enumerable_thread_specific.h

/*
    Copyright 2005-2011 Intel Corporation.  All Rights Reserved.

    The source code contained or described herein and all documents related
    to the source code ("Material") are owned by Intel Corporation or its
    suppliers or licensors.  Title to the Material remains with Intel
    Corporation or its suppliers and licensors.  The Material is protected
    by worldwide copyright laws and treaty provisions.  No part of the
    Material may be used, copied, reproduced, modified, published, uploaded,
    posted, transmitted, distributed, or disclosed in any way without
    Intel's prior express written permission.

    No license under any patent, copyright, trade secret or other
    intellectual property right is granted to or conferred upon you by
    disclosure or delivery of the Materials, either expressly, by
    implication, inducement, estoppel or otherwise.  Any license under such
    intellectual property rights must be express and approved by Intel in
    writing.
*/

#ifndef __TBB_enumerable_thread_specific_H
#define __TBB_enumerable_thread_specific_H

#include "concurrent_vector.h"
#include "tbb_thread.h"
#include "tbb_allocator.h"
#include "cache_aligned_allocator.h"
#include "aligned_space.h"
#include <string.h>  // for memcpy

#if _WIN32||_WIN64
#include "machine/windows_api.h"
#else
#include <pthread.h>
#endif

namespace tbb {

enum ets_key_usage_type { ets_key_per_instance, ets_no_key };

namespace interface6 {
 
    namespace internal { 

        template<ets_key_usage_type ETS_key_type>
        class ets_base: tbb::internal::no_copy {
        protected:
#if _WIN32||_WIN64
            typedef DWORD key_type;
#else
            typedef pthread_t key_type;
#endif
#if __TBB_GCC_3_3_PROTECTED_BROKEN
        public:
#endif
            struct slot;

            struct array {
                array* next;
                size_t lg_size;
                slot& at( size_t k ) {
                    return ((slot*)(void*)(this+1))[k];
                }
                size_t size() const {return (size_t)1<<lg_size;}
                size_t mask() const {return size()-1;}
                size_t start( size_t h ) const {
                    return h>>(8*sizeof(size_t)-lg_size);
                }
            };
            struct slot {
                key_type key;
                void* ptr;
                bool empty() const {return !key;}
                bool match( key_type k ) const {return key==k;}
                bool claim( key_type k ) {
                    __TBB_ASSERT(sizeof(tbb::atomic<key_type>)==sizeof(key_type), NULL);
                    return tbb::internal::punned_cast<tbb::atomic<key_type>*>(&key)->compare_and_swap(k,0)==0;
                }
            };
#if __TBB_GCC_3_3_PROTECTED_BROKEN
        protected:
#endif
        
            static key_type key_of_current_thread() {
               tbb::tbb_thread::id id = tbb::this_tbb_thread::get_id();
               key_type k;
               memcpy( &k, &id, sizeof(k) );
               return k;
            }


            atomic<array*> my_root;
            atomic<size_t> my_count;
            virtual void* create_local() = 0;
            virtual void* create_array(size_t _size) = 0;  // _size in bytes
            virtual void free_array(void* ptr, size_t _size) = 0; // _size in bytes
            array* allocate( size_t lg_size ) {
                size_t n = 1<<lg_size;  
                array* a = static_cast<array*>(create_array( sizeof(array)+n*sizeof(slot) ));
                a->lg_size = lg_size;
                std::memset( a+1, 0, n*sizeof(slot) );
                return a;
            }
            void free(array* a) {
                size_t n = 1<<(a->lg_size);  
                free_array( (void *)a, size_t(sizeof(array)+n*sizeof(slot)) );
            }
            static size_t hash( key_type k ) {
                // Multiplicative hashing.  Client should use *upper* bits.
                // casts required for Mac gcc4.* compiler
#if __TBB_WORDSIZE == 4
                return uintptr_t(k)*0x9E3779B9;
#else
                return uintptr_t(k)*0x9E3779B97F4A7C15;
#endif 
            } 
        
