root / lib / workerpool.py @ 81f7ea25
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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 logging |
27 | 76094e37 | Michael Hanselmann | import threading |
28 | 52c47e4e | Michael Hanselmann | import heapq |
29 | 76094e37 | Michael Hanselmann | |
30 | 25e557a5 | Guido Trotter | from ganeti import compat |
31 | 52c47e4e | Michael Hanselmann | from ganeti import errors |
32 | 25e557a5 | Guido Trotter | |
33 | 76094e37 | Michael Hanselmann | |
34 | 21c5ad52 | Michael Hanselmann | _TERMINATE = object()
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35 | 52c47e4e | Michael Hanselmann | _DEFAULT_PRIORITY = 0
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36 | 52c47e4e | Michael Hanselmann | |
37 | 52c47e4e | Michael Hanselmann | |
38 | 52c47e4e | Michael Hanselmann | class DeferTask(Exception): |
39 | 52c47e4e | Michael Hanselmann | """Special exception class to defer a task.
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40 | 52c47e4e | Michael Hanselmann |
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41 | 52c47e4e | Michael Hanselmann | This class can be raised by L{BaseWorker.RunTask} to defer the execution of a
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42 | 52c47e4e | Michael Hanselmann | task. Optionally, the priority of the task can be changed.
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43 | 52c47e4e | Michael Hanselmann |
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44 | 52c47e4e | Michael Hanselmann | """
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45 | 52c47e4e | Michael Hanselmann | def __init__(self, priority=None): |
46 | 52c47e4e | Michael Hanselmann | """Initializes this class.
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47 | 52c47e4e | Michael Hanselmann |
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48 | 52c47e4e | Michael Hanselmann | @type priority: number
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49 | 52c47e4e | Michael Hanselmann | @param priority: New task priority (None means no change)
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50 | 52c47e4e | Michael Hanselmann |
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51 | 52c47e4e | Michael Hanselmann | """
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52 | 52c47e4e | Michael Hanselmann | Exception.__init__(self) |
53 | 52c47e4e | Michael Hanselmann | self.priority = priority
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54 | 21c5ad52 | Michael Hanselmann | |
55 | 21c5ad52 | Michael Hanselmann | |
56 | 76094e37 | Michael Hanselmann | class BaseWorker(threading.Thread, object): |
57 | 76094e37 | Michael Hanselmann | """Base worker class for worker pools.
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58 | 76094e37 | Michael Hanselmann |
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59 | 76094e37 | Michael Hanselmann | Users of a worker pool must override RunTask in a subclass.
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60 | 76094e37 | Michael Hanselmann |
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61 | 76094e37 | Michael Hanselmann | """
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62 | b459a848 | Andrea Spadaccini | # pylint: disable=W0212
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63 | 76094e37 | Michael Hanselmann | def __init__(self, pool, worker_id): |
64 | 76094e37 | Michael Hanselmann | """Constructor for BaseWorker thread.
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65 | 76094e37 | Michael Hanselmann |
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66 | 116db7c7 | Iustin Pop | @param pool: the parent worker pool
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67 | 116db7c7 | Iustin Pop | @param worker_id: identifier for this worker
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68 | 76094e37 | Michael Hanselmann |
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69 | 76094e37 | Michael Hanselmann | """
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70 | d16e6fd9 | Michael Hanselmann | super(BaseWorker, self).__init__(name=worker_id) |
71 | 76094e37 | Michael Hanselmann | self.pool = pool
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72 | daba67c7 | Michael Hanselmann | self._worker_id = worker_id
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73 | 76094e37 | Michael Hanselmann | self._current_task = None |
74 | 76094e37 | Michael Hanselmann | |
75 | daba67c7 | Michael Hanselmann | assert self.getName() == worker_id |
76 | daba67c7 | Michael Hanselmann | |
77 | 76094e37 | Michael Hanselmann | def ShouldTerminate(self): |
78 | 2f4e1516 | Michael Hanselmann | """Returns whether this worker should terminate.
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79 | 2f4e1516 | Michael Hanselmann |
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80 | 2f4e1516 | Michael Hanselmann | Should only be called from within L{RunTask}.
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81 | 76094e37 | Michael Hanselmann |
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82 | 76094e37 | Michael Hanselmann | """
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83 | 2f4e1516 | Michael Hanselmann | self.pool._lock.acquire()
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84 | 2f4e1516 | Michael Hanselmann | try:
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85 | 2f4e1516 | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
86 | 2f4e1516 | Michael Hanselmann | return self.pool._ShouldWorkerTerminateUnlocked(self) |
87 | 2f4e1516 | Michael Hanselmann | finally:
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88 | 2f4e1516 | Michael Hanselmann | self.pool._lock.release()
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89 | 76094e37 | Michael Hanselmann | |
90 | 52c47e4e | Michael Hanselmann | def GetCurrentPriority(self): |
91 | 52c47e4e | Michael Hanselmann | """Returns the priority of the current task.
