concurrent_queue.h

/*
    Copyright 2005-2016 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks. Threading Building Blocks is free software;
    you can redistribute it and/or modify it under the terms of the GNU General Public License
    version 2  as  published  by  the  Free Software Foundation.  Threading Building Blocks is
    distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
    implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    See  the GNU General Public License for more details.   You should have received a copy of
    the  GNU General Public License along with Threading Building Blocks; if not, write to the
    Free Software Foundation, Inc.,  51 Franklin St,  Fifth Floor,  Boston,  MA 02110-1301 USA

    As a special exception,  you may use this file  as part of a free software library without
    restriction.  Specifically,  if other files instantiate templates  or use macros or inline
    functions from this file, or you compile this file and link it with other files to produce
    an executable,  this file does not by itself cause the resulting executable to be covered
    by the GNU General Public License. This exception does not however invalidate any other
    reasons why the executable file might be covered by the GNU General Public License.
*/

#ifndef __TBB_concurrent_queue_H
#define __TBB_concurrent_queue_H

#include "internal/_concurrent_queue_impl.h"

namespace tbb {

namespace strict_ppl {


template<typename T, typename A = cache_aligned_allocator<T> >
class concurrent_queue: public internal::concurrent_queue_base_v3<T> {
    template<typename Container, typename Value> friend class internal::concurrent_queue_iterator;

    typedef typename A::template rebind<char>::other page_allocator_type;
    page_allocator_type my_allocator;

    /*override*/ virtual void *allocate_block( size_t n ) {
        void *b = reinterpret_cast<void*>(my_allocator.allocate( n ));
        if( !b )
            internal::throw_exception(internal::eid_bad_alloc);
        return b;
    }

    /*override*/ virtual void deallocate_block( void *b, size_t n ) {
        my_allocator.deallocate( reinterpret_cast<char*>(b), n );
    }

    static void copy_construct_item(T* location, const void* src){
        new (location) T(*static_cast<const T*>(src));
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    static void move_construct_item(T* location, const void* src) {
        new (location) T( std::move(*static_cast<T*>(const_cast<void*>(src))) );
    }
#endif /* __TBB_CPP11_RVALUE_REF_PRESENT */
public:
    typedef T value_type;

    typedef T& reference;

    typedef const T& const_reference;

    typedef size_t size_type;

    typedef ptrdiff_t difference_type;

    typedef A allocator_type;

    explicit concurrent_queue(const allocator_type& a = allocator_type()) :
        my_allocator( a )
    {
    }

    template<typename InputIterator>
    concurrent_queue( InputIterator begin, InputIterator end, const allocator_type& a = allocator_type()) :
        my_allocator( a )
    {
        for( ; begin != end; ++begin )
            this->push(*begin);
    }

    concurrent_queue( const concurrent_queue& src, const allocator_type& a = allocator_type()) :
        internal::concurrent_queue_base_v3<T>(), my_allocator( a )
    {
        this->assign( src, copy_construct_item );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    concurrent_queue( concurrent_queue&& src ) :
        internal::concurrent_queue_base_v3<T>(), my_allocator( std::move(src.my_allocator) )
    {
        this->internal_swap( src );
    }

    concurrent_queue( concurrent_queue&& src, const allocator_type& a ) :
        internal::concurrent_queue_base_v3<T>(), my_allocator( a )
    {
        // checking that memory allocated by one instance of allocator can be deallocated
        // with another
        if( my_allocator == src.my_allocator) {
            this->internal_swap( src );
        } else {
            // allocators are different => performing per-element move
            this->assign( src, move_construct_item );
            src.clear();
        }
    }
#endif /* __TBB_CPP11_RVALUE_REF_PRESENT */

    ~concurrent_queue();

    void push( const T& source ) {
        this->internal_push( &source, copy_construct_item );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    void push( T&& source ) {
        this->internal_push( &source, move_construct_item );
    }

