root / lib / workerpool.py @ eb202c13
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1 | 76094e37 | Michael Hanselmann | #
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2 | 76094e37 | Michael Hanselmann | #
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3 | 76094e37 | Michael Hanselmann | |
4 | 189d2714 | Michael Hanselmann | # Copyright (C) 2008, 2009, 2010 Google Inc.
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5 | 76094e37 | Michael Hanselmann | #
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6 | 76094e37 | Michael Hanselmann | # This program is free software; you can redistribute it and/or modify
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7 | 76094e37 | Michael Hanselmann | # it under the terms of the GNU General Public License as published by
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8 | 76094e37 | Michael Hanselmann | # the Free Software Foundation; either version 2 of the License, or
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9 | 76094e37 | Michael Hanselmann | # (at your option) any later version.
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10 | 76094e37 | Michael Hanselmann | #
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11 | 76094e37 | Michael Hanselmann | # This program is distributed in the hope that it will be useful, but
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12 | 76094e37 | Michael Hanselmann | # WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | 76094e37 | Michael Hanselmann | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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14 | 76094e37 | Michael Hanselmann | # General Public License for more details.
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15 | 76094e37 | Michael Hanselmann | #
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16 | 76094e37 | Michael Hanselmann | # You should have received a copy of the GNU General Public License
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17 | 76094e37 | Michael Hanselmann | # along with this program; if not, write to the Free Software
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18 | 76094e37 | Michael Hanselmann | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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19 | 76094e37 | Michael Hanselmann | # 02110-1301, USA.
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20 | 76094e37 | Michael Hanselmann | |
21 | 76094e37 | Michael Hanselmann | |
22 | 76094e37 | Michael Hanselmann | """Base classes for worker pools.
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23 | 76094e37 | Michael Hanselmann |
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24 | 76094e37 | Michael Hanselmann | """
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25 | 76094e37 | Michael Hanselmann | |
26 | 76094e37 | Michael Hanselmann | import collections |
27 | 76094e37 | Michael Hanselmann | import logging |
28 | 76094e37 | Michael Hanselmann | import threading |
29 | 76094e37 | Michael Hanselmann | |
30 | 25e557a5 | Guido Trotter | from ganeti import compat |
31 | 25e557a5 | Guido Trotter | |
32 | 76094e37 | Michael Hanselmann | |
33 | 21c5ad52 | Michael Hanselmann | _TERMINATE = object()
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34 | 21c5ad52 | Michael Hanselmann | |
35 | 21c5ad52 | Michael Hanselmann | |
36 | 76094e37 | Michael Hanselmann | class BaseWorker(threading.Thread, object): |
37 | 76094e37 | Michael Hanselmann | """Base worker class for worker pools.
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38 | 76094e37 | Michael Hanselmann |
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39 | 76094e37 | Michael Hanselmann | Users of a worker pool must override RunTask in a subclass.
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40 | 76094e37 | Michael Hanselmann |
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41 | 76094e37 | Michael Hanselmann | """
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42 | 7260cfbe | Iustin Pop | # pylint: disable-msg=W0212
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43 | 76094e37 | Michael Hanselmann | def __init__(self, pool, worker_id): |
44 | 76094e37 | Michael Hanselmann | """Constructor for BaseWorker thread.
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45 | 76094e37 | Michael Hanselmann |
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46 | 116db7c7 | Iustin Pop | @param pool: the parent worker pool
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47 | 116db7c7 | Iustin Pop | @param worker_id: identifier for this worker
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48 | 76094e37 | Michael Hanselmann |
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49 | 76094e37 | Michael Hanselmann | """
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50 | d16e6fd9 | Michael Hanselmann | super(BaseWorker, self).__init__(name=worker_id) |
51 | 76094e37 | Michael Hanselmann | self.pool = pool
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52 | 76094e37 | Michael Hanselmann | self._current_task = None |
53 | 76094e37 | Michael Hanselmann | |
54 | 76094e37 | Michael Hanselmann | def ShouldTerminate(self): |
55 | 2f4e1516 | Michael Hanselmann | """Returns whether this worker should terminate.
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56 | 2f4e1516 | Michael Hanselmann |
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57 | 2f4e1516 | Michael Hanselmann | Should only be called from within L{RunTask}.
