Mercurial Repositories > eric / file comparison
comparison: DebugClients/Python/coverage/monkey.py
DebugClients/Python/coverage/monkey.py
- branch
- maintenance
- changeset 6273
- 0daf79d65080
- parent 6207
- 0a74c1efab70
- parent 6272
- b8006def4317
- child 6274
- 44249d49d892
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| 6207:0a74c1efab70 | 6273:0daf79d65080 |
|---|---|
| 1 # Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 | |
| 2 # For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt | |
| 3 | |
| 4 """Monkey-patching to make coverage.py work right in some cases.""" | |
| 5 | |
| 6 import multiprocessing | |
| 7 import multiprocessing.process | |
| 8 import sys | |
| 9 | |
| 10 # An attribute that will be set on modules to indicate that they have been | |
| 11 # monkey-patched. | |
| 12 PATCHED_MARKER = "_coverage$patched" | |
| 13 | |
| 14 if sys.version_info >= (3, 4): | |
| 15 klass = multiprocessing.process.BaseProcess | |
| 16 else: | |
| 17 klass = multiprocessing.Process | |
| 18 | |
| 19 original_bootstrap = klass._bootstrap | |
| 20 | |
| 21 | |
| 22 class ProcessWithCoverage(klass): | |
| 23 """A replacement for multiprocess.Process that starts coverage.""" | |
| 24 def _bootstrap(self): | |
| 25 """Wrapper around _bootstrap to start coverage.""" | |
| 26 from coverage import Coverage | |
| 27 cov = Coverage(data_suffix=True) | |
| 28 cov.start() | |
| 29 try: | |
| 30 return original_bootstrap(self) | |
| 31 finally: | |
| 32 cov.stop() | |
| 33 cov.save() | |
| 34 | |
| 35 | |
| 36 class Stowaway(object): | |
| 37 """An object to pickle, so when it is unpickled, it can apply the monkey-patch.""" | |
| 38 def __getstate__(self): | |
| 39 return {} | |
| 40 | |
| 41 def __setstate__(self, state_unused): | |
| 42 patch_multiprocessing() | |
| 43 | |
| 44 | |
| 45 def patch_multiprocessing(): | |
| 46 """Monkey-patch the multiprocessing module. | |
| 47 | |
| 48 This enables coverage measurement of processes started by multiprocessing. | |
| 49 This is wildly experimental! | |
| 50 | |
| 51 """ | |
| 52 if hasattr(multiprocessing, PATCHED_MARKER): | |
| 53 return | |
| 54 | |
| 55 if sys.version_info >= (3, 4): | |
| 56 klass._bootstrap = ProcessWithCoverage._bootstrap | |
| 57 else: | |
| 58 multiprocessing.Process = ProcessWithCoverage | |
| 59 | |
| 60 # When spawning processes rather than forking them, we have no state in the | |
| 61 # new process. We sneak in there with a Stowaway: we stuff one of our own | |
| 62 # objects into the data that gets pickled and sent to the sub-process. When | |
| 63 # the Stowaway is unpickled, it's __setstate__ method is called, which | |
| 64 # re-applies the monkey-patch. | |
| 65 # Windows only spawns, so this is needed to keep Windows working. | |
| 66 try: | |
| 67 from multiprocessing import spawn # pylint: disable=no-name-in-module | |
| 68 original_get_preparation_data = spawn.get_preparation_data | |
| 69 except (ImportError, AttributeError): | |
| 70 pass | |
| 71 else: | |
| 72 def get_preparation_data_with_stowaway(name): | |
| 73 """Get the original preparation data, and also insert our stowaway.""" | |
| 74 d = original_get_preparation_data(name) | |
| 75 d['stowaway'] = Stowaway() | |
| 76 return d | |
| 77 | |
| 78 spawn.get_preparation_data = get_preparation_data_with_stowaway | |
| 79 | |
| 80 setattr(multiprocessing, PATCHED_MARKER, True) |
