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
|
# Copyright 1999-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
import array
import errno
import logging
import os
from portage.util import writemsg_level
from _emerge.AsynchronousTask import AsynchronousTask
class AbstractPollTask(AsynchronousTask):
__slots__ = ("scheduler",) + \
("_registered",)
_bufsize = 4096
@property
def _exceptional_events(self):
return self.scheduler.IO_ERR | self.scheduler.IO_NVAL
@property
def _registered_events(self):
return self.scheduler.IO_IN | self.scheduler.IO_HUP | \
self._exceptional_events
def isAlive(self):
return bool(self._registered)
def _read_array(self, f, event):
"""
NOTE: array.fromfile() is used here only for testing purposes,
because it has bugs in all known versions of Python (including
Python 2.7 and Python 3.2). See PipeReaderArrayTestCase.
| POLLIN | RETURN
| BIT | VALUE
| ---------------------------------------------------
| 1 | Read self._bufsize into an instance of
| | array.array('B') and return it, handling
| | EOFError and IOError. An empty array
| | indicates EOF.
| ---------------------------------------------------
| 0 | None
"""
buf = None
if event & self.scheduler.IO_IN:
buf = array.array('B')
try:
buf.fromfile(f, self._bufsize)
except EOFError:
pass
except TypeError:
# Python 3.2:
# TypeError: read() didn't return bytes
pass
except IOError as e:
# EIO happens with pty on Linux after the
# slave end of the pty has been closed.
if e.errno == errno.EIO:
# EOF: return empty string of bytes
pass
elif e.errno == errno.EAGAIN:
# EAGAIN: return None
buf = None
else:
raise
if buf is not None:
try:
# Python >=3.2
buf = buf.tobytes()
except AttributeError:
buf = buf.tostring()
return buf
def _read_buf(self, fd, event):
"""
| POLLIN | RETURN
| BIT | VALUE
| ---------------------------------------------------
| 1 | Read self._bufsize into a string of bytes,
| | handling EAGAIN and EIO. An empty string
| | of bytes indicates EOF.
| ---------------------------------------------------
| 0 | None
"""
# NOTE: array.fromfile() is no longer used here because it has
# bugs in all known versions of Python (including Python 2.7
# and Python 3.2).
buf = None
if event & self.scheduler.IO_IN:
try:
buf = os.read(fd, self._bufsize)
except OSError as e:
# EIO happens with pty on Linux after the
# slave end of the pty has been closed.
if e.errno == errno.EIO:
# EOF: return empty string of bytes
buf = b''
elif e.errno == errno.EAGAIN:
# EAGAIN: return None
buf = None
else:
raise
return buf
def _unregister(self):
raise NotImplementedError(self)
def _log_poll_exception(self, event):
writemsg_level(
"!!! %s received strange poll event: %s\n" % \
(self.__class__.__name__, event,),
level=logging.ERROR, noiselevel=-1)
def _unregister_if_appropriate(self, event):
if self._registered:
if event & self._exceptional_events:
self._log_poll_exception(event)
self._unregister()
self.cancel()
self.wait()
elif event & self.scheduler.IO_HUP:
self._unregister()
self.wait()
def _wait(self):
if self.returncode is not None:
return self.returncode
self._wait_loop()
return self.returncode
def _wait_loop(self, timeout=None):
if timeout is None:
while self._registered:
self.scheduler.iteration()
return
def timeout_cb():
timeout_cb.timed_out = True
return False
timeout_cb.timed_out = False
timeout_cb.timeout_id = self.scheduler.timeout_add(timeout, timeout_cb)
try:
while self._registered and not timeout_cb.timed_out:
self.scheduler.iteration()
finally:
self.scheduler.source_remove(timeout_cb.timeout_id)
|