1 """Various Windows specific bits and pieces."""
2
3 import sys
4
5 if sys.platform != 'win32': # pragma: no cover
6 raise ImportError('win32 only')
7
8 import _winapi
9 import itertools
10 import msvcrt
11 import os
12 import subprocess
13 import tempfile
14 import warnings
15
16
17 __all__ = 'pipe', 'Popen', 'PIPE', 'PipeHandle'
18
19
20 # Constants/globals
21
22
23 BUFSIZE = 8192
24 PIPE = subprocess.PIPE
25 STDOUT = subprocess.STDOUT
26 _mmap_counter = itertools.count()
27
28
29 # Replacement for os.pipe() using handles instead of fds
30
31
32 def pipe(*, duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
33 """Like os.pipe() but with overlapped support and using handles not fds."""
34 address = tempfile.mktemp(
35 prefix=r'\\.\pipe\python-pipe-{:d}-{:d}-'.format(
36 os.getpid(), next(_mmap_counter)))
37
38 if duplex:
39 openmode = _winapi.PIPE_ACCESS_DUPLEX
40 access = _winapi.GENERIC_READ | _winapi.GENERIC_WRITE
41 obsize, ibsize = bufsize, bufsize
42 else:
43 openmode = _winapi.PIPE_ACCESS_INBOUND
44 access = _winapi.GENERIC_WRITE
45 obsize, ibsize = 0, bufsize
46
47 openmode |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE
48
49 if overlapped[0]:
50 openmode |= _winapi.FILE_FLAG_OVERLAPPED
51
52 if overlapped[1]:
53 flags_and_attribs = _winapi.FILE_FLAG_OVERLAPPED
54 else:
55 flags_and_attribs = 0
56
57 h1 = h2 = None
58 try:
59 h1 = _winapi.CreateNamedPipe(
60 address, openmode, _winapi.PIPE_WAIT,
61 1, obsize, ibsize, _winapi.NMPWAIT_WAIT_FOREVER, _winapi.NULL)
62
63 h2 = _winapi.CreateFile(
64 address, access, 0, _winapi.NULL, _winapi.OPEN_EXISTING,
65 flags_and_attribs, _winapi.NULL)
66
67 ov = _winapi.ConnectNamedPipe(h1, overlapped=True)
68 ov.GetOverlappedResult(True)
69 return h1, h2
70 except:
71 if h1 is not None:
72 _winapi.CloseHandle(h1)
73 if h2 is not None:
74 _winapi.CloseHandle(h2)
75 raise
76
77
78 # Wrapper for a pipe handle
79
80
81 class ESC[4;38;5;81mPipeHandle:
82 """Wrapper for an overlapped pipe handle which is vaguely file-object like.
83
84 The IOCP event loop can use these instead of socket objects.
85 """
86 def __init__(self, handle):
87 self._handle = handle
88
89 def __repr__(self):
90 if self._handle is not None:
91 handle = f'handle={self._handle!r}'
92 else:
93 handle = 'closed'
94 return f'<{self.__class__.__name__} {handle}>'
95
96 @property
97 def handle(self):
98 return self._handle
99
100 def fileno(self):
101 if self._handle is None:
102 raise ValueError("I/O operation on closed pipe")
103 return self._handle
104
105 def close(self, *, CloseHandle=_winapi.CloseHandle):
106 if self._handle is not None:
107 CloseHandle(self._handle)
108 self._handle = None
109
110 def __del__(self, _warn=warnings.warn):
111 if self._handle is not None:
112 _warn(f"unclosed {self!r}", ResourceWarning, source=self)
113 self.close()
114
115 def __enter__(self):
116 return self
117
118 def __exit__(self, t, v, tb):
119 self.close()
120
121
122 # Replacement for subprocess.Popen using overlapped pipe handles
123
124
125 class ESC[4;38;5;81mPopen(ESC[4;38;5;149msubprocessESC[4;38;5;149m.ESC[4;38;5;149mPopen):
126 """Replacement for subprocess.Popen using overlapped pipe handles.
127
128 The stdin, stdout, stderr are None or instances of PipeHandle.
129 """
130 def __init__(self, args, stdin=None, stdout=None, stderr=None, **kwds):
131 assert not kwds.get('universal_newlines')
132 assert kwds.get('bufsize', 0) == 0
133 stdin_rfd = stdout_wfd = stderr_wfd = None
134 stdin_wh = stdout_rh = stderr_rh = None
135 if stdin == PIPE:
136 stdin_rh, stdin_wh = pipe(overlapped=(False, True), duplex=True)
137 stdin_rfd = msvcrt.open_osfhandle(stdin_rh, os.O_RDONLY)
138 else:
139 stdin_rfd = stdin
140 if stdout == PIPE:
141 stdout_rh, stdout_wh = pipe(overlapped=(True, False))
142 stdout_wfd = msvcrt.open_osfhandle(stdout_wh, 0)
143 else:
144 stdout_wfd = stdout
145 if stderr == PIPE:
146 stderr_rh, stderr_wh = pipe(overlapped=(True, False))
147 stderr_wfd = msvcrt.open_osfhandle(stderr_wh, 0)
148 elif stderr == STDOUT:
149 stderr_wfd = stdout_wfd
150 else:
151 stderr_wfd = stderr
152 try:
153 super().__init__(args, stdin=stdin_rfd, stdout=stdout_wfd,
154 stderr=stderr_wfd, **kwds)
155 except:
156 for h in (stdin_wh, stdout_rh, stderr_rh):
157 if h is not None:
158 _winapi.CloseHandle(h)
159 raise
160 else:
161 if stdin_wh is not None:
162 self.stdin = PipeHandle(stdin_wh)
163 if stdout_rh is not None:
164 self.stdout = PipeHandle(stdout_rh)
165 if stderr_rh is not None:
166 self.stderr = PipeHandle(stderr_rh)
167 finally:
168 if stdin == PIPE:
169 os.close(stdin_rfd)
170 if stdout == PIPE:
171 os.close(stdout_wfd)
172 if stderr == PIPE:
173 os.close(stderr_wfd)