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92 | 52c47e4e | Michael Hanselmann |
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93 | 52c47e4e | Michael Hanselmann | Should only be called from within L{RunTask}.
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94 | 52c47e4e | Michael Hanselmann |
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95 | 52c47e4e | Michael Hanselmann | """
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96 | 52c47e4e | Michael Hanselmann | self.pool._lock.acquire()
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97 | 52c47e4e | Michael Hanselmann | try:
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98 | 52c47e4e | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
99 | 52c47e4e | Michael Hanselmann | |
100 | 52c47e4e | Michael Hanselmann | (priority, _, _) = self._current_task
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101 | 52c47e4e | Michael Hanselmann | |
102 | 52c47e4e | Michael Hanselmann | return priority
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103 | 52c47e4e | Michael Hanselmann | finally:
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104 | 52c47e4e | Michael Hanselmann | self.pool._lock.release()
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105 | 52c47e4e | Michael Hanselmann | |
106 | daba67c7 | Michael Hanselmann | def SetTaskName(self, taskname): |
107 | daba67c7 | Michael Hanselmann | """Sets the name of the current task.
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108 | daba67c7 | Michael Hanselmann |
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109 | daba67c7 | Michael Hanselmann | Should only be called from within L{RunTask}.
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110 | daba67c7 | Michael Hanselmann |
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111 | daba67c7 | Michael Hanselmann | @type taskname: string
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112 | daba67c7 | Michael Hanselmann | @param taskname: Task's name
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113 | daba67c7 | Michael Hanselmann |
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114 | daba67c7 | Michael Hanselmann | """
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115 | daba67c7 | Michael Hanselmann | if taskname:
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116 | daba67c7 | Michael Hanselmann | name = "%s/%s" % (self._worker_id, taskname) |
117 | daba67c7 | Michael Hanselmann | else:
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118 | daba67c7 | Michael Hanselmann | name = self._worker_id
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119 | daba67c7 | Michael Hanselmann | |
120 | daba67c7 | Michael Hanselmann | # Set thread name
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121 | daba67c7 | Michael Hanselmann | self.setName(name)
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122 | daba67c7 | Michael Hanselmann | |
123 | b3558df1 | Michael Hanselmann | def _HasRunningTaskUnlocked(self): |
124 | b3558df1 | Michael Hanselmann | """Returns whether this worker is currently running a task.
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125 | b3558df1 | Michael Hanselmann |
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126 | b3558df1 | Michael Hanselmann | """
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127 | b3558df1 | Michael Hanselmann | return (self._current_task is not None) |
128 | b3558df1 | Michael Hanselmann | |
129 | 76094e37 | Michael Hanselmann | def run(self): |
130 | 76094e37 | Michael Hanselmann | """Main thread function.
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131 | 76094e37 | Michael Hanselmann |
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132 | 76094e37 | Michael Hanselmann | Waits for new tasks to show up in the queue.
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133 | 76094e37 | Michael Hanselmann |
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134 | 76094e37 | Michael Hanselmann | """
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135 | 76094e37 | Michael Hanselmann | pool = self.pool
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136 | 76094e37 | Michael Hanselmann | |
137 | 76094e37 | Michael Hanselmann | while True: |
138 | 46d0a3d0 | Michael Hanselmann | assert self._current_task is None |
139 | 52c47e4e | Michael Hanselmann | |
140 | 52c47e4e | Michael Hanselmann | defer = None
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141 | 76094e37 | Michael Hanselmann | try:
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142 | 21c5ad52 | Michael Hanselmann | # Wait on lock to be told either to terminate or to do a task
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143 | 76094e37 | Michael Hanselmann | pool._lock.acquire() |
144 | 76094e37 | Michael Hanselmann | try:
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145 | 21c5ad52 | Michael Hanselmann | task = pool._WaitForTaskUnlocked(self)
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146 | 76094e37 | Michael Hanselmann | |
147 | 21c5ad52 | Michael Hanselmann | if task is _TERMINATE: |
148 | 21c5ad52 | Michael Hanselmann | # Told to terminate
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149 | 21c5ad52 | Michael Hanselmann | break
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150 | b3558df1 | Michael Hanselmann | |
151 | 21c5ad52 | Michael Hanselmann | if task is None: |
152 | 21c5ad52 | Michael Hanselmann | # Spurious notification, ignore
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153 | 21c5ad52 | Michael Hanselmann | continue
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154 | 76094e37 | Michael Hanselmann | |
155 | 21c5ad52 | Michael Hanselmann | self._current_task = task
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156 | 76094e37 | Michael Hanselmann | |
157 | 46d0a3d0 | Michael Hanselmann | # No longer needed, dispose of reference