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58 | 76094e37 | Michael Hanselmann |
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59 | 76094e37 | Michael Hanselmann | """
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60 | 2f4e1516 | Michael Hanselmann | self.pool._lock.acquire()
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61 | 2f4e1516 | Michael Hanselmann | try:
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62 | 2f4e1516 | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
63 | 2f4e1516 | Michael Hanselmann | return self.pool._ShouldWorkerTerminateUnlocked(self) |
64 | 2f4e1516 | Michael Hanselmann | finally:
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65 | 2f4e1516 | Michael Hanselmann | self.pool._lock.release()
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66 | 76094e37 | Michael Hanselmann | |
67 | b3558df1 | Michael Hanselmann | def _HasRunningTaskUnlocked(self): |
68 | b3558df1 | Michael Hanselmann | """Returns whether this worker is currently running a task.
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69 | b3558df1 | Michael Hanselmann |
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70 | b3558df1 | Michael Hanselmann | """
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71 | b3558df1 | Michael Hanselmann | return (self._current_task is not None) |
72 | b3558df1 | Michael Hanselmann | |
73 | 76094e37 | Michael Hanselmann | def run(self): |
74 | 76094e37 | Michael Hanselmann | """Main thread function.
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75 | 76094e37 | Michael Hanselmann |
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76 | 76094e37 | Michael Hanselmann | Waits for new tasks to show up in the queue.
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77 | 76094e37 | Michael Hanselmann |
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78 | 76094e37 | Michael Hanselmann | """
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79 | 76094e37 | Michael Hanselmann | pool = self.pool
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80 | 76094e37 | Michael Hanselmann | |
81 | 76094e37 | Michael Hanselmann | while True: |
82 | 46d0a3d0 | Michael Hanselmann | assert self._current_task is None |
83 | 76094e37 | Michael Hanselmann | try:
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84 | 21c5ad52 | Michael Hanselmann | # Wait on lock to be told either to terminate or to do a task
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85 | 76094e37 | Michael Hanselmann | pool._lock.acquire() |
86 | 76094e37 | Michael Hanselmann | try:
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87 | 21c5ad52 | Michael Hanselmann | task = pool._WaitForTaskUnlocked(self)
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88 | 76094e37 | Michael Hanselmann | |
89 | 21c5ad52 | Michael Hanselmann | if task is _TERMINATE: |
90 | 21c5ad52 | Michael Hanselmann | # Told to terminate
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91 | 21c5ad52 | Michael Hanselmann | break
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92 | b3558df1 | Michael Hanselmann | |
93 | 21c5ad52 | Michael Hanselmann | if task is None: |
94 | 21c5ad52 | Michael Hanselmann | # Spurious notification, ignore
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95 | 21c5ad52 | Michael Hanselmann | continue
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96 | 76094e37 | Michael Hanselmann | |
97 | 21c5ad52 | Michael Hanselmann | self._current_task = task
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98 | 76094e37 | Michael Hanselmann | |
99 | 46d0a3d0 | Michael Hanselmann | # No longer needed, dispose of reference
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100 | 46d0a3d0 | Michael Hanselmann | del task
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101 | 46d0a3d0 | Michael Hanselmann | |
102 | 21c5ad52 | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
103 | 46d0a3d0 | Michael Hanselmann | |
104 | 76094e37 | Michael Hanselmann | finally:
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105 | 76094e37 | Michael Hanselmann | pool._lock.release() |
106 | 76094e37 | Michael Hanselmann | |
107 | 76094e37 | Michael Hanselmann | # Run the actual task
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108 | 76094e37 | Michael Hanselmann | try:
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109 | 02fc74da | Michael Hanselmann | logging.debug("Starting task %r", self._current_task) |
110 | 76094e37 | Michael Hanselmann | self.RunTask(*self._current_task) |
111 | 02fc74da | Michael Hanselmann | logging.debug("Done with task %r", self._current_task) |
112 | 7260cfbe | Iustin Pop | except: # pylint: disable-msg=W0702 |
113 | 02fc74da | Michael Hanselmann | logging.exception("Caught unhandled exception")
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114 | c1cf1fe5 | Michael Hanselmann | |
115 | c1cf1fe5 | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
116 | 76094e37 | Michael Hanselmann | finally:
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117 | 76094e37 | Michael Hanselmann | # Notify pool
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118 | 76094e37 | Michael Hanselmann | pool._lock.acquire() |
119 | 76094e37 | Michael Hanselmann | try:
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120 | b3558df1 | Michael Hanselmann | if self._current_task: |
121 | b3558df1 | Michael Hanselmann | self._current_task = None |
122 | 53b1d12b | Michael Hanselmann | pool._worker_to_pool.notifyAll() |
123 | 76094e37 | Michael Hanselmann | finally:
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124 | 76094e37 | Michael Hanselmann | pool._lock.release() |
125 | 76094e37 | Michael Hanselmann | |
126 | c1cf1fe5 | Michael Hanselmann | assert not self._HasRunningTaskUnlocked() |
127 | c1cf1fe5 | Michael Hanselmann | |
128 | 02fc74da | Michael Hanselmann | logging.debug("Terminates")
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129 | b3558df1 | Michael Hanselmann | |
130 | 76094e37 | Michael Hanselmann | def RunTask(self, *args): |
131 | 76094e37 | Michael Hanselmann | """Function called to start a task.
