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    Copyright 2005-2018 Intel Corporation.

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    rights must be express and approved by Intel in writing.

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*/

#ifndef __TBB_parallel_for_H
#define __TBB_parallel_for_H

#include <new>
#include "task.h"
#include "partitioner.h"
#include "blocked_range.h"
#include "tbb_exception.h"
#include "internal/_tbb_trace_impl.h"

namespace tbb {

namespace interface9 {
//! @cond INTERNAL
namespace internal {

    //! allocate right task with new parent
    void* allocate_sibling(task* start_for_task, size_t bytes);

    //! Task type used in parallel_for
    /** @ingroup algorithms */
    template<typename Range, typename Body, typename Partitioner>
    class start_for: public task {
        Range my_range;
        const Body my_body;
        typename Partitioner::task_partition_type my_partition;
        task* execute() __TBB_override;

        //! Update affinity info, if any.
        void note_affinity( affinity_id id ) __TBB_override {
            my_partition.note_affinity( id );
        }

    public:
        //! Constructor for root task.
        start_for( const Range& range, const Body& body, Partitioner& partitioner ) :
            my_range(range),
            my_body(body),
            my_partition(partitioner)
        {
            tbb::internal::fgt_algorithm(tbb::internal::PARALLEL_FOR_TASK, this, NULL);
        }
        //! 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) :
            my_range(parent_.my_range, split_obj),
            my_body(parent_.my_body),
            my_partition(parent_.my_partition, split_obj)
        {
            my_partition.set_affinity(*this);
            tbb::internal::fgt_algorithm(tbb::internal::PARALLEL_FOR_TASK, this, (void *)&parent_);
        }
        //! 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 ) :
            my_range(r),
            my_body(parent_.my_body),
            my_partition(parent_.my_partition, split())
        {
            my_partition.set_affinity(*this);
            my_partition.align_depth( d );
            tbb::internal::fgt_algorithm(tbb::internal::PARALLEL_FOR_TASK, this, (void *)&parent_);
        }
        static void run(  const Range& range, const Body& body, Partitioner& partitioner ) {
            if( !range.empty() ) {
#if !__TBB_TASK_GROUP_CONTEXT || TBB_JOIN_OUTER_TASK_GROUP
                start_for& a = *new(task::allocate_root()) start_for(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(PARALLEL_FOR);
                start_for& a = *new(task::allocate_root(context)) start_for(range,body,partitioner);
#endif /* __TBB_TASK_GROUP_CONTEXT && !TBB_JOIN_OUTER_TASK_GROUP */
		// REGION BEGIN
                fgt_begin_algorithm( tbb::internal::PARALLEL_FOR_TASK, (void*)&context );
                task::spawn_root_and_wait(a);
                fgt_end_algorithm( (void*)&context );
		// REGION END
            }
        }
#if __TBB_TASK_GROUP_CONTEXT
        static void run(  const Range& range, const Body& body, Partitioner& partitioner, task_group_context& context ) {
            if( !range.empty() ) {
                start_for& a = *new(task::allocate_root(context)) start_for(range,body,partitioner);
		// REGION BEGIN
                fgt_begin_algorithm( tbb::internal::PARALLEL_FOR_TASK, (void*)&context );
                task::spawn_root_and_wait(a);
                fgt_end_algorithm( (void*)&context );
		// END REGION
            }
        }
#endif /* __TBB_TASK_GROUP_CONTEXT */
        //! Run body for range, serves as callback for partitioner
        void run_body( Range &r ) { 
            fgt_alg_begin_body( tbb::internal::PARALLEL_FOR_TASK, (void *)const_cast<Body*>(&(this->my_body)), (void*)this );
            my_body( r ); 
            fgt_alg_end_body( (void *)const_cast<Body*>(&(this->my_body)) );
        }

        //! spawn right task, serves as callback for partitioner
        void offer_work(typename Partitioner::split_type& split_obj) {
            spawn( *new( allocate_sibling(static_cast<task*>(this), sizeof(start_for)) ) start_for(*this, split_obj) );
        }
        //! spawn right task, serves as callback for partitioner
        void offer_work(const Range& r, depth_t d = 0) {
            spawn( *new( allocate_sibling(static_cast<task*>(this), sizeof(start_for)) ) start_for(*this, r, d) );
        }
    };

    //! 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_for_task, size_t bytes) {
        task* parent_ptr = new( start_for_task->allocate_continuation() ) flag_task();
        start_for_task->set_parent(parent_ptr);
        parent_ptr->set_ref_count(2);
        return &parent_ptr->allocate_child().allocate(bytes);
    }

