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@@ -1,165 +1,152 b'' | |||
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1 | 1 | # worker.py - master-slave parallelism support |
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2 | 2 | # |
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3 | 3 | # Copyright 2013 Facebook, Inc. |
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4 | 4 | # |
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5 | 5 | # This software may be used and distributed according to the terms of the |
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6 | 6 | # GNU General Public License version 2 or any later version. |
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7 | 7 | |
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8 | 8 | from __future__ import absolute_import |
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9 | 9 | |
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10 | 10 | import errno |
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11 | import multiprocessing | |
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11 | 12 | import os |
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12 | 13 | import signal |
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13 | 14 | import sys |
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14 | 15 | import threading |
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15 | 16 | |
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16 | 17 | from .i18n import _ |
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17 | 18 | from . import util |
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18 | 19 | |
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19 | 20 | def countcpus(): |
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20 | 21 | '''try to count the number of CPUs on the system''' |
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21 | ||
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22 | # posix | |
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23 | 22 | try: |
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24 | n = int(os.sysconf('SC_NPROCESSORS_ONLN')) | |
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25 | if n > 0: | |
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26 |
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27 | except (AttributeError, ValueError): | |
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28 | pass | |
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29 | ||
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30 | # windows | |
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31 | try: | |
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32 | n = int(os.environ['NUMBER_OF_PROCESSORS']) | |
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33 | if n > 0: | |
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34 | return n | |
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35 | except (KeyError, ValueError): | |
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36 | pass | |
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37 | ||
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38 | return 1 | |
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23 | return multiprocessing.cpu_count() | |
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24 | except NotImplementedError: | |
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25 | return 1 | |
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39 | 26 | |
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40 | 27 | def _numworkers(ui): |
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41 | 28 | s = ui.config('worker', 'numcpus') |
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42 | 29 | if s: |
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43 | 30 | try: |
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44 | 31 | n = int(s) |
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45 | 32 | if n >= 1: |
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46 | 33 | return n |
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47 | 34 | except ValueError: |
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48 | 35 | raise util.Abort(_('number of cpus must be an integer')) |
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49 | 36 | return min(max(countcpus(), 4), 32) |
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50 | 37 | |
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51 | 38 | if os.name == 'posix': |
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52 | 39 | _startupcost = 0.01 |
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53 | 40 | else: |
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54 | 41 | _startupcost = 1e30 |
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55 | 42 | |
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56 | 43 | def worthwhile(ui, costperop, nops): |
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57 | 44 | '''try to determine whether the benefit of multiple processes can |
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58 | 45 | outweigh the cost of starting them''' |
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59 | 46 | linear = costperop * nops |
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60 | 47 | workers = _numworkers(ui) |
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61 | 48 | benefit = linear - (_startupcost * workers + linear / workers) |
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62 | 49 | return benefit >= 0.15 |
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63 | 50 | |
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64 | 51 | def worker(ui, costperarg, func, staticargs, args): |
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65 | 52 | '''run a function, possibly in parallel in multiple worker |
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66 | 53 | processes. |
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67 | 54 | |
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68 | 55 | returns a progress iterator |
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69 | 56 | |
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70 | 57 | costperarg - cost of a single task |
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71 | 58 | |
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72 | 59 | func - function to run |
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73 | 60 | |
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74 | 61 | staticargs - arguments to pass to every invocation of the function |
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75 | 62 | |
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76 | 63 | args - arguments to split into chunks, to pass to individual |
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77 | 64 | workers |
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78 | 65 | ''' |
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79 | 66 | if worthwhile(ui, costperarg, len(args)): |
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80 | 67 | return _platformworker(ui, func, staticargs, args) |
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81 | 68 | return func(*staticargs + (args,)) |
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82 | 69 | |
