""" Overview ======== The multiprocess plugin enables you to distribute your test run among a set of worker processes that run tests in parallel. This can speed up CPU-bound test runs (as long as the number of work processeses is around the number of processors or cores available), but is mainly useful for IO-bound tests that spend most of their time waiting for data to arrive from someplace else. .. _multiprocessing : http://code.google.com/p/python-multiprocessing/ How tests are distributed ========================= The ideal case would be to dispatch each test to a worker process separately. This ideal is not attainable in all cases, however, because many test suites depend on context (class, module, or package) fixtures. The plugin can't know (unless you tell it -- see below!) if a context fixture can be called many times concurrently (is re-entrant), or if it can be shared among tests running in different processes. Therefore, if a context has fixtures, the default behavior is to dispatch the suite to a worker as a unit. Controlling distribution ======================== There are two context-level variables to control this default behavior: * If a context's fixtures are re-entrant, set `_multiprocess_can_split_ = True` in the context, and the plugin will dispatch tests in suites bound to that context as if the context had no fixtures. This means that the fixtures will execute concurrently and multiple times, typically once per test. * If a context's fixtures can be shared by tests running in different processes (such as a package-level fixture that starts an external http server or initializes a shared database) then set ``_multiprocess_shared_ = True`` in the context. These fixtures will then execute in the primary nose process, and tests in those contexts will be individually dispatched to run in parallel. How results are collected and reported ====================================== As each test or suite executes in a worker process, results (failures, errors, and specially handled exceptions like SkipTest) are collected in that process. When the worker process finishes, it returns results to the main nose process. There, any progress output is printed (dots!), and the results from the test run are combined into a consolidated result set. When results have been received for all dispatched tests, or all workers have died, the result summary is output as normal. Beware! ======= Not all test suites will benefit from, or even operate correctly using this plugin. For example, CPU-bound tests will run more slowly if you don't have multiple processors. There are also some differences in plugin interactions and behaviors due to the way in which tests are dispatched and loaded. In general, tests loaded under this plugin operate as if they were always in directed mode instead of discovered mode. For instance, doctests in test modules will always be found when using this plugin with the doctest plugin. But the biggest issue you will face is probably concurrency. Unless you have kept your tests as religiously pure unit tests, with no side-effects, no ordering issues, and no external dependencies, chances are you will experience odd, intermittent and unexplainable failures and errors when using this plugin. This doesn't necessarily mean the plugin is broken; it may mean that your test suite is not safe for concurrency.""" import logging import os import sys import time import unittest import pickle import signal import nose.case from nose.core import TextTestRunner from nose import failure from nose import loader from nose.plugins.base import Plugin from nose.pyversion import bytes_ from nose.suite import ContextSuite from nose.util import test_address from unittest.runner import _WritelnDecorator from queue import Empty from warnings import warn from io import StringIO _instantiate_plugins = None log = logging.getLogger(__name__) Process = Queue = Pool = Event = Value = Array = None class TimedOutException(KeyboardInterrupt): def __init__(self, value="Timed Out"): self.value = value def __str__(self): return repr(self.value) def _import_mp(): global Process, Queue, Pool, Event, Value, Array try: from multiprocessing import Manager, Process old = signal.signal(signal.SIGINT, signal.SIG_IGN) m = Manager() signal.signal(signal.SIGINT, old) Queue, Pool, Event, Value, Array = ( m.Queue, m.Pool, m.Event, m.Value, m.Array ) except ImportError: warn("multiprocessing module is not available, multiprocess plugin " "cannot be used", RuntimeWarning) class TestLet: def __init__(self, case): try: self._id = case.id() except AttributeError: pass self._short_description = case.shortDescription() self._str = str(case) def id(self): return self._id def shortDescription(self): return self._short_description def __str__(self): return self._str class MultiProcess(Plugin): """Run tests in multiple processes. Requires processing module.""" score = 1000 status = {} def options(self, parser, env): """Register command-line options.""" parser.add_option( "--processes", action="store", default=env.get('NOSE_PROCESSES', 0), dest="multiprocess_workers", metavar="NUM", help="Spread test run among this many processes. " "Set a number equal to the number of processors " "or cores in your machine for best results. " "Pass a negative number to have the number of " "processes automatically set to the number of cores. " "Passing 0 means to disable parallel testing. " "Default is 0 unless NOSE_PROCESSES is set. [NOSE_PROCESSES]") parser.add_option( "--process-timeout", action="store", default=env.get('NOSE_PROCESS_TIMEOUT', 10), dest="multiprocess_timeout", metavar="SECONDS", help="Set timeout for return of results from each " "test runner process. Default is 10. [NOSE_PROCESS_TIMEOUT]") parser.add_option( "--process-restartworker", action="store_true", default=env.get('NOSE_PROCESS_RESTARTWORKER', False), dest="multiprocess_restartworker", help="If set, will restart each worker process once" " their tests are done, this helps control memory " "leaks from killing the system. [NOSE_PROCESS_RESTARTWORKER]") def configure(self, options, config): """Configure plugin.""" try: self.status.pop('active') except KeyError: pass if not hasattr(options, 'multiprocess_workers'): self.enabled = False return if config.worker: return # Don't start inside of a worker process self.config = config try: workers = int(options.multiprocess_workers) except (TypeError, ValueError): workers = 0 if workers: _import_mp() if Process is None: self.enabled = False return if workers < 0: import multiprocessing workers = multiprocessing.cpu_count() self.enabled = True self.config.multiprocess_workers = workers t = float(options.multiprocess_timeout) self.config.multiprocess_timeout = t r = int(options.multiprocess_restartworker) self.config.multiprocess_restartworker = r self.status['active'] = True def prepareTestLoader(self, loader): """Remember loader class so MultiProcessTestRunner can instantiate the right loader.""" self.loaderClass = loader.__class__ def prepareTestRunner(self, runner): """Replace test runner with MultiProcessTestRunner.""" return MultiProcessTestRunner( stream=runner.stream, verbosity=self.config.verbosity, config=self.config, loaderClass=self.loaderClass) def signalhandler(sig, frame): raise TimedOutException() class MultiProcessTestRunner(TextTestRunner): # Max time to wait to terminate a process that does not respond to SIGILL. waitkilltime = 5.0 def __init__(self, **kw): self.loaderClass = kw.pop('loaderClass', loader.defaultTestLoader) super(MultiProcessTestRunner, self).__init__(**kw) def collect(self, test, testQueue, tasks, to_teardown, result): for case in self.nextBatch(test): log.debug("Next batch %s (%s)", case, type(case)) if ( isinstance(case, nose.case.Test) and isinstance(case.test, failure.Failure) ): log.debug("Case is a Failure") case(result) continue if isinstance( case, ContextSuite ) and case.context is failure.Failure: log.debug("Case is a Failure") case(result) continue elif isinstance(case, ContextSuite) and self.sharedFixtures(case): log.debug("%s has shared fixtures", case) try: case.setUp() except (KeyboardInterrupt, SystemExit): raise except Exception: log.debug("%s setup failed", sys.exc_info()) result.addError(case, sys.exc_info()) else: to_teardown.append(case) if case.factory: ancestors = case.factory.context.get(case, []) for an in ancestors[:2]: if getattr(an, '_multiprocess_shared_', False): an._multiprocess_can_split_ = True self.collect(case, testQueue, tasks, to_teardown, result) else: test_addr = self.addtask(testQueue, tasks, case) log.debug( "Queued test %s (%s) to %s", len(tasks), test_addr, testQueue, ) def startProcess( self, iworker, testQueue, resultQueue, shouldStop, result ): currentaddr = Value('c', bytes_('')) currentstart = Value('d', time.time()) keyboardCaught = Event() p = Process( target=runner, args=( iworker, testQueue, resultQueue, currentaddr, currentstart, keyboardCaught, shouldStop, self.loaderClass, result.