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132 | 76094e37 | Michael Hanselmann |
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133 | 116db7c7 | Iustin Pop | This needs to be implemented by child classes.
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134 | 116db7c7 | Iustin Pop |
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135 | 76094e37 | Michael Hanselmann | """
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136 | 76094e37 | Michael Hanselmann | raise NotImplementedError() |
137 | 76094e37 | Michael Hanselmann | |
138 | 76094e37 | Michael Hanselmann | |
139 | 76094e37 | Michael Hanselmann | class WorkerPool(object): |
140 | 76094e37 | Michael Hanselmann | """Worker pool with a queue.
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141 | 76094e37 | Michael Hanselmann |
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142 | 76094e37 | Michael Hanselmann | This class is thread-safe.
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143 | 76094e37 | Michael Hanselmann |
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144 | 116db7c7 | Iustin Pop | Tasks are guaranteed to be started in the order in which they're
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145 | 116db7c7 | Iustin Pop | added to the pool. Due to the nature of threading, they're not
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146 | 116db7c7 | Iustin Pop | guaranteed to finish in the same order.
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147 | 76094e37 | Michael Hanselmann |
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148 | 76094e37 | Michael Hanselmann | """
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149 | 89e2b4d2 | Michael Hanselmann | def __init__(self, name, num_workers, worker_class): |
150 | 76094e37 | Michael Hanselmann | """Constructor for worker pool.
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151 | 76094e37 | Michael Hanselmann |
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152 | 116db7c7 | Iustin Pop | @param num_workers: number of workers to be started
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153 | 116db7c7 | Iustin Pop | (dynamic resizing is not yet implemented)
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154 | 116db7c7 | Iustin Pop | @param worker_class: the class to be instantiated for workers;
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155 | 116db7c7 | Iustin Pop | should derive from L{BaseWorker}
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156 | 76094e37 | Michael Hanselmann |
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157 | 76094e37 | Michael Hanselmann | """
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158 | 76094e37 | Michael Hanselmann | # Some of these variables are accessed by BaseWorker
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159 | 53b1d12b | Michael Hanselmann | self._lock = threading.Lock()
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160 | 53b1d12b | Michael Hanselmann | self._pool_to_pool = threading.Condition(self._lock) |
161 | 53b1d12b | Michael Hanselmann | self._pool_to_worker = threading.Condition(self._lock) |
162 | 53b1d12b | Michael Hanselmann | self._worker_to_pool = threading.Condition(self._lock) |
163 | 76094e37 | Michael Hanselmann | self._worker_class = worker_class
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164 | 89e2b4d2 | Michael Hanselmann | self._name = name
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165 | 76094e37 | Michael Hanselmann | self._last_worker_id = 0 |
166 | 76094e37 | Michael Hanselmann | self._workers = []
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167 | 76094e37 | Michael Hanselmann | self._quiescing = False |
168 | 76094e37 | Michael Hanselmann | |
169 | 76094e37 | Michael Hanselmann | # Terminating workers
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170 | 76094e37 | Michael Hanselmann | self._termworkers = []
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171 | 76094e37 | Michael Hanselmann | |
172 | 76094e37 | Michael Hanselmann | # Queued tasks
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173 | 76094e37 | Michael Hanselmann | self._tasks = collections.deque()
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174 | 76094e37 | Michael Hanselmann | |
175 | 76094e37 | Michael Hanselmann | # Start workers
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176 | 76094e37 | Michael Hanselmann | self.Resize(num_workers)
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177 | 76094e37 | Michael Hanselmann | |
178 | 76094e37 | Michael Hanselmann | # TODO: Implement dynamic resizing?
