Source code for

import logging
import multiprocessing
import multiprocessing.connection as connection
import os
import select
import sys
import unittest
from import Sequence

from nose2 import events, loader, result, runner, session, util

log = logging.getLogger(__name__)

[docs]class MultiProcess(events.Plugin): configSection = "multiprocess" def __init__(self): self.addArgument( self.setProcs, "N", "processes", "Number of processes used to run tests (0 = auto)", ) self.testRunTimeout = self.config.as_float("test-run-timeout", 60.0) self._procs = self.config.as_int("processes", 0) self.setAddress(self.config.as_str("bind_address", None)) self.cases = {} @property def procs(self): """Get the appropriate number of procs for self.procs if self._procs is 0.""" if self._procs == 0: try: self._procs = multiprocessing.cpu_count() except NotImplementedError: self._procs = 1 return self._procs @procs.setter def procs(self, value): """Setter for procs property""" if value < 0: raise ValueError("Number of processes cannot be less than 0") self._procs = value def setProcs(self, num): self.procs = int(num[0]) # FIXME merge n fix self.register() def setAddress(self, address): if address is None or address.strip() == "": address = [] else: address = [x.strip() for x in address.split(":")[:2]] # Background: On Windows, only works on sockets. So the # ability to select a bindable address and optionally port for the mp # plugin was added. Pipes should support a form of select, but this # would require using pywin32. There are alternatives but all have # some kind of downside. An alternative might be creating a connection # like object using a shared queue for incomings events. self.bind_host = None self.bind_port = 0 if sys.platform == "win32" or address: self.bind_host = "" if address and address[0]: self.bind_host = address[0] self.bind_port = 0 if len(address) >= 2: self.bind_port = int(address[1]) def pluginsLoaded(self, event): self.addMethods("registerInSubprocess", "startSubprocess", "stopSubprocess") def startTestRun(self, event): event.executeTests = self._runmp def beforeInteraction(self, event): # prevent interactive plugins from running event.handled = True return False def _runmp(self, test, result): # flatten technically modifies a hash of test cases, let's # only run it once per run. flat = list(self._flatten(test)) # do not send import failures to the subprocesses, which will mangle them # but 'run' them in the main process. failed_import_id = "nose2.loader.LoadTestsFailure" result_ = self.session.testResult for testid in flat: if testid.startswith(failed_import_id): self.cases[testid].run(result_) # XXX Process-Handling: The length of the filtered list needs to be # known for _startProcs, until this can be cleaned up. This # wasn't the best way to deal with too few tests flat = [x for x in flat if not x.startswith(failed_import_id)] procs = self._startProcs(len(flat)) # send one initial task to each process for _proc, conn in procs: if not flat: break caseid = flat.pop(0) # NOTE: it throws errors on broken pipes and bad serialization conn.send(caseid) rdrs = [conn for proc, conn in procs if proc.is_alive()] while flat or rdrs: ready, _, _ =, [], [], self.testRunTimeout) for conn in ready: # XXX Process-Handling: If we get an EOFError on receive the # process finished= or we lost the process and the test it was # working on. Also do we rebuild the process? try: remote_events = conn.recv() except EOFError: # probably dead/12 log.warning("Subprocess connection closed unexpectedly") continue # If remote_events is None, the process exited normally, # which should mean that we didn't any more tests for it. if remote_events is None: log.debug("Conn closed %s", conn) rdrs.remove(conn) continue # replay events testid, events = remote_events log.debug("Received results for %s", testid) for hook, event in events: log.debug("Received %s(%s)", hook, event) self._localize(event) getattr(self.session.hooks, hook)(event) # Send the next test_id # NOTE: send throws errors on broken pipes and bad serialization if not flat: # If there are no more, send None - it's the 'done' flag conn.send(None) continue caseid = flat.pop(0) conn.send(caseid) for _, conn in procs: conn.close() # ensure we wait until all processes are done before # exiting, to allow plugins running there to finalize for proc, _ in procs: proc.join() def _prepConns(self): """ If the ``bind_host`` is not ``None``, return: (multiprocessing.connection.Listener, (address, port, authkey)) else: (parent_connection, child_connection) For the former case: ``accept`` must be called on the listener. In order to get a ``Connection`` object for the socket. """ if self.bind_host