/* Copyright (c) 2005-2021 Intel Corporation Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ #ifndef __TBB_parallel_for_H #define __TBB_parallel_for_H #include "detail/_config.h" #include "detail/_namespace_injection.h" #include "detail/_exception.h" #include "detail/_task.h" #include "detail/_small_object_pool.h" #include "profiling.h" #include "partitioner.h" #include "blocked_range.h" #include "task_group.h" #include #include namespace tbb { namespace detail { #if __TBB_CPP20_CONCEPTS_PRESENT inline namespace d0 { template concept parallel_for_body = std::copy_constructible && requires( const std::remove_reference_t& body, Range& range ) { body(range); }; template concept parallel_for_index = std::constructible_from && std::copyable && requires( const std::remove_reference_t& lhs, const std::remove_reference_t& rhs ) { { lhs < rhs } -> adaptive_same_as; { lhs - rhs } -> std::convertible_to; { lhs + (rhs - lhs) } -> std::convertible_to; }; template concept parallel_for_function = requires( const std::remove_reference_t& func, Index index ) { func(index); }; } // namespace d0 #endif // __TBB_CPP20_CONCEPTS_PRESENT namespace d1 { //! Task type used in parallel_for /** @ingroup algorithms */ template struct start_for : public task { Range my_range; const Body my_body; node* my_parent; typename Partitioner::task_partition_type my_partition; small_object_allocator my_allocator; task* execute(execution_data&) override; task* cancel(execution_data&) override; void finalize(const execution_data&); //! Constructor for root task. start_for( const Range& range, const Body& body, Partitioner& partitioner, small_object_allocator& alloc ) : my_range(range), my_body(body), my_partition(partitioner), my_allocator(alloc) {} //! Splitting constructor used to generate children. /** parent_ becomes left child. Newly constructed object is right child. */ start_for( start_for& parent_, typename Partitioner::split_type& split_obj, small_object_allocator& alloc ) : my_range(parent_.my_range, get_range_split_object(split_obj)), my_body(parent_.my_body), my_partition(parent_.my_partition, split_obj), my_allocator(alloc) {} //! Construct right child from the given range as response to the demand. /** parent_ remains left child. Newly constructed object is right child. */ start_for( start_for& parent_, const Range& r, depth_t d, small_object_allocator& alloc ) : my_range(r), my_body(parent_.my_body), my_partition(parent_.my_partition, split()), my_allocator(alloc) { my_partition.align_depth( d ); } static void run(const Range& range, const Body& body, Partitioner& partitioner) { task_group_context context(PARALLEL_FOR); run(range, body, partitioner, context); } static void run(const Range& range, const Body& body, Partitioner& partitioner, task_group_context& context) { if ( !range.empty() ) { small_object_allocator alloc{}; start_for& for_task = *alloc.new_object(range, body, partitioner, alloc); // defer creation of the wait node until task allocation succeeds wait_node wn; for_task.my_parent = &wn; execute_and_wait(for_task, context, wn.m_wait, context); } } //! Run body for range, serves as callback for partitioner void run_body( Range &r ) { my_body( r ); } //! spawn right task, serves as callback for partitioner void offer_work(typename Partitioner::split_type& split_obj, execution_data& ed) { offer_work_impl(ed, *this, split_obj); } //! spawn right task, serves as callback for partitioner void offer_work(const Range& r, depth_t d, execution_data& ed) { offer_work_impl(ed, *this, r, d); } private: template void offer_work_impl(execution_data& ed, Args&&... constructor_args) { // New right child small_object_allocator alloc{}; start_for& right_child = *alloc.new_object(ed, std::forward(constructor_args)..., alloc); // New root node as a continuation and ref count. Left and right child attach to the new parent. right_child.my_parent = my_parent = alloc.new_object(ed, my_parent, 2, alloc); // Spawn the right sibling right_child.spawn_self(ed); } void spawn_self(execution_data& ed) { my_partition.spawn_task(*this, *context(ed)); } }; //! fold the tree and deallocate the task template void start_for::finalize(const execution_data& ed) { // Get the current parent and allocator an object destruction node* parent = my_parent; auto allocator = my_allocator; // Task execution finished - destroy it this->~start_for(); // Unwind the tree decrementing the parent`s reference count fold_tree(parent, ed); allocator.deallocate(this, ed); } //! execute task for parallel_for template task* start_for::execute(execution_data& ed) { if (!is_same_affinity(ed)) { my_partition.note_affinity(execution_slot(ed)); } my_partition.check_being_stolen(*this, ed); my_partition.execute(*this, my_range, ed); finalize(ed); return nullptr; } //! cancel task for parallel_for template task* start_for::cancel(execution_data& ed) { finalize(ed); return nullptr; } //! Calls the function with values from range [begin, end) with a step provided template class parallel_for_body_wrapper : detail::no_assign { const Function &my_func; const Index my_begin; const Index