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179 | 76094e37 | Michael Hanselmann | |
180 | c2a8e8ba | Guido Trotter | def _WaitWhileQuiescingUnlocked(self): |
181 | c2a8e8ba | Guido Trotter | """Wait until the worker pool has finished quiescing.
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182 | c2a8e8ba | Guido Trotter |
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183 | c2a8e8ba | Guido Trotter | """
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184 | c2a8e8ba | Guido Trotter | while self._quiescing: |
185 | c2a8e8ba | Guido Trotter | self._pool_to_pool.wait()
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186 | c2a8e8ba | Guido Trotter | |
187 | 189d2714 | Michael Hanselmann | def _AddTaskUnlocked(self, args): |
188 | 189d2714 | Michael Hanselmann | assert isinstance(args, (tuple, list)), "Arguments must be a sequence" |
189 | 189d2714 | Michael Hanselmann | |
190 | 189d2714 | Michael Hanselmann | self._tasks.append(args)
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191 | 189d2714 | Michael Hanselmann | |
192 | 189d2714 | Michael Hanselmann | # Notify a waiting worker
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193 | 189d2714 | Michael Hanselmann | self._pool_to_worker.notify()
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194 | 189d2714 | Michael Hanselmann | |
195 | b2e8a4d9 | Michael Hanselmann | def AddTask(self, args): |
196 | 76094e37 | Michael Hanselmann | """Adds a task to the queue.
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197 | 76094e37 | Michael Hanselmann |
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198 | b2e8a4d9 | Michael Hanselmann | @type args: sequence
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199 | 116db7c7 | Iustin Pop | @param args: arguments passed to L{BaseWorker.RunTask}
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200 | 76094e37 | Michael Hanselmann |
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201 | 76094e37 | Michael Hanselmann | """
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202 | 76094e37 | Michael Hanselmann | self._lock.acquire()
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203 | 76094e37 | Michael Hanselmann | try:
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204 | c2a8e8ba | Guido Trotter | self._WaitWhileQuiescingUnlocked()
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205 | 189d2714 | Michael Hanselmann | self._AddTaskUnlocked(args)
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206 | 76094e37 | Michael Hanselmann | finally:
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207 | 76094e37 | Michael Hanselmann | self._lock.release()
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208 | 76094e37 | Michael Hanselmann | |
209 | c2a8e8ba | Guido Trotter | def AddManyTasks(self, tasks): |
210 | c2a8e8ba | Guido Trotter | """Add a list of tasks to the queue.
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211 | c2a8e8ba | Guido Trotter |
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212 | c2a8e8ba | Guido Trotter | @type tasks: list of tuples
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213 | c2a8e8ba | Guido Trotter | @param tasks: list of args passed to L{BaseWorker.RunTask}
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214 | c2a8e8ba | Guido Trotter |
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215 | c2a8e8ba | Guido Trotter | """
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216 | 25e557a5 | Guido Trotter | assert compat.all(isinstance(task, (tuple, list)) for task in tasks), \ |
217 | 25e557a5 | Guido Trotter | "Each task must be a sequence"
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218 | 25e557a5 | Guido Trotter | |
219 | c2a8e8ba | Guido Trotter | self._lock.acquire()
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220 | c2a8e8ba | Guido Trotter | try:
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221 | c2a8e8ba | Guido Trotter | self._WaitWhileQuiescingUnlocked()
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222 | c2a8e8ba | Guido Trotter | |
223 | 189d2714 | Michael Hanselmann | for args in tasks: |
224 | 189d2714 | Michael Hanselmann | self._AddTaskUnlocked(args)
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225 | c2a8e8ba | Guido Trotter | finally:
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226 | c2a8e8ba | Guido Trotter | self._lock.release()
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227 | c2a8e8ba | Guido Trotter | |
228 | 21c5ad52 | Michael Hanselmann | def _WaitForTaskUnlocked(self, worker): |
229 | 21c5ad52 | Michael Hanselmann | """Waits for a task for a worker.
