junction/striped/ConditionBank.h

   1 /*------------------------------------------------------------------------
   2   Junction: Concurrent data structures in C++
   3   Copyright (c) 2016 Jeff Preshing
   4
   5   Distributed under the Simplified BSD License.
   6   Original location: https://github.com/preshing/junction
   7
   8   This software is distributed WITHOUT ANY WARRANTY; without even the
   9   implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  10   See the LICENSE file for more information.
  11 ------------------------------------------------------------------------*/
  12
  13 #ifndef JUNCTION_STRIPED_CONDITIONBANK_H
  14 #define JUNCTION_STRIPED_CONDITIONBANK_H
  15
  16 #include <junction/Core.h>
  17 #include <junction/striped/ConditionPair.h>
  18
  19 #if JUNCTION_USE_STRIPING
  20
  21 //-----------------------------------
  22 // Striping enabled
  23 //-----------------------------------
  24 #include <turf/impl/Mutex_SpinLock.h>
  25 #include <turf/Util.h>
  26
  27 namespace junction {
  28 namespace striped {
  29
  30 class ConditionBank {
  31 private:
  32     static const ureg SizeMask = 1023;
  33     turf::Mutex_SpinLock m_initSpinLock;
  34     turf::Atomic<ConditionPair*> m_pairs;
  35
  36     ConditionPair* initialize();
  37
  38 public:
  39     ConditionPair& get(void* ptr) {
  40         ConditionPair* pairs = m_pairs.load(turf::Consume);
  41         if (!pairs) {
  42             pairs = initialize();
  43         }
  44         ureg index = turf::util::avalanche(uptr(ptr)) & SizeMask;
  45         return pairs[index];
  46     }
  47 };
  48
  49 extern ConditionBank DefaultConditionBank;
  50
  51 } // namespace striped
  52 } // namespace junction
  53
  54 #define JUNCTION_STRIPED_CONDITIONBANK_DEFINE_MEMBER()
  55 #define JUNCTION_STRIPED_CONDITIONBANK_GET(objectPtr) (junction::striped::DefaultConditionBank.get(objectPtr))
  56
  57 #else // JUNCTION_USE_STRIPING
  58
  59 //-----------------------------------
  60 // Striping disabled
  61 //-----------------------------------
  62 #define JUNCTION_STRIPED_CONDITIONBANK_DEFINE_MEMBER() junction::striped::ConditionPair m_conditionPair;
  63 #define JUNCTION_STRIPED_CONDITIONBANK_GET(objectPtr) ((objectPtr)->m_conditionPair)
  64
  65 #endif // JUNCTION_USE_STRIPING
  66
  67 #endif // JUNCTION_STRIPED_CONDITIONBANK_H