            ets_base() {my_root=NULL; my_count=0;}
            virtual ~ets_base();  // g++ complains if this is not virtual...
            void* table_lookup( bool& exists );
            void table_clear();
            slot& table_find( key_type k ) {
                size_t h = hash(k);
                array* r = my_root;
                size_t mask = r->mask();
                for(size_t i = r->start(h);;i=(i+1)&mask) {
                    slot& s = r->at(i);
                    if( s.empty() || s.match(k) )
                        return s;
                }
            }
            void table_reserve_for_copy( const ets_base& other ) {
                __TBB_ASSERT(!my_root,NULL);
                __TBB_ASSERT(!my_count,NULL);
                if( other.my_root ) {
                    array* a = allocate(other.my_root->lg_size);
                    a->next = NULL;
                    my_root = a;
                    my_count = other.my_count;
                }
            }
        };

        template<ets_key_usage_type ETS_key_type>
        ets_base<ETS_key_type>::~ets_base() {
            __TBB_ASSERT(!my_root, NULL);
        }

        template<ets_key_usage_type ETS_key_type>
        void ets_base<ETS_key_type>::table_clear() {
            while( array* r = my_root ) {
                my_root = r->next;
                free(r);
            }
            my_count = 0;
        }
                
        template<ets_key_usage_type ETS_key_type>
        void* ets_base<ETS_key_type>::table_lookup( bool& exists ) {
            const key_type k = key_of_current_thread(); 

            __TBB_ASSERT(k!=0,NULL);
            void* found;
            size_t h = hash(k);
            for( array* r=my_root; r; r=r->next ) {
                size_t mask=r->mask();
                for(size_t i = r->start(h); ;i=(i+1)&mask) {
                    slot& s = r->at(i);
                    if( s.empty() ) break;
                    if( s.match(k) ) {
                        if( r==my_root ) {
                            // Success at top level
                            exists = true;
                            return s.ptr;
                        } else {
                            // Success at some other level.  Need to insert at top level.
                            exists = true;
                            found = s.ptr;
                            goto insert;
                        }
                    }
                }
            }
            // Key does not yet exist
            exists = false;
            found = create_local();
            {
                size_t c = ++my_count;
                array* r = my_root;
                if( !r || c>r->size()/2 ) {
                    size_t s = r ? r->lg_size : 2;
                    while( c>size_t(1)<<(s-1) ) ++s;
                    array* a = allocate(s);
                    for(;;) {
                        a->next = my_root;
                        array* new_r = my_root.compare_and_swap(a,r);
                        if( new_r==r ) break;
                        if( new_r->lg_size>=s ) {
                            // Another thread inserted an equal or  bigger array, so our array is superfluous.
                            free(a);
                            break;
                        }
                        r = new_r;
                    }
                }
            }
        insert:
            // Guaranteed to be room for it, and it is not present, so search for empty slot and grab it.
            array* ir = my_root;
            size_t mask = ir->mask();
            for(size_t i = ir->start(h);;i=(i+1)&mask) {
                slot& s = ir->at(i);
                if( s.empty() ) {
                    if( s.claim(k) ) {
                        s.ptr = found;
                        return found;
                    }
                }
            }
        }

        template <>
        class ets_base<ets_key_per_instance>: protected ets_base<ets_no_key> {
            typedef ets_base<ets_no_key> super;
#if _WIN32||_WIN64
            typedef DWORD tls_key_t;
            void create_key() { my_key = TlsAlloc(); }
            void destroy_key() { TlsFree(my_key); }
            void set_tls(void * value) { TlsSetValue(my_key, (LPVOID)value); }
            void* get_tls() { return (void *)TlsGetValue(my_key); }
#else
            typedef pthread_key_t tls_key_t;
            void create_key() { pthread_key_create(&my_key, NULL); }
            void destroy_key() { pthread_key_delete(my_key); }
            void set_tls( void * value ) const { pthread_setspecific(my_key, value); }
            void* get_tls() const { return pthread_getspecific(my_key); }
#endif
            tls_key_t my_key;
            virtual void* create_local() = 0;
            virtual void* create_array(size_t _size) = 0;  // _size in bytes
            virtual void free_array(void* ptr, size_t _size) = 0; // size in bytes
        public:
            ets_base() {create_key();}
            ~ets_base() {destroy_key();}
            void* table_lookup( bool& exists ) {
                void* found = get_tls();
                if( found ) {
                    exists=true;
                } else {
                    found = super::table_lookup(exists);
                    set_tls(found);
                }
                return found; 
            }
            void table_clear() {
                destroy_key();
                create_key(); 
                super::table_clear();
            }
        };

