/* 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_reduce_H #define __TBB_parallel_reduce_H #include #include "task.h" #include "aligned_space.h" #include "partitioner.h" #include "tbb_profiling.h" namespace tbb { namespace interface9 { //! @cond INTERNAL namespace internal { using namespace tbb::internal; /** Values for reduction_context. */ enum { root_task, left_child, right_child }; /** Represented as a char, not enum, for compactness. */ typedef char reduction_context; //! Task type used to combine the partial results of parallel_reduce. /** @ingroup algorithms */ template class finish_reduce: public flag_task { //! Pointer to body, or NULL if the left child has not yet finished. bool has_right_zombie; const reduction_context my_context; Body* my_body; aligned_space zombie_space; finish_reduce( reduction_context context_ ) : has_right_zombie(false), // TODO: substitute by flag_task::child_stolen? my_context(context_), my_body(NULL) { } ~finish_reduce() { if( has_right_zombie ) zombie_space.begin()->~Body(); } task* execute() __TBB_override { if( has_right_zombie ) { // Right child was stolen. Body* s = zombie_space.begin(); my_body->join( *s ); // Body::join() won't be called if canceled. Defer destruction to destructor } if( my_context==left_child ) itt_store_word_with_release( static_cast(parent())->my_body, my_body ); return NULL; } template friend class start_reduce; }; //! allocate right task with new parent void allocate_sibling(task* start_reduce_task, task *tasks[], size_t start_bytes, size_t finish_bytes); //! Task type used to split the work of parallel_reduce. /** @ingroup algorithms */ template class start_reduce: public task { typedef finish_reduce finish_type; Body* my_body; Range my_range; typename Partitioner::task_partition_type my_partition; reduction_context my_context; task* execute() __TBB_override; //! Update affinity info, if any void note_affinity( affinity_id id ) __TBB_override { my_partition.note_affinity( id ); } template friend class finish_reduce; public: //! Constructor used for root task start_reduce( const Range& range, Body* body, Partitioner& partitioner ) : my_body(body), my_range(range), my_partition(partitioner), my_context(root_task) { } //! Splitting constructor used to generate children. /** parent_ becomes left child. Newly constructed object is right child. */ start_reduce( start_reduce& parent_, typename Partitioner::split_type& split_obj ) : my_body(parent_.my_body), my_range(parent_.my_range, split_obj), my_partition(parent_.my_partition, split_obj), my_context(right_child) { my_partition.set_affinity(*this); parent_.my_context = left_child; } //! Construct right child from the given range as response to the demand. /** parent_ remains left child. Newly constructed object is right child. */ start_reduce( start_reduce& parent_, const Range& r, depth_t d ) : my_body(parent_.my_body), my_range(r), my_partition(parent_.my_partition, split()), my_context(right_child) { my_partition.set_affinity(*this); my_partition.align_depth( d ); // TODO: move into constructor of partitioner parent_.my_context = left_child; } static void run( const Range& range, Body& body, Partitioner& partitioner ) { if( !range.empty() ) { #if !__TBB_TASK_GROUP_CONTEXT || TBB_JOIN_OUTER_TASK_GROUP task::spawn_root_and_wait( *new(task::allocate_root()) start_reduce(range,&body,partitioner) ); #else // Bound context prevents exceptions from body to affect nesting or sibling algorithms, // and allows users to handle exceptions safely by wrapping parallel_for in the try-block. task_group_context context; task::spawn_root_and_wait( *new(task::allocate_root(context)) start_reduce(range,&body,partitioner) ); #endif /* __TBB_TASK_GROUP_CONTEXT && !TBB_JOIN_OUTER_TASK_GROUP */ } } #if __TBB_TASK_GROUP_CONTEXT static void run( const Range& range, Body& body, Partitioner& partitioner, task_group_context& context ) { if( !range.empty() ) task::spawn_root_and_wait( *new(task::allocate_root(context)) start_reduce(range,&body,partitioner) ); } #endif /* __TBB_TASK_GROUP_CONTEXT */ //! Run body for range void run_body( Range &r ) { (*my_body)( r ); } //! spawn right task, serves as callback for partitioner // TODO: remove code duplication from 'offer_work' methods void offer_work(typename Partitioner::split_type& split_obj) { task *tasks[2]; allocate_sibling(static_cast(this), tasks, sizeof(start_reduce), sizeof(finish_type)); new((void*)tasks[0]) finish_type(my_context); new((void*)tasks[1]) start_reduce(*this, split_obj); spawn(*tasks[1]); } //! spawn right