This repository was archived by the owner on Apr 14, 2024. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 9
Expand file tree
/
Copy pathutil.py
More file actions
283 lines (241 loc) · 8.88 KB
/
util.py
File metadata and controls
283 lines (241 loc) · 8.88 KB
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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
# Copyright (C) 2010, 2011 Sebastian Thiel (byronimo@gmail.com) and contributors
#
# This module is part of async and is released under
# the New BSD License: http://www.opensource.org/licenses/bsd-license.php
"""Module with utilities related to async operations"""
from threading import (
Lock,
_allocate_lock,
_time,
)
try:
from queue import Empty
except ImportError:
from Queue import Empty
from collections import deque
import sys
import os
import time
#{ Routines
def cpu_count():
""":return:number of CPUs in the system
:note: inspired by multiprocessing"""
num = 0
try:
if sys.platform == 'win32':
num = int(os.environ['NUMBER_OF_PROCESSORS'])
elif 'bsd' in sys.platform or sys.platform == 'darwin':
num = int(os.popen('sysctl -n hw.ncpu').read())
else:
num = os.sysconf('SC_NPROCESSORS_ONLN')
except (ValueError, KeyError, OSError, AttributeError):
pass
# END exception handling
if num == 0:
raise NotImplementedError('cannot determine number of cpus')
return num
#} END routines
class DummyLock(object):
"""An object providing a do-nothing lock interface for use in sync mode"""
__slots__ = tuple()
def acquire(self):
pass
def release(self):
pass
class SyncQueue(deque):
"""Adapter to allow using a deque like a queue, without locking"""
def get(self, block=True, timeout=None):
try:
return self.popleft()
except IndexError:
raise Empty
# END raise empty
def empty(self):
return len(self) == 0
def set_writable(self, state):
pass
def writable(self):
return True
def put(self, item, block=True, timeout=None):
self.append(item)
class HSCondition(deque):
"""Cleaned up code of the original condition object in order
to make it run and respond faster."""
__slots__ = ("_lock")
delay = 0.0002 # reduces wait times, but increases overhead
def __init__(self, lock=None):
if lock is None:
lock = Lock()
self._lock = lock
def release(self):
self._lock.release()
def acquire(self, block=None):
if block is None:
self._lock.acquire()
else:
self._lock.acquire(block)
def wait(self, timeout=None):
waiter = _allocate_lock()
waiter.acquire() # get it the first time, no blocking
self.append(waiter)
try:
# restore state no matter what (e.g., KeyboardInterrupt)
# now we block, as we hold the lock already
# in the momemnt we release our lock, someone else might actually resume
self._lock.release()
if timeout is None:
waiter.acquire()
else:
# Balancing act: We can't afford a pure busy loop, because of the
# GIL, so we have to sleep
# We try to sleep only tiny amounts of time though to be very responsive
# NOTE: this branch is not used by the async system anyway, but
# will be hit when the user reads with timeout
endtime = _time() + timeout
delay = self.delay
acquire = waiter.acquire
while True:
gotit = acquire(0)
if gotit:
break
remaining = endtime - _time()
if remaining <= 0:
break
# this makes 4 threads working as good as two, but of course
# it causes more frequent micro-sleeping
#delay = min(delay * 2, remaining, .05)
time.sleep(delay)
# END endless loop
if not gotit:
try:
self.remove(waiter)
except AttributeError:
# handle python 2.4 - actually this should be made thread-safe
# but lets see ...
try:
# lets hope we pop the right one - we don't loop over it
# yet-we just keep minimal compatability with py 2.4
item = self.pop()
if item != waiter:
self.append(item)
except IndexError:
pass
except ValueError:
pass
# END didn't ever get it
finally:
# reacquire the lock
self._lock.acquire()
# END assure release lock
def notify(self, n=1):
"""Its vital that this method is threadsafe - we absolutely have to
get a lock at the beginning of this method to be sure we get the
correct amount of waiters back. If we bail out, although a waiter
is about to be added, it will miss its wakeup notification, and block
forever (possibly)"""
self._lock.acquire()
try:
if not self: # len(self) == 0, but this should be faster
return
if n == 1:
try:
self.popleft().release()
except IndexError:
pass
else:
for i in range(min(n, len(self))):
self.popleft().release()
# END for each waiter to resume
# END handle n = 1 case faster
finally:
self._lock.release()
# END assure lock is released
def notify_all(self):
self.notify(len(self))
class ReadOnly(Exception):
"""Thrown when trying to write to a read-only queue"""
class AsyncQueue(deque):
"""A queue using different condition objects to gain multithreading performance.
Additionally it has a threadsafe writable flag, which will alert all readers
that there is nothing more to get here.
All default-queue code was cleaned up for performance."""
__slots__ = ('mutex', 'not_empty', '_writable')
def __init__(self, maxsize=0):
self.mutex = Lock()
self.not_empty = HSCondition(self.mutex)
self._writable = True
def qsize(self):
self.mutex.acquire()
try:
return len(self)
finally:
self.mutex.release()
def writable(self):
self.mutex.acquire()
try:
return self._writable
finally:
self.mutex.release()
def set_writable(self, state):
"""Set the writable flag of this queue to True or False
:return: The previous state"""
self.mutex.acquire()
try:
old = self._writable
self._writable = state
return old
finally:
self.mutex.release()
# if we won't receive anymore items, inform the getters
if not state:
self.not_empty.notify_all()
# END tell everyone
# END handle locking
def empty(self):
self.mutex.acquire()
try:
return not len(self)
finally:
self.mutex.release()
def put(self, item, block=True, timeout=None):
self.mutex.acquire()
# NOTE: we explicitly do NOT check for our writable state
# Its just used as a notification signal, and we need to be able
# to continue writing to prevent threads ( easily ) from failing
# to write their computed results, which we want in fact
# NO: we want them to fail and stop processing, as the one who caused
# the channel to close had a reason and wants the threads to
# stop on the task as soon as possible
if not self._writable:
self.mutex.release()
raise ReadOnly
# END handle read-only
self.append(item)
self.mutex.release()
self.not_empty.notify()
def get(self, block=True, timeout=None):
self.mutex.acquire()
try:
if block:
if timeout is None:
while not len(self) and self._writable:
self.not_empty.wait()
else:
endtime = _time() + timeout
while not len(self) and self._writable:
remaining = endtime - _time()
if remaining <= 0.0:
raise Empty
self.not_empty.wait(remaining)
# END handle timeout mode
# END handle block
# can throw if we woke up because we are not writable anymore
try:
return self.popleft()
except IndexError:
raise Empty
# END handle unblocking reason
finally:
self.mutex.release()
# END assure lock is released
#} END utilities