        template< typename Container, typename Value >
        class enumerable_thread_specific_iterator 
#if defined(_WIN64) && defined(_MSC_VER) 
            // Ensure that Microsoft's internal template function _Val_type works correctly.
            : public std::iterator<std::random_access_iterator_tag,Value>
#endif /* defined(_WIN64) && defined(_MSC_VER) */
        {
        
            Container *my_container;
            typename Container::size_type my_index;
            mutable Value *my_value;
        
            template<typename C, typename T>
            friend enumerable_thread_specific_iterator<C,T> operator+( ptrdiff_t offset, 
                                                                       const enumerable_thread_specific_iterator<C,T>& v );
        
            template<typename C, typename T, typename U>
            friend bool operator==( const enumerable_thread_specific_iterator<C,T>& i, 
                                    const enumerable_thread_specific_iterator<C,U>& j );
        
            template<typename C, typename T, typename U>
            friend bool operator<( const enumerable_thread_specific_iterator<C,T>& i, 
                                   const enumerable_thread_specific_iterator<C,U>& j );
        
            template<typename C, typename T, typename U>
            friend ptrdiff_t operator-( const enumerable_thread_specific_iterator<C,T>& i, const enumerable_thread_specific_iterator<C,U>& j );
            
            template<typename C, typename U> 
            friend class enumerable_thread_specific_iterator;
        
            public:
        
            enumerable_thread_specific_iterator( const Container &container, typename Container::size_type index ) : 
                my_container(&const_cast<Container &>(container)), my_index(index), my_value(NULL) {}
        
            enumerable_thread_specific_iterator() : my_container(NULL), my_index(0), my_value(NULL) {}
        
            template<typename U>
            enumerable_thread_specific_iterator( const enumerable_thread_specific_iterator<Container, U>& other ) :
                    my_container( other.my_container ), my_index( other.my_index), my_value( const_cast<Value *>(other.my_value) ) {}
        
            enumerable_thread_specific_iterator operator+( ptrdiff_t offset ) const {
                return enumerable_thread_specific_iterator(*my_container, my_index + offset);
            }
        
            enumerable_thread_specific_iterator &operator+=( ptrdiff_t offset ) {
                my_index += offset;
                my_value = NULL;
                return *this;
            }
        
            enumerable_thread_specific_iterator operator-( ptrdiff_t offset ) const {
                return enumerable_thread_specific_iterator( *my_container, my_index-offset );
            }
        
            enumerable_thread_specific_iterator &operator-=( ptrdiff_t offset ) {
                my_index -= offset;
                my_value = NULL;
                return *this;
            }
        
            Value& operator*() const {
                Value* value = my_value;
                if( !value ) {
                    value = my_value = reinterpret_cast<Value *>(&(*my_container)[my_index].value);
                }
                __TBB_ASSERT( value==reinterpret_cast<Value *>(&(*my_container)[my_index].value), "corrupt cache" );
                return *value;
            }
        
            Value& operator[]( ptrdiff_t k ) const {
               return (*my_container)[my_index + k].value;
            }
        
            Value* operator->() const {return &operator*();}
        
            enumerable_thread_specific_iterator& operator++() {
                ++my_index;
                my_value = NULL;
                return *this;
            }
        
            enumerable_thread_specific_iterator& operator--() {
                --my_index;
                my_value = NULL;
                return *this;
            }
        
            enumerable_thread_specific_iterator operator++(int) {
                enumerable_thread_specific_iterator result = *this;
                ++my_index;
                my_value = NULL;
                return result;
            }
        
            enumerable_thread_specific_iterator operator--(int) {
                enumerable_thread_specific_iterator result = *this;
                --my_index;
                my_value = NULL;
                return result;
            }
        