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158 | 46d0a3d0 | Michael Hanselmann | del task
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159 | 46d0a3d0 | Michael Hanselmann | |
160 | 21c5ad52 | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
161 | 46d0a3d0 | Michael Hanselmann | |
162 | 76094e37 | Michael Hanselmann | finally:
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163 | 76094e37 | Michael Hanselmann | pool._lock.release() |
164 | 76094e37 | Michael Hanselmann | |
165 | 52c47e4e | Michael Hanselmann | (priority, _, args) = self._current_task
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166 | 76094e37 | Michael Hanselmann | try:
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167 | 52c47e4e | Michael Hanselmann | # Run the actual task
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168 | 52c47e4e | Michael Hanselmann | assert defer is None |
169 | 52c47e4e | Michael Hanselmann | logging.debug("Starting task %r, priority %s", args, priority)
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170 | daba67c7 | Michael Hanselmann | assert self.getName() == self._worker_id |
171 | daba67c7 | Michael Hanselmann | try:
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172 | b459a848 | Andrea Spadaccini | self.RunTask(*args) # pylint: disable=W0142 |
173 | daba67c7 | Michael Hanselmann | finally:
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174 | daba67c7 | Michael Hanselmann | self.SetTaskName(None) |
175 | 52c47e4e | Michael Hanselmann | logging.debug("Done with task %r, priority %s", args, priority)
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176 | 52c47e4e | Michael Hanselmann | except DeferTask, err:
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177 | 52c47e4e | Michael Hanselmann | defer = err |
178 | 52c47e4e | Michael Hanselmann | |
179 | 52c47e4e | Michael Hanselmann | if defer.priority is None: |
180 | 52c47e4e | Michael Hanselmann | # Use same priority
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181 | 52c47e4e | Michael Hanselmann | defer.priority = priority |
182 | 52c47e4e | Michael Hanselmann | |
183 | e1ea54e9 | Michael Hanselmann | logging.debug("Deferring task %r, new priority %s",
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184 | e1ea54e9 | Michael Hanselmann | args, defer.priority) |
185 | 52c47e4e | Michael Hanselmann | |
186 | 52c47e4e | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
187 | b459a848 | Andrea Spadaccini | except: # pylint: disable=W0702 |
188 | 02fc74da | Michael Hanselmann | logging.exception("Caught unhandled exception")
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189 | c1cf1fe5 | Michael Hanselmann | |
190 | c1cf1fe5 | Michael Hanselmann | assert self._HasRunningTaskUnlocked() |
191 | 76094e37 | Michael Hanselmann | finally:
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192 | 76094e37 | Michael Hanselmann | # Notify pool
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193 | 76094e37 | Michael Hanselmann | pool._lock.acquire() |
194 | 76094e37 | Michael Hanselmann | try:
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195 | 52c47e4e | Michael Hanselmann | if defer:
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196 | 52c47e4e | Michael Hanselmann | assert self._current_task |
197 | 52c47e4e | Michael Hanselmann | # Schedule again for later run
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198 | 52c47e4e | Michael Hanselmann | (_, _, args) = self._current_task
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199 | 52c47e4e | Michael Hanselmann | pool._AddTaskUnlocked(args, defer.priority) |
200 | 52c47e4e | Michael Hanselmann | |
201 | b3558df1 | Michael Hanselmann | if self._current_task: |
202 | b3558df1 | Michael Hanselmann | self._current_task = None |
203 | 53b1d12b | Michael Hanselmann | pool._worker_to_pool.notifyAll() |
204 | 76094e37 | Michael Hanselmann | finally:
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205 | 76094e37 | Michael Hanselmann | pool._lock.release() |
206 | 76094e37 | Michael Hanselmann | |
207 | c1cf1fe5 | Michael Hanselmann | assert not self._HasRunningTaskUnlocked() |
208 | c1cf1fe5 | Michael Hanselmann | |
209 | 02fc74da | Michael Hanselmann | logging.debug("Terminates")
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210 | b3558df1 | Michael Hanselmann | |
211 | 76094e37 | Michael Hanselmann | def RunTask(self, *args): |
212 | 76094e37 | Michael Hanselmann | """Function called to start a task.
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213 | 76094e37 | Michael Hanselmann |
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214 | 116db7c7 | Iustin Pop | This needs to be implemented by child classes.
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215 | 116db7c7 | Iustin Pop |
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216 | 76094e37 | Michael Hanselmann | """
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217 | 76094e37 | Michael Hanselmann | raise NotImplementedError() |
218 | 76094e37 | Michael Hanselmann | |
219 | 76094e37 | Michael Hanselmann | |
220 | 76094e37 | Michael Hanselmann | class WorkerPool(object): |
221 | 76094e37 | Michael Hanselmann | """Worker pool with a queue.
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222 | 76094e37 | Michael Hanselmann |
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223 | 76094e37 | Michael Hanselmann | This class is thread-safe.
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224 | 76094e37 | Michael Hanselmann |
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225 | 116db7c7 | Iustin Pop | Tasks are guaranteed to be started in the order in which they're
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226 | 116db7c7 | Iustin Pop | added to the pool. Due to the nature of threading, they're not
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227 | 116db7c7 | Iustin Pop | guaranteed to finish in the same order.
