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Class template adaptive_pool

boost::interprocess::adaptive_pool

Synopsis

// In header: <boost/interprocess/allocators/adaptive_pool.hpp>

template<typename T, typename SegmentManager,  NodesPerBlock, 
          MaxFreeBlocks,  OverheadPercent> 
class adaptive_pool {
public:
  // types
  typedef  ;
  typedef            ;   
  typedef          ;        
  typedef    ;  
  typedef                                        ;     
  typedef                              ;      
  typedef                              ;
  typedef               ;      
  typedef         ;

  // member classes/structs/unions
  template<typename T2> 
  struct rebind {
    // types
    typedef adaptive_pool<  ;
  };

  // construct/copy/destruct
  ();
  (adaptive_pool &);
  template<typename T2> 
    (adaptive_pool< );
  template<typename T2, typename SegmentManager2,  N2, 
            F2,  OP2> 
    adaptive_pool & 
    (adaptive_pool< );
  ~();

  // public member functions
   () ;
   () ;
   () ;
   (,  = );
   (, );
   ();
   () ;
   () ;
   () ;
   (, , 
                             , );
   (, , );
   (, , );
   ();
   ();
   (, );
   ();
   ();

  // friend functions
   (, );
};

Description

An STL node allocator that uses a segment manager as memory source. The internal pointer type will of the same type (raw, smart) as "typename SegmentManager::void_pointer" type. This allows placing the allocator in shared memory, memory mapped-files, etc...

This node allocator shares a segregated storage between all instances of adaptive_pool with equal sizeof(T) placed in the same segment group. NodesPerBlock is the number of nodes allocated at once when the allocator needs runs out of nodes. MaxFreeBlocks is the maximum number of totally free blocks that the adaptive node pool will hold. The rest of the totally free blocks will be deallocated with the segment manager.

OverheadPercent is the (approximated) maximum size overhead (1-20%) of the allocator: (memory usable for nodes / total memory allocated from the segment manager)

adaptive_pool public construct/copy/destruct

  1. ( segment_mngr);

    Not assignable from other adaptive_pool Constructor from a segment manager. If not present, constructs a node pool. Increments the reference count of the associated node pool. Can throw boost::interprocess::bad_alloc

  2. (adaptive_pool & other);

    Copy constructor from other adaptive_pool. Increments the reference count of the associated node pool. Never throws

  3. template<typename T2> 
      (adaptive_pool<  other);

    Copy constructor from related adaptive_pool. If not present, constructs a node pool. Increments the reference count of the associated node pool. Can throw boost::interprocess::bad_alloc

  4. template<typename T2, typename SegmentManager2,  N2, 
              F2,  OP2> 
      adaptive_pool & 
      (adaptive_pool< );

    Not assignable from related adaptive_pool

  5. ~();

    Destructor, removes node_pool_t from memory if its reference count reaches to zero. Never throws

adaptive_pool public member functions

  1.  () ;

    Returns a pointer to the node pool. Never throws

  2.  () ;

    Returns the segment manager. Never throws

  3.  () ;

    Returns the number of elements that could be allocated. Never throws

  4.  ( count,  hint = );

    Allocate memory for an array of count elements. Throws boost::interprocess::bad_alloc if there is no enough memory

  5.  ( ptr,  count);

    Deallocate allocated memory. Never throws

  6.  ();

    Deallocates all free blocks of the pool

  7.  ( value) ;

    Returns address of mutable object. Never throws

  8.  ( value) ;

    Returns address of non mutable object. Never throws

  9.  ( p) ;

    Returns maximum the number of objects the previously allocated memory pointed by p can hold. This size only works for memory allocated with allocate, allocation_command and allocate_many.

  10.  ( command, 
                                limit_size, 
                                prefer_in_recvd_out_size, 
                                reuse);
  11.  ( elem_size,  num_elements, 
                        chain);

    Allocates many elements of size elem_size in a contiguous block of memory. The minimum number to be allocated is min_elements, the preferred and maximum number is preferred_elements. The number of actually allocated elements is will be assigned to received_size. The elements must be deallocated with deallocate(...)

  12.  ( elem_sizes,  n_elements, 
                        chain);

    Allocates n_elements elements, each one of size elem_sizes[i]in a contiguous block of memory. The elements must be deallocated

  13.  ( chain);

    Allocates many elements of size elem_size in a contiguous block of memory. The minimum number to be allocated is min_elements, the preferred and maximum number is preferred_elements. The number of actually allocated elements is will be assigned to received_size. The elements must be deallocated with deallocate(...)

  14.  ();

    Allocates just one object. Memory allocated with this function must be deallocated only with deallocate_one(). Throws boost::interprocess::bad_alloc if there is no enough memory

  15.  ( num_elements, 
                              chain);

    Allocates many elements of size == 1 in a contiguous block of memory. The minimum number to be allocated is min_elements, the preferred and maximum number is preferred_elements. The number of actually allocated elements is will be assigned to received_size. Memory allocated with this function must be deallocated only with deallocate_one().

  16.  ( p);

    Deallocates memory previously allocated with allocate_one(). You should never use deallocate_one to deallocate memory allocated with other functions different from allocate_one(). Never throws

  17.  ( chain);

    Allocates many elements of size == 1 in a contiguous block of memory. The minimum number to be allocated is min_elements, the preferred and maximum number is preferred_elements. The number of actually allocated elements is will be assigned to received_size. Memory allocated with this function must be deallocated only with deallocate_one().

adaptive_pool friend functions

  1.  ( alloc1,  alloc2);

    Swaps allocators. Does not throw. If each allocator is placed in a different memory segment, the result is undefined.


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