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Diffstat (limited to 'timings/JTimer/TimeSCons-run.py')
-rw-r--r-- | timings/JTimer/TimeSCons-run.py | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/timings/JTimer/TimeSCons-run.py b/timings/JTimer/TimeSCons-run.py new file mode 100644 index 000000000..36b016f1b --- /dev/null +++ b/timings/JTimer/TimeSCons-run.py @@ -0,0 +1,43 @@ +# +# __COPYRIGHT__ +# +# Permission is hereby granted, free of charge, to any person obtaining +# a copy of this software and associated documentation files (the +# "Software"), to deal in the Software without restriction, including +# without limitation the rights to use, copy, modify, merge, publish, +# distribute, sublicense, and/or sell copies of the Software, and to +# permit persons to whom the Software is furnished to do so, subject to +# the following conditions: +# +# The above copyright notice and this permission notice shall be included +# in all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY +# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE +# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +# + +""" +This configuration is for timing how we evaluate long chains of +dependencies, specifically when -j is used. + +We set up a chain of 500 targets that get built from a Python function +action with no source files (equivalent to "echo junk > $TARGET"). +Each target explicitly depends on the next target in turn, so the +Taskmaster will do a deep walk of the dependency graph. + +This test case was contributed by Kevin Massey. Prior to revision 1468, +we had a serious O(N^2) problem in the Taskmaster when handling long +dependency chains like this. That was fixed by adding reference counts +to the Taskmaster so it could be smarter about not re-evaluating Nodes. +""" + +import TestSCons + +target_count = 500 + +TestSCons.TimeSCons().main(options='TARGET_COUNT=%d' % target_count) |