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228 | 76094e37 | Michael Hanselmann |
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229 | 76094e37 | Michael Hanselmann | """
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230 | 89e2b4d2 | Michael Hanselmann | def __init__(self, name, num_workers, worker_class): |
231 | 76094e37 | Michael Hanselmann | """Constructor for worker pool.
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232 | 76094e37 | Michael Hanselmann |
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233 | 116db7c7 | Iustin Pop | @param num_workers: number of workers to be started
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234 | 116db7c7 | Iustin Pop | (dynamic resizing is not yet implemented)
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235 | 116db7c7 | Iustin Pop | @param worker_class: the class to be instantiated for workers;
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236 | 116db7c7 | Iustin Pop | should derive from L{BaseWorker}
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237 | 76094e37 | Michael Hanselmann |
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238 | 76094e37 | Michael Hanselmann | """
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239 | 76094e37 | Michael Hanselmann | # Some of these variables are accessed by BaseWorker
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240 | 53b1d12b | Michael Hanselmann | self._lock = threading.Lock()
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241 | 53b1d12b | Michael Hanselmann | self._pool_to_pool = threading.Condition(self._lock) |
242 | 53b1d12b | Michael Hanselmann | self._pool_to_worker = threading.Condition(self._lock) |
243 | 53b1d12b | Michael Hanselmann | self._worker_to_pool = threading.Condition(self._lock) |
244 | 76094e37 | Michael Hanselmann | self._worker_class = worker_class
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245 | 89e2b4d2 | Michael Hanselmann | self._name = name
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246 | 76094e37 | Michael Hanselmann | self._last_worker_id = 0 |
247 | 76094e37 | Michael Hanselmann | self._workers = []
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248 | 76094e37 | Michael Hanselmann | self._quiescing = False |
249 | 27caa993 | Michael Hanselmann | self._active = True |
250 | 76094e37 | Michael Hanselmann | |
251 | 76094e37 | Michael Hanselmann | # Terminating workers
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252 | 76094e37 | Michael Hanselmann | self._termworkers = []
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253 | 76094e37 | Michael Hanselmann | |
254 | 76094e37 | Michael Hanselmann | # Queued tasks
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255 | 52c47e4e | Michael Hanselmann | self._counter = 0 |
256 | 52c47e4e | Michael Hanselmann | self._tasks = []
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257 | 76094e37 | Michael Hanselmann | |
258 | 76094e37 | Michael Hanselmann | # Start workers
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259 | 76094e37 | Michael Hanselmann | self.Resize(num_workers)
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260 | 76094e37 | Michael Hanselmann | |
261 | 76094e37 | Michael Hanselmann | # TODO: Implement dynamic resizing?
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262 | 76094e37 | Michael Hanselmann | |
263 | c2a8e8ba | Guido Trotter | def _WaitWhileQuiescingUnlocked(self): |
264 | c2a8e8ba | Guido Trotter | """Wait until the worker pool has finished quiescing.
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265 | c2a8e8ba | Guido Trotter |
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266 | c2a8e8ba | Guido Trotter | """
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267 | c2a8e8ba | Guido Trotter | while self._quiescing: |
268 | c2a8e8ba | Guido Trotter | self._pool_to_pool.wait()
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269 | c2a8e8ba | Guido Trotter | |
270 | 52c47e4e | Michael Hanselmann | def _AddTaskUnlocked(self, args, priority): |
271 | 52c47e4e | Michael Hanselmann | """Adds a task to the internal queue.
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272 | 52c47e4e | Michael Hanselmann |
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273 | 52c47e4e | Michael Hanselmann | @type args: sequence
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274 | 52c47e4e | Michael Hanselmann | @param args: Arguments passed to L{BaseWorker.RunTask}
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275 | 52c47e4e | Michael Hanselmann | @type priority: number
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276 | 52c47e4e | Michael Hanselmann | @param priority: Task priority
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277 | 52c47e4e | Michael Hanselmann |
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278 | 52c47e4e | Michael Hanselmann | """
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279 | 189d2714 | Michael Hanselmann | assert isinstance(args, (tuple, list)), "Arguments must be a sequence" |
280 | 52c47e4e | Michael Hanselmann | assert isinstance(priority, (int, long)), "Priority must be numeric" |
281 | 189d2714 | Michael Hanselmann | |
282 | 52c47e4e | Michael Hanselmann | # This counter is used to ensure elements are processed in their
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283 | 52c47e4e | Michael Hanselmann | # incoming order. For processing they're sorted by priority and then
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284 | 52c47e4e | Michael Hanselmann | # counter.
