Commit Graph

4 Commits

Author SHA1 Message Date
Daniel J. Hofmann
9231335eef Use Intel TBB's parallel_sort even for nested parallelism.
TBB has a global task scheduler (that's one of the reason TBB is not
linked statically but dyanmically instead). This allows control over all
running threads, enabling us to use nested parallelism and the scheduler
doing all the task allocation itself.

That is, nested parallel execution such as in

    parallel_for(seq, [](const auto& rng){
      parallel_sort(rng);
    });

is no problem at all, as the scheduler still claims control over the
global environment.

Therefore, use `parallel_sort` Range overload where possible.

References:

- https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/algorithms.htm
- https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/algorithms/parallel_sort_func.htm
- https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/task_scheduler.htm
- https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/task_scheduler/task_scheduler_init_cls.htm
- https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#tbb_userguide/Initializing_and_Terminating_the_Library.htm
2015-09-28 20:26:03 +02:00
Patrick Niklaus
48d1a5ec5d Make sure to terminate when the core heaps are empty 2015-08-19 12:27:44 +02:00
Patrick Niklaus
7cc875b8db Initial version of core based search 2015-08-19 12:27:44 +02:00
MoKob
b526cadebd Initial version of core ch
This improves preprocessing times in favour of worse query performance.
Core size can be set over the --core parameater, default is the old
behaviour to fully contract the graph.
2015-08-01 18:00:48 +02:00