concurrentqueue/benchmarks/tbb/concurrent_queue.h

/*
    Copyright 2005-2014 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 {

//! A high-performance thread-safe non-blocking concurrent queue.
/** Multiple threads may each push and pop concurrently.
    Assignment construction is not allowed.
    @ingroup containers */
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;

    //! Allocator type
    typedef typename A::template rebind<char>::other page_allocator_type;
    page_allocator_type my_allocator;

    //! Allocates a block of size n (bytes)
    /*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;
    }

    //! Deallocates block created by allocate_block.
    /*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:
    //! Element type in the queue.
    typedef T value_type;

    //! Reference type
    typedef T& reference;

    //! Const reference type
    typedef const T& const_reference;

    //! Integral type for representing size of the queue.
    typedef size_t size_type;

    //! Difference type for iterator
    typedef ptrdiff_t difference_type;

    //! Allocator type
    typedef A allocator_type;

    //! Construct empty queue
    explicit concurrent_queue(const allocator_type& a = allocator_type()) :
        my_allocator( a )
    {
    }

    //! [begin,end) constructor
    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);
    }

    //! Copy constructor
    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
    //! Move constructors
    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 */

    //! Destroy queue
    ~concurrent_queue();

    //! Enqueue an item at tail of 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 */

    //! Attempt to dequeue an item from head of queue.
    /** Does not wait for item to become available.
        Returns true if successful; false otherwise. */
    bool try_pop( T& result ) {
        return this->internal_try_pop( &result );
    }

    //! Return the number of items in the queue; thread unsafe
    size_type unsafe_size() const {return this->internal_size();}

    //! Equivalent to size()==0.
    bool empty() const {return this->internal_empty();}

    //! Clear the queue. not thread-safe.
    void clear() ;

    //! Return allocator object
    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() {
    while( !empty() ) {
        T value;
        this->internal_try_pop(&value);
    }
}

} // namespace strict_ppl

//! A high-performance thread-safe blocking concurrent bounded queue.
/** This is the pre-PPL TBB concurrent queue which supports boundedness and blocking semantics.
    Note that method names agree with the PPL-style concurrent queue.
    Multiple threads may each push and pop concurrently.
    Assignment construction is not allowed.
    @ingroup containers */
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;

    //! Allocator type
    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 used to ensure exception-safety of method "pop"
    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:
    //! Element type in the queue.
    typedef T value_type;

    //! Allocator type
    typedef A allocator_type;

    //! Reference type
    typedef T& reference;

    //! Const reference type
    typedef const T& const_reference;

    //! Integral type for representing size of the queue.
    /** Note that the size_type is a signed integral type.
        This is because the size can be negative if there are pending pops without corresponding pushes. */
    typedef std::ptrdiff_t size_type;

    //! Difference type for iterator
    typedef std::ptrdiff_t difference_type;

    //! Construct empty queue
    explicit concurrent_bounded_queue(const allocator_type& a = allocator_type()) : 
        concurrent_queue_base_v8( sizeof(T) ), my_allocator( a )
    {
    }

    //! Copy constructor
    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
    //! Move constructors
    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 */

    //! [begin,end) constructor
    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);
    }

    //! Destroy queue
    ~concurrent_bounded_queue();

    //! Enqueue an item at tail of queue.
    void push( const T& source ) {
        internal_push( &source );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    //! Move an item at tail of queue.
    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 */

    //! Dequeue item from head of queue.
    /** Block until an item becomes available, and then dequeue it. */
    void pop( T& destination ) {
        internal_pop( &destination );
    }

#if TBB_USE_EXCEPTIONS
    //! Abort all pending queue operations
    void abort() {
        internal_abort();
    }
#endif

    //! Enqueue an item at tail of queue if queue is not already full.
    /** Does not wait for queue to become not full.
        Returns true if item is pushed; false if queue was already full. */
    bool try_push( const T& source ) {
        return internal_push_if_not_full( &source );
    }

#if __TBB_CPP11_RVALUE_REF_PRESENT
    //! Move an item at tail of queue if queue is not already full.
    /** Does not wait for queue to become not full.
        Returns true if item is pushed; false if queue was already full. */
    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 */

    //! Attempt to dequeue an item from head of queue.
    /** Does not wait for item to become available.
        Returns true if successful; false otherwise. */
    bool try_pop( T& destination ) {
        return internal_pop_if_present( &destination );
    }

    //! Return number of pushes minus number of pops.
    /** Note that the result can be negative if there are pops waiting for the 
        corresponding pushes.  The result can also exceed capacity() if there 
        are push operations in flight. */
    size_type size() const {return internal_size();}

    //! Equivalent to size()<=0.
    bool empty() const {return internal_empty();}

    //! Maximum number of allowed elements
    size_type capacity() const {
        return my_capacity;
    }

    //! Set the capacity
    /** Setting the capacity to 0 causes subsequent try_push operations to always fail,
        and subsequent push operations to block forever. */
    void set_capacity( size_type new_capacity ) {
        internal_set_capacity( new_capacity, sizeof(T) );
    }

    //! return allocator object
    allocator_type get_allocator() const { return this->my_allocator; }

    //! clear the queue. not thread-safe.
    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() {
    while( !empty() ) {
        T value;
        internal_pop_if_present(&value);
    }
}

using strict_ppl::concurrent_queue;

} // namespace tbb

#endif /* __TBB_concurrent_queue_H */