task, serves as callback for partitioner void offer_work(const Range& r, depth_t d = 0) { task *tasks[2]; allocate_sibling(static_cast(this), tasks, sizeof(start_reduce), sizeof(finish_type)); new((void*)tasks[0]) finish_type(my_context); new((void*)tasks[1]) start_reduce(*this, r, d); spawn(*tasks[1]); } }; //! allocate right task with new parent // TODO: 'inline' here is to avoid multiple definition error but for sake of code size this should not be inlined inline void allocate_sibling(task* start_reduce_task, task *tasks[], size_t start_bytes, size_t finish_bytes) { tasks[0] = &start_reduce_task->allocate_continuation().allocate(finish_bytes); start_reduce_task->set_parent(tasks[0]); tasks[0]->set_ref_count(2); tasks[1] = &tasks[0]->allocate_child().allocate(start_bytes); } template task* start_reduce::execute() { my_partition.check_being_stolen( *this ); if( my_context==right_child ) { finish_type* parent_ptr = static_cast(parent()); if( !itt_load_word_with_acquire(parent_ptr->my_body) ) { // TODO: replace by is_stolen_task() or by parent_ptr->ref_count() == 2??? my_body = new( parent_ptr->zombie_space.begin() ) Body(*my_body,split()); parent_ptr->has_right_zombie = true; } } else __TBB_ASSERT(my_context==root_task,NULL);// because left leaf spawns right leafs without recycling my_partition.execute(*this, my_range); if( my_context==left_child ) { finish_type* parent_ptr = static_cast(parent()); __TBB_ASSERT(my_body!=parent_ptr->zombie_space.begin(),NULL); itt_store_word_with_release(parent_ptr->my_body, my_body ); } return NULL; } //! Task type used to combine the partial results of parallel_deterministic_reduce. /** @ingroup algorithms */ template class finish_deterministic_reduce: public task { Body &my_left_body; Body my_right_body; finish_deterministic_reduce( Body &body ) : my_left_body( body ), my_right_body( body, split() ) { } task* execute() __TBB_override { my_left_body.join( my_right_body ); return NULL; } template friend class start_deterministic_reduce; }; //! Task type used to split the work of parallel_deterministic_reduce. /** @ingroup algorithms */ template class start_deterministic_reduce: public task { typedef finish_deterministic_reduce finish_type; Body &my_body; Range my_range; task* execute() __TBB_override; //! Constructor used for root task start_deterministic_reduce( const Range& range, Body& body ) : my_body( body ), my_range( range ) { } //! Splitting constructor used to generate children. /** parent_ becomes left child. Newly constructed object is right child. */ start_deterministic_reduce( start_deterministic_reduce& parent_, finish_type& c ) : my_body( c.my_right_body ), my_range( parent_.my_range, split() ) { } public: static void run( const Range& range, Body& body ) { if( !range.empty() ) { #if !__TBB_TASK_GROUP_CONTEXT || TBB_JOIN_OUTER_TASK_GROUP task::spawn_root_and_wait( *new(task::allocate_root()) start_deterministic_reduce(range,&body) ); #else // Bound context prevents exceptions from body to affect nesting or sibling algorithms, // and allows users to handle exceptions safely by wrapping parallel_for in the try-block. task_group_context context; task::spawn_root_and_wait( *new(task::allocate_root(context)) start_deterministic_reduce(range,body) ); #endif /* __TBB_TASK_GROUP_CONTEXT && !TBB_JOIN_OUTER_TASK_GROUP */ } } #if __TBB_TASK_GROUP_CONTEXT static void run( const Range& range, Body& body, task_group_context& context ) { if( !range.empty() ) task::spawn_root_and_wait( *new(task::allocate_root(context)) start_deterministic_reduce(range,body) ); } #endif /* __TBB_TASK_GROUP_CONTEXT */ }; template task* start_deterministic_reduce::execute() { if( !my_range.is_divisible() ) { my_body( my_range ); return NULL; } else { finish_type& c = *new( allocate_continuation() ) finish_type( my_body ); recycle_as_child_of(c); c.set_ref_count(2); start_deterministic_reduce& b = *new( c.allocate_child() ) start_deterministic_reduce( *this, c ); task::spawn(b); return this; } } } // namespace internal //! @endcond } //namespace interfaceX //! @cond INTERNAL namespace internal { using interface9::internal::start_reduce; using interface9::internal::start_deterministic_reduce; //! Auxiliary class for parallel_reduce; for internal use only. /** The adaptor class that implements \ref parallel_reduce_body_req "parallel_reduce Body" using given \ref parallel_reduce_lambda_req "anonymous function objects". **/ /** @ingroup algorithms */ template class lambda_reduce_body { //FIXME: decide if my_real_body, my_reduction, and identity_element should be