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285 | 52c47e4e | Michael Hanselmann | self._counter += 1 |
286 | 52c47e4e | Michael Hanselmann | |
287 | 52c47e4e | Michael Hanselmann | heapq.heappush(self._tasks, (priority, self._counter, args)) |
288 | 189d2714 | Michael Hanselmann | |
289 | 189d2714 | Michael Hanselmann | # Notify a waiting worker
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290 | 189d2714 | Michael Hanselmann | self._pool_to_worker.notify()
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291 | 189d2714 | Michael Hanselmann | |
292 | 52c47e4e | Michael Hanselmann | def AddTask(self, args, priority=_DEFAULT_PRIORITY): |
293 | 76094e37 | Michael Hanselmann | """Adds a task to the queue.
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294 | 76094e37 | Michael Hanselmann |
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295 | b2e8a4d9 | Michael Hanselmann | @type args: sequence
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296 | 116db7c7 | Iustin Pop | @param args: arguments passed to L{BaseWorker.RunTask}
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297 | 52c47e4e | Michael Hanselmann | @type priority: number
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298 | 52c47e4e | Michael Hanselmann | @param priority: Task priority
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299 | 76094e37 | Michael Hanselmann |
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300 | 76094e37 | Michael Hanselmann | """
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301 | 76094e37 | Michael Hanselmann | self._lock.acquire()
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302 | 76094e37 | Michael Hanselmann | try:
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303 | c2a8e8ba | Guido Trotter | self._WaitWhileQuiescingUnlocked()
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304 | 52c47e4e | Michael Hanselmann | self._AddTaskUnlocked(args, priority)
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305 | 76094e37 | Michael Hanselmann | finally:
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306 | 76094e37 | Michael Hanselmann | self._lock.release()
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307 | 76094e37 | Michael Hanselmann | |
308 | 52c47e4e | Michael Hanselmann | def AddManyTasks(self, tasks, priority=_DEFAULT_PRIORITY): |
309 | c2a8e8ba | Guido Trotter | """Add a list of tasks to the queue.
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310 | c2a8e8ba | Guido Trotter |
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311 | c2a8e8ba | Guido Trotter | @type tasks: list of tuples
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312 | c2a8e8ba | Guido Trotter | @param tasks: list of args passed to L{BaseWorker.RunTask}
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313 | 52c47e4e | Michael Hanselmann | @type priority: number or list of numbers
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314 | 52c47e4e | Michael Hanselmann | @param priority: Priority for all added tasks or a list with the priority
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315 | 52c47e4e | Michael Hanselmann | for each task
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316 | c2a8e8ba | Guido Trotter |
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317 | c2a8e8ba | Guido Trotter | """
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318 | 25e557a5 | Guido Trotter | assert compat.all(isinstance(task, (tuple, list)) for task in tasks), \ |
319 | 25e557a5 | Guido Trotter | "Each task must be a sequence"
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320 | 25e557a5 | Guido Trotter | |
321 | 52c47e4e | Michael Hanselmann | assert (isinstance(priority, (int, long)) or |
322 | 52c47e4e | Michael Hanselmann | compat.all(isinstance(prio, (int, long)) for prio in priority)), \ |
323 | 52c47e4e | Michael Hanselmann | "Priority must be numeric or be a list of numeric values"
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324 | 52c47e4e | Michael Hanselmann | |
325 | 52c47e4e | Michael Hanselmann | if isinstance(priority, (int, long)): |
326 | 52c47e4e | Michael Hanselmann | priority = [priority] * len(tasks)
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327 | 52c47e4e | Michael Hanselmann | elif len(priority) != len(tasks): |
328 | 52c47e4e | Michael Hanselmann | raise errors.ProgrammerError("Number of priorities (%s) doesn't match" |
329 | 52c47e4e | Michael Hanselmann | " number of tasks (%s)" %
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330 | 52c47e4e | Michael Hanselmann | (len(priority), len(tasks))) |
331 | 52c47e4e | Michael Hanselmann | |
332 | c2a8e8ba | Guido Trotter | self._lock.acquire()
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333 | c2a8e8ba | Guido Trotter | try:
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334 | c2a8e8ba | Guido Trotter | self._WaitWhileQuiescingUnlocked()
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335 | c2a8e8ba | Guido Trotter | |
336 | 52c47e4e | Michael Hanselmann | assert compat.all(isinstance(prio, (int, long)) for prio in priority) |
337 | 52c47e4e | Michael Hanselmann | assert len(tasks) == len(priority) |
338 | 52c47e4e | Michael Hanselmann | |
339 | 52c47e4e | Michael Hanselmann | for args, priority in zip(tasks, priority): |
340 | 52c47e4e | Michael Hanselmann | self._AddTaskUnlocked(args, priority)
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341 | c2a8e8ba | Guido Trotter | finally:
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342 | c2a8e8ba | Guido Trotter | self._lock.release()
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343 | c2a8e8ba | Guido Trotter | |
344 | 27caa993 | Michael Hanselmann | def SetActive(self, active): |
345 | 27caa993 | Michael Hanselmann | """Enable/disable processing of tasks.