my_step; public: parallel_for_body_wrapper( const Function& _func, Index& _begin, Index& _step ) : my_func(_func), my_begin(_begin), my_step(_step) {} void operator()( const blocked_range& r ) const { // A set of local variables to help the compiler with vectorization of the following loop. Index b = r.begin(); Index e = r.end(); Index ms = my_step; Index k = my_begin + b*ms; #if __INTEL_COMPILER #pragma ivdep #if __TBB_ASSERT_ON_VECTORIZATION_FAILURE #pragma vector always assert #endif #endif for ( Index i = b; i < e; ++i, k += ms ) { my_func( k ); } } }; // Requirements on Range concept are documented in blocked_range.h /** \page parallel_for_body_req Requirements on parallel_for body Class \c Body implementing the concept of parallel_for body must define: - \code Body::Body( const Body& ); \endcode Copy constructor - \code Body::~Body(); \endcode Destructor - \code void Body::operator()( Range& r ) const; \endcode Function call operator applying the body to range \c r. **/ /** \name parallel_for See also requirements on \ref range_req "Range" and \ref parallel_for_body_req "parallel_for Body". **/ //@{ //! Parallel iteration over range with default partitioner. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body ) { start_for::run(range,body,__TBB_DEFAULT_PARTITIONER()); } //! Parallel iteration over range with simple partitioner. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, const simple_partitioner& partitioner ) { start_for::run(range,body,partitioner); } //! Parallel iteration over range with auto_partitioner. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, const auto_partitioner& partitioner ) { start_for::run(range,body,partitioner); } //! Parallel iteration over range with static_partitioner. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, const static_partitioner& partitioner ) { start_for::run(range,body,partitioner); } //! Parallel iteration over range with affinity_partitioner. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, affinity_partitioner& partitioner ) { start_for::run(range,body,partitioner); } //! Parallel iteration over range with default partitioner and user-supplied context. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, task_group_context& context ) { start_for::run(range, body, __TBB_DEFAULT_PARTITIONER(), context); } //! Parallel iteration over range with simple partitioner and user-supplied context. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, const simple_partitioner& partitioner, task_group_context& context ) { start_for::run(range, body, partitioner, context); } //! Parallel iteration over range with auto_partitioner and user-supplied context. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, const auto_partitioner& partitioner, task_group_context& context ) { start_for::run(range, body, partitioner, context); } //! Parallel iteration over range with static_partitioner and user-supplied context. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, const static_partitioner& partitioner, task_group_context& context ) { start_for::run(range, body, partitioner, context); } //! Parallel iteration over range with affinity_partitioner and user-supplied context. /** @ingroup algorithms **/ template __TBB_requires(tbb_range && parallel_for_body) void parallel_for( const Range& range, const Body& body, affinity_partitioner& partitioner, task_group_context& context ) { start_for::run(range,body,partitioner, context); } //! Implementation of parallel iteration over stepped range of integers with explicit step and partitioner template void parallel_for_impl(Index first, Index last, Index step, const Function& f, Partitioner& partitioner) { if (step <= 0 ) throw_exception(exception_id::nonpositive_step); // throws std::invalid_argument else if (first < last) { // Above "else" avoids "potential divide by zero" warning on some platforms Index end = (last - first - Index(1)) / step + Index(1); blocked_range range(static_cast(0), end); parallel_for_body_wrapper body(f, first, step); parallel_for(range, body, partitioner); } } //! Parallel iteration over a range of integers with a step provided and default partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f) { parallel_for_impl(first, last, step, f, auto_partitioner()); } //! Parallel iteration over a range of integers with a step provided and simple partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, const simple_partitioner& partitioner) { parallel_for_impl(first, last, step, f, partitioner); } //! Parallel iteration over a range of integers with a step provided and auto partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, const auto_partitioner& partitioner) { parallel_for_impl(first, last, step, f, partitioner); } //! Parallel iteration over a range of integers with a step provided and static partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, const static_partitioner& partitioner) { parallel_for_impl(first, last, step, f, partitioner); } //! Parallel iteration over a range of integers with a step provided and affinity partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, affinity_partitioner& partitioner) { parallel_for_impl(first, last, step, f, partitioner); } //! Parallel iteration over a range of integers with a default step value and default partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f) { parallel_for_impl(first, last, static_cast(1), f, auto_partitioner()); } //! Parallel iteration over a range of integers with a default step value and simple partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, const simple_partitioner& partitioner) { parallel_for_impl(first, last, static_cast(1), f, partitioner); } //! Parallel iteration over a range of integers with a default step value and auto partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, const auto_partitioner& partitioner) { parallel_for_impl(first, last, static_cast(1), f, partitioner); } //! Parallel iteration over a range of integers with a default step value and static partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, const static_partitioner& partitioner) { parallel_for_impl(first, last, static_cast(1), f, partitioner); } //! Parallel iteration over a range of integers with a default step value and affinity partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, affinity_partitioner& partitioner) { parallel_for_impl(first, last, static_cast(1), f, partitioner); } //! Implementation of parallel iteration over stepped range of integers with explicit step, task group context, and partitioner template void parallel_for_impl(Index first, Index last, Index step, const Function& f, Partitioner& partitioner, task_group_context &context) { if (step <= 0 ) throw_exception(exception_id::nonpositive_step); // throws std::invalid_argument else if (first < last) { // Above "else" avoids "potential divide by zero" warning on some platforms Index end = (last - first - Index(1)) / step + Index(1); blocked_range range(static_cast(0), end); parallel_for_body_wrapper body(f, first, step); parallel_for(range, body, partitioner, context); } } //! Parallel iteration over a range of integers with explicit step, task group context, and default partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, task_group_context &context) { parallel_for_impl(first, last, step, f, auto_partitioner(), context); } //! Parallel iteration over a range of integers with explicit step, task group context, and simple partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, const simple_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, step, f, partitioner, context); } //! Parallel iteration over a range of integers with explicit step, task group context, and auto partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, const auto_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, step, f, partitioner, context); } //! Parallel iteration over a range of integers with explicit step, task group context, and static partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, const static_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, step, f, partitioner, context); } //! Parallel iteration over a range of integers with explicit step, task group context, and affinity partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, Index step, const Function& f, affinity_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, step, f, partitioner, context); } //! Parallel iteration over a range of integers with a default step value, explicit task group context, and default partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, task_group_context &context) { parallel_for_impl(first, last, static_cast(1), f, auto_partitioner(), context); } //! Parallel iteration over a range of integers with a default step value, explicit task group context, and simple partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, const simple_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, static_cast(1), f, partitioner, context); } //! Parallel iteration over a range of integers with a default step value, explicit task group context, and auto partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, const auto_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, static_cast(1), f, partitioner, context); } //! Parallel iteration over a range of integers with a default step value, explicit task group context, and static partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, const static_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, static_cast(1), f, partitioner, context); } //! Parallel iteration over a range of integers with a default step value, explicit task group context, and affinity_partitioner template __TBB_requires(parallel_for_index && parallel_for_function) void parallel_for(Index first, Index last, const Function& f, affinity_partitioner& partitioner, task_group_context &context) { parallel_for_impl(first, last, static_cast(1), f, partitioner, context); } // @} } // namespace d1 } // namespace detail inline namespace v1 { using detail::d1::parallel_for; // Split types using detail::split; using detail::proportional_split; } // namespace v1 } // namespace tbb #endif /* __TBB_parallel_for_H */