Preview: popen_spawn_win32.py
Size: 3.92 KB
//lib64/python3.9/multiprocessing/popen_spawn_win32.py
import os
import msvcrt
import signal
import sys
import _winapi
from .context import reduction, get_spawning_popen, set_spawning_popen
from . import spawn
from . import util
__all__ = ['Popen']
#
#
#
TERMINATE = 0x10000
WINEXE = (sys.platform == 'win32' and getattr(sys, 'frozen', False))
WINSERVICE = sys.executable.lower().endswith("pythonservice.exe")
def _path_eq(p1, p2):
return p1 == p2 or os.path.normcase(p1) == os.path.normcase(p2)
WINENV = not _path_eq(sys.executable, sys._base_executable)
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.
#
class Popen(object):
'''
Start a subprocess to run the code of a process object
'''
method = 'spawn'
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
# -- 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(),
pipe_handle=rhandle)
cmd = ' '.join('"%s"' % x for x in cmd)
python_exe = spawn.get_executable()
# bpo-35797: When running in a venv, we bypass the redirect
# executor and launch our base Python.
if WINENV and _path_eq(python_exe, sys.executable):
python_exe = sys._base_executable
env = os.environ.copy()
env["__PYVENV_LAUNCHER__"] = sys.executable
else:
env = None
with open(wfd, 'wb', closefd=True) as to_child:
# start process
try:
hp, ht, pid, tid = _winapi.CreateProcess(
python_exe, cmd,
None, None, False, 0, env, None, None)
_winapi.CloseHandle(ht)
except:
_winapi.CloseHandle(rhandle)
raise
# set attributes of self
self.pid = pid
self.returncode = None
self._handle = hp
self.sentinel = int(hp)
self.finalizer = util.Finalize(self, _close_handles,
(self.sentinel, int(rhandle)))
# send information to child
set_spawning_popen(self)
try:
reduction.dump(prep_data, to_child)
reduction.dump(process_obj, to_child)
finally:
set_spawning_popen(None)
def duplicate_for_child(self, handle):
assert self is get_spawning_popen()
return reduction.duplicate(handle, self.sentinel)
def wait(self, timeout=None):
if self.returncode is None:
if timeout is None:
msecs = _winapi.INFINITE
else:
msecs = max(0, int(timeout * 1000 + 0.5))
res = _winapi.WaitForSingleObject(int(self._handle), msecs)
if res == _winapi.WAIT_OBJECT_0:
code = _winapi.GetExitCodeProcess(self._handle)
if code == TERMINATE:
code = -signal.SIGTERM
self.returncode = code
return self.returncode
def poll(self):
return self.wait(timeout=0)
def terminate(self):
if self.returncode is None:
try:
_winapi.TerminateProcess(int(self._handle), TERMINATE)
except OSError:
if self.wait(timeout=1.0) is None:
raise
kill = terminate
def close(self):
self.finalizer()
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