    //! execute task for parallel_for
    template<typename Range, typename Body, typename Partitioner>
    task* start_for<Range,Body,Partitioner>::execute() {
        my_partition.check_being_stolen( *this );
        my_partition.execute(*this, my_range);
        return NULL;
    }
} // namespace internal
//! @endcond
} // namespace interfaceX

//! @cond INTERNAL
namespace internal {
    using interface9::internal::start_for;

    //! Calls the function with values from range [begin, end) with a step provided
    template<typename Function, typename Index>
    class parallel_for_body : internal::no_assign {
        const Function &my_func;
        const Index my_begin;
        const Index my_step;
    public:
        parallel_for_body( const Function& _func, Index& _begin, Index& _step )
            : my_func(_func), my_begin(_begin), my_step(_step) {}

        void operator()( const tbb::blocked_range<Index>& 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 );
            }
        }
    };
} // namespace internal
//! @endcond

// 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<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body ) {
    internal::start_for<Range,Body,const __TBB_DEFAULT_PARTITIONER>::run(range,body,__TBB_DEFAULT_PARTITIONER());
}

//! Parallel iteration over range with simple partitioner.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, const simple_partitioner& partitioner ) {
    internal::start_for<Range,Body,const simple_partitioner>::run(range,body,partitioner);
}

//! Parallel iteration over range with auto_partitioner.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, const auto_partitioner& partitioner ) {
    internal::start_for<Range,Body,const auto_partitioner>::run(range,body,partitioner);
}

//! Parallel iteration over range with static_partitioner.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, const static_partitioner& partitioner ) {
    internal::start_for<Range,Body,const static_partitioner>::run(range,body,partitioner);
}

//! Parallel iteration over range with affinity_partitioner.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, affinity_partitioner& partitioner ) {
    internal::start_for<Range,Body,affinity_partitioner>::run(range,body,partitioner);
}

#if __TBB_TASK_GROUP_CONTEXT
//! Parallel iteration over range with default partitioner and user-supplied context.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, task_group_context& context ) {
    internal::start_for<Range,Body,const __TBB_DEFAULT_PARTITIONER>::run(range, body, __TBB_DEFAULT_PARTITIONER(), context);
}

//! Parallel iteration over range with simple partitioner and user-supplied context.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, const simple_partitioner& partitioner, task_group_context& context ) {
    internal::start_for<Range,Body,const simple_partitioner>::run(range, body, partitioner, context);
}

//! Parallel iteration over range with auto_partitioner and user-supplied context.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, const auto_partitioner& partitioner, task_group_context& context ) {
    internal::start_for<Range,Body,const auto_partitioner>::run(range, body, partitioner, context);
}

//! Parallel iteration over range with static_partitioner and user-supplied context.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, const static_partitioner& partitioner, task_group_context& context ) {
    internal::start_for<Range,Body,const static_partitioner>::run(range, body, partitioner, context);
}

//! Parallel iteration over range with affinity_partitioner and user-supplied context.
/** @ingroup algorithms **/
template<typename Range, typename Body>
void parallel_for( const Range& range, const Body& body, affinity_partitioner& partitioner, task_group_context& context ) {
    internal::start_for<Range,Body,affinity_partitioner>::run(range,body,partitioner, context);
}
#endif /* __TBB_TASK_GROUP_CONTEXT */
//@}

namespace strict_ppl {

//@{
//! Implementation of parallel iteration over stepped range of integers with explicit step and partitioner
template <typename Index, typename Function, typename Partitioner>
void parallel_for_impl(Index first, Index last, Index step, const Function& f, Partitioner& partitioner) {
    if (step <= 0 )
        internal::throw_exception(internal::eid_nonpositive_step); // throws std::invalid_argument
    else if (last > first) {
        // Above "else" avoids "potential divide by zero" warning on some platforms
        Index end = (last - first - Index(1)) / step + Index(1);
        tbb::blocked_range<Index> range(static_cast<Index>(0), end);
        internal::parallel_for_body<Function, Index> body(f, first, step);
        tbb::parallel_for(range, body, partitioner);
    }
}

