1 | # Some simple queue module tests, plus some failure conditions |
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2 | # to ensure the Queue locks remain stable. |
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3 | import Queue |
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4 | import time |
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5 | import unittest |
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6 | from test import test_support |
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7 | threading = test_support.import_module('threading') |
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8 | |
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9 | QUEUE_SIZE = 5 |
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10 | |
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11 | # A thread to run a function that unclogs a blocked Queue. |
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12 | class _TriggerThread(threading.Thread): |
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13 | def __init__(self, fn, args): |
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14 | self.fn = fn |
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15 | self.args = args |
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16 | self.startedEvent = threading.Event() |
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17 | threading.Thread.__init__(self) |
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18 | |
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19 | def run(self): |
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20 | # The sleep isn't necessary, but is intended to give the blocking |
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21 | # function in the main thread a chance at actually blocking before |
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22 | # we unclog it. But if the sleep is longer than the timeout-based |
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23 | # tests wait in their blocking functions, those tests will fail. |
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24 | # So we give them much longer timeout values compared to the |
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25 | # sleep here (I aimed at 10 seconds for blocking functions -- |
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26 | # they should never actually wait that long - they should make |
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27 | # progress as soon as we call self.fn()). |
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28 | time.sleep(0.1) |
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29 | self.startedEvent.set() |
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30 | self.fn(*self.args) |
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31 | |
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32 | |
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33 | # Execute a function that blocks, and in a separate thread, a function that |
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34 | # triggers the release. Returns the result of the blocking function. Caution: |
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35 | # block_func must guarantee to block until trigger_func is called, and |
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36 | # trigger_func must guarantee to change queue state so that block_func can make |
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37 | # enough progress to return. In particular, a block_func that just raises an |
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38 | # exception regardless of whether trigger_func is called will lead to |
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39 | # timing-dependent sporadic failures, and one of those went rarely seen but |
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40 | # undiagnosed for years. Now block_func must be unexceptional. If block_func |
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41 | # is supposed to raise an exception, call do_exceptional_blocking_test() |
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42 | # instead. |
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43 | |
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44 | class BlockingTestMixin: |
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45 | |
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46 | def tearDown(self): |
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47 | self.t = None |
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48 | |
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49 | def do_blocking_test(self, block_func, block_args, trigger_func, trigger_args): |
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50 | self.t = _TriggerThread(trigger_func, trigger_args) |
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51 | self.t.start() |
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52 | self.result = block_func(*block_args) |
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53 | # If block_func returned before our thread made the call, we failed! |
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54 | if not self.t.startedEvent.is_set(): |
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55 | self.fail("blocking function '%r' appeared not to block" % |
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56 | block_func) |
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57 | self.t.join(10) # make sure the thread terminates |
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58 | if self.t.is_alive(): |
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59 | self.fail("trigger function '%r' appeared to not return" % |
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60 | trigger_func) |
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61 | return self.result |
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62 | |
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63 | # Call this instead if block_func is supposed to raise an exception. |
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64 | def do_exceptional_blocking_test(self,block_func, block_args, trigger_func, |
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65 | trigger_args, expected_exception_class): |
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66 | self.t = _TriggerThread(trigger_func, trigger_args) |
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67 | self.t.start() |
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68 | try: |
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69 | try: |
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70 | block_func(*block_args) |
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71 | except expected_exception_class: |
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72 | raise |
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73 | else: |
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74 | self.fail("expected exception of kind %r" % |
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75 | expected_exception_class) |
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76 | finally: |
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77 | self.t.join(10) # make sure the thread terminates |
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78 | if self.t.is_alive(): |
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79 | self.fail("trigger function '%r' appeared to not return" % |
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80 | trigger_func) |
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81 | if not self.t.startedEvent.is_set(): |
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82 | self.fail("trigger thread ended but event never set") |
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83 | |
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84 | |
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85 | class BaseQueueTest(BlockingTestMixin): |
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86 | def setUp(self): |
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87 | self.cum = 0 |
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88 | self.cumlock = threading.Lock() |
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89 | |
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90 | def simple_queue_test(self, q): |
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91 | if not q.empty(): |
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92 | raise RuntimeError, "Call this function with an empty queue" |
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93 | # I guess we better check things actually queue correctly a little :) |
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94 | q.put(111) |
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95 | q.put(333) |
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96 | q.put(222) |
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97 | target_order = dict(Queue = [111, 333, 222], |
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98 | LifoQueue = [222, 333, 111], |
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99 | PriorityQueue = [111, 222, 333]) |
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100 | actual_order = [q.get(), q.get(), q.get()] |
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101 | self.assertEqual(actual_order, target_order[q.__class__.__name__], |
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102 | "Didn't seem to queue the correct data!") |
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103 | for i in range(QUEUE_SIZE-1): |
