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1import os
2import msvcrt
3import signal
4import sys
5import _winapi
6from subprocess import STARTUPINFO, STARTF_FORCEOFFFEEDBACK
7
8from .context import reduction, get_spawning_popen, set_spawning_popen
9from . import spawn
10from . import util
11
12__all__ = ['Popen']
13
14#
15#
16#
17
18# Exit code used by Popen.terminate()
19TERMINATE = 0x10000
20WINEXE = (sys.platform == 'win32' and getattr(sys, 'frozen', False))
21WINSERVICE = sys.executable.lower().endswith("pythonservice.exe")
22
23
24def _path_eq(p1, p2):
25    return p1 == p2 or os.path.normcase(p1) == os.path.normcase(p2)
26
27WINENV = not _path_eq(sys.executable, sys._base_executable)
28
29
30def _close_handles(*handles):
31    for handle in handles:
32        _winapi.CloseHandle(handle)
33
34
35#
36# We define a Popen class similar to the one from subprocess, but
37# whose constructor takes a process object as its argument.
38#
39
40class Popen(object):
41    '''
42    Start a subprocess to run the code of a process object
43    '''
44    method = 'spawn'
45
46    def __init__(self, process_obj):
47        prep_data = spawn.get_preparation_data(process_obj._name)
48
49        # read end of pipe will be duplicated by the child process
50        # -- see spawn_main() in spawn.py.
51        #
52        # bpo-33929: Previously, the read end of pipe was "stolen" by the child
53        # process, but it leaked a handle if the child process had been
54        # terminated before it could steal the handle from the parent process.
55        rhandle, whandle = _winapi.CreatePipe(None, 0)
56        wfd = msvcrt.open_osfhandle(whandle, 0)
57        cmd = spawn.get_command_line(parent_pid=os.getpid(),
58                                     pipe_handle=rhandle)
59
60        python_exe = spawn.get_executable()
61
62        # bpo-35797: When running in a venv, we bypass the redirect
63        # executor and launch our base Python.
64        if WINENV and _path_eq(python_exe, sys.executable):
65            cmd[0] = python_exe = sys._base_executable
66            env = os.environ.copy()
67            env["__PYVENV_LAUNCHER__"] = sys.executable
68        else:
69            env = None
70
71        cmd = ' '.join('"%s"' % x for x in cmd)
72
73        with open(wfd, 'wb', closefd=True) as to_child:
74            # start process
75            try:
76                hp, ht, pid, tid = _winapi.CreateProcess(
77                    python_exe, cmd,
78                    None, None, False, 0, env, None,
79                    STARTUPINFO(dwFlags=STARTF_FORCEOFFFEEDBACK))
80                _winapi.CloseHandle(ht)
81            except:
82                _winapi.CloseHandle(rhandle)
83                raise
84
85            # set attributes of self
86            self.pid = pid
87            self.returncode = None
88            self._handle = hp
89            self.sentinel = int(hp)
90            self.finalizer = util.Finalize(self, _close_handles,
91                                           (self.sentinel, int(rhandle)))
92
93            # send information to child
94            set_spawning_popen(self)
95            try:
96                reduction.dump(prep_data, to_child)
97                reduction.dump(process_obj, to_child)
98            finally:
99                set_spawning_popen(None)
100
101    def duplicate_for_child(self, handle):
102        assert self is get_spawning_popen()
103        return reduction.duplicate(handle, self.sentinel)
104
105    def wait(self, timeout=None):
106        if self.returncode is not None:
107            return self.returncode
108
109        if timeout is None:
110            msecs = _winapi.INFINITE
111        else:
112            msecs = max(0, int(timeout * 1000 + 0.5))
113
114        res = _winapi.WaitForSingleObject(int(self._handle), msecs)
115        if res == _winapi.WAIT_OBJECT_0:
116            code = _winapi.GetExitCodeProcess(self._handle)
117            if code == TERMINATE:
118                code = -signal.SIGTERM
119            self.returncode = code
120
121        return self.returncode
122
123    def poll(self):
124        return self.wait(timeout=0)
125
126    def terminate(self):
127        if self.returncode is not None:
128            return
129
130        try:
131            _winapi.TerminateProcess(int(self._handle), TERMINATE)
132        except PermissionError:
133            # ERROR_ACCESS_DENIED (winerror 5) is received when the
134            # process already died.
135            code = _winapi.GetExitCodeProcess(int(self._handle))
136            if code == _winapi.STILL_ACTIVE:
137                raise
138
139        # gh-113009: Don't set self.returncode. Even if GetExitCodeProcess()
140        # returns an exit code different than STILL_ACTIVE, the process can
141        # still be running. Only set self.returncode once WaitForSingleObject()
142        # returns WAIT_OBJECT_0 in wait().
143
144    kill = terminate
145
146    def close(self):
147        self.finalizer()
148