algorithms_cpp: using block size partitioner in Reduce and Count

algorithms_cpp/include/embb/algorithms/internal/count-inl.h

@@ -37,42 +37,47 @@ namespace internal {
 template<typename ValueType>
 class ValueComparisonFunction{
  public:
-  explicit ValueComparisonFunction(const ValueType &value)
-  :value_(value) {}
-  ValueComparisonFunction(const ValueComparisonFunction &other)
-  :value_(other.value_) {}
+  explicit ValueComparisonFunction(const ValueType& value)
+  : value_(value) {}
+  ValueComparisonFunction(const ValueComparisonFunction& other)
+  : value_(other.value_) {}
 
   template<typename ElementType>
   int operator()(ElementType element) {
-    if(element == value_)
+    if (element == value_) {
       return 1;
-    else
+    }
+    else {
       return 0;
     }
+  }
  private:
   const ValueType &value_;
-  ValueComparisonFunction &operator=(const ValueComparisonFunction &other);
+  ValueComparisonFunction &operator=(
+    const ValueComparisonFunction& other);
 };
 
 template<typename Function>
 class FunctionComparisonFunction{
  public:
   explicit FunctionComparisonFunction(Function function)
-  :function_(function) {}
+  : function_(function) {}
   FunctionComparisonFunction(const FunctionComparisonFunction &other)
-  :function_(other.function_) {}
+  : function_(other.function_) {}
 
   template<typename ElementType>
   int operator()(ElementType element) {
-    if(function_(element))
+    if (function_(element)) {
       return 1;
-    else
+    }
+    else {
       return 0;
     }
+  }
  private:
   Function function_;
-  FunctionComparisonFunction &operator=(const FunctionComparisonFunction &
-      other);
+  FunctionComparisonFunction &operator=(
+    const FunctionComparisonFunction& other);
 };
 
 }  // namespace internal

algorithms_cpp/include/embb/algorithms/internal/for_each-inl.h

@@ -77,15 +77,15 @@ class ForEachFunctor {
       mtapi::Task task_l = mtapi::Node::GetInstance().Spawn(
         mtapi::Action(
           base::MakeFunction(
-          functor_l, &ForEachFunctor<RAI, Function>::Action), 
+          functor_l, &self_t::Action),
           policy_));
       mtapi::Task task_r = mtapi::Node::GetInstance().Spawn(
         mtapi::Action(
           base::MakeFunction(
-          functor_r, &ForEachFunctor<RAI, Function>::Action), 
+          functor_r, &self_t::Action),
           policy_));
-      task_r.Wait(MTAPI_INFINITE);
       task_l.Wait(MTAPI_INFINITE);
+      task_r.Wait(MTAPI_INFINITE);
     }
   }
 
@@ -118,7 +118,6 @@ void ForEachRecursive(RAI first, RAI last, Function unary,
       block_size = 1;
     }
   }
-
   // Perform check of task number sufficiency
   if (((distance / block_size) * 2) + 1 > MTAPI_NODE_MAX_TASKS_DEFAULT) {
     EMBB_THROW(embb::base::ErrorException, "Not enough MTAPI tasks available "

algorithms_cpp/include/embb/algorithms/internal/reduce-inl.h

@@ -41,64 +41,75 @@ namespace internal {
 template<typename RAI, typename ReturnType, typename ReductionFunction,
          typename TransformationFunction>
 class ReduceFunctor {
+ private:
+  typedef ReduceFunctor<RAI, ReturnType, 
+                        ReductionFunction, 
+                        TransformationFunction> self_t;
  public:
-  ReduceFunctor(RAI first, RAI last, ReturnType neutral,
+  ReduceFunctor(size_t chunk_first, size_t chunk_last,
+                ReturnType neutral,
                 ReductionFunction reduction,
                 TransformationFunction transformation,
-                const embb::mtapi::ExecutionPolicy &policy, size_t block_size,
+                const embb::mtapi::ExecutionPolicy& policy,
+                const BlockSizePartitioner<RAI>& partitioner,
                 ReturnType& result)
-  :
-      first_(first), last_(last), neutral_(neutral), reduction_(reduction),
-      transformation_(transformation), policy_(policy),
-      block_size_(block_size), result_(result) {
+  : chunk_first_(chunk_first), chunk_last_(chunk_last), neutral_(neutral), 
+    reduction_(reduction), transformation_(transformation), policy_(policy),
+    partitioner_(partitioner), result_(result) {
   }
 