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346 | 27caa993 | Michael Hanselmann |
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347 | 27caa993 | Michael Hanselmann | This is different from L{Quiesce} in the sense that this function just
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348 | 27caa993 | Michael Hanselmann | changes an internal flag and doesn't wait for the queue to be empty. Tasks
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349 | 27caa993 | Michael Hanselmann | already being processed continue normally, but no new tasks will be
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350 | 27caa993 | Michael Hanselmann | started. New tasks can still be added.
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351 | 27caa993 | Michael Hanselmann |
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352 | 27caa993 | Michael Hanselmann | @type active: bool
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353 | 27caa993 | Michael Hanselmann | @param active: Whether tasks should be processed
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354 | 27caa993 | Michael Hanselmann |
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355 | 27caa993 | Michael Hanselmann | """
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356 | 27caa993 | Michael Hanselmann | self._lock.acquire()
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357 | 27caa993 | Michael Hanselmann | try:
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358 | 27caa993 | Michael Hanselmann | self._active = active
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359 | 27caa993 | Michael Hanselmann | |
360 | 27caa993 | Michael Hanselmann | if active:
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361 | 27caa993 | Michael Hanselmann | # Tell all workers to continue processing
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362 | 27caa993 | Michael Hanselmann | self._pool_to_worker.notifyAll()
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363 | 27caa993 | Michael Hanselmann | finally:
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364 | 27caa993 | Michael Hanselmann | self._lock.release()
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365 | 27caa993 | Michael Hanselmann | |
366 | 21c5ad52 | Michael Hanselmann | def _WaitForTaskUnlocked(self, worker): |
367 | 21c5ad52 | Michael Hanselmann | """Waits for a task for a worker.
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368 | 21c5ad52 | Michael Hanselmann |
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369 | 21c5ad52 | Michael Hanselmann | @type worker: L{BaseWorker}
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370 | 21c5ad52 | Michael Hanselmann | @param worker: Worker thread
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371 | 21c5ad52 | Michael Hanselmann |
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372 | 21c5ad52 | Michael Hanselmann | """
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373 | 21c5ad52 | Michael Hanselmann | if self._ShouldWorkerTerminateUnlocked(worker): |
374 | 21c5ad52 | Michael Hanselmann | return _TERMINATE
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375 | 21c5ad52 | Michael Hanselmann | |
376 | 21c5ad52 | Michael Hanselmann | # We only wait if there's no task for us.
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377 | 27caa993 | Michael Hanselmann | if not (self._active and self._tasks): |
378 | 21c5ad52 | Michael Hanselmann | logging.debug("Waiting for tasks")
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379 | 21c5ad52 | Michael Hanselmann | |
380 | 2db05c94 | Michael Hanselmann | while True: |
381 | 2db05c94 | Michael Hanselmann | # wait() releases the lock and sleeps until notified
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382 | 2db05c94 | Michael Hanselmann | self._pool_to_worker.wait()
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383 | 21c5ad52 | Michael Hanselmann | |
384 | 2db05c94 | Michael Hanselmann | logging.debug("Notified while waiting")
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385 | 21c5ad52 | Michael Hanselmann | |
386 | 2db05c94 | Michael Hanselmann | # Were we woken up in order to terminate?
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387 | 2db05c94 | Michael Hanselmann | if self._ShouldWorkerTerminateUnlocked(worker): |
388 | 2db05c94 | Michael Hanselmann | return _TERMINATE
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389 | 21c5ad52 | Michael Hanselmann | |
390 | 27caa993 | Michael Hanselmann | # Just loop if pool is not processing tasks at this time
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391 | 27caa993 | Michael Hanselmann | if self._active and self._tasks: |
392 | 2db05c94 | Michael Hanselmann | break
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393 | 21c5ad52 | Michael Hanselmann | |
394 | 21c5ad52 | Michael Hanselmann | # Get task from queue and tell pool about it
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395 | 21c5ad52 | Michael Hanselmann | try:
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396 | 52c47e4e | Michael Hanselmann | return heapq.heappop(self._tasks) |
397 | 21c5ad52 | Michael Hanselmann | finally:
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398 | 21c5ad52 | Michael Hanselmann | self._worker_to_pool.notifyAll()
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399 | 21c5ad52 | Michael Hanselmann | |
400 | 76094e37 | Michael Hanselmann | def _ShouldWorkerTerminateUnlocked(self, worker): |
401 | 76094e37 | Michael Hanselmann | """Returns whether a worker should terminate.
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402 | 76094e37 | Michael Hanselmann |
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403 | 76094e37 | Michael Hanselmann | """
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404 | 76094e37 | Michael Hanselmann | return (worker in self._termworkers) |
405 | 76094e37 | Michael Hanselmann | |
406 | 76094e37 | Michael Hanselmann | def _HasRunningTasksUnlocked(self): |
407 | 76094e37 | Michael Hanselmann | """Checks whether there's a task running in a worker.