            // STL support
            typedef ptrdiff_t difference_type;
            typedef Value value_type;
            typedef Value* pointer;
            typedef Value& reference;
            typedef std::random_access_iterator_tag iterator_category;
        };
        
        template<typename Container, typename T>
        enumerable_thread_specific_iterator<Container,T> operator+( ptrdiff_t offset, 
                                                                    const enumerable_thread_specific_iterator<Container,T>& v ) {
            return enumerable_thread_specific_iterator<Container,T>( v.my_container, v.my_index + offset );
        }
        
        template<typename Container, typename T, typename U>
        bool operator==( const enumerable_thread_specific_iterator<Container,T>& i, 
                         const enumerable_thread_specific_iterator<Container,U>& j ) {
            return i.my_index==j.my_index && i.my_container == j.my_container;
        }
        
        template<typename Container, typename T, typename U>
        bool operator!=( const enumerable_thread_specific_iterator<Container,T>& i, 
                         const enumerable_thread_specific_iterator<Container,U>& j ) {
            return !(i==j);
        }
        
        template<typename Container, typename T, typename U>
        bool operator<( const enumerable_thread_specific_iterator<Container,T>& i, 
                        const enumerable_thread_specific_iterator<Container,U>& j ) {
            return i.my_index<j.my_index;
        }
        
        template<typename Container, typename T, typename U>
        bool operator>( const enumerable_thread_specific_iterator<Container,T>& i, 
                        const enumerable_thread_specific_iterator<Container,U>& j ) {
            return j<i;
        }
        
        template<typename Container, typename T, typename U>
        bool operator>=( const enumerable_thread_specific_iterator<Container,T>& i, 
                         const enumerable_thread_specific_iterator<Container,U>& j ) {
            return !(i<j);
        }
        
        template<typename Container, typename T, typename U>
        bool operator<=( const enumerable_thread_specific_iterator<Container,T>& i, 
                         const enumerable_thread_specific_iterator<Container,U>& j ) {
            return !(j<i);
        }
        
        template<typename Container, typename T, typename U>
        ptrdiff_t operator-( const enumerable_thread_specific_iterator<Container,T>& i, 
                             const enumerable_thread_specific_iterator<Container,U>& j ) {
            return i.my_index-j.my_index;
        }

    template<typename SegmentedContainer, typename Value >
        class segmented_iterator
#if defined(_WIN64) && defined(_MSC_VER)
        : public std::iterator<std::input_iterator_tag, Value>
#endif
        {
            template<typename C, typename T, typename U>
            friend bool operator==(const segmented_iterator<C,T>& i, const segmented_iterator<C,U>& j);

            template<typename C, typename T, typename U>
            friend bool operator!=(const segmented_iterator<C,T>& i, const segmented_iterator<C,U>& j);
            
            template<typename C, typename U> 
            friend class segmented_iterator;

            public:

                segmented_iterator() {my_segcont = NULL;}

                segmented_iterator( const SegmentedContainer& _segmented_container ) : 
                    my_segcont(const_cast<SegmentedContainer*>(&_segmented_container)),
                    outer_iter(my_segcont->end()) { }

                ~segmented_iterator() {}

                typedef typename SegmentedContainer::iterator outer_iterator;
                typedef typename SegmentedContainer::value_type InnerContainer;
                typedef typename InnerContainer::iterator inner_iterator;

                // STL support
                typedef ptrdiff_t difference_type;
                typedef Value value_type;
                typedef typename SegmentedContainer::size_type size_type;
                typedef Value* pointer;
                typedef Value& reference;
                typedef std::input_iterator_tag iterator_category;

                // Copy Constructor
                template<typename U>
                segmented_iterator(const segmented_iterator<SegmentedContainer, U>& other) :
                    my_segcont(other.my_segcont),
                    outer_iter(other.outer_iter),
                    // can we assign a default-constructed iterator to inner if we're at the end?
                    inner_iter(other.inner_iter)
                {}

