ACE/ace/Sbrk_Memory_Pool.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file     Sbrk_Memory_Pool.h
   6  *
   7  *  @author Dougls C. Schmidt <d.schmidt@vanderbilt.edu>
   8  *  @author Prashant Jain <pjain@cs.wustl.edu>
   9  */
  10 //=============================================================================
  11
  12 #ifndef ACE_SBRK_MEMORY_POOL_H
  13 #define ACE_SBRK_MEMORY_POOL_H
  14
  15 #include /**/ "ace/pre.h"
  16
  17 #include /**/ "ace/ACE_export.h"
  18
  19 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  20 # pragma once
  21 #endif /* ACE_LACKS_PRAGMA_ONCE */
  22
  23 #if !defined (ACE_LACKS_SBRK)
  24
  25 #include "ace/ACE.h"
  26 #include "ace/os_include/sys/os_mman.h"
  27
  28
  29 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  30
  31 /**
  32  * @class ACE_Sbrk_Memory_Pool_Options
  33  *
  34  * @brief Helper class for Sbrk Memory Pool constructor options.
  35  *
  36  * This should be a nested class, but that breaks too many
  37  * compilers.
  38  */
  39 class ACE_Export ACE_Sbrk_Memory_Pool_Options
  40 {
  41 };
  42
  43 /**
  44  * @class ACE_Sbrk_Memory_Pool
  45  *
  46  * @brief Make a memory pool that is based on <sbrk(2)>.
  47  */
  48 class ACE_Export ACE_Sbrk_Memory_Pool
  49 {
  50 public:
  51   typedef ACE_Sbrk_Memory_Pool_Options OPTIONS;
  52
  53   /// Initialize the pool.
  54   ACE_Sbrk_Memory_Pool (const ACE_TCHAR