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230 | 21c5ad52 | Michael Hanselmann |
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231 | 21c5ad52 | Michael Hanselmann | @type worker: L{BaseWorker}
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232 | 21c5ad52 | Michael Hanselmann | @param worker: Worker thread
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233 | 21c5ad52 | Michael Hanselmann |
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234 | 21c5ad52 | Michael Hanselmann | """
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235 | 21c5ad52 | Michael Hanselmann | if self._ShouldWorkerTerminateUnlocked(worker): |
236 | 21c5ad52 | Michael Hanselmann | return _TERMINATE
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237 | 21c5ad52 | Michael Hanselmann | |
238 | 21c5ad52 | Michael Hanselmann | # We only wait if there's no task for us.
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239 | 21c5ad52 | Michael Hanselmann | if not self._tasks: |
240 | 21c5ad52 | Michael Hanselmann | logging.debug("Waiting for tasks")
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241 | 21c5ad52 | Michael Hanselmann | |
242 | 21c5ad52 | Michael Hanselmann | # wait() releases the lock and sleeps until notified
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243 | 21c5ad52 | Michael Hanselmann | self._pool_to_worker.wait()
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244 | 21c5ad52 | Michael Hanselmann | |
245 | 21c5ad52 | Michael Hanselmann | logging.debug("Notified while waiting")
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246 | 21c5ad52 | Michael Hanselmann | |
247 | 21c5ad52 | Michael Hanselmann | # Were we woken up in order to terminate?
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248 | 21c5ad52 | Michael Hanselmann | if self._ShouldWorkerTerminateUnlocked(worker): |
249 | 21c5ad52 | Michael Hanselmann | return _TERMINATE
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250 | 21c5ad52 | Michael Hanselmann | |
251 | 21c5ad52 | Michael Hanselmann | if not self._tasks: |
252 | 21c5ad52 | Michael Hanselmann | # Spurious notification, ignore
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253 | 21c5ad52 | Michael Hanselmann | return None |
254 | 21c5ad52 | Michael Hanselmann | |
255 | 21c5ad52 | Michael Hanselmann | # Get task from queue and tell pool about it
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256 | 21c5ad52 | Michael Hanselmann | try:
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257 | 21c5ad52 | Michael Hanselmann | return self._tasks.popleft() |
258 | 21c5ad52 | Michael Hanselmann | finally:
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259 | 21c5ad52 | Michael Hanselmann | self._worker_to_pool.notifyAll()
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260 | 21c5ad52 | Michael Hanselmann | |
261 | 76094e37 | Michael Hanselmann | def _ShouldWorkerTerminateUnlocked(self, worker): |
262 | 76094e37 | Michael Hanselmann | """Returns whether a worker should terminate.
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263 | 76094e37 | Michael Hanselmann |
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264 | 76094e37 | Michael Hanselmann | """
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265 | 76094e37 | Michael Hanselmann | return (worker in self._termworkers) |
266 | 76094e37 | Michael Hanselmann | |
267 | 76094e37 | Michael Hanselmann | def _HasRunningTasksUnlocked(self): |
268 | 76094e37 | Michael Hanselmann | """Checks whether there's a task running in a worker.
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269 | 76094e37 | Michael Hanselmann |
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270 | 76094e37 | Michael Hanselmann | """
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271 | 76094e37 | Michael Hanselmann | for worker in self._workers + self._termworkers: |
272 | 7260cfbe | Iustin Pop | if worker._HasRunningTaskUnlocked(): # pylint: disable-msg=W0212 |
273 | 76094e37 | Michael Hanselmann | return True |
274 | 76094e37 | Michael Hanselmann | return False |
275 | 76094e37 | Michael Hanselmann | |
276 | 76094e37 | Michael Hanselmann | def Quiesce(self): |
277 | 76094e37 | Michael Hanselmann | """Waits until the task queue is empty.