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408 | 76094e37 | Michael Hanselmann |
|
409 | 76094e37 | Michael Hanselmann | """
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410 | 76094e37 | Michael Hanselmann | for worker in self._workers + self._termworkers: |
411 | b459a848 | Andrea Spadaccini | if worker._HasRunningTaskUnlocked(): # pylint: disable=W0212 |
412 | 76094e37 | Michael Hanselmann | return True |
413 | 76094e37 | Michael Hanselmann | return False |
414 | 76094e37 | Michael Hanselmann | |
415 | ef52306a | Michael Hanselmann | def HasRunningTasks(self): |
416 | ef52306a | Michael Hanselmann | """Checks whether there's at least one task running.
|
417 | ef52306a | Michael Hanselmann |
|
418 | ef52306a | Michael Hanselmann | """
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419 | ef52306a | Michael Hanselmann | self._lock.acquire()
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420 | ef52306a | Michael Hanselmann | try:
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421 | ef52306a | Michael Hanselmann | return self._HasRunningTasksUnlocked() |
422 | ef52306a | Michael Hanselmann | finally:
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423 | ef52306a | Michael Hanselmann | self._lock.release()
|
424 | ef52306a | Michael Hanselmann | |
425 | 76094e37 | Michael Hanselmann | def Quiesce(self): |
426 | 76094e37 | Michael Hanselmann | """Waits until the task queue is empty.
|
427 | 76094e37 | Michael Hanselmann |
|
428 | 76094e37 | Michael Hanselmann | """
|
429 | 76094e37 | Michael Hanselmann | self._lock.acquire()
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430 | 76094e37 | Michael Hanselmann | try:
|
431 | 76094e37 | Michael Hanselmann | self._quiescing = True |
432 | 76094e37 | Michael Hanselmann | |
433 | 76094e37 | Michael Hanselmann | # Wait while there are tasks pending or running
|
434 | 76094e37 | Michael Hanselmann | while self._tasks or self._HasRunningTasksUnlocked(): |
435 | 53b1d12b | Michael Hanselmann | self._worker_to_pool.wait()
|
436 | 76094e37 | Michael Hanselmann | |
437 | 76094e37 | Michael Hanselmann | finally:
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438 | 76094e37 | Michael Hanselmann | self._quiescing = False |
439 | 76094e37 | Michael Hanselmann | |
440 | 76094e37 | Michael Hanselmann | # Make sure AddTasks continues in case it was waiting
|
441 | 53b1d12b | Michael Hanselmann | self._pool_to_pool.notifyAll()
|
442 | 76094e37 | Michael Hanselmann | |
443 | 76094e37 | Michael Hanselmann | self._lock.release()
|
444 | 76094e37 | Michael Hanselmann | |
445 | 76094e37 | Michael Hanselmann | def _NewWorkerIdUnlocked(self): |
446 | 116db7c7 | Iustin Pop | """Return an identifier for a new worker.
|
447 | 116db7c7 | Iustin Pop |
|
448 | 116db7c7 | Iustin Pop | """
|
449 | 76094e37 | Michael Hanselmann | self._last_worker_id += 1 |
450 | 89e2b4d2 | Michael Hanselmann | |
451 | 89e2b4d2 | Michael Hanselmann | return "%s%d" % (self._name, self._last_worker_id) |
452 | 76094e37 | Michael Hanselmann | |
453 | 76094e37 | Michael Hanselmann | def _ResizeUnlocked(self, num_workers): |
454 | 76094e37 | Michael Hanselmann | """Changes the number of workers.
|
455 | 76094e37 | Michael Hanselmann |
|
456 | 76094e37 | Michael Hanselmann | """
|
457 | 76094e37 | Michael Hanselmann | assert num_workers >= 0, "num_workers must be >= 0" |
458 | 76094e37 | Michael Hanselmann | |
459 | 76094e37 | Michael Hanselmann | logging.debug("Resizing to %s workers", num_workers)
|
460 | 76094e37 | Michael Hanselmann | |
461 | 76094e37 | Michael Hanselmann | current_count = len(self._workers) |
462 | 76094e37 | Michael Hanselmann | |
463 | 76094e37 | Michael Hanselmann | if current_count == num_workers:
|
464 | 76094e37 | Michael Hanselmann | # Nothing to do
|
465 | 76094e37 | Michael Hanselmann | pass
|
466 | 76094e37 | Michael Hanselmann | |
467 | 76094e37 | Michael Hanselmann | elif current_count > num_workers:
|
468 | 76094e37 | Michael Hanselmann | if num_workers == 0: |
469 | 76094e37 | Michael Hanselmann | # Create copy of list to iterate over while lock isn't held.
|
470 | 76094e37 | Michael Hanselmann | termworkers = self._workers[:]
|
471 | 76094e37 | Michael Hanselmann | del self._workers[:] |
472 | 76094e37 | Michael Hanselmann | else:
|
473 | 76094e37 | Michael Hanselmann | # TODO: Implement partial downsizing
|
474 | 76094e37 | Michael Hanselmann | raise NotImplementedError() |
475 | 76094e37 | Michael Hanselmann | #termworkers = ...
