diff options
Diffstat (limited to 'Lib/subprocess.py')
| -rw-r--r-- | Lib/subprocess.py | 48 |
1 files changed, 32 insertions, 16 deletions
diff --git a/Lib/subprocess.py b/Lib/subprocess.py index 53a5e72..2c30e34 100644 --- a/Lib/subprocess.py +++ b/Lib/subprocess.py @@ -217,22 +217,38 @@ if _mswindows: __str__ = __repr__ -# This lists holds Popen instances for which the underlying process had not -# exited at the time its __del__ method got called: those processes are wait()ed -# for synchronously from _cleanup() when a new Popen object is created, to avoid -# zombie processes. -_active = [] - -def _cleanup(): - for inst in _active[:]: - res = inst._internal_poll(_deadstate=sys.maxsize) - if res is not None: - try: - _active.remove(inst) - except ValueError: - # This can happen if two threads create a new Popen instance. - # It's harmless that it was already removed, so ignore. - pass +if _mswindows: + # On Windows we just need to close `Popen._handle` when we no longer need + # it, so that the kernel can free it. `Popen._handle` gets closed + # implicitly when the `Popen` instance is finalized (see `Handle.__del__`, + # which is calling `CloseHandle` as requested in [1]), so there is nothing + # for `_cleanup` to do. + # + # [1] https://docs.microsoft.com/en-us/windows/desktop/ProcThread/ + # creating-processes + _active = None + + def _cleanup(): + pass +else: + # This lists holds Popen instances for which the underlying process had not + # exited at the time its __del__ method got called: those processes are + # wait()ed for synchronously from _cleanup() when a new Popen object is + # created, to avoid zombie processes. + _active = [] + + def _cleanup(): + if _active is None: + return + for inst in _active[:]: + res = inst._internal_poll(_deadstate=sys.maxsize) + if res is not None: + try: + _active.remove(inst) + except ValueError: + # This can happen if two threads create a new Popen instance. + # It's harmless that it was already removed, so ignore. + pass PIPE = -1 STDOUT = -2 |