//! Parallel iteration over a range of integers with a step provided and default partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, step, f, auto_partitioner());
}
//! Parallel iteration over a range of integers with a step provided and simple partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, const simple_partitioner& partitioner) {
    parallel_for_impl<Index,Function,const simple_partitioner>(first, last, step, f, partitioner);
}
//! Parallel iteration over a range of integers with a step provided and auto partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, const auto_partitioner& partitioner) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, step, f, partitioner);
}
//! Parallel iteration over a range of integers with a step provided and static partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, const static_partitioner& partitioner) {
    parallel_for_impl<Index,Function,const static_partitioner>(first, last, step, f, partitioner);
}
//! Parallel iteration over a range of integers with a step provided and affinity partitioner
template <typename Index, typename 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 <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, static_cast<Index>(1), f, auto_partitioner());
}
//! Parallel iteration over a range of integers with a default step value and simple partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, const simple_partitioner& partitioner) {
    parallel_for_impl<Index,Function,const simple_partitioner>(first, last, static_cast<Index>(1), f, partitioner);
}
//! Parallel iteration over a range of integers with a default step value and auto partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, const auto_partitioner& partitioner) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, static_cast<Index>(1), f, partitioner);
}
//! Parallel iteration over a range of integers with a default step value and static partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, const static_partitioner& partitioner) {
    parallel_for_impl<Index,Function,const static_partitioner>(first, last, static_cast<Index>(1), f, partitioner);
}
//! Parallel iteration over a range of integers with a default step value and affinity partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, affinity_partitioner& partitioner) {
    parallel_for_impl(first, last, static_cast<Index>(1), f, partitioner);
}

#if __TBB_TASK_GROUP_CONTEXT
//! Implementation of parallel iteration over stepped range of integers with explicit step, task group context, and partitioner
template <typename Index, typename Function, typename Partitioner>
void parallel_for_impl(Index first, Index last, Index step, const Function& f, Partitioner& partitioner, tbb::task_group_context &context) {
    if (step <= 0 )
        internal::throw_exception(internal::eid_nonpositive_step); // throws std::invalid_argument
    else if (last > first) {
        // Above "else" avoids "potential divide by zero" warning on some platforms
        Index end = (last - first - Index(1)) / step + Index(1);
        tbb::blocked_range<Index> range(static_cast<Index>(0), end);
        internal::parallel_for_body<Function, Index> body(f, first, step);
        tbb::parallel_for(range, body, partitioner, context);
    }
}

//! Parallel iteration over a range of integers with explicit step, task group context, and default partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, step, f, auto_partitioner(), context);
}
//! Parallel iteration over a range of integers with explicit step, task group context, and simple partitioner
 template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, const simple_partitioner& partitioner, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const simple_partitioner>(first, last, step, f, partitioner, context);
}
//! Parallel iteration over a range of integers with explicit step, task group context, and auto partitioner
 template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, const auto_partitioner& partitioner, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, step, f, partitioner, context);
}
//! Parallel iteration over a range of integers with explicit step, task group context, and static partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, const static_partitioner& partitioner, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const static_partitioner>(first, last, step, f, partitioner, context);
}
//! Parallel iteration over a range of integers with explicit step, task group context, and affinity partitioner
 template <typename Index, typename Function>
void parallel_for(Index first, Index last, Index step, const Function& f, affinity_partitioner& partitioner, tbb::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 <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, static_cast<Index>(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 <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, const simple_partitioner& partitioner, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const simple_partitioner>(first, last, static_cast<Index>(1), f, partitioner, context);
}
//! Parallel iteration over a range of integers with a default step value, explicit task group context, and auto partitioner
 template <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, const auto_partitioner& partitioner, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const auto_partitioner>(first, last, static_cast<Index>(1), f, partitioner, context);
}
//! Parallel iteration over a range of integers with a default step value, explicit task group context, and static partitioner
template <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, const static_partitioner& partitioner, tbb::task_group_context &context) {
    parallel_for_impl<Index,Function,const static_partitioner>(first, last, static_cast<Index>(1), f, partitioner, context);
}
//! Parallel iteration over a range of integers with a default step value, explicit task group context, and affinity_partitioner
 template <typename Index, typename Function>
void parallel_for(Index first, Index last, const Function& f, affinity_partitioner& partitioner, tbb::task_group_context &context) {
    parallel_for_impl(first, last, static_cast<Index>(1), f, partitioner, context);
}

#endif /* __TBB_TASK_GROUP_CONTEXT */
//@}

} // namespace strict_ppl

using strict_ppl::parallel_for;

} // namespace tbb

#if TBB_PREVIEW_SERIAL_SUBSET
#define __TBB_NORMAL_EXECUTION
#include "../serial/tbb/parallel_for.h"
#undef __TBB_NORMAL_EXECUTION
#endif

#endif /* __TBB_parallel_for_H */