                // assignment
                template<typename U>
                segmented_iterator& operator=( const segmented_iterator<SegmentedContainer, U>& other) {
                    if(this != &other) {
                        my_segcont = other.my_segcont;
                        outer_iter = other.outer_iter;
                        if(outer_iter != my_segcont->end()) inner_iter = other.inner_iter;
                    }
                    return *this;
                }

                // allow assignment of outer iterator to segmented iterator.  Once it is
                // assigned, move forward until a non-empty inner container is found or
                // the end of the outer container is reached.
                segmented_iterator& operator=(const outer_iterator& new_outer_iter) {
                    __TBB_ASSERT(my_segcont != NULL, NULL);
                    // check that this iterator points to something inside the segmented container
                    for(outer_iter = new_outer_iter ;outer_iter!=my_segcont->end(); ++outer_iter) {
                        if( !outer_iter->empty() ) {
                            inner_iter = outer_iter->begin();
                            break;
                        }
                    }
                    return *this;
                }

                // pre-increment
                segmented_iterator& operator++() {
                    advance_me();
                    return *this;
                }

                // post-increment
                segmented_iterator operator++(int) {
                    segmented_iterator tmp = *this;
                    operator++();
                    return tmp;
                }

                bool operator==(const outer_iterator& other_outer) const {
                    __TBB_ASSERT(my_segcont != NULL, NULL);
                    return (outer_iter == other_outer &&
                            (outer_iter == my_segcont->end() || inner_iter == outer_iter->begin()));
                }

                bool operator!=(const outer_iterator& other_outer) const {
                    return !operator==(other_outer);

                }

                // (i)* RHS
                reference operator*() const {
                    __TBB_ASSERT(my_segcont != NULL, NULL);
                    __TBB_ASSERT(outer_iter != my_segcont->end(), "Dereferencing a pointer at end of container");
                    __TBB_ASSERT(inner_iter != outer_iter->end(), NULL); // should never happen
                    return *inner_iter;
                }

                // i->
                pointer operator->() const { return &operator*();}

            private:
                SegmentedContainer*             my_segcont;
                outer_iterator outer_iter;
                inner_iterator inner_iter;

                void advance_me() {
                    __TBB_ASSERT(my_segcont != NULL, NULL);
                    __TBB_ASSERT(outer_iter != my_segcont->end(), NULL); // not true if there are no inner containers
                    __TBB_ASSERT(inner_iter != outer_iter->end(), NULL); // not true if the inner containers are all empty.
                    ++inner_iter;
                    while(inner_iter == outer_iter->end() && ++outer_iter != my_segcont->end()) {
                        inner_iter = outer_iter->begin();
                    }
                }
        };    // segmented_iterator

        template<typename SegmentedContainer, typename T, typename U>
        bool operator==( const segmented_iterator<SegmentedContainer,T>& i, 
                         const segmented_iterator<SegmentedContainer,U>& j ) {
            if(i.my_segcont != j.my_segcont) return false;
            if(i.my_segcont == NULL) return true;
            if(i.outer_iter != j.outer_iter) return false;
            if(i.outer_iter == i.my_segcont->end()) return true;
            return i.inner_iter == j.inner_iter;
        }

        // !=
        template<typename SegmentedContainer, typename T, typename U>
        bool operator!=( const segmented_iterator<SegmentedContainer,T>& i, 
                         const segmented_iterator<SegmentedContainer,U>& j ) {
            return !(i==j);
        }

        template<typename T>
        struct destruct_only: tbb::internal::no_copy {
            tbb::aligned_space<T,1> value;
            ~destruct_only() {value.begin()[0].~T();}
        };

        template<typename T>
        struct construct_by_default: tbb::internal::no_assign {
            void construct(void*where) {new(where) T();} // C++ note: the () in T() ensure zero initialization.
            construct_by_default( int ) {}
        };

        template<typename T>
        struct construct_by_exemplar: tbb::internal::no_assign {
            const T exemplar;
            void construct(void*where) {new(where) T(exemplar);}
            construct_by_exemplar( const T& t ) : exemplar(t) {}
        };

        template<typename T, typename Finit>
        struct construct_by_finit: tbb::internal::no_assign {
            Finit f;
            void construct(void* where) {new(where) T(f());}
            construct_by_finit( const Finit& f_ ) : f(f_) {}
        };