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104 | q.put(i) |
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105 | self.assertTrue(not q.empty(), "Queue should not be empty") |
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106 | self.assertTrue(not q.full(), "Queue should not be full") |
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107 | last = 2 * QUEUE_SIZE |
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108 | full = 3 * 2 * QUEUE_SIZE |
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109 | q.put(last) |
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110 | self.assertTrue(q.full(), "Queue should be full") |
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111 | try: |
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112 | q.put(full, block=0) |
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113 | self.fail("Didn't appear to block with a full queue") |
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114 | except Queue.Full: |
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115 | pass |
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116 | try: |
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117 | q.put(full, timeout=0.01) |
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118 | self.fail("Didn't appear to time-out with a full queue") |
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119 | except Queue.Full: |
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120 | pass |
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121 | # Test a blocking put |
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122 | self.do_blocking_test(q.put, (full,), q.get, ()) |
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123 | self.do_blocking_test(q.put, (full, True, 10), q.get, ()) |
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124 | # Empty it |
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125 | for i in range(QUEUE_SIZE): |
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126 | q.get() |
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127 | self.assertTrue(q.empty(), "Queue should be empty") |
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128 | try: |
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129 | q.get(block=0) |
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130 | self.fail("Didn't appear to block with an empty queue") |
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131 | except Queue.Empty: |
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132 | pass |
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133 | try: |
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134 | q.get(timeout=0.01) |
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135 | self.fail("Didn't appear to time-out with an empty queue") |
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136 | except Queue.Empty: |
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137 | pass |
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138 | # Test a blocking get |
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139 | self.do_blocking_test(q.get, (), q.put, ('empty',)) |
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140 | self.do_blocking_test(q.get, (True, 10), q.put, ('empty',)) |
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141 | |
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142 | |
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143 | def worker(self, q): |
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144 | while True: |
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145 | x = q.get() |
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146 | if x is None: |
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147 | q.task_done() |
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148 | return |
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149 | with self.cumlock: |
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150 | self.cum += x |
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151 | q.task_done() |
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152 | |
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153 | def queue_join_test(self, q): |
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154 | self.cum = 0 |
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155 | for i in (0,1): |
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156 | threading.Thread(target=self.worker, args=(q,)).start() |
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157 | for i in xrange(100): |
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158 | q.put(i) |
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159 | q.join() |
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160 | self.assertEqual(self.cum, sum(range(100)), |
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161 | "q.join() did not block until all tasks were done") |
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162 | for i in (0,1): |
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163 | q.put(None) # instruct the threads to close |
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164 | q.join() # verify that you can join twice |
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165 | |
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166 | def test_queue_task_done(self): |
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167 | # Test to make sure a queue task completed successfully. |
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168 | q = self.type2test() |
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169 | try: |
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170 | q.task_done() |
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171 | except ValueError: |
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172 | pass |
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173 | else: |
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174 | self.fail("Did not detect task count going negative") |
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175 | |
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176 | def test_queue_join(self): |
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177 | # Test that a queue join()s successfully, and before anything else |
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178 | # (done twice for insurance). |
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179 | q = self.type2test() |
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180 | self.queue_join_test(q) |
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181 | self.queue_join_test(q) |
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182 | try: |
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183 | q.task_done() |
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184 | except ValueError: |
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185 | pass |
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186 | else: |
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187 | self.fail("Did not detect task count going negative") |
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188 | |
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189 | def test_simple_queue(self): |
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190 | # Do it a couple of times on the same queue. |
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191 | # Done twice to make sure works with same instance reused. |
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192 | q = self.type2test(QUEUE_SIZE) |
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193 | self.simple_queue_test(q) |
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194 | self.simple_queue_test(q) |
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195 | |
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196 | |
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197 | class QueueTest(BaseQueueTest, unittest.TestCase): |
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198 | type2test = Queue.Queue |
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199 | |
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200 | class LifoQueueTest(BaseQueueTest, unittest.TestCase): |
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201 | type2test = Queue.LifoQueue |
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202 | |
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203 | class PriorityQueueTest(BaseQueueTest, unittest.TestCase): |
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204 | type2test = Queue.PriorityQueue |
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205 | |
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206 | |
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207 | |
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208 | # A Queue subclass that can provoke failure at a moment's notice :) |
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209 | class FailingQueueException(Exception): |
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210 | pass |
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211 | |
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212 | class FailingQueue(Queue.Queue): |
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213 | def __init__(self, *args): |
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214 | self.fail_next_put = False |
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215 | self.fail_next_get = False |
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216 | Queue.Queue.__init__(self, *args) |
