ACE_Dynamic_Cached_Allocator< ACE_LOCK > Class Template Reference

A size-based allocator that caches blocks for quicker access. More...

#include <Malloc_T.h>

Inheritance diagram for ACE_Dynamic_Cached_Allocator< ACE_LOCK >:

[legend]Collaboration diagram for ACE_Dynamic_Cached_Allocator< ACE_LOCK >:

[legend]List of all members.

Public Member Functions
	ACE_Dynamic_Cached_Allocator (size_t n_chunks, size_t chunk_size)
	~ACE_Dynamic_Cached_Allocator (void)
	Clear things up.
void *	malloc (size_t nbytes=0)
virtual void *	calloc (size_t nbytes, char initial_value= '\0')
virtual void *	calloc (size_t n_elem, size_t elem_size, char initial_value= '\0')
void	free (void *)
	Return a chunk of memory back to free list cache.
size_t	pool_depth (void)
	Return the number of chunks available in the cache.
Private Attributes
char *	pool_
ACE_Locked_Free_List< ACE_Cached_Mem_Pool_Node< char >, ACE_LOCK >	free_list_
size_t	chunk_size_
	Remember the size of our chunks.

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Detailed Description

template<class ACE_LOCK>
class ACE_Dynamic_Cached_Allocator< ACE_LOCK >

A size-based allocator that caches blocks for quicker access.

This class enables caching of dynamically allocated, fixed-size chunks. Notice that the chunk_size must be greater than or equal to sizeof (void*) for this to work properly.

This class can be configured flexibly with different types of ACE_LOCK strategies that support the ACE_Thread_Mutex and ACE_Process_Mutex constructor API.

See also:

ACE_Cached_Allocator

Definition at line 150 of file Malloc_T.h.

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Constructor & Destructor Documentation

template<class ACE_LOCK> ACE_Dynamic_Cached_Allocator< ACE_LOCK >::ACE_Dynamic_Cached_Allocator (  size_t  n_chunks, size_t  chunk_size )

Create a cached memory pool with n_chunks chunks each with chunk_size size. Definition at line 105 of file Malloc_T.cpp. References ACE_MALLOC_ALIGN, ACE_MALLOC_ROUNDUP, and ACE_NEW. : pool_ (0), free_list_ (ACE_PURE_FREE_LIST), chunk_size_(chunk_size) { chunk_size = ACE_MALLOC_ROUNDUP (chunk_size, ACE_MALLOC_ALIGN); ACE_NEW (this->pool_, char[n_chunks * chunk_size_]); for (size_t c = 0; c < n_chunks; c++) { void* placement = this->pool_ + c * chunk_size_; this->free_list_.add (new (placement) ACE_Cached_Mem_Pool_Node<char>); } // Put into free list using placement contructor, no real memory // allocation in the above <new>. }

template<class ACE_LOCK> ACE_Dynamic_Cached_Allocator< ACE_LOCK >::~ACE_Dynamic_Cached_Allocator (  void   )

Clear things up. Definition at line 126 of file Malloc_T.cpp. References ACE_Dynamic_Cached_Allocator< ACE_LOCK >::chunk_size_. { delete [] this->pool_; this->pool_ = 0; chunk_size_ = 0; }

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Member Function Documentation

template<class ACE_LOCK> void * ACE_Dynamic_Cached_Allocator< ACE_LOCK >::calloc (  size_t  n_elem, size_t  elem_size, char  initial_value = '\0' )  [virtual]

This method is a no-op and just returns 0 since the free list only works with fixed sized entities. Reimplemented from ACE_New_Allocator. Definition at line 162 of file Malloc_T.cpp. References ACE_NOTSUP_RETURN. { ACE_NOTSUP_RETURN (0); }

template<class ACE_LOCK> void * ACE_Dynamic_Cached_Allocator< ACE_LOCK >::calloc (  size_t  nbytes, char  initial_value = '\0' )  [virtual]