        // storage for initialization function pointer
        template<typename T>
        class callback_base {
        public:
            // Clone *this
            virtual callback_base* clone() = 0;
            // Destruct and free *this
            virtual void destroy() = 0;
            // Need virtual destructor to satisfy GCC compiler warning
            virtual ~callback_base() { }
            // Construct T at where
            virtual void construct(void* where) = 0;
        };

        template <typename T, typename Constructor>
        class callback_leaf: public callback_base<T>, Constructor {
            template<typename X> callback_leaf( const X& x ) : Constructor(x) {}

            typedef typename tbb::tbb_allocator<callback_leaf> my_allocator_type;

            /*override*/ callback_base<T>* clone() {
                void* where = my_allocator_type().allocate(1);
                return new(where) callback_leaf(*this);
            }

            /*override*/ void destroy() {
                my_allocator_type().destroy(this);
                my_allocator_type().deallocate(this,1);
            }

            /*override*/ void construct(void* where) {
                Constructor::construct(where);
            }  
        public:
            template<typename X>
            static callback_base<T>* make( const X& x ) {
                void* where = my_allocator_type().allocate(1);
                return new(where) callback_leaf(x);
            }
        };


        template<typename U, size_t ModularSize>
        struct ets_element {
            char value[ModularSize==0 ? sizeof(U) : sizeof(U)+(tbb::internal::NFS_MaxLineSize-ModularSize)];
            void unconstruct() {
                tbb::internal::punned_cast<U*>(&value)->~U();
            }
        };

    } // namespace internal


    template <typename T, 
              typename Allocator=cache_aligned_allocator<T>, 
              ets_key_usage_type ETS_key_type=ets_no_key > 
    class enumerable_thread_specific: internal::ets_base<ETS_key_type> { 

        template<typename U, typename A, ets_key_usage_type C> friend class enumerable_thread_specific;
    
        typedef internal::ets_element<T,sizeof(T)%tbb::internal::NFS_MaxLineSize> padded_element;

        template<typename I>
        class generic_range_type: public blocked_range<I> {
        public:
            typedef T value_type;
            typedef T& reference;
            typedef const T& const_reference;
            typedef I iterator;
            typedef ptrdiff_t difference_type;
            generic_range_type( I begin_, I end_, size_t grainsize_ = 1) : blocked_range<I>(begin_,end_,grainsize_) {} 
            template<typename U>
            generic_range_type( const generic_range_type<U>& r) : blocked_range<I>(r.begin(),r.end(),r.grainsize()) {} 
            generic_range_type( generic_range_type& r, split ) : blocked_range<I>(r,split()) {}
        };
    
        typedef typename Allocator::template rebind< padded_element >::other padded_allocator_type;
        typedef tbb::concurrent_vector< padded_element, padded_allocator_type > internal_collection_type;
        
        internal::callback_base<T> *my_construct_callback;

        internal_collection_type my_locals;
   
        /*override*/ void* create_local() {
#if TBB_DEPRECATED
            void* lref = &my_locals[my_locals.push_back(padded_element())];
#else
            void* lref = &*my_locals.push_back(padded_element());
#endif
            my_construct_callback->construct(lref);
            return lref;
        } 

        void unconstruct_locals() {
            for(typename internal_collection_type::iterator cvi = my_locals.begin(); cvi != my_locals.end(); ++cvi) {
                cvi->unconstruct();
            }
        }

        typedef typename Allocator::template rebind< uintptr_t >::other array_allocator_type;

        // _size is in bytes
        /*override*/ void* create_array(size_t _size) {
            size_t nelements = (_size + sizeof(uintptr_t) -1) / sizeof(uintptr_t);
            return array_allocator_type().allocate(nelements);
        }