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278 | 76094e37 | Michael Hanselmann |
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279 | 76094e37 | Michael Hanselmann | """
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280 | 76094e37 | Michael Hanselmann | self._lock.acquire()
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281 | 76094e37 | Michael Hanselmann | try:
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282 | 76094e37 | Michael Hanselmann | self._quiescing = True |
283 | 76094e37 | Michael Hanselmann | |
284 | 76094e37 | Michael Hanselmann | # Wait while there are tasks pending or running
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285 | 76094e37 | Michael Hanselmann | while self._tasks or self._HasRunningTasksUnlocked(): |
286 | 53b1d12b | Michael Hanselmann | self._worker_to_pool.wait()
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287 | 76094e37 | Michael Hanselmann | |
288 | 76094e37 | Michael Hanselmann | finally:
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289 | 76094e37 | Michael Hanselmann | self._quiescing = False |
290 | 76094e37 | Michael Hanselmann | |
291 | 76094e37 | Michael Hanselmann | # Make sure AddTasks continues in case it was waiting
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292 | 53b1d12b | Michael Hanselmann | self._pool_to_pool.notifyAll()
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293 | 76094e37 | Michael Hanselmann | |
294 | 76094e37 | Michael Hanselmann | self._lock.release()
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295 | 76094e37 | Michael Hanselmann | |
296 | 76094e37 | Michael Hanselmann | def _NewWorkerIdUnlocked(self): |
297 | 116db7c7 | Iustin Pop | """Return an identifier for a new worker.
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298 | 116db7c7 | Iustin Pop |
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299 | 116db7c7 | Iustin Pop | """
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300 | 76094e37 | Michael Hanselmann | self._last_worker_id += 1 |
301 | 89e2b4d2 | Michael Hanselmann | |
302 | 89e2b4d2 | Michael Hanselmann | return "%s%d" % (self._name, self._last_worker_id) |
303 | 76094e37 | Michael Hanselmann | |
304 | 76094e37 | Michael Hanselmann | def _ResizeUnlocked(self, num_workers): |
305 | 76094e37 | Michael Hanselmann | """Changes the number of workers.
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306 | 76094e37 | Michael Hanselmann |
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307 | 76094e37 | Michael Hanselmann | """
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308 | 76094e37 | Michael Hanselmann | assert num_workers >= 0, "num_workers must be >= 0" |
309 | 76094e37 | Michael Hanselmann | |
310 | 76094e37 | Michael Hanselmann | logging.debug("Resizing to %s workers", num_workers)
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311 | 76094e37 | Michael Hanselmann | |
312 | 76094e37 | Michael Hanselmann | current_count = len(self._workers) |
313 | 76094e37 | Michael Hanselmann | |
314 | 76094e37 | Michael Hanselmann | if current_count == num_workers:
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315 | 76094e37 | Michael Hanselmann | # Nothing to do
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316 | 76094e37 | Michael Hanselmann | pass
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317 | 76094e37 | Michael Hanselmann | |
318 | 76094e37 | Michael Hanselmann | elif current_count > num_workers:
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319 | 76094e37 | Michael Hanselmann | if num_workers == 0: |
320 | 76094e37 | Michael Hanselmann | # Create copy of list to iterate over while lock isn't held.
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321 | 76094e37 | Michael Hanselmann | termworkers = self._workers[:]
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322 | 76094e37 | Michael Hanselmann | del self._workers[:] |
323 | 76094e37 | Michael Hanselmann | else:
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324 | 76094e37 | Michael Hanselmann | # TODO: Implement partial downsizing
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325 | 76094e37 | Michael Hanselmann | raise NotImplementedError() |
326 | 76094e37 | Michael Hanselmann | #termworkers = ...
