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 Any, Literal, TextIO
from test import support
from test.support import os_helper, MS_WINDOWS
from .logger import Logger
from .result import TestResult, State
from .results import TestResults
from .runtests import RunTests, WorkerRunTests, JsonFile, JsonFileType
from .single import PROGRESS_MIN_TIME
from .utils import (
StrPath, TestName,
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
WAIT_COMPLETED_TIMEOUT = 30.0 # seconds
# Time to wait a killed process (in seconds)
WAIT_KILLED_TIMEOUT = 60.0
# 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
@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
class WorkerThreadExited:
"""Indicates that a worker thread has exited"""
ExcStr = str
QueueOutput = tuple[Literal[False], MultiprocessResult] | tuple[Literal[True], ExcStr]
QueueContent = QueueOutput | WorkerThreadExited
class ExitThread(Exception):
pass
class WorkerError(Exception):
def __init__(self,
test_name: TestName,
err_msg: str | None,
stdout: str | None,
state: str):
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: TestName | None = None
self.start_time: float | None = None
self._popen: subprocess.Popen[str] | None = 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
use_killpg = USE_PROCESS_GROUP
if use_killpg:
parent_sid = os.getsid(0)
sid = os.getsid(popen.pid)
use_killpg = (sid != parent_sid)
if use_killpg:
what = f"{self} process group"
else:
what = f"{self} process"
print(f"Kill {what}", file=sys.stderr, flush=True)
try:
if use_killpg:
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: WorkerRunTests, output_fd: int,
tmp_dir: StrPath | None = None) -> int | None:
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 temporary 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.
# gh-109425: Use "backslashreplace" error handler: log corrupted
# stdout+stderr, instead of failing with a UnicodeDecodeError and not
# logging stdout+stderr at all.
stdout_file = tempfile.TemporaryFile('w+',
encoding=encoding,
errors='backslashreplace')
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:
# The msvcrt module is only available on Windows;
# we run mypy with `--platform=linux` in CI
json_handle: int = msvcrt.get_osfhandle(json_fd) # type: ignore[attr-defined]
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) -> WorkerRunTests:
tests = (test_name,)
if self.runtests.rerun:
match_tests = self.runtests.get_match_tests(test_name)
else:
match_tests = None
kwargs: dict[str, Any] = {}
if match_tests:
kwargs['match_tests'] = [(test, True) for test in match_tests]
if self.runtests.output_on_failure:
kwargs['verbose'] = True
kwargs['output_on_failure'] = False
return self.runtests.create_worker_runtests(
tests=tests,
json_file=json_file,
**kwargs)
def run_tmp_files(self, worker_runtests: WorkerRunTests,
stdout_fd: int) -> tuple[int | None, 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 doesn'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}",
stdout=None,
state=State.WORKER_BUG)
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 = 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 = 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.WORKER_BUG)
if not worker_json:
raise WorkerError(self.test_name, "empty JSON", stdout,
state=State.WORKER_BUG)
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.WORKER_BUG)
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: str | int | None
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, stdout=stdout,
err_msg=None,
state=State.TIMEOUT)
if retcode != 0:
name = support.get_signal_name(retcode)
if name:
retcode = f"{retcode} ({name})"
raise WorkerError(self.test_name, f"Exit code {retcode}", stdout,
state=State.WORKER_FAILED)
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
try:
while not self._stopped:
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:
pass
except BaseException:
self.output.put((True, traceback.format_exc()))
finally:
self.output.put(WorkerThreadExited())
def _wait_completed(self) -> None:
popen = self._popen
try:
popen.wait(WAIT_COMPLETED_TIMEOUT)
except (subprocess.TimeoutExpired, OSError) as exc:
print_warning(f"Failed to wait for {self} completion "
f"(timeout={format_duration(WAIT_COMPLETED_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 > WAIT_KILLED_TIMEOUT:
print_warning(f"Failed to join {self} in {format_duration(dt)}")
break
def get_running(workers: list[WorkerThread]) -> str | None:
running: list[str] = []
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: TestResults) -> None:
self.num_workers = num_workers
self.runtests = runtests
self.log = logger.log
self.display_progress = logger.display_progress
self.results: TestResults = results
self.live_worker_count = 0
self.output: queue.Queue[QueueContent] = 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: float | None = min(self.timeout * 1.5, self.timeout + 5 * 60)
else:
self.worker_timeout = None
self.workers: list[WorkerThread] | None = 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()
self.live_worker_count += 1
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 self.live_worker_count > 0:
if use_faulthandler:
faulthandler.dump_traceback_later(MAIN_PROCESS_TIMEOUT,
exit=True)
# wait for a thread
try:
result = self.output.get(timeout=PROGRESS_UPDATE)
if isinstance(result, WorkerThreadExited):
self.live_worker_count -= 1
continue
return result
except queue.Empty:
pass
if not pgo:
# display progress
running = get_running(self.workers)
if running:
self.log(running)
def display_result(self, mp_result: MultiprocessResult) -> None:
result = mp_result.result
pgo = self.runtests.pgo
text = str(result)
if mp_result.err_msg:
# WORKER_BUG
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) -> TestResult:
"""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("<regrtest worker>", state=State.WORKER_BUG)
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)
# Display worker stdout
if not self.runtests.output_on_failure:
show_stdout = True
else:
# --verbose3 ignores stdout on success
show_stdout = (result.state != State.PASSED)
if show_stdout:
stdout = mp_result.worker_stdout
if stdout:
print(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()
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