        /*override*/ void free_array( void* _ptr, size_t _size) {
            size_t nelements = (_size + sizeof(uintptr_t) -1) / sizeof(uintptr_t);
            array_allocator_type().deallocate( reinterpret_cast<uintptr_t *>(_ptr),nelements);
        }
   
    public:
    
        typedef Allocator allocator_type;
        typedef T value_type;
        typedef T& reference;
        typedef const T& const_reference;
        typedef T* pointer;
        typedef const T* const_pointer;
        typedef typename internal_collection_type::size_type size_type;
        typedef typename internal_collection_type::difference_type difference_type;
    
        // Iterator types
        typedef typename internal::enumerable_thread_specific_iterator< internal_collection_type, value_type > iterator;
        typedef typename internal::enumerable_thread_specific_iterator< internal_collection_type, const value_type > const_iterator;

        // Parallel range types
        typedef generic_range_type< iterator > range_type;
        typedef generic_range_type< const_iterator > const_range_type;
    
        enumerable_thread_specific() : 
            my_construct_callback( internal::callback_leaf<T,internal::construct_by_default<T> >::make(/*dummy argument*/0) ) 
        {}

        template <typename Finit>
        enumerable_thread_specific( Finit finit ) : 
            my_construct_callback( internal::callback_leaf<T,internal::construct_by_finit<T,Finit> >::make( finit ) ) 
        {}
    
        enumerable_thread_specific(const T& exemplar) : 
            my_construct_callback( internal::callback_leaf<T,internal::construct_by_exemplar<T> >::make( exemplar ) )
        {}
    
        ~enumerable_thread_specific() { 
            my_construct_callback->destroy();
            this->clear();  // deallocation before the derived class is finished destructing
            // So free(array *) is still accessible
        }
      
        reference local() {
            bool exists;
            return local(exists);
        }

        reference local(bool& exists)  {
            void* ptr = this->table_lookup(exists);
            return *(T*)ptr;
        }

        size_type size() const { return my_locals.size(); }
    
        bool empty() const { return my_locals.empty(); }
    
        iterator begin() { return iterator( my_locals, 0 ); }
        iterator end() { return iterator(my_locals, my_locals.size() ); }
    
        const_iterator begin() const { return const_iterator(my_locals, 0); }
    
        const_iterator end() const { return const_iterator(my_locals, my_locals.size()); }

        range_type range( size_t grainsize=1 ) { return range_type( begin(), end(), grainsize ); } 
        
        const_range_type range( size_t grainsize=1 ) const { return const_range_type( begin(), end(), grainsize ); }

        void clear() {
            unconstruct_locals();
            my_locals.clear();
            this->table_clear();
            // callback is not destroyed
            // exemplar is not destroyed
        }

    private:

        template<typename U, typename A2, ets_key_usage_type C2>
        void internal_copy( const enumerable_thread_specific<U, A2, C2>& other);

    public:

        template<typename U, typename Alloc, ets_key_usage_type Cachetype>
        enumerable_thread_specific( const enumerable_thread_specific<U, Alloc, Cachetype>& other ) : internal::ets_base<ETS_key_type> ()
        {
            internal_copy(other);
        }

        enumerable_thread_specific( const enumerable_thread_specific& other ) : internal::ets_base<ETS_key_type> ()
        {
            internal_copy(other);
        }

    private:

        template<typename U, typename A2, ets_key_usage_type C2>
        enumerable_thread_specific &
        internal_assign(const enumerable_thread_specific<U, A2, C2>& other) {
            if(static_cast<void *>( this ) != static_cast<const void *>( &other )) {
                this->clear(); 
                my_construct_callback->destroy();
                my_construct_callback = 0;
                internal_copy( other );
            }
            return *this;
        }

    public:

        // assignment
        enumerable_thread_specific& operator=(const enumerable_thread_specific& other) {
            return internal_assign(other);
        }

        template<typename U, typename Alloc, ets_key_usage_type Cachetype>
        enumerable_thread_specific& operator=(const enumerable_thread_specific<U, Alloc, Cachetype>& other)
        {
            return internal_assign(other);
        }

