/* Copyright (c) 2005-2017 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_do_H #define __TBB_parallel_do_H #include "internal/_range_iterator.h" #include "internal/_template_helpers.h" #include "task.h" #include "aligned_space.h" #include namespace tbb { namespace interface9 { //! @cond INTERNAL namespace internal { template class parallel_do_feeder_impl; } // namespace internal //! @endcond //! Class the user supplied algorithm body uses to add new tasks /** \param Item Work item type **/ template class parallel_do_feeder: ::tbb::internal::no_copy { parallel_do_feeder() {} virtual ~parallel_do_feeder () {} virtual void internal_add_copy( const Item& item ) = 0; #if __TBB_CPP11_RVALUE_REF_PRESENT virtual void internal_add_move( Item&& item ) = 0; #endif template friend class internal::parallel_do_feeder_impl; public: //! Add a work item to a running parallel_do. void add( const Item& item ) {internal_add_copy(item);} #if __TBB_CPP11_RVALUE_REF_PRESENT void add( Item&& item ) {internal_add_move(std::move(item));} #endif }; //! @cond INTERNAL namespace internal { template class do_group_task; //! For internal use only. /** Selects one of the two possible forms of function call member operator. @ingroup algorithms **/ template class parallel_do_operator_selector { typedef parallel_do_feeder Feeder; template static void internal_call( const Body& obj, __TBB_FORWARDING_REF(A1) arg1, A2&, void (Body::*)(CvItem) const ) { obj(tbb::internal::forward(arg1)); } template static void internal_call( const Body& obj, __TBB_FORWARDING_REF(A1) arg1, A2& arg2, void (Body::*)(CvItem, parallel_do_feeder&) const ) { obj(tbb::internal::forward(arg1), arg2); } template static void internal_call( const Body& obj, __TBB_FORWARDING_REF(A1) arg1, A2&, void (Body::*)(CvItem&) const ) { obj(arg1); } template static void internal_call( const Body& obj, __TBB_FORWARDING_REF(A1) arg1, A2& arg2, void (Body::*)(CvItem&, parallel_do_feeder&) const ) { obj(arg1, arg2); } public: template static void call( const Body& obj, __TBB_FORWARDING_REF(A1) arg1, A2& arg2 ) { internal_call( obj, tbb::internal::forward(arg1), arg2, &Body::operator() ); } }; //! For internal use only. /** Executes one iteration of a do. @ingroup algorithms */ template class do_iteration_task: public task { typedef parallel_do_feeder_impl feeder_type; Item my_value; feeder_type& my_feeder; do_iteration_task( const Item& value, feeder_type& feeder ) : my_value(value), my_feeder(feeder) {} #if __TBB_CPP11_RVALUE_REF_PRESENT do_iteration_task( Item&& value, feeder_type& feeder ) : my_value(std::move(value)), my_feeder(feeder) {} #endif task* execute() __TBB_override { parallel_do_operator_selector::call(*my_feeder.my_body, tbb::internal::move(my_value), my_feeder); return NULL; } template friend class parallel_do_feeder_impl; }; // class do_iteration_task template class do_iteration_task_iter: public task { typedef parallel_do_feeder_impl feeder_type; Iterator my_iter; feeder_type& my_feeder; do_iteration_task_iter( const Iterator& iter, feeder_type& feeder ) : my_iter(iter), my_feeder(feeder) {} task* execute() __TBB_override { parallel_do_operator_selector::call(*my_feeder.my_body, *my_iter, my_feeder); return NULL; } template friend class do_group_task_forward; template friend class do_group_task_input; template friend class do_task_iter; }; // class do_iteration_task_iter //! For internal use only. /** Implements new task adding procedure. @ingroup algorithms **/ template class parallel_do_feeder_impl : public parallel_do_feeder { #if __TBB_CPP11_RVALUE_REF_PRESENT //Avoiding use of copy constructor in a virtual method if the type does not support it void internal_add_copy_impl(std::true_type, const Item& item) { typedef do_iteration_task iteration_type; iteration_type& t = *new (task::allocate_additional_child_of(*my_barrier)) iteration_type(item, *this); task::spawn(t); } void internal_add_copy_impl(std::false_type, const Item&) { __TBB_ASSERT(false, "Overloading for r-value reference doesn't work or it's not movable and not copyable object"); } void internal_add_copy( const Item& item ) __TBB_override { #if __TBB_CPP11_IS_COPY_CONSTRUCTIBLE_PRESENT internal_add_copy_impl(typename std::is_copy_constructible::type(), item); #else internal_add_copy_impl(std::true_type(), item); #endif } void internal_add_move( Item&& item ) __TBB_override { typedef do_iteration_task iteration_type; iteration_type& t = *new (task::allocate_additional_child_of(*my_barrier)) iteration_type(std::move(item), *this); task::spawn(t); } #else /* ! __TBB_CPP11_RVALUE_REF_PRESENT */ void internal_add_copy(const Item& item) __TBB_override { typedef do_iteration_task iteration_type; iteration_type& t = *new (task::allocate_additional_child_of(*my_barrier)) iteration_type(item, *this); task::spawn(t); } #endif /* __TBB_CPP11_RVALUE_REF_PRESENT */ public: const Body* my_body; empty_task* my_barrier; parallel_do_feeder_impl() { my_barrier = new( task::allocate_root() ) empty_task(); __TBB_ASSERT(my_barrier, "root task allocation failed"); } #if __TBB_TASK_GROUP_CONTEXT parallel_do_feeder_impl(tbb::task_group_context &context) { my_barrier = new( task::allocate_root(context) ) empty_task(); __TBB_ASSERT(my_barrier, "root task allocation failed"); } #endif ~parallel_do_feeder_impl() { my_barrier->destroy(*my_barrier); } }; // class parallel_do_feeder_impl //! For internal use only /** Unpacks a block of iterations. @ingroup algorithms */ template class do_group_task_forward: public task { static const size_t max_arg_size = 4; typedef parallel_do_feeder_impl feeder_type; feeder_type& my_feeder; Iterator my_first; size_t my_size; do_group_task_forward( Iterator first, size_t size, feeder_type& feeder ) : my_feeder(feeder), my_first(first), my_size(size) {} task* execute() __TBB_override { typedef do_iteration_task_iter iteration_type; __TBB_ASSERT( my_size>0, NULL ); task_list list; task* t; size_t k=0; for(;;) { t = new( allocate_child() ) iteration_type( my_first, my_feeder ); ++my_first; if( ++k==my_size ) break; list.push_back(*t); } set_ref_count(int(k+1)); spawn(list); spawn_and_wait_for_all(*t); return NULL; } template friend class do_task_iter; }; // class do_group_task_forward template class do_group_task_input: public task { static const size_t max_arg_size = 4; typedef parallel_do_feeder_impl feeder_type; feeder_type& my_feeder; size_t my_size; aligned_space my_arg; do_group_task_input( feeder_type& feeder ) : my_feeder(feeder), my_size(0) {} task* execute() __TBB_override { #if __TBB_CPP11_RVALUE_REF_PRESENT typedef std::move_iterator Item_iterator; #else typedef Item* Item_iterator; #endif typedef do_iteration_task_iter iteration_type; __TBB_ASSERT( my_size>0, NULL ); task_list list; task* t; size_t k=0; for(;;) { t = new( allocate_child() ) iteration_type( Item_iterator(my_arg.begin() + k), my_feeder ); if( ++k==my_size ) break; list.push_back(*t); } set_ref_count(int(k+1)); spawn(list); spawn_and_wait_for_all(*t); return NULL; } ~do_group_task_input(){ for( size_t k=0; k~Item(); } template friend class do_task_iter; }; // class do_group_task_input //! For internal use only. /** Gets block of iterations and packages them into a do_group_task. @ingroup algorithms */ template class do_task_iter: public task { typedef parallel_do_feeder_impl feeder_type; public: do_task_iter( Iterator first, Iterator last , feeder_type& feeder ) : my_first(first), my_last(last), my_feeder(feeder) {} private: Iterator my_first; Iterator my_last; feeder_type& my_feeder; /* Do not merge run(xxx) and run_xxx() methods. They are separated in order to make sure that compilers will eliminate unused argument of type xxx (that is will not put it on stack). The sole purpose of this argument is overload resolution. An alternative could be using template functions, but explicit specialization of member function templates is not supported for non specialized class templates. Besides template functions would always fall back to the least efficient variant (the one for input iterators) in case of iterators having custom tags derived from basic ones. */ task* execute() __TBB_override { typedef typename std::iterator_traits::iterator_category iterator_tag; return run( (iterator_tag*)NULL ); } /** This is the most restricted variant that operates on input iterators or iterators with unknown tags (tags not derived from the standard ones). **/ inline task* run( void* ) { return run_for_input_iterator(); } task* run_for_input_iterator() { typedef do_group_task_input block_type; block_type& t = *new( allocate_additional_child_of(*my_feeder.my_barrier) ) block_type(my_feeder); size_t k=0; while( !(my_first == my_last) ) { // Move semantics are automatically used when supported by the iterator new (t.my_arg.begin() + k) Item(*my_first); ++my_first; if( ++k==block_type::max_arg_size ) { if ( !(my_first == my_last) ) recycle_to_reexecute(); break; } } if( k==0 ) { destroy(t); return NULL; } else { t.my_size = k; return &t; } } inline task* run( std::forward_iterator_tag* ) { return run_for_forward_iterator(); } task* run_for_forward_iterator() { typedef do_group_task_forward block_type; Iterator first = my_first; size_t k=0; while( !(my_first==my_last) ) { ++my_first; if( ++k==block_type::max_arg_size ) { if ( !