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83 | 70 | def _posixworker(ui, func, staticargs, args): |
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84 | 71 | rfd, wfd = os.pipe() |
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85 | 72 | workers = _numworkers(ui) |
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86 | 73 | oldhandler = signal.getsignal(signal.SIGINT) |
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87 | 74 | signal.signal(signal.SIGINT, signal.SIG_IGN) |
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88 | 75 | pids, problem = [], [0] |
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89 | 76 | for pargs in partition(args, workers): |
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90 | 77 | pid = os.fork() |
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91 | 78 | if pid == 0: |
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92 | 79 | signal.signal(signal.SIGINT, oldhandler) |
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93 | 80 | try: |
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94 | 81 | os.close(rfd) |
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95 | 82 | for i, item in func(*(staticargs + (pargs,))): |
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96 | 83 | os.write(wfd, '%d %s\n' % (i, item)) |
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97 | 84 | os._exit(0) |
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98 | 85 | except KeyboardInterrupt: |
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99 | 86 | os._exit(255) |
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100 | 87 | # other exceptions are allowed to propagate, we rely |
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101 | 88 | # on lock.py's pid checks to avoid release callbacks |
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102 | 89 | pids.append(pid) |
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103 | 90 | pids.reverse() |
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104 | 91 | os.close(wfd) |
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105 | 92 | fp = os.fdopen(rfd, 'rb', 0) |
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106 | 93 | def killworkers(): |
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107 | 94 | # if one worker bails, there's no good reason to wait for the rest |
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108 | 95 | for p in pids: |
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109 | 96 | try: |
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110 | 97 | os.kill(p, signal.SIGTERM) |
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111 | 98 | except OSError as err: |
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112 | 99 | if err.errno != errno.ESRCH: |
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113 | 100 | raise |
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114 | 101 | def waitforworkers(): |
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115 | 102 | for _pid in pids: |
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116 | 103 | st = _exitstatus(os.wait()[1]) |
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117 | 104 | if st and not problem[0]: |
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118 | 105 | problem[0] = st |
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119 | 106 | killworkers() |
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120 | 107 | t = threading.Thread(target=waitforworkers) |
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121 | 108 | t.start() |
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122 | 109 | def cleanup(): |
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123 | 110 | signal.signal(signal.SIGINT, oldhandler) |
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124 | 111 | t.join() |
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125 | 112 | status = problem[0] |
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126 | 113 | if status: |
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127 | 114 | if status < 0: |
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128 | 115 | os.kill(os.getpid(), -status) |
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129 | 116 | sys.exit(status) |
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130 | 117 | try: |
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131 | 118 | for line in fp: |
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132 | 119 | l = line.split(' ', 1) |
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133 | 120 | yield int(l[0]), l[1][:-1] |
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134 | 121 | except: # re-raises |
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135 | 122 | killworkers() |
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136 | 123 | cleanup() |
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137 | 124 | raise |
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138 | 125 | cleanup() |
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139 | 126 | |
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140 | 127 | def _posixexitstatus(code): |
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141 | 128 | '''convert a posix exit status into the same form returned by |
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142 | 129 | os.spawnv |
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143 | 130 | |
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144 | 131 | returns None if the process was stopped instead of exiting''' |
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145 | 132 | if os.WIFEXITED(code): |
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146 | 133 | return os.WEXITSTATUS(code) |
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147 | 134 | elif os.WIFSIGNALED(code): |
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148 | 135 | return -os.WTERMSIG(code) |
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149 | 136 | |
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150 | 137 | if os.name != 'nt': |
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151 | 138 | _platformworker = _posixworker |
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152 | 139 | _exitstatus = _posixexitstatus |
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153 | 140 | |
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154 | 141 | def partition(lst, nslices): |
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155 | 142 | '''partition a list into N slices of equal size''' |
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156 | 143 | n = len(lst) |
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157 | 144 | chunk, slop = n / nslices, n % nslices |
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158 | 145 | end = 0 |
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159 | 146 | for i in xrange(nslices): |
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160 | 147 | start = end |
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161 | 148 | end = start + chunk |
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162 | 149 | if slop: |
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163 | 150 | end += 1 |
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164 | 151 | slop -= 1 |
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165 | 152 | yield lst[start:end] |
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