtests.fail_fast fail_env_changed = self.runtests.fail_env_changed self.start_workers() self.test_index = 0 try: while True: item = self._get_result() if item is None: break result = self._process_result(item) if result.must_stop(fail_fast, fail_env_changed): break except KeyboardInterrupt: print() self.results.interrupted = True finally: if self.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()