KDBG/MachineCPU.impl.hpp

   1 //
   2 //  MachineCPU.impl.hpp
   3 //  KDBG
   4 //
   5 //  Created by James McIlree on 11/7/12.
   6 //  Copyright (c) 2014 Apple. All rights reserved.
   7 //
   8
   9 //
  10 // NOTE! activity match behavior explanation...
  11 //
  12 // CPUActivity entries are contiguous, there are no holes in the timeline.
  13 //
  14 // Note the operator< definitions above, std::lower_bounds is not using the
  15 // default AbsInterval <. The comparsions are against the interval(s) max() - 1.
  16 //
  17 // std::lower_bound returns a match doing <=, std::upper_bound returns a match doing <
  18 //
  19 // 8/26/13...
  20 //
  21 // Okay, based on a better understanding of the behavior of xxx_bounds, this
  22 // should be switchable to std::upper_bounds using a comparator without the
  23 // subtraction, and so slightly more efficient.
  24 //
  25
  26 template <typename SIZE>
  27 const CPUActivity<SIZE>* MachineCPU<SIZE>::activity_for_timestamp(AbsTime timestamp) const {
  28         auto it = std::upper_bound(_timeline.begin(), _timeline.end(), timestamp, AbsIntervalMaxVsAbsTimeComparator());
  29
  30         // The upper bound will report that 0 is lower than [ 10, 20 ), need to check contains!
  31         if (it != _timeline.end() && it->contains(timestamp)) {
  32                 return &*it;
  33         }
  34
  35         return NULL;
  36 }