copied or referenced // (might require some performance measurements) const Value& identity_element; const RealBody& my_real_body; const Reduction& my_reduction; Value my_value; lambda_reduce_body& operator= ( const lambda_reduce_body& other ); public: lambda_reduce_body( const Value& identity, const RealBody& body, const Reduction& reduction ) : identity_element(identity) , my_real_body(body) , my_reduction(reduction) , my_value(identity) { } lambda_reduce_body( const lambda_reduce_body& other ) : identity_element(other.identity_element) , my_real_body(other.my_real_body) , my_reduction(other.my_reduction) , my_value(other.my_value) { } lambda_reduce_body( lambda_reduce_body& other, tbb::split ) : identity_element(other.identity_element) , my_real_body(other.my_real_body) , my_reduction(other.my_reduction) , my_value(other.identity_element) { } void operator()(Range& range) { my_value = my_real_body(range, const_cast(my_value)); } void join( lambda_reduce_body& rhs ) { my_value = my_reduction(const_cast(my_value), const_cast(rhs.my_value)); } Value result() const { return my_value; } }; } // namespace internal //! @endcond // Requirements on Range concept are documented in blocked_range.h /** \page parallel_reduce_body_req Requirements on parallel_reduce body Class \c Body implementing the concept of parallel_reduce body must define: - \code Body::Body( Body&, split ); \endcode Splitting constructor. Must be able to run concurrently with operator() and method \c join - \code Body::~Body(); \endcode Destructor - \code void Body::operator()( Range& r ); \endcode Function call operator applying body to range \c r and accumulating the result - \code void Body::join( Body& b ); \endcode Join results. The result in \c b should be merged into the result of \c this **/ /** \page parallel_reduce_lambda_req Requirements on parallel_reduce anonymous function objects (lambda functions) TO BE DOCUMENTED **/ /** \name parallel_reduce See also requirements on \ref range_req "Range" and \ref parallel_reduce_body_req "parallel_reduce Body". **/ //@{ //! Parallel iteration with reduction and default partitioner. /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body ) { internal::start_reduce::run( range, body, __TBB_DEFAULT_PARTITIONER() ); } //! Parallel iteration with reduction and simple_partitioner /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, const simple_partitioner& partitioner ) { internal::start_reduce::run( range, body, partitioner ); } //! Parallel iteration with reduction and auto_partitioner /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, const auto_partitioner& partitioner ) { internal::start_reduce::run( range, body, partitioner ); } //! Parallel iteration with reduction and static_partitioner /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, const static_partitioner& partitioner ) { internal::start_reduce::run( range, body, partitioner ); } //! Parallel iteration with reduction and affinity_partitioner /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, affinity_partitioner& partitioner ) { internal::start_reduce::run( range, body, partitioner ); } #if __TBB_TASK_GROUP_CONTEXT //! Parallel iteration with reduction, simple partitioner and user-supplied context. /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, const simple_partitioner& partitioner, task_group_context& context ) { internal::start_reduce::run( range, body, partitioner, context ); } //! Parallel iteration with reduction, auto_partitioner and user-supplied context /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, const auto_partitioner& partitioner, task_group_context& context ) { internal::start_reduce::run( range, body, partitioner, context ); } //! Parallel iteration with reduction, static_partitioner and user-supplied context /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, const static_partitioner& partitioner, task_group_context& context ) { internal::start_reduce::run( range, body, partitioner, context ); } //! Parallel iteration with reduction, affinity_partitioner and user-supplied context /** @ingroup algorithms **/ template void parallel_reduce( const Range& range, Body& body, affinity_partitioner& partitioner, task_group_context& context ) { internal::start_reduce::run( range, body, partitioner, context ); } #endif /* __TBB_TASK_GROUP_CONTEXT */ /** parallel_reduce overloads that work with anonymous function objects (see also \ref parallel_reduce_lambda_req "requirements on parallel_reduce anonymous function objects"). **/ //! Parallel iteration