Revert "bpo-33929: multiprocessing: fix handle leak on race condition (GH-7921)" (GH-7963)
This reverts commit 8b1ebcd7cb3319273ea635df78ebf9ad40171514.
diff --git a/Lib/multiprocessing/popen_spawn_win32.py b/Lib/multiprocessing/popen_spawn_win32.py
index 3b92c8a..3e42e9c 100644
--- a/Lib/multiprocessing/popen_spawn_win32.py
+++ b/Lib/multiprocessing/popen_spawn_win32.py
@@ -18,12 +18,6 @@
WINEXE = (sys.platform == 'win32' and getattr(sys, 'frozen', False))
WINSERVICE = sys.executable.lower().endswith("pythonservice.exe")
-
-def _close_handles(*handles):
- for handle in handles:
- _winapi.CloseHandle(handle)
-
-
#
# We define a Popen class similar to the one from subprocess, but
# whose constructor takes a process object as its argument.
@@ -38,12 +32,8 @@
def __init__(self, process_obj):
prep_data = spawn.get_preparation_data(process_obj._name)
- # read end of pipe will be duplicated by the child process
+ # read end of pipe will be "stolen" by the child process
# -- see spawn_main() in spawn.py.
- #
- # bpo-33929: Previously, the read end of pipe was "stolen" by the child
- # process, but it leaked a handle if the child process had been
- # terminated before it could steal the handle from the parent process.
rhandle, whandle = _winapi.CreatePipe(None, 0)
wfd = msvcrt.open_osfhandle(whandle, 0)
cmd = spawn.get_command_line(parent_pid=os.getpid(),
@@ -66,8 +56,7 @@
self.returncode = None
self._handle = hp
self.sentinel = int(hp)
- self.finalizer = util.Finalize(self, _close_handles,
- (self.sentinel, int(rhandle)))
+ self.finalizer = util.Finalize(self, _winapi.CloseHandle, (self.sentinel,))
# send information to child
set_spawning_popen(self)
diff --git a/Lib/multiprocessing/reduction.py b/Lib/multiprocessing/reduction.py
index 473fd59..deca19c 100644
--- a/Lib/multiprocessing/reduction.py
+++ b/Lib/multiprocessing/reduction.py
@@ -68,16 +68,12 @@
__all__ += ['DupHandle', 'duplicate', 'steal_handle']
import _winapi
- def duplicate(handle, target_process=None, inheritable=False,
- *, source_process=None):
+ def duplicate(handle, target_process=None, inheritable=False):
'''Duplicate a handle. (target_process is a handle not a pid!)'''
- current_process = _winapi.GetCurrentProcess()
- if source_process is None:
- source_process = current_process
if target_process is None:
- target_process = current_process
+ target_process = _winapi.GetCurrentProcess()
return _winapi.DuplicateHandle(
- source_process, handle, target_process,
+ _winapi.GetCurrentProcess(), handle, target_process,
0, inheritable, _winapi.DUPLICATE_SAME_ACCESS)
def steal_handle(source_pid, handle):
diff --git a/Lib/multiprocessing/spawn.py b/Lib/multiprocessing/spawn.py
index 2de4cb7..1f4f3f4 100644
--- a/Lib/multiprocessing/spawn.py
+++ b/Lib/multiprocessing/spawn.py
@@ -96,15 +96,7 @@
assert is_forking(sys.argv), "Not forking"
if sys.platform == 'win32':
import msvcrt
- import _winapi
-
- if parent_pid is not None:
- source_process = _winapi.OpenProcess(
- _winapi.PROCESS_DUP_HANDLE, False, parent_pid)
- else:
- source_process = None
- new_handle = reduction.duplicate(pipe_handle,
- source_process=source_process)
+ new_handle = reduction.steal_handle(parent_pid, pipe_handle)
fd = msvcrt.open_osfhandle(new_handle, os.O_RDONLY)
else:
from . import semaphore_tracker