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327 | 76094e37 | Michael Hanselmann | |
328 | 76094e37 | Michael Hanselmann | self._termworkers += termworkers
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329 | 76094e37 | Michael Hanselmann | |
330 | 76094e37 | Michael Hanselmann | # Notify workers that something has changed
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331 | 53b1d12b | Michael Hanselmann | self._pool_to_worker.notifyAll()
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332 | 76094e37 | Michael Hanselmann | |
333 | 76094e37 | Michael Hanselmann | # Join all terminating workers
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334 | 76094e37 | Michael Hanselmann | self._lock.release()
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335 | 76094e37 | Michael Hanselmann | try:
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336 | 76094e37 | Michael Hanselmann | for worker in termworkers: |
337 | c0a8eb9e | Michael Hanselmann | logging.debug("Waiting for thread %s", worker.getName())
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338 | 76094e37 | Michael Hanselmann | worker.join() |
339 | 76094e37 | Michael Hanselmann | finally:
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340 | 76094e37 | Michael Hanselmann | self._lock.acquire()
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341 | 76094e37 | Michael Hanselmann | |
342 | 76094e37 | Michael Hanselmann | # Remove terminated threads. This could be done in a more efficient way
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343 | 76094e37 | Michael Hanselmann | # (del self._termworkers[:]), but checking worker.isAlive() makes sure we
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344 | 76094e37 | Michael Hanselmann | # don't leave zombie threads around.
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345 | 76094e37 | Michael Hanselmann | for worker in termworkers: |
346 | 76094e37 | Michael Hanselmann | assert worker in self._termworkers, ("Worker not in list of" |
347 | 76094e37 | Michael Hanselmann | " terminating workers")
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348 | 76094e37 | Michael Hanselmann | if not worker.isAlive(): |
349 | 76094e37 | Michael Hanselmann | self._termworkers.remove(worker)
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350 | 76094e37 | Michael Hanselmann | |
351 | 76094e37 | Michael Hanselmann | assert not self._termworkers, "Zombie worker detected" |
352 | 76094e37 | Michael Hanselmann | |
353 | 76094e37 | Michael Hanselmann | elif current_count < num_workers:
|
354 | 76094e37 | Michael Hanselmann | # Create (num_workers - current_count) new workers
|
355 | f1501b3f | Michael Hanselmann | for _ in range(num_workers - current_count): |
356 | 76094e37 | Michael Hanselmann | worker = self._worker_class(self, self._NewWorkerIdUnlocked()) |
357 | 76094e37 | Michael Hanselmann | self._workers.append(worker)
|
358 | 76094e37 | Michael Hanselmann | worker.start() |
359 | 76094e37 | Michael Hanselmann | |
360 | 76094e37 | Michael Hanselmann | def Resize(self, num_workers): |
361 | 76094e37 | Michael Hanselmann | """Changes the number of workers in the pool.
|
362 | 76094e37 | Michael Hanselmann |
|
363 | 116db7c7 | Iustin Pop | @param num_workers: the new number of workers
|
364 | 76094e37 | Michael Hanselmann |
|
365 | 76094e37 | Michael Hanselmann | """
|
366 | 76094e37 | Michael Hanselmann | self._lock.acquire()
|
367 | 76094e37 | Michael Hanselmann | try:
|
368 | 76094e37 | Michael Hanselmann | return self._ResizeUnlocked(num_workers) |
369 | 76094e37 | Michael Hanselmann | finally:
|
370 | 76094e37 | Michael Hanselmann | self._lock.release()
|
371 | 76094e37 | Michael Hanselmann | |
372 | 76094e37 | Michael Hanselmann | def TerminateWorkers(self): |
373 | 76094e37 | Michael Hanselmann | """Terminate all worker threads.
|
374 | 76094e37 | Michael Hanselmann |
|
375 | 76094e37 | Michael Hanselmann | Unstarted tasks will be ignored.
|
376 | 76094e37 | Michael Hanselmann |
|
377 | 76094e37 | Michael Hanselmann | """
|
378 | 76094e37 | Michael Hanselmann | logging.debug("Terminating all workers")
|
379 | 76094e37 | Michael Hanselmann | |
380 | 76094e37 | Michael Hanselmann | self._lock.acquire()
|
381 | 76094e37 | Michael Hanselmann | try:
|
382 | 76094e37 | Michael Hanselmann | self._ResizeUnlocked(0) |
383 | 76094e37 | Michael Hanselmann | |
384 | 76094e37 | Michael Hanselmann | if self._tasks: |
385 | 76094e37 | Michael Hanselmann | logging.debug("There are %s tasks left", len(self._tasks)) |
386 | 76094e37 | Michael Hanselmann | finally:
|
387 | 76094e37 | Michael Hanselmann | self._lock.release()
|
388 | 76094e37 | Michael Hanselmann | |
389 | 76094e37 | Michael Hanselmann | logging.debug("All workers terminated") |