TiledArray::detail::ReducePairTask< opT > Class Template Reference
Inheritance diagram for TiledArray::detail::ReducePairTask< opT >:
Collaboration diagram for TiledArray::detail::ReducePairTask< opT >:
Documentation
template<typename opT>
class TiledArray::detail::ReducePairTask< opT >
Reduce pair task.
This task will reduce an arbitrary number of pairs of objects. This task is optimized for reduction of data that is the result of other tasks or remote data. Also, it is assumed that individual reduction operations require a substantial amount of work (i.e. your reduction operation should reduce a vector of data, not two numbers). The reduction arguments are reduced as they become ready, which results in non- deterministic reduction order. This is much faster than a simple binary tree reduction since the reduction tasks do not have to wait for specific pairs of data. Though data that is not stored in a future can be used, it may not be the best choice in that case.
The reduction operation must have the following form:
struct ReductionOp {
// typedefs
typedef ... result_type;
typedef ... first_argument_type;
typedef ... second_argument_type;
// Constructors
ReductionOp();
ReductionOp(const ReductionOp&);
ReductionOp& operator=(const ReductionOp&);
// Reduction functions
// Make an empty result object
result_type operator()() const;
// Post process the result
const result_type& operator()(const result_type&) const;
// Reduce two result objects
void operator()(result_type&, const result_type&) const;
// Reduce an argument pair
void operator()(result_type&, const first_argument_type&,
const second_argument_type&) const;
}; // struct ReductionOp
For example, a dot product function might look like:
struct DotProduct {
// typedefs
typedef double result_type;
typedef std::vector<double> first_argument_type;
tyepdef std::vector<double> second_argument_type;
// Compiler generated constructors or assignment operator OK here
// Reduction functions
// Make an empty result object
result_type operator()() const { return 0; }
// Post process the result (no operation, passthrough)
const result_type& operator()(const result_type& result) const {
return result;
}
void operator()(result_type& result, const result_type& arg) const {
result += arg;
}
void operator()(result_type& result,
const first_argument_type& first, const second_argument_type&
second) const
{
assert(first.size() == second.size());
for(std::size_t i = 0ul; i < first.size(); ++i)
result += first[i] * second[i];
}
}; // struct DotProduct
- Note
- There is no need to add this object to the MADNESS task queue. It will be handled internally by the object. Simply call
submit()to add this task to the task queue.
- Template Parameters
-
opT The reduction operation type
Definition at line 910 of file reduce_task.h.
Public Member Functions | |
| ReducePairTask () | |
| Default constructor. More... | |
| ReducePairTask (World &world, const opT &op=opT(), madness::CallbackInterface *callback=nullptr) | |
| Constructor. More... | |
| ReducePairTask (ReducePairTask< opT > &&other) noexcept | |
| Move constructor. More... | |
| ReducePairTask< opT > & | operator= (ReducePairTask< opT > &&other) noexcept |
| Move assignment operator. More... | |
| ReducePairTask (const ReducePairTask< opT > &)=delete | |
| Non-copyable. More... | |
| ReducePairTask< opT > | operator= (const ReducePairTask< opT > &)=delete |
| template<typename L , typename R > | |
| void | add (const L &left, const R &right, madness::CallbackInterface *callback=nullptr) |
| Add a pair of arguments to the reduction task. More... | |
 Public Member Functions inherited from TiledArray::detail::ReduceTask< ReducePairOpWrapper< opT > > | |
| ReduceTask () | |
| Default constructor. More... | |
| ReduceTask (World &world, const ReducePairOpWrapper< opT > &op=ReducePairOpWrapper< opT >(), madness::CallbackInterface *callback=nullptr) | |
| Constructor. More... | |
| ReduceTask (ReduceTask< ReducePairOpWrapper< opT > > &&other) noexcept | |
| Move constructor. More... | |
| ReduceTask (const ReduceTask< ReducePairOpWrapper< opT > > &)=delete | |
| ~ReduceTask () | |
| Destructor. More... | |
| ReduceTask< ReducePairOpWrapper< opT > > & | operator= (ReduceTask< ReducePairOpWrapper< opT > > &&other) noexcept |
| Move assignment operator. More... | |
| ReduceTask< ReducePairOpWrapper< opT > > & | operator= (const ReduceTask< ReducePairOpWrapper< opT > > &)=delete |
| int | add (const Arg &arg, madness::CallbackInterface *callback=nullptr) |
| Add an argument to the reduction task. More... | |
| int | count () const |
| Argument count. More... | |
| Future< result_type > | submit () |
| Submit the reduction task to the task queue. More... | |
| operator bool () const | |
| Type conversion operator. More... | |
Constructor & Destructor Documentation
◆ ReducePairTask() [1/4]
template<typename opT >
|
inline |
Default constructor.
Definition at line 923 of file reduce_task.h.
◆ ReducePairTask() [2/4]
template<typename opT >
|
inline |
Constructor.
- Parameters
-
world The world that owns this task op The pair reduction operation [ default = opT() ] callback The callback that will be invoked when this task is complete
Definition at line 931 of file reduce_task.h.
◆ ReducePairTask() [3/4]
template<typename opT >
|
inlinenoexcept |
Move constructor.
- Parameters
-
other The object to be moved
Definition at line 938 of file reduce_task.h.
◆ ReducePairTask() [4/4]
template<typename opT >
|
delete |
Non-copyable.
Member Function Documentation
◆ add()
template<typename opT >
template<typename L , typename R >
|
inline |
Add a pair of arguments to the reduction task.
left and right may be of the argument types of opT, a Future to the argument types, RemoteReference<FutureImpl> to the argument types, or any combination of the above.
- Template Parameters
-
L The left-hand object type R The right-hand object type
- Parameters
-
left The left-hand argument that will be reduced right The right-hand argument that will be reduced callback The callback that will be invoked when this argument pair has been reduced [ default = nullptr ]
Definition at line 966 of file reduce_task.h.
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◆ operator=() [1/2]
template<typename opT >
|
delete |
◆ operator=() [2/2]
template<typename opT >
|
inlinenoexcept |
Move assignment operator.
- Parameters
-
other The object to be moved
Definition at line 944 of file reduce_task.h.
The documentation for this class was generated from the following file:
- TiledArray/reduce_task.h
ReducePairTask< opT > & operator=(ReducePairTask< opT > &&other) noexcept
Move assignment operator.
Definition: reduce_task.h:944