Get a chunk of memory from free list cache, giving them initial_value. Note that nbytes is only checked to make sure that it's less or equal to chunk_size, and is otherwise ignored since calloc() always returns a pointer to an item of chunk_size. Reimplemented from ACE_New_Allocator. Definition at line 146 of file Malloc_T.cpp. References ACE_Cached_Mem_Pool_Node< char >::addr(), ACE_Dynamic_Cached_Allocator< ACE_LOCK >::chunk_size_, ACE_OS::memset(), and ACE_Locked_Free_List< ACE_Cached_Mem_Pool_Node< char >, ACE_LOCK >::remove(). { // Check if size requested fits within pre-determined size. if (nbytes > chunk_size_) return 0; // addr() call is really not absolutely necessary because of the way // ACE_Cached_Mem_Pool_Node's internal structure arranged. void *ptr = this->free_list_.remove ()->addr (); if (ptr != 0) ACE_OS::memset (ptr, initial_value, chunk_size_); return ptr; }

template<class ACE_LOCK> void ACE_Dynamic_Cached_Allocator< ACE_LOCK >::free (  void *   )  [virtual]

Return a chunk of memory back to free list cache. Reimplemented from ACE_New_Allocator. Definition at line 168 of file Malloc_T.cpp. References ACE_Locked_Free_List< ACE_Cached_Mem_Pool_Node< char >, ACE_LOCK >::add(). { if (ptr != 0) this->free_list_.add ((ACE_Cached_Mem_Pool_Node<char> *) ptr); }

template<class ACE_LOCK> void * ACE_Dynamic_Cached_Allocator< ACE_LOCK >::malloc (  size_t  nbytes = 0  )  [virtual]

Get a chunk of memory from free list cache. Note that nbytes is only checked to make sure that it's less or equal to chunk_size, and is otherwise ignored since malloc() always returns a pointer to an item of chunk_size size. Reimplemented from ACE_New_Allocator. Definition at line 134 of file Malloc_T.cpp. References ACE_Cached_Mem_Pool_Node< char >::addr(), ACE_Dynamic_Cached_Allocator< ACE_LOCK >::chunk_size_, and ACE_Locked_Free_List< ACE_Cached_Mem_Pool_Node< char >, ACE_LOCK >::remove(). { // Check if size requested fits within pre-determined size. if (nbytes > chunk_size_) return 0; // addr() call is really not absolutely necessary because of the way // ACE_Cached_Mem_Pool_Node's internal structure arranged. return this->free_list_.remove ()->addr (); }

template<class ACE_LOCK> ACE_INLINE size_t ACE_Dynamic_Cached_Allocator< ACE_LOCK >::pool_depth (  void   )

Return the number of chunks available in the cache. Definition at line 37 of file Malloc_T.inl. References ACE_Locked_Free_List< ACE_Cached_Mem_Pool_Node< char >, ACE_LOCK >::size(). { return this->free_list_.size (); }

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Member Data Documentation

template<class ACE_LOCK> size_t ACE_Dynamic_Cached_Allocator< ACE_LOCK >::chunk_size_ [private]

Remember the size of our chunks. Definition at line 201 of file Malloc_T.h. Referenced by ACE_Dynamic_Cached_Allocator< ACE_LOCK >::calloc(), ACE_Dynamic_Cached_Allocator< ACE_LOCK >::malloc(), and ACE_Dynamic_Cached_Allocator< ACE_LOCK >::~ACE_Dynamic_Cached_Allocator().

template<class ACE_LOCK> ACE_Locked_Free_List<ACE_Cached_Mem_Pool_Node<char>, ACE_LOCK> ACE_Dynamic_Cached_Allocator< ACE_LOCK >::free_list_ [private]

Maintain a cached memory free list. We use char as template parameter, although sizeof(char) is usually less than sizeof(void*). Really important is that chunk_size must be greater or equal to sizeof(void*). Definition at line 198 of file Malloc_T.h.

template<class ACE_LOCK> char* ACE_Dynamic_Cached_Allocator< ACE_LOCK >::pool_ [private]

Remember how we allocate the memory in the first place so we can clear things up later. Definition at line 192 of file Malloc_T.h.

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The documentation for this class was generated from the following files:

• Malloc_T.h
• Malloc_T.cpp
• Malloc_T.inl

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