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217 | def _put(self, item): |
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218 | if self.fail_next_put: |
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219 | self.fail_next_put = False |
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220 | raise FailingQueueException, "You Lose" |
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221 | return Queue.Queue._put(self, item) |
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222 | def _get(self): |
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223 | if self.fail_next_get: |
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224 | self.fail_next_get = False |
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225 | raise FailingQueueException, "You Lose" |
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226 | return Queue.Queue._get(self) |
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227 | |
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228 | class FailingQueueTest(BlockingTestMixin, unittest.TestCase): |
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229 | |
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230 | def failing_queue_test(self, q): |
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231 | if not q.empty(): |
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232 | raise RuntimeError, "Call this function with an empty queue" |
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233 | for i in range(QUEUE_SIZE-1): |
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234 | q.put(i) |
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235 | # Test a failing non-blocking put. |
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236 | q.fail_next_put = True |
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237 | try: |
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238 | q.put("oops", block=0) |
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239 | self.fail("The queue didn't fail when it should have") |
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240 | except FailingQueueException: |
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241 | pass |
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242 | q.fail_next_put = True |
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243 | try: |
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244 | q.put("oops", timeout=0.1) |
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245 | self.fail("The queue didn't fail when it should have") |
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246 | except FailingQueueException: |
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247 | pass |
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248 | q.put("last") |
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249 | self.assertTrue(q.full(), "Queue should be full") |
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250 | # Test a failing blocking put |
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251 | q.fail_next_put = True |
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252 | try: |
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253 | self.do_blocking_test(q.put, ("full",), q.get, ()) |
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254 | self.fail("The queue didn't fail when it should have") |
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255 | except FailingQueueException: |
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256 | pass |
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257 | # Check the Queue isn't damaged. |
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258 | # put failed, but get succeeded - re-add |
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259 | q.put("last") |
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260 | # Test a failing timeout put |
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261 | q.fail_next_put = True |
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262 | try: |
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263 | self.do_exceptional_blocking_test(q.put, ("full", True, 10), q.get, (), |
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264 | FailingQueueException) |
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265 | self.fail("The queue didn't fail when it should have") |
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266 | except FailingQueueException: |
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267 | pass |
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268 | # Check the Queue isn't damaged. |
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269 | # put failed, but get succeeded - re-add |
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270 | q.put("last") |
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271 | self.assertTrue(q.full(), "Queue should be full") |
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272 | q.get() |
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273 | self.assertTrue(not q.full(), "Queue should not be full") |
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274 | q.put("last") |
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275 | self.assertTrue(q.full(), "Queue should be full") |
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276 | # Test a blocking put |
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277 | self.do_blocking_test(q.put, ("full",), q.get, ()) |
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278 | # Empty it |
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279 | for i in range(QUEUE_SIZE): |
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280 | q.get() |
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281 | self.assertTrue(q.empty(), "Queue should be empty") |
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282 | q.put("first") |
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283 | q.fail_next_get = True |
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284 | try: |
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285 | q.get() |
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286 | self.fail("The queue didn't fail when it should have") |
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287 | except FailingQueueException: |
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288 | pass |
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289 | self.assertTrue(not q.empty(), "Queue should not be empty") |
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290 | q.fail_next_get = True |
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291 | try: |
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292 | q.get(timeout=0.1) |
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293 | self.fail("The queue didn't fail when it should have") |
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294 | except FailingQueueException: |
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295 | pass |
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296 | self.assertTrue(not q.empty(), "Queue should not be empty") |
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297 | q.get() |
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298 | self.assertTrue(q.empty(), "Queue should be empty") |
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299 | q.fail_next_get = True |
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300 | try: |
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301 | self.do_exceptional_blocking_test(q.get, (), q.put, ('empty',), |
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302 | FailingQueueException) |
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303 | self.fail("The queue didn't fail when it should have") |
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304 | except FailingQueueException: |
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305 | pass |
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306 | # put succeeded, but get failed. |
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307 | self.assertTrue(not q.empty(), "Queue should not be empty") |
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308 | q.get() |
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309 | self.assertTrue(q.empty(), "Queue should be empty") |
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310 | |
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311 | def test_failing_queue(self): |
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312 | # Test to make sure a queue is functioning correctly. |
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313 | # Done twice to the same instance. |
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314 | q = FailingQueue(QUEUE_SIZE) |
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315 | self.failing_queue_test(q) |
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316 | self.failing_queue_test(q) |
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317 | |
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318 | |
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319 | def test_main(): |
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320 | test_support.run_unittest(QueueTest, LifoQueueTest, PriorityQueueTest, |
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321 | FailingQueueTest) |
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322 | |
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323 | |
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324 | if __name__ == "__main__": |
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325 | test_main() |
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