#if __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT
    template<typename... Arguments>
    void emplace( Arguments&&... args ) {
        push( T(std::forward<Arguments>( args )...) );
    }
#endif //__TBB_CPP11_VARIADIC_TEMPLATES_PRESENT
#endif /* __TBB_CPP11_RVALUE_REF_PRESENT */


    bool try_pop( T& result ) {
        return this->internal_try_pop( &result );
    }

    size_type unsafe_size() const {return this->internal_size();}

    bool empty() const {return this->internal_empty();}

    void clear() ;

    allocator_type get_allocator() const { return this->my_allocator; }

    typedef internal::concurrent_queue_iterator<concurrent_queue,T> iterator;
    typedef internal::concurrent_queue_iterator<concurrent_queue,const T> const_iterator;

    //------------------------------------------------------------------------
    // The iterators are intended only for debugging.  They are slow and not thread safe.
    //------------------------------------------------------------------------
    iterator unsafe_begin() {return iterator(*this);}
    iterator unsafe_end() {return iterator();}
    const_iterator unsafe_begin() const {return const_iterator(*this);}
    const_iterator unsafe_end() const {return const_iterator();}
} ;

template<typename T, class A>
concurrent_queue<T,A>::~concurrent_queue() {
    clear();
    this->internal_finish_clear();
}

template<typename T, class A>
void concurrent_queue<T,A>::clear() {
    T value;
    while( !empty() ) try_pop(value);
}

} // namespace strict_ppl


template<typename T, class A = cache_aligned_allocator<T> >
class concurrent_bounded_queue: public internal::concurrent_queue_base_v8 {
    template<typename Container, typename Value> friend class internal::concurrent_queue_iterator;

    typedef typename A::template rebind<char>::other page_allocator_type;
    page_allocator_type my_allocator;

    typedef typename concurrent_queue_base_v3::padded_page<T> padded_page;
    typedef typename concurrent_queue_base_v3::copy_specifics copy_specifics;

    class destroyer: internal::no_copy {
        T& my_value;
    public:
        destroyer( T& value ) : my_value(value) {}
        ~destroyer() {my_value.~T();}
    };

    T& get_ref( page& p, size_t index ) {
        __TBB_ASSERT( index<items_per_page, NULL );
        return (&static_cast<padded_page*>(static_cast<void*>(&p))->last)[index];
    }

    /*override*/ virtual void copy_item( page& dst, size_t index, const void* src ) {
        new( &get_ref(dst,index) ) T(*static_cast<const T*>(src));
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    /*override*/ virtual void move_item( page& dst, size_t index, const void* src ) {
        new( &get_ref(dst,index) ) T( std::move(*static_cast<T*>(const_cast<void*>(src))) );
    }
#else
    /*override*/ virtual void move_item( page&, size_t, const void* ) {
        __TBB_ASSERT( false, "Unreachable code" );
    }
#endif

    /*override*/ virtual void copy_page_item( page& dst, size_t dindex, const page& src, size_t sindex ) {
        new( &get_ref(dst,dindex) ) T( get_ref( const_cast<page&>(src), sindex ) );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    /*override*/ virtual void move_page_item( page& dst, size_t dindex, const page& src, size_t sindex ) {
        new( &get_ref(dst,dindex) ) T( std::move(get_ref( const_cast<page&>(src), sindex )) );
    }
#else
    /*override*/ virtual void move_page_item( page&, size_t, const page&, size_t ) {
        __TBB_ASSERT( false, "Unreachable code" );
    }
#endif

    /*override*/ virtual void assign_and_destroy_item( void* dst, page& src, size_t index ) {
        T& from = get_ref(src,index);
        destroyer d(from);
        *static_cast<T*>(dst) = tbb::internal::move( from );
    }

    /*override*/ virtual page *allocate_page() {
        size_t n = sizeof(padded_page) + (items_per_page-1)*sizeof(T);
        page *p = reinterpret_cast<page*>(my_allocator.allocate( n ));
        if( !p )
            internal::throw_exception(internal::eid_bad_alloc);
        return p;
    }