is not None: # prevent "accidental" wire crossing authkey = os.urandom(20) address = (self.bind_host, self.bind_port) listener = connection.Listener(address, authkey=authkey) return (listener, listener.address + (authkey,)) else: return multiprocessing.Pipe() def _acceptConns(self, parent_conn): """ When listener is is a :class:`connection.Listener` instance: accept the next incoming connection. However, a timeout mechanism is needed. Since this functionality was added to support mp over inet sockets, this method assumes a Socket-based listen, and will accept the private _socket member to get a low_level socket to do a select on. """ if isinstance(parent_conn, connection.Listener): # ick private interface rdrs = [parent_conn._listener._socket] readable, _, _ =, [], [], self.testRunTimeout) if readable: return parent_conn.accept() else: raise RuntimeError("MP: Socket Connection Failed") else: return parent_conn def _startProcs(self, test_count): # Create session export session_export = self._exportSession() procs = [] count = min(test_count, self.procs) log.debug("Creating %i worker processes", count) for _ in range(0, count): parent_conn, child_conn = self._prepConns() proc = multiprocessing.Process( target=procserver, args=(session_export, child_conn) ) proc.daemon = True proc.start() parent_conn = self._acceptConns(parent_conn) procs.append((proc, parent_conn)) return procs def _flatten(self, suite): """ Flatten test-suite into list of IDs, AND record all test case into self.cases CAVEAT: Due to current limitation of the MP plugin, examine the suite tests to find out if they have class or module fixtures and group them that way into name of test classes or module. This is aid in their dispatch. """ log.debug("Flattening test into list of IDs") mods = {} classes = {} stack = [suite] while stack: suite = stack.pop() for test in suite: if isinstance(test, unittest.TestSuite): stack.append(test) else: testid = util.test_name(test) self.cases[testid] = test if util.has_module_fixtures(test): mods.setdefault(test.__class__.__module__, []).append(testid) elif util.has_class_fixtures(test): # testclasses support if test.__class__.__name__ == "_MethodTestCase": test = test.obj classes.setdefault( "%s.%s" % (test.__class__.__module__, test.__class__.__name__), [], ).append(testid) else: yield testid yield from sorted(classes.keys()) yield from sorted(mods.keys()) def _localize(self, event): # XXX set loader, case, result etc to local ones, if present in event # (event case will be just the id) # (traceback in exc_info if any won't be real!) if hasattr(event, "result"): event.result = self.session.testResult if hasattr(event, "loader"): event.loader = self.session.testLoader if hasattr(event, "runner"): event.runner = self.session.testRunner if hasattr(event, "test") and isinstance(event.test, str): # remote is the test id try: event.test = self.cases[event.test] except KeyError: # this happens when _flatten augments the test suite # due to a class or module fixture being present event.test = self.session.testLoader.loadTestsFromName( event.test )._tests[0] # subtest support if "subtest" in event.metadata: message, params = event.metadata.pop("subtest") # XXX the sentinel value does not survive the pickle # round-trip and must be reset by hand if type(message) == type(object()): # noqa: E721 message = event.test =, message, params) def _exportSession(self): """ Generate the session information passed to work process. CAVEAT: The entire contents of which *MUST* be pickleable and safe to use in the subprocess. This probably includes: * No argparse namespaces/named-tuples * No plugin instances * No hokes :return: """ export = { "config": self.session.config, "verbosity": self.session.verbosity, "startDir": self.session.startDir, "topLevelDir": self.session.topLevelDir, "logLevel": self.session.logLevel, "pluginClasses": [], } event = RegisterInSubprocessEvent() # fire registerInSubprocess on plugins -- add those plugin classes # CAVEAT: classes must be pickleable! self.session.hooks.registerInSubprocess(event) export["pluginClasses"].extend(event.pluginClasses) return export