|
476 | 76094e37 | Michael Hanselmann | |
477 | 76094e37 | Michael Hanselmann | self._termworkers += termworkers
|
478 | 76094e37 | Michael Hanselmann | |
479 | 76094e37 | Michael Hanselmann | # Notify workers that something has changed
|
480 | 53b1d12b | Michael Hanselmann | self._pool_to_worker.notifyAll()
|
481 | 76094e37 | Michael Hanselmann | |
482 | 76094e37 | Michael Hanselmann | # Join all terminating workers
|
483 | 76094e37 | Michael Hanselmann | self._lock.release()
|
484 | 76094e37 | Michael Hanselmann | try:
|
485 | 76094e37 | Michael Hanselmann | for worker in termworkers: |
486 | c0a8eb9e | Michael Hanselmann | logging.debug("Waiting for thread %s", worker.getName())
|
487 | 76094e37 | Michael Hanselmann | worker.join() |
488 | 76094e37 | Michael Hanselmann | finally:
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489 | 76094e37 | Michael Hanselmann | self._lock.acquire()
|
490 | 76094e37 | Michael Hanselmann | |
491 | 76094e37 | Michael Hanselmann | # Remove terminated threads. This could be done in a more efficient way
|
492 | 76094e37 | Michael Hanselmann | # (del self._termworkers[:]), but checking worker.isAlive() makes sure we
|
493 | 76094e37 | Michael Hanselmann | # don't leave zombie threads around.
|
494 | 76094e37 | Michael Hanselmann | for worker in termworkers: |
495 | 76094e37 | Michael Hanselmann | assert worker in self._termworkers, ("Worker not in list of" |
496 | 76094e37 | Michael Hanselmann | " terminating workers")
|
497 | 76094e37 | Michael Hanselmann | if not worker.isAlive(): |
498 | 76094e37 | Michael Hanselmann | self._termworkers.remove(worker)
|
499 | 76094e37 | Michael Hanselmann | |
500 | 76094e37 | Michael Hanselmann | assert not self._termworkers, "Zombie worker detected" |
501 | 76094e37 | Michael Hanselmann | |
502 | 76094e37 | Michael Hanselmann | elif current_count < num_workers:
|
503 | 76094e37 | Michael Hanselmann | # Create (num_workers - current_count) new workers
|
504 | f1501b3f | Michael Hanselmann | for _ in range(num_workers - current_count): |
505 | 76094e37 | Michael Hanselmann | worker = self._worker_class(self, self._NewWorkerIdUnlocked()) |
506 | 76094e37 | Michael Hanselmann | self._workers.append(worker)
|
507 | 76094e37 | Michael Hanselmann | worker.start() |
508 | 76094e37 | Michael Hanselmann | |
509 | 76094e37 | Michael Hanselmann | def Resize(self, num_workers): |
510 | 76094e37 | Michael Hanselmann | """Changes the number of workers in the pool.
|
511 | 76094e37 | Michael Hanselmann |
|
512 | 116db7c7 | Iustin Pop | @param num_workers: the new number of workers
|
513 | 76094e37 | Michael Hanselmann |
|
514 | 76094e37 | Michael Hanselmann | """
|
515 | 76094e37 | Michael Hanselmann | self._lock.acquire()
|
516 | 76094e37 | Michael Hanselmann | try:
|
517 | 76094e37 | Michael Hanselmann | return self._ResizeUnlocked(num_workers) |
518 | 76094e37 | Michael Hanselmann | finally:
|
519 | 76094e37 | Michael Hanselmann | self._lock.release()
|
520 | 76094e37 | Michael Hanselmann | |
521 | 76094e37 | Michael Hanselmann | def TerminateWorkers(self): |
522 | 76094e37 | Michael Hanselmann | """Terminate all worker threads.
|
523 | 76094e37 | Michael Hanselmann |
|
524 | 76094e37 | Michael Hanselmann | Unstarted tasks will be ignored.
|
525 | 76094e37 | Michael Hanselmann |
|
526 | 76094e37 | Michael Hanselmann | """
|
527 | 76094e37 | Michael Hanselmann | logging.debug("Terminating all workers")
|
528 | 76094e37 | Michael Hanselmann | |
529 | 76094e37 | Michael Hanselmann | self._lock.acquire()
|
530 | 76094e37 | Michael Hanselmann | try:
|
531 | 76094e37 | Michael Hanselmann | self._ResizeUnlocked(0) |
532 | 76094e37 | Michael Hanselmann | |
533 | 76094e37 | Michael Hanselmann | if self._tasks: |
534 | 76094e37 | Michael Hanselmann | logging.debug("There are %s tasks left", len(self._tasks)) |
535 | 76094e37 | Michael Hanselmann | finally:
|
536 | 76094e37 | Michael Hanselmann | self._lock.release()
|
537 | 76094e37 | Michael Hanselmann | |
538 | 76094e37 | Michael Hanselmann | logging.debug("All workers terminated") |