        // combine_func_t has signature T(T,T) or T(const T&, const T&)
        template <typename combine_func_t>
        T combine(combine_func_t f_combine) {
            if(begin() == end()) {
                internal::destruct_only<T> location;
                my_construct_callback->construct(location.value.begin());
                return *location.value.begin();
            }
            const_iterator ci = begin();
            T my_result = *ci;
            while(++ci != end()) 
                my_result = f_combine( my_result, *ci );
            return my_result;
        }

        // combine_func_t has signature void(T) or void(const T&)
        template <typename combine_func_t>
        void combine_each(combine_func_t f_combine) {
            for(const_iterator ci = begin(); ci != end(); ++ci) {
                f_combine( *ci );
            }
        }

    }; // enumerable_thread_specific

    template <typename T, typename Allocator, ets_key_usage_type ETS_key_type> 
    template<typename U, typename A2, ets_key_usage_type C2>
    void enumerable_thread_specific<T,Allocator,ETS_key_type>::internal_copy( const enumerable_thread_specific<U, A2, C2>& other) {
        // Initialize my_construct_callback first, so that it is valid even if rest of this routine throws an exception.
        my_construct_callback = other.my_construct_callback->clone();

        typedef internal::ets_base<ets_no_key> base;
        __TBB_ASSERT(my_locals.size()==0,NULL);
        this->table_reserve_for_copy( other );
        for( base::array* r=other.my_root; r; r=r->next ) {
            for( size_t i=0; i<r->size(); ++i ) {
                base::slot& s1 = r->at(i);
                if( !s1.empty() ) {
                    base::slot& s2 = this->table_find(s1.key);
                    if( s2.empty() ) { 
#if TBB_DEPRECATED
                        void* lref = &my_locals[my_locals.push_back(padded_element())];
#else
                        void* lref = &*my_locals.push_back(padded_element());
#endif
                        s2.ptr = new(lref) T(*(U*)s1.ptr);
                        s2.key = s1.key;
                    } else {
                        // Skip the duplicate
                    } 
                }
            }
        }
    }

    template< typename Container >
    class flattened2d {

        // This intermediate typedef is to address issues with VC7.1 compilers
        typedef typename Container::value_type conval_type;

    public:

        typedef typename conval_type::size_type size_type;
        typedef typename conval_type::difference_type difference_type;
        typedef typename conval_type::allocator_type allocator_type;
        typedef typename conval_type::value_type value_type;
        typedef typename conval_type::reference reference;
        typedef typename conval_type::const_reference const_reference;
        typedef typename conval_type::pointer pointer;
        typedef typename conval_type::const_pointer const_pointer;

        typedef typename internal::segmented_iterator<Container, value_type> iterator;
        typedef typename internal::segmented_iterator<Container, const value_type> const_iterator;

        flattened2d( const Container &c, typename Container::const_iterator b, typename Container::const_iterator e ) : 
            my_container(const_cast<Container*>(&c)), my_begin(b), my_end(e) { }

        flattened2d( const Container &c ) : 
            my_container(const_cast<Container*>(&c)), my_begin(c.begin()), my_end(c.end()) { }

        iterator begin() { return iterator(*my_container) = my_begin; }
        iterator end() { return iterator(*my_container) = my_end; }
        const_iterator begin() const { return const_iterator(*my_container) = my_begin; }
        const_iterator end() const { return const_iterator(*my_container) = my_end; }

        size_type size() const {
            size_type tot_size = 0;
            for(typename Container::const_iterator i = my_begin; i != my_end; ++i) {
                tot_size += i->size();
            }
            return tot_size;
        }

    private:

        Container *my_container;
        typename Container::const_iterator my_begin;
        typename Container::const_iterator my_end;

    };

    template <typename Container>
    flattened2d<Container> flatten2d(const Container &c, const typename Container::const_iterator b, const typename Container::const_iterator e) {
        return flattened2d<Container>(c, b, e);
    }

    template <typename Container>
    flattened2d<Container> flatten2d(const Container &c) {
        return flattened2d<Container>(c);
    }

} // interface6

namespace internal {
using interface6::internal::segmented_iterator;
}

using interface6::enumerable_thread_specific;
using interface6::flattened2d;
using interface6::flatten2d;

} // namespace tbb

#endif

---

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