    /*override*/ virtual void deallocate_page( page *p ) {
        size_t n = sizeof(padded_page) + (items_per_page-1)*sizeof(T);
        my_allocator.deallocate( reinterpret_cast<char*>(p), n );
    }

public:
    typedef T value_type;

    typedef A allocator_type;

    typedef T& reference;

    typedef const T& const_reference;


    typedef std::ptrdiff_t size_type;

    typedef std::ptrdiff_t difference_type;

    explicit concurrent_bounded_queue(const allocator_type& a = allocator_type()) :
        concurrent_queue_base_v8( sizeof(T) ), my_allocator( a )
    {
    }

    concurrent_bounded_queue( const concurrent_bounded_queue& src, const allocator_type& a = allocator_type())
        : concurrent_queue_base_v8( sizeof(T) ), my_allocator( a )
    {
        assign( src );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    concurrent_bounded_queue( concurrent_bounded_queue&& src )
        : concurrent_queue_base_v8( sizeof(T) ), my_allocator( std::move(src.my_allocator) )
    {
        internal_swap( src );
    }

    concurrent_bounded_queue( concurrent_bounded_queue&& src, const allocator_type& a )
        : concurrent_queue_base_v8( sizeof(T) ), my_allocator( a )
    {
        // checking that memory allocated by one instance of allocator can be deallocated
        // with another
        if( my_allocator == src.my_allocator) {
            this->internal_swap( src );
        } else {
            // allocators are different => performing per-element move
            this->move_content( src );
            src.clear();
        }
    }
#endif /* __TBB_CPP11_RVALUE_REF_PRESENT */

    template<typename InputIterator>
    concurrent_bounded_queue( InputIterator begin, InputIterator end,
                              const allocator_type& a = allocator_type())
        : concurrent_queue_base_v8( sizeof(T) ), my_allocator( a )
    {
        for( ; begin != end; ++begin )
            internal_push_if_not_full(&*begin);
    }

    ~concurrent_bounded_queue();

    void push( const T& source ) {
        internal_push( &source );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    void push( T&& source ) {
        internal_push_move( &source );
    }

#if __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT
    template<typename... Arguments>
    void emplace( Arguments&&... args ) {
        push( T(std::forward<Arguments>( args )...) );
    }
#endif /* __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT */
#endif /* __TBB_CPP11_RVALUE_REF_PRESENT */


    void pop( T& destination ) {
        internal_pop( &destination );
    }

#if TBB_USE_EXCEPTIONS
    void abort() {
        internal_abort();
    }
#endif


    bool try_push( const T& source ) {
        return internal_push_if_not_full( &source );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT

    bool try_push( T&& source ) {
        return internal_push_move_if_not_full( &source );
    }
#if __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT
    template<typename... Arguments>
    bool try_emplace( Arguments&&... args ) {
        return try_push( T(std::forward<Arguments>( args )...) );
    }
#endif /* __TBB_CPP11_VARIADIC_TEMPLATES_PRESENT */
#endif /* __TBB_CPP11_RVALUE_REF_PRESENT */


    bool try_pop( T& destination ) {
        return internal_pop_if_present( &destination );
    }


    size_type size() const {return internal_size();}

    bool empty() const {return internal_empty();}

    size_type capacity() const {
        return my_capacity;
    }


    void set_capacity( size_type new_capacity ) {
        internal_set_capacity( new_capacity, sizeof(T) );
    }

    allocator_type get_allocator() const { return this->my_allocator; }

    void clear() ;

    typedef internal::concurrent_queue_iterator<concurrent_bounded_queue,T> iterator;
    typedef internal::concurrent_queue_iterator<concurrent_bounded_queue,const T> const_iterator;

    //------------------------------------------------------------------------
    // The iterators are intended only for debugging.  They are slow and not thread safe.
    //------------------------------------------------------------------------
    iterator unsafe_begin() {return iterator(*this);}
    iterator unsafe_end() {return iterator();}
    const_iterator unsafe_begin() const {return const_iterator(*this);}
    const_iterator unsafe_end() const {return const_iterator();}

};

template<typename T, class A>
concurrent_bounded_queue<T,A>::~concurrent_bounded_queue() {
    clear();
    internal_finish_clear();
}

template<typename T, class A>
void concurrent_bounded_queue<T,A>::clear() {
    T value;
    while( try_pop(value) ) /*noop*/;
}

using strict_ppl::concurrent_queue;

} // namespace tbb

#endif /* __TBB_concurrent_queue_H */