object_pool.hpp provides a template type that can be used for fast and efficient memory allocation. It also provides automatic destruction of non-deallocated objects. For information on other pool-based interfaces, see the other pool interfaces.
template <typename ElementType, typename UserAllocator = default_user_allocator_new_delete>
class object_pool
{
private:
object_pool(const object_pool &);
void operator=(const object_pool &);
public:
typedef ElementType element_type;
typedef UserAllocator user_allocator;
typedef typename pool<UserAllocator>::size_type size_type;
typedef typename pool<UserAllocator>::difference_type difference_type;
object_pool();
~object_pool();
element_type * malloc();
void free(element_type * p);
bool is_from(element_type * p) const;
element_type * construct();
// other construct() functions
void destroy(element_type * p);
};
The template parameter is the type of object to allocate/deallocate. It must have a non-throwing destructor.
Defines the method that the underlying Pool will use to allocate memory from the system. See User Allocators for details.
| Symbol | Meaning |
|---|---|
| ObjectPool | object_pool<ElementType, UserAllocator> |
| t | value of type ObjectPool |
| u | value of type const ObjectPool |
| p | value of type ElementType * |
| Expression | Type |
|---|---|
| ObjectPool::element_type | ElementType |
| ObjectPool::user_allocator | UserAllocator |
| ObjectPool::size_type | pool<UserAllocator>::size_type |
| ObjectPool::difference_type | pool<UserAllocator>::difference_type |
| Expression | Return Type | Notes |
|---|---|---|
| ObjectPool() | not used | Constructs a new empty ObjectPool |
| (&t)->~ObjectPool() | not used | Destructs the ObjectPool; ~ElementType() is called for each allocated ElementType that has not been deallocated. O(N). |
| u.is_from(p) | bool | Returns true if p was allocated from u or may be returned as the result of a future allocation from u. Returns false if p was allocated from some other pool or may be returned as the result of a future allocation from some other pool. Otherwise, the return value is meaningless; note that this function may not be used to reliably test random pointer values. |
| Expression | Return Type | Pre-Condition | Semantic Equivalence | Notes |
|---|---|---|---|---|
| t.malloc() | ElementType * | Allocates memory that can hold an object of type ElementType. If out of memory, returns 0. Amortized O(1). | ||
| t.free(p) | not used | p must have been previously allocated from t | Deallocates a chunk of memory. Note that p may not be 0. Note that the destructor for p is not called. O(N). | |
| t.construct(???) | ElementType * | ElementType must have a constructor matching ???; the number of parameters given must not exceed what is supported through pool_construct | Allocates and initializes an object of type ElementType. If out of memory, returns 0. Amortized O(1). | |
| t.destroy(p) | not used | p must have been previously allocated from t | p->~ElementType(); t.free(p); |
Revised 05 December, 2006
Copyright © 2000, 2001 Stephen Cleary (scleary AT jerviswebb DOT com)
Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)