def procserver(session_export, conn): # init logging system rlog = multiprocessing.log_to_stderr() rlog.setLevel(session_export["logLevel"]) # make a real session from the "session" we got ssn = import_session(rlog, session_export) if isinstance(conn, Sequence): conn = connection.Client(conn[:2], authkey=conn[2]) event = SubprocessEvent( ssn.testLoader, ssn.testResult, ssn.testRunner, ssn.plugins, conn ) res = ssn.hooks.startSubprocess(event) if event.handled and not res: conn.send(None) conn.close() ssn.hooks.stopSubprocess(event) return # receive and run tests executor = event.executeTests for testid in gentests(conn): if testid is None: break # XXX to handle weird cases like layers, need to # deal with the case that testid is something other # than a simple string. test = event.loader.loadTestsFromName(testid) # XXX If there a need to protect the loop? try/except? rlog.debug("Execute test %s (%s)", testid, test) executor(test, event.result) events = list(ssn.hooks.flush()) try: conn.send((testid, events)) rlog.debug("Log for %s returned", testid) except Exception: rlog.exception(f"Fail sending event {testid}: {events}") # Send empty event list to unblock the conn.recv on main process. conn.send((testid, [])) conn.send(None) conn.close() ssn.hooks.stopSubprocess(event) def import_session(rlog, session_export): ssn = session.Session() ssn.config = session_export["config"] ssn.hooks = RecordingPluginInterface() ssn.verbosity = session_export["verbosity"] ssn.startDir = session_export["startDir"] ssn.topLevelDir = session_export["topLevelDir"] ssn.prepareSysPath() loader_ = loader.PluggableTestLoader(ssn) ssn.testLoader = loader_ result_ = result.PluggableTestResult(ssn) ssn.testResult = result_ runner_ = runner.PluggableTestRunner(ssn) # needed?? ssn.testRunner = runner_ # load and register plugins, forcing multiprocess to the end ssn.plugins = [ plugin(session=ssn) for plugin in session_export["pluginClasses"] if plugin is not MultiProcess ] rlog.debug("Plugins loaded: %s", ssn.plugins) for plugin in ssn.plugins: plugin.register() rlog.debug("Registered %s in subprocess", plugin) # instantiating the plugin will register it. ssn.plugins.append(MultiProcess(session=ssn)) rlog.debug("Registered %s in subprocess", MultiProcess) ssn.plugins[-1].pluginsLoaded(events.PluginsLoadedEvent(ssn.plugins)) return ssn # test generator def gentests(conn): while True: try: testid = conn.recv() if testid is None: return yield testid except EOFError: return # custom event classes
[docs]class SubprocessEvent(events.Event): """Event fired at start and end of subprocess execution. .. attribute :: loader Test loader instance .. attribute :: result Test result .. attribute :: plugins List of plugins loaded in the subprocess. .. attribute :: connection The :class:`multiprocessing.Connection` instance that the subprocess uses for communication with the main process. .. attribute :: executeTests Callable that will be used to execute tests. Plugins may set this attribute to wrap or otherwise change test execution. The callable must match the signature:: def execute(suite, result): ... """ def __init__(self, loader, result, runner, plugins, connection, **metadata): self.loader = loader self.result = result self.runner = runner self.plugins = plugins self.connection = connection self.executeTests = lambda test, result: test(result) super().__init__(**metadata)
[docs]class RegisterInSubprocessEvent(events.Event): """Event fired to notify plugins that multiprocess testing will occur .. attribute :: pluginClasses Add a plugin class to this list to cause the plugin to be instantiated in each test-running subprocess. The most common thing to do, for plugins that need to run in subprocesses, is:: def registerInSubprocess(self, event): event.pluginClasses.append(self.__class__) """ def __init__(self, **metadata): self.pluginClasses = [] super().__init__(**metadata)
# custom hook system that records calls and events class RecordingHook(events.Hook): def __init__(self, method, interface): super().__init__(method) self.interface = interface def __call__(self, event): res = super().__call__(event) self.interface.log(self.method, event) return res class RecordingPluginInterface(events.PluginInterface): hookClass = RecordingHook noLogMethods = { "getTestCaseNames", "startSubprocess", "stopSubprocess", "registerInSubprocess", "moduleLoadedSuite", "getTestMethodNames", } def __init__(self): super().__init__() = [] def log(self, method, event):, event)) def flush(self): events =[:] = [] return events def register(self, method, plugin): """Register a plugin for a method. :param method: A method name :param plugin: A plugin instance """ self._hookForMethod(method).append(plugin) def __getattr__(self, attr): if attr.startswith("__"): raise AttributeError(f"No {attr} in {self}") return self._hookForMethod(attr) def _hookForMethod(self, method): # return recording hook for most hooks, normal hook for those # (like test loading and subprocess events) that we don't want # to send back to the main process. try: return self.hooks[method] except KeyError: if method in self.noLogMethods or method.startswith("loadTest"): hook = events.Hook(method) else: hook = self.hookClass(method, self) self.hooks[method] = hook return hook