with reduction and default partitioner. /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,const __TBB_DEFAULT_PARTITIONER> ::run(range, body, __TBB_DEFAULT_PARTITIONER() ); return body.result(); } //! Parallel iteration with reduction and simple_partitioner. /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, const simple_partitioner& partitioner ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,const simple_partitioner> ::run(range, body, partitioner ); return body.result(); } //! Parallel iteration with reduction and auto_partitioner /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, const auto_partitioner& partitioner ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,const auto_partitioner> ::run( range, body, partitioner ); return body.result(); } //! Parallel iteration with reduction and static_partitioner /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, const static_partitioner& partitioner ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,const static_partitioner> ::run( range, body, partitioner ); return body.result(); } //! Parallel iteration with reduction and affinity_partitioner /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, affinity_partitioner& partitioner ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,affinity_partitioner> ::run( range, body, partitioner ); return body.result(); } #if __TBB_TASK_GROUP_CONTEXT //! Parallel iteration with reduction, simple partitioner and user-supplied context. /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, const simple_partitioner& partitioner, task_group_context& context ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,const simple_partitioner> ::run( range, body, partitioner, context ); return body.result(); } //! Parallel iteration with reduction, auto_partitioner and user-supplied context /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, const auto_partitioner& partitioner, task_group_context& context ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,const auto_partitioner> ::run( range, body, partitioner, context ); return body.result(); } //! Parallel iteration with reduction, static_partitioner and user-supplied context /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, const static_partitioner& partitioner, task_group_context& context ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,const static_partitioner> ::run( range, body, partitioner, context ); return body.result(); } //! Parallel iteration with reduction, affinity_partitioner and user-supplied context /** @ingroup algorithms **/ template Value parallel_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, affinity_partitioner& partitioner, task_group_context& context ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_reduce,affinity_partitioner> ::run( range, body, partitioner, context ); return body.result(); } #endif /* __TBB_TASK_GROUP_CONTEXT */ //! Parallel iteration with deterministic reduction and default partitioner. /** @ingroup algorithms **/ template void parallel_deterministic_reduce( const Range& range, Body& body ) { internal::start_deterministic_reduce::run( range, body ); } #if __TBB_TASK_GROUP_CONTEXT //! Parallel iteration with deterministic reduction, simple partitioner and user-supplied context. /** @ingroup algorithms **/ template void parallel_deterministic_reduce( const Range& range, Body& body, task_group_context& context ) { internal::start_deterministic_reduce::run( range, body, context ); } #endif /* __TBB_TASK_GROUP_CONTEXT */ /** parallel_reduce overloads that work with anonymous function objects (see also \ref parallel_reduce_lambda_req "requirements on parallel_reduce anonymous function objects"). **/ //! Parallel iteration with deterministic reduction and default partitioner. /** @ingroup algorithms **/ template Value parallel_deterministic_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_deterministic_reduce > ::run(range, body); return body.result(); } #if __TBB_TASK_GROUP_CONTEXT //! Parallel iteration with deterministic reduction, simple partitioner and user-supplied context. /** @ingroup algorithms **/ template Value parallel_deterministic_reduce( const Range& range, const Value& identity, const RealBody& real_body, const Reduction& reduction, task_group_context& context ) { internal::lambda_reduce_body body(identity, real_body, reduction); internal::start_deterministic_reduce > ::run( range, body, context ); return body.result(); } #endif /* __TBB_TASK_GROUP_CONTEXT */ //@} } // namespace tbb #endif /* __TBB_parallel_reduce_H */