__class__, pickle.dumps(self.config), ) ) p.currentaddr = currentaddr p.currentstart = currentstart p.keyboardCaught = keyboardCaught old = signal.signal(signal.SIGILL, signalhandler) p.start() signal.signal(signal.SIGILL, old) return p def run(self, test): """Execute the test (which may be a suite). If the test is a suite, distribute it out among as many processes as have been configured, at as fine a level as is possible given the context fixtures defined in the suite or any sub-suites.""" log.debug("%s.run(%s) (%s)", self, test, os.getpid()) wrapper = self.config.plugins.prepareTest(test) if wrapper is not None: test = wrapper wrapped = self.config.plugins.setOutputStream(self.stream) if wrapped is not None: self.stream = wrapped testQueue = Queue() resultQueue = Queue() tasks = [] completed = [] workers = [] to_teardown = [] shouldStop = Event() result = self._makeResult() start = time.time() self.collect(test, testQueue, tasks, to_teardown, result) log.debug("Starting %s workers", self.config.multiprocess_workers) for i in range(self.config.multiprocess_workers): p = self.startProcess( i, testQueue, resultQueue, shouldStop, result ) workers.append(p) log.debug("Started worker process %s", i+1) total_tasks = len(tasks) nexttimeout = self.config.multiprocess_timeout thrownError = None try: while tasks: log.debug( "Waiting for results (%s/%s tasks), next timeout=%.3fs", len(completed), total_tasks, nexttimeout, ) try: iworker, addr, newtask_addrs, batch_result = ( resultQueue.get(timeout=nexttimeout) ) log.debug( 'Results received for worker %d, %s, new tasks: %d', iworker, addr, len(newtask_addrs), ) try: try: tasks.remove(addr) except ValueError: log.warning( 'worker %s failed to remove from tasks: %s', iworker, addr, ) total_tasks += len(newtask_addrs) tasks.extend(newtask_addrs) except KeyError: log.debug("Got result for unknown task? %s", addr) log.debug("current: %s", str(list(tasks)[0])) else: completed.append([addr, batch_result]) self.consolidate(result, batch_result) if ( self.config.stopOnError and not result.wasSuccessful() ): shouldStop.set() break if self.config.multiprocess_restartworker: log.debug('joining worker %s', iworker) workers[iworker].join(timeout=1) if not shouldStop.is_set() and not testQueue.empty(): log.debug( 'starting new process on worker %s', iworker ) workers[iworker] = self.startProcess( iworker, testQueue, resultQueue, shouldStop, result, ) except Empty: msg = "Timeout - %s tasks pending (empty testQueue=%r): %s" log.debug(msg, len(tasks), testQueue.empty(), str(tasks)) any_alive = False for iworker, w in enumerate(workers): if w.is_alive(): worker_addr = bytes_(w.currentaddr.value, 'ascii') timeprocessing = time.time() - w.currentstart.value if ( len(worker_addr) == 0 and timeprocessing > self.config.multiprocess_timeout - 0.1 ): log.debug( 'Worker %d finished its work item, but is ' 'not exiting. Do we wait for it?', iworker, ) else: any_alive = True if ( len(worker_addr) > 0 and timeprocessing > self.config.multiprocess_timeout - 0.1 ): msg = 'Timed out worker %s: %s' log.debug(msg, iworker, worker_addr) w.currentaddr.value = bytes_('') w.keyboardCaught.clear() startkilltime = time.time() while ( not w.keyboardCaught.is_set() and w.is_alive() ): if ( time.time() - startkilltime > self.waitkilltime ): msg = "terminating worker %s" log.error(msg, iworker) w.terminate() workers[iworker] = w = ( self.startProcess( iworker, testQueue, resultQueue, shouldStop, result, ) ) break os.kill(w.pid, signal.SIGILL) time.sleep(0.1) if not any_alive and testQueue.empty(): log.debug("All workers are dead") break nexttimeout = self.config.multiprocess_timeout for w in workers: if w.is_alive() and len(w.currentaddr.value) > 0: timeprocessing = time.time() - w.currentstart.value if timeprocessing <= self.config.multiprocess_timeout: nexttimeout = min( nexttimeout, self.config.multiprocess_timeout - timeprocessing, ) log.debug( "Completed %s tasks (%s remain)", len(completed), len(tasks) ) except (KeyboardInterrupt, SystemExit) as e: log.info('parent received ctrl-c when waiting for test results') thrownError = e result.addError(test, sys.exc_info()) try: for case in to_teardown: log.debug("Tearing down shared fixtures for %s", case) try: case.tearDown() except (KeyboardInterrupt, SystemExit): raise except Exception: result.addError(case, sys.exc_info()) stop = time.time() result.printErrors() result.printSummary(start, stop) self.config.plugins.finalize(result) if thrownError is None: log.debug("Tell all workers to stop") for w in workers: if w.is_alive(): testQueue.put('STOP', block=False) for iworker, worker in enumerate(workers): if worker.is_alive(): log.debug('joining worker %s', iworker) worker.join() if worker.is_alive(): log.debug('failed to join worker %s', iworker) except (KeyboardInterrupt, SystemExit): log.info( 'parent received ctrl-c when shutting down: stop all processes' ) for worker in workers: if worker.is_alive(): worker.terminate() if thrownError: raise thrownError else: raise return result def addtask(testQueue, tasks, case): arg = None if isinstance(case, nose.case.Test) and hasattr(case.test, 'arg'): case.test.descriptor = None arg = case.test.arg test_addr = MultiProcessTestRunner.address(case) testQueue.put((test_addr, arg), block=False) if arg is not None: test_addr += str(arg) if tasks is not None: tasks.append(test_addr) return test_addr addtask = staticmethod(addtask) def address(case): if hasattr(case, 'address'): file, mod, call = case.address() elif hasattr(case, 'context'): file, mod, call = test_address(case.context) else: raise Exception("Unable to convert %s to address" % case) parts = [] if file is None: if mod is None: raise Exception("Unaddressable case %s" % case) else: parts.append(mod) else: dirname, basename = os.path.split(file) if basename.startswith('__init__'): file = dirname parts.append(file) if call is not None: parts.append(call) return ':'.join(map(str, parts)) address = staticmethod(address) def nextBatch(self, test): # Tests can mark themselves as not safe for multiprocess execution. if hasattr(test, 'context'): if not getattr(test.context, '_multiprocess_', True): return if ( ( isinstance(test, ContextSuite) and test.hasFixtures(self.checkCanSplit) ) or not getattr(test, 'can_split', True) or not isinstance(test, unittest.TestSuite) ): if isinstance(test, ContextSuite): contained = list(test) if ( len(contained) == 1 and getattr(contained[0], 'context', None) == test.context ): test = contained[0] yield test else: for case in test: yield from self.nextBatch(case) def checkCanSplit(context, fixt): """Callback to check whether the fixtures found in a context or ancestor are ones we care about. Contexts can tell us that their fixtures are reentrant by setting _multiprocess_can_split_.""" if not fixt: return False if getattr(context, '_multiprocess_can_split_', False): return False return True checkCanSplit = staticmethod(checkCanSplit) def sharedFixtures(self, case): context = getattr(case, 'context', None) if not context: return False return getattr(context, '_multiprocess_shared_', False) def consolidate(self, result, batch_result): log.debug("batch result is %s", batch_result) try: output, testsRun, failures, errors, errorClasses = batch_result except ValueError: log.debug("result in unexpected format %s", batch_result) failure.Failure(*sys.exc_info())(result) return self.stream.write(output) result.testsRun += testsRun result.failures.extend(failures) result.errors.extend(errors) for key, (storage, label, isfail) in list(errorClasses.items()): if key not in result.errorClasses: result.errorClasses[key] = ([], label, isfail) mystorage, _junk, _junk = result.errorClasses[key] mystorage.extend(storage) log.debug("Ran %s tests (total: %s)", testsRun, result.testsRun) def runner( ix, testQueue, resultQueue, currentaddr, currentstart, keyboardCaught, shouldStop, loaderClass, resultClass, config ): try: try: return __runner( ix, testQueue, resultQueue, currentaddr, currentstart, keyboardCaught, shouldStop, loaderClass, resultClass, config ) except KeyboardInterrupt: log.debug('Worker %s keyboard interrupt, stopping', ix) except Empty: log.debug("Worker %s timed out waiting for tasks", ix) def __runner( ix, testQueue, resultQueue, currentaddr, currentstart, keyboardCaught, shouldStop, loaderClass, resultClass, config ): config = pickle.loads(config) dummy_parser = config.parserClass() if _instantiate_plugins is not None: for pluginclass in _instantiate_plugins: plugin = pluginclass() plugin.addOptions(dummy_parser, {}) config.plugins.addPlugin(plugin) config.plugins.configure(config.options, config) config.plugins.begin() log.debug("Worker %s executing, pid=%d", ix, os.getpid()) loader = loaderClass(config=config) loader.suiteClass.suiteClass = NoSharedFixtureContextSuite def get(): return testQueue.get(timeout=config.multiprocess_timeout) def makeResult(): stream = _WritelnDecorator(StringIO()) result = resultClass( stream, descriptions=1, verbosity=config.verbosity, config=config ) plug_result = config.plugins.prepareTestResult(result) if plug_result: return plug_result return result def batch(result): failures = [(TestLet(c), err) for c, err in result.failures] errors = [(TestLet(c), err) for c, err in result.errors] errorClasses = {} for key, (storage, label, isfail) in list(result.errorClasses.items()): errorClasses[key] = ( [(TestLet(c), err) for c, err in storage], label, isfail ) return ( result.stream.getvalue(), result.testsRun, failures, errors, errorClasses ) for test_addr, arg in iter(get, 'STOP'): if shouldStop.is_set(): log.exception('Worker %d STOPPED', ix) break result = makeResult() test = loader.loadTestsFromNames([test_addr]) test.testQueue = testQueue test.tasks = [] test.arg = arg log.debug("Worker %s Test is %s (%s)", ix, test_addr, test) try: if arg is not None: test_addr = test_addr + str(arg) currentaddr.value = bytes_(test_addr) currentstart.value = time.time() test(result) currentaddr.value = bytes_('') resultQueue.put((ix, test_addr, test.tasks, batch(result))) except KeyboardInterrupt as e: timeout = isinstance(e, TimedOutException) if timeout: keyboardCaught.set() if len(currentaddr.value): if timeout: msg = 'Worker %s timed out, failing current test %s' else: msg = ( 'Worker %s keyboard interrupt, failing current test %s' ) log.exception(msg, ix, test_addr) currentaddr.value = bytes_('') failure.Failure(*sys.exc_info())(result) resultQueue.put((ix, test_addr, test.tasks, batch(result))) else: if timeout: msg = 'Worker %s test %s timed out' else: msg = 'Worker %s test %s keyboard interrupt' log.debug(msg, ix, test_addr) resultQueue.put((ix, test_addr, test.tasks, batch(result))) if not timeout: raise except SystemExit: currentaddr.value = bytes_('') log.exception('Worker %s system exit', ix) raise except Exception: currentaddr.value = bytes_('') log.exception( "Worker %s error running test or returning results", ix ) failure.Failure(*sys.exc_info())(result) resultQueue.put((ix, test_addr, test.tasks, batch(result))) if config.multiprocess_restartworker: break log.debug("Worker %s ending", ix) class NoSharedFixtureContextSuite(ContextSuite): """Context suite that never fires shared fixtures. When a context sets _multiprocess_shared_, fixtures in that context are executed by the main process. Using this class prevents them from executing in the runner process as well.""" testQueue = None tasks = None arg = None def setupContext(self, context): if getattr(context, '_multiprocess_shared_', False): return super(NoSharedFixtureContextSuite, self).setupContext(context) def teardownContext(self, context): if getattr(context, '_multiprocess_shared_', False): return super(NoSharedFixtureContextSuite, self).teardownContext(context) def run(self, result): """Run tests in suite inside of suite fixtures.""" log.debug( "suite %s (%s) run called, tests: %s", id(self), self, self._tests ) if self.resultProxy: result, orig = self.resultProxy(result, self), result else: result, orig = result, result try: # log.debug('setUp for %s', id(self)); self.setUp() except KeyboardInterrupt: raise except Exception: self.error_context = 'setup' result.addError(self, self._exc_info()) return try: for test in self._tests: if isinstance(test, nose.case.Test) and self.arg is not None: test.test.arg = self.arg else: test.arg = self.arg test.testQueue = self.testQueue test.tasks = self.tasks if result.shouldStop: log.debug("stopping") break try: test(orig) except KeyboardInterrupt as e: timeout = isinstance(e, TimedOutException) if timeout: msg = 'Timeout when running test %s in suite %s' else: msg = ( 'KeyboardInterrupt ' 'when running test %s in suite %s' ) log.debug(msg, test, self) err = ( TimedOutException, TimedOutException(str(test)), sys.exc_info()[2], ) test.config.plugins.addError(test, err) orig.addError(test, err) if not timeout: raise finally: self.has_run = True try: # log.debug('tearDown for %s', id(self)) self.tearDown() except KeyboardInterrupt: raise except Exception: self.error_context = 'teardown' result.addError(self, self._exc_info())