--- a/DebugClients/Python3/coverage/monkey.py Sat Jul 23 13:33:54 2016 +0200 +++ b/DebugClients/Python3/coverage/monkey.py Sun Jul 24 12:01:01 2016 +0200 @@ -11,6 +11,36 @@ # monkey-patched. PATCHED_MARKER = "_coverage$patched" +if sys.version_info >= (3, 4): + klass = multiprocessing.process.BaseProcess +else: + klass = multiprocessing.Process + +original_bootstrap = klass._bootstrap + + +class ProcessWithCoverage(klass): + """A replacement for multiprocess.Process that starts coverage.""" + def _bootstrap(self): + """Wrapper around _bootstrap to start coverage.""" + from coverage import Coverage + cov = Coverage(data_suffix=True) + cov.start() + try: + return original_bootstrap(self) + finally: + cov.stop() + cov.save() + + +class Stowaway(object): + """An object to pickle, so when it is unpickled, it can apply the monkey-patch.""" + def __getstate__(self): + return {} + + def __setstate__(self, state_unused): + patch_multiprocessing() + def patch_multiprocessing(): """Monkey-patch the multiprocessing module. @@ -23,28 +53,28 @@ return if sys.version_info >= (3, 4): - klass = multiprocessing.process.BaseProcess - else: - klass = multiprocessing.Process - - original_bootstrap = klass._bootstrap - - class ProcessWithCoverage(klass): - """A replacement for multiprocess.Process that starts coverage.""" - def _bootstrap(self): - """Wrapper around _bootstrap to start coverage.""" - from coverage import Coverage - cov = Coverage(data_suffix=True) - cov.start() - try: - return original_bootstrap(self) - finally: - cov.stop() - cov.save() - - if sys.version_info >= (3, 4): klass._bootstrap = ProcessWithCoverage._bootstrap else: multiprocessing.Process = ProcessWithCoverage + # When spawning processes rather than forking them, we have no state in the + # new process. We sneak in there with a Stowaway: we stuff one of our own + # objects into the data that gets pickled and sent to the sub-process. When + # the Stowaway is unpickled, it's __setstate__ method is called, which + # re-applies the monkey-patch. + # Windows only spawns, so this is needed to keep Windows working. + try: + from multiprocessing import spawn # pylint: disable=no-name-in-module + original_get_preparation_data = spawn.get_preparation_data + except (ImportError, AttributeError): + pass + else: + def get_preparation_data_with_stowaway(name): + """Get the original preparation data, and also insert our stowaway.""" + d = original_get_preparation_data(name) + d['stowaway'] = Stowaway() + return d + + spawn.get_preparation_data = get_preparation_data_with_stowaway + setattr(multiprocessing, PATCHED_MARKER, True)