summaryrefslogtreecommitdiffstats
path: root/Lib/asyncio/windows_utils.py
blob: b47581235cb2a7021a816787da76e447bc70a094 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
"""
Various Windows specific bits and pieces
"""

import sys

if sys.platform != 'win32':  # pragma: no cover
    raise ImportError('win32 only')

import socket
import itertools
import msvcrt
import os
import subprocess
import tempfile
import _winapi


__all__ = ['socketpair', 'pipe', 'Popen', 'PIPE', 'PipeHandle']


# Constants/globals


BUFSIZE = 8192
PIPE = subprocess.PIPE
STDOUT = subprocess.STDOUT
_mmap_counter = itertools.count()


if hasattr(socket, 'socketpair'):
    # Since Python 3.5, socket.socketpair() is now also available on Windows
    socketpair = socket.socketpair
else:
    # Replacement for socket.socketpair()
    def socketpair(family=socket.AF_INET, type=socket.SOCK_STREAM, proto=0):
        """A socket pair usable as a self-pipe, for Windows.

        Origin: https://gist.github.com/4325783, by Geert Jansen.
        Public domain.
        """
        if family == socket.AF_INET:
            host = '127.0.0.1'
        elif family == socket.AF_INET6:
            host = '::1'
        else:
            raise ValueError("Only AF_INET and AF_INET6 socket address "
                             "families are supported")
        if type != socket.SOCK_STREAM:
            raise ValueError("Only SOCK_STREAM socket type is supported")
        if proto != 0:
            raise ValueError("Only protocol zero is supported")

        # We create a connected TCP socket. Note the trick with setblocking(0)
        # that prevents us from having to create a thread.
        lsock = socket.socket(family, type, proto)
        try:
            lsock.bind((host, 0))
            lsock.listen(1)
            # On IPv6, ignore flow_info and scope_id
            addr, port = lsock.getsockname()[:2]
            csock = socket.socket(family, type, proto)
            try:
                csock.setblocking(False)
                try:
                    csock.connect((addr, port))
                except (BlockingIOError, InterruptedError):
                    pass
                csock.setblocking(True)
                ssock, _ = lsock.accept()
            except:
                csock.close()
                raise
        finally:
            lsock.close()
        return (ssock, csock)


# Replacement for os.pipe() using handles instead of fds


def pipe(*, duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
    """Like os.pipe() but with overlapped support and using handles not fds."""
    address = tempfile.mktemp(prefix=r'\\.\pipe\python-pipe-%d-%d-' %
                              (os.getpid(), next(_mmap_counter)))

    if duplex:
        openmode = _winapi.PIPE_ACCESS_DUPLEX
        access = _winapi.GENERIC_READ | _winapi.GENERIC_WRITE
        obsize, ibsize = bufsize, bufsize
    else:
        openmode = _winapi.PIPE_ACCESS_INBOUND
        access = _winapi.GENERIC_WRITE
        obsize, ibsize = 0, bufsize

    openmode |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE

    if overlapped[0]:
        openmode |= _winapi.FILE_FLAG_OVERLAPPED

    if overlapped[1]:
        flags_and_attribs = _winapi.FILE_FLAG_OVERLAPPED
    else:
        flags_and_attribs = 0

    h1 = h2 = None
    try:
        h1 = _winapi.CreateNamedPipe(
            address, openmode, _winapi.PIPE_WAIT,
            1, obsize, ibsize, _winapi.NMPWAIT_WAIT_FOREVER, _winapi.NULL)

        h2 = _winapi.CreateFile(
            address, access, 0, _winapi.NULL, _winapi.OPEN_EXISTING,
            flags_and_attribs, _winapi.NULL)

        ov = _winapi.ConnectNamedPipe(h1, overlapped=True)
        ov.GetOverlappedResult(True)
        return h1, h2
    except:
        if h1 is not None:
            _winapi.CloseHandle(h1)
        if h2 is not None:
            _winapi.CloseHandle(h2)
        raise


# Wrapper for a pipe handle


class PipeHandle:
    """Wrapper for an overlapped pipe handle which is vaguely file-object like.

    The IOCP event loop can use these instead of socket objects.
    """
    def __init__(self, handle):
        self._handle = handle

    def __repr__(self):
        if self._handle != -1:
            handle = 'handle=%r' % self._handle
        else:
            handle = 'closed'
        return '<%s %s>' % (self.__class__.__name__, handle)

    @property
    def handle(self):
        return self._handle

    def fileno(self):
        return self._handle

    def close(self, *, CloseHandle=_winapi.CloseHandle):
        if self._handle != -1:
            CloseHandle(self._handle)
            self._handle = -1

    __del__ = close

    def __enter__(self):
        return self

    def __exit__(self, t, v, tb):
        self.close()


# Replacement for subprocess.Popen using overlapped pipe handles


class Popen(subprocess.Popen):
    """Replacement for subprocess.Popen using overlapped pipe handles.

    The stdin, stdout, stderr are None or instances of PipeHandle.
    """
    def __init__(self, args, stdin=None, stdout=None, stderr=None, **kwds):
        assert not kwds.get('universal_newlines')
        assert kwds.get('bufsize', 0) == 0
        stdin_rfd = stdout_wfd = stderr_wfd = None
        stdin_wh = stdout_rh = stderr_rh = None
        if stdin == PIPE:
            stdin_rh, stdin_wh = pipe(overlapped=(False, True), duplex=True)
            stdin_rfd = msvcrt.open_osfhandle(stdin_rh, os.O_RDONLY)
        else:
            stdin_rfd = stdin
        if stdout == PIPE:
            stdout_rh, stdout_wh = pipe(overlapped=(True, False))
            stdout_wfd = msvcrt.open_osfhandle(stdout_wh, 0)
        else:
            stdout_wfd = stdout
        if stderr == PIPE:
            stderr_rh, stderr_wh = pipe(overlapped=(True, False))
            stderr_wfd = msvcrt.open_osfhandle(stderr_wh, 0)
        elif stderr == STDOUT:
            stderr_wfd = stdout_wfd
        else:
            stderr_wfd = stderr
        try:
            super().__init__(args, stdin=stdin_rfd, stdout=stdout_wfd,
                             stderr=stderr_wfd, **kwds)
        except:
            for h in (stdin_wh, stdout_rh, stderr_rh):
                if h is not None:
                    _winapi.CloseHandle(h)
            raise
        else:
            if stdin_wh is not None:
                self.stdin = PipeHandle(stdin_wh)
            if stdout_rh is not None:
                self.stdout = PipeHandle(stdout_rh)
            if stderr_rh is not None:
                self.stderr = PipeHandle(stderr_rh)
        finally:
            if stdin == PIPE:
                os.close(stdin_rfd)
            if stdout == PIPE:
                os.close(stdout_wfd)
            if stderr == PIPE:
                os.close(stderr_wfd)