Local_Memory_Pool.h

Go to the documentation of this file.

// -*- C++ -*-

//=============================================================================
/**
 *  @file     Local_Memory_Pool.h
 *
 *  $Id: Local_Memory_Pool.h 78476 2007-05-24 07:55:50Z johnnyw $
 *
 *  @author Dougls C. Schmidt <schmidt@cs.wustl.edu>
 *  @author Prashant Jain <pjain@cs.wustl.edu>
 */
//=============================================================================

#ifndef ACE_LOCAL_MEMORY_POOL_H
#define ACE_LOCAL_MEMORY_POOL_H
#include /**/ "ace/pre.h"

#include "ace/os_include/sys/os_mman.h"   /* Need PROT_RDWR */
#include "ace/ACE.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

#include "ace/Unbounded_Set.h"

ACE_BEGIN_VERSIONED_NAMESPACE_DECL

/**
 * @class ACE_Local_Memory_Pool_Options
 *
 * @brief Helper class for Local Memory Pool constructor options.
 *
 * This should be a nested class, but that breaks too many
 * compilers.
 */
class ACE_Export ACE_Local_Memory_Pool_Options
{
};

/**
 * @class ACE_Local_Memory_Pool
 *
 * @brief Make a memory pool that is based on C++ new/delete.  This is
 * useful for integrating existing components that use new/delete
 * into the ACE Malloc scheme...
 */
class ACE_Export ACE_Local_Memory_Pool
{
public:
  typedef ACE_Local_Memory_Pool_Options OPTIONS;

  /// Initialize the pool.
  ACE_Local_Memory_Pool (const ACE_TCHAR *backing_store_name = 0,
                         const OPTIONS *options = 0);

  virtual ~ACE_Local_Memory_Pool (void);

  /// Ask system for initial chunk of local memory.
  virtual void *init_acquire (size_t nbytes,
                              size_t &rounded_bytes,
                              int &first_time);

  /// Acquire at least @a nbytes from the memory pool. @a rounded_bytes is
  /// the actual number of bytes allocated.
  virtual void *acquire (size_t nbytes,
                         size_t &rounded_bytes);

  /// Instruct the memory pool to release all of its resources.
  virtual int release (int destroy = 1);

  /**
   * Sync @a len bytes of the memory region to the backing store
   * starting at <this->base_addr_>.  If @a len == -1 then sync the
   * whole region.
   */
  virtual int sync (ssize_t len = -1, int flags = MS_SYNC);

  /// Sync @a len bytes of the memory region to the backing store
  /// starting at @a add_.
  virtual int sync (void *addr, size_t len, int flags = MS_SYNC);

  /**
   * Change the protection of the pages of the mapped region to @a prot
   * starting at <this->base_addr_> up to @a len bytes.  If @a len == -1
   * then change protection of all pages in the mapped region.
   */
  virtual int protect (ssize_t len = -1, int prot = PROT_RDWR);

  /// Change the protection of the pages of the mapped region to @a prot
  /// starting at @a addr up to @a len bytes.
  virtual int protect (void *addr, size_t len, int prot = PROT_RDWR);

#if defined (ACE_WIN32)
  /**
   * Win32 Structural exception selector.  The return value decides
   * how to handle memory pool related structural exceptions.  Returns
   * 1, 0, or , -1.
   */
  virtual int seh_selector (void *);
#endif /* ACE_WIN32 */

  /**
   * Try to extend the virtual address space so that @a addr is now
   * covered by the address mapping.  Always returns 0 since we can't
   * remap a local memory pool.
   */
  virtual int remap (void *addr);

  /// Return the base address of this memory pool, 0 if base_addr
  /// never changes.
  virtual void *base_addr (void) const;

  /// Dump the state of an object.
  virtual void dump (void) const;

  /// Declare the dynamic allocation hooks.
  ACE_ALLOC_HOOK_DECLARE;

protected:
  /// List of memory that we have allocated.
  ACE_Unbounded_Set<char *> allocated_chunks_;

  /// Implement the algorithm for rounding up the request to an
  /// appropriate chunksize.
  virtual size_t round_up (size_t nbytes);

};

ACE_END_VERSIONED_NAMESPACE_DECL

#include /**/ "ace/post.h"
#endif /* ACE_LOCAL_MEMORY_POOL_H */

---