-  void Action(mtapi::TaskContext& context) {
-    if (first_ == last_) {
-      return;
-    }
-    size_t distance = static_cast<size_t>(std::distance(first_, last_));
-    if (distance <= block_size_) {  // leaf case -> do work
+  void Action(mtapi::TaskContext&) {
+    if (chunk_first_ == chunk_last_) {
+      // Leaf case, recursed to single chunk. Do work on chunk:
+      ChunkDescriptor<RAI> chunk = partitioner_[chunk_first_];
+      RAI first = chunk.GetFirst();
+      RAI last  = chunk.GetLast();
       ReturnType result(neutral_);
-      for (RAI iter = first_; iter != last_; ++iter) {
-        result = reduction_(result, transformation_(*iter));
+      for (RAI it = first; it != last; ++it) {
+        result = reduction_(result, transformation_(*it));
       }
       result_ = result;
-    } else {  // recurse further
-      internal::ChunkPartitioner<RAI> partitioner(first_, last_, 2);
-      ChunkDescriptor<RAI> chunk_l = partitioner[0];
-      ChunkDescriptor<RAI> chunk_r = partitioner[1];
+    }
+    else {
+      // Recurse further:
+      size_t chunk_split_index = (chunk_first_ + chunk_last_) / 2;
+      // Split chunks into left / right branches:
       ReturnType result_l(neutral_);
       ReturnType result_r(neutral_);
-      ReduceFunctor functor_l(chunk_l.GetFirst(),
-                              chunk_l.GetLast(),
+      self_t functor_l(chunk_first_,
+                       chunk_split_index,
                        neutral_, reduction_, transformation_, policy_,
-                              block_size_, result_l);
-      ReduceFunctor functor_r(chunk_r.GetFirst(),
-                              chunk_r.GetLast(),
+                       partitioner_,
+                       result_l);
+      self_t functor_r(chunk_split_index + 1,
+                       chunk_last_,
                        neutral_, reduction_, transformation_, policy_,
-                              block_size_, result_r);
-      // Spawn tasks for right partition first:
+                       partitioner_,
+                       result_r);
+      mtapi::Task task_l = mtapi::Node::GetInstance().Spawn(
+        mtapi::Action(
+          base::MakeFunction(
+          functor_l, &self_t::Action),
+          policy_));
       mtapi::Task task_r = mtapi::Node::GetInstance().Spawn(
-        mtapi::Action(base::MakeFunction(
-          functor_r, &ReduceFunctor::Action), 
+        mtapi::Action(
+          base::MakeFunction(
+          functor_r, &self_t::Action), 
           policy_));
-      // Recurse on left partition:
-      functor_l.Action(context);
-      // Wait for tasks on right partition to complete:
+      task_l.Wait(MTAPI_INFINITE);
       task_r.Wait(MTAPI_INFINITE);
       result_ = reduction_(result_l, result_r);
     }
   }
 
  private:
-  RAI first_;
-  RAI last_;
+  size_t chunk_first_;
+  size_t chunk_last_;
   ReturnType neutral_;
   ReductionFunction reduction_;
   TransformationFunction transformation_;
   const embb::mtapi::ExecutionPolicy& policy_;
-  size_t block_size_;
+  const BlockSizePartitioner<RAI>& partitioner_;
   ReturnType& result_;
 
   /**
@@ -120,25 +131,34 @@ ReturnType ReduceRecursive(RAI first, RAI last, ReturnType neutral,
   if (distance == 0) {
     EMBB_THROW(embb::base::ErrorException, "Distance for Reduce is 0");
   }
-  // Determine actually used block size
   mtapi::Node& node = mtapi::Node::GetInstance();
-  size_t used_block_size = block_size;
-  if (used_block_size == 0) {
-      used_block_size = static_cast<size_t>(distance) / node.GetCoreCount();
-      if (used_block_size == 0) used_block_size = 1;
+  // Determine actually used block size
+  if (block_size == 0) {
+    block_size = (static_cast<size_t>(distance) / node.GetCoreCount());
+    if (block_size == 0) {
+      block_size = 1;
+    }
   }
   // Perform check of task number sufficiency
-  if (((distance / used_block_size) * 2) + 1 > MTAPI_NODE_MAX_TASKS_DEFAULT) {
+  if (((distance / block_size) * 2) + 1 > MTAPI_NODE_MAX_TASKS_DEFAULT) {
     EMBB_THROW(embb::base::ErrorException,
                "Number of computation tasks required in reduction would "
                "exceed MTAPI maximum number of tasks");
   }
-  ReturnType result = neutral;
+  
   typedef ReduceFunctor<RAI, ReturnType, ReductionFunction,
                         TransformationFunction> Functor;
-  Functor functor(first, last, neutral, reduction, transformation, policy,
-                  used_block_size, result);
-  mtapi::Task task = node.Spawn(mtapi::Action(base::MakeFunction(
+  BlockSizePartitioner<RAI> partitioner(first, last, block_size);
+  ReturnType result = neutral;
+  Functor functor(0,
+                  partitioner.Size() - 1,
+                  neutral, 
+                  reduction, transformation, 
+                  policy,
+                  partitioner, 
+                  result);
+  mtapi::Task task = node.Spawn(
+    mtapi::Action(base::MakeFunction(
       functor, &Functor::Action), policy));
   task.Wait(MTAPI_INFINITE);
   return result;