(my_first==my_last) ) recycle_to_reexecute(); break; } } return k==0 ? NULL : new( allocate_additional_child_of(*my_feeder.my_barrier) ) block_type(first, k, my_feeder); } inline task* run( std::random_access_iterator_tag* ) { return run_for_random_access_iterator(); } task* run_for_random_access_iterator() { typedef do_group_task_forward block_type; typedef do_iteration_task_iter iteration_type; size_t k = static_cast(my_last-my_first); if( k > block_type::max_arg_size ) { Iterator middle = my_first + k/2; empty_task& c = *new( allocate_continuation() ) empty_task; do_task_iter& b = *new( c.allocate_child() ) do_task_iter(middle, my_last, my_feeder); recycle_as_child_of(c); my_last = middle; c.set_ref_count(2); c.spawn(b); return this; }else if( k != 0 ) { task_list list; task* t; size_t k1=0; for(;;) { t = new( allocate_child() ) iteration_type(my_first, my_feeder); ++my_first; if( ++k1==k ) break; list.push_back(*t); } set_ref_count(int(k+1)); spawn(list); spawn_and_wait_for_all(*t); } return NULL; } }; // class do_task_iter //! For internal use only. /** Implements parallel iteration over a range. @ingroup algorithms */ template void run_parallel_do( Iterator first, Iterator last, const Body& body #if __TBB_TASK_GROUP_CONTEXT , task_group_context& context #endif ) { typedef do_task_iter root_iteration_task; #if __TBB_TASK_GROUP_CONTEXT parallel_do_feeder_impl feeder(context); #else parallel_do_feeder_impl feeder; #endif feeder.my_body = &body; root_iteration_task &t = *new( feeder.my_barrier->allocate_child() ) root_iteration_task(first, last, feeder); feeder.my_barrier->set_ref_count(2); feeder.my_barrier->spawn_and_wait_for_all(t); } //! For internal use only. /** Detects types of Body's operator function arguments. @ingroup algorithms **/ template void select_parallel_do( Iterator first, Iterator last, const Body& body, void (Body::*)(Item) const #if __TBB_TASK_GROUP_CONTEXT , task_group_context& context #endif ) { run_parallel_do::type>( first, last, body #if __TBB_TASK_GROUP_CONTEXT , context #endif ); } //! For internal use only. /** Detects types of Body's operator function arguments. @ingroup algorithms **/ template void select_parallel_do( Iterator first, Iterator last, const Body& body, void (Body::*)(Item, parallel_do_feeder<_Item>&) const #if __TBB_TASK_GROUP_CONTEXT , task_group_context& context #endif ) { run_parallel_do::type>( first, last, body #if __TBB_TASK_GROUP_CONTEXT , context #endif ); } } // namespace internal } // namespace interface9 //! @endcond /** \page parallel_do_body_req Requirements on parallel_do body Class \c Body implementing the concept of parallel_do body must define: - \code B::operator()( cv_item_type item, parallel_do_feeder& feeder ) const OR B::operator()( cv_item_type& item ) const \endcode Process item. May be invoked concurrently for the same \c this but different \c item. - \code item_type( const item_type& ) \endcode Copy a work item. - \code ~item_type() \endcode Destroy a work item **/ /** \name parallel_do See also requirements on \ref parallel_do_body_req "parallel_do Body". **/ //@{ //! Parallel iteration over a range, with optional addition of more work. /** @ingroup algorithms */ template void parallel_do( Iterator first, Iterator last, const Body& body ) { if ( first == last ) return; #if __TBB_TASK_GROUP_CONTEXT task_group_context context; #endif interface9::internal::select_parallel_do( first, last, body, &Body::operator() #if __TBB_TASK_GROUP_CONTEXT , context #endif ); } template void parallel_do(Range& rng, const Body& body) { parallel_do(tbb::internal::first(rng), tbb::internal::last(rng), body); } template void parallel_do(const Range& rng, const Body& body) { parallel_do(tbb::internal::first(rng), tbb::internal::last(rng), body); } #if __TBB_TASK_GROUP_CONTEXT //! Parallel iteration over a range, with optional addition of more work and user-supplied context /** @ingroup algorithms */ template void parallel_do( Iterator first, Iterator last, const Body& body, task_group_context& context ) { if ( first == last ) return; interface9::internal::select_parallel_do( first, last, body, &Body::operator(), context ); } template void parallel_do(Range& rng, const Body& body, task_group_context& context) { parallel_do(tbb::internal::first(rng), tbb::internal::last(rng), body, context); } template void parallel_do(const Range& rng, const Body& body, task_group_context& context) { parallel_do(tbb::internal::first(rng), tbb::internal::last(rng), body, context); } #endif // __TBB_TASK_GROUP_CONTEXT //@} using interface9::parallel_do_feeder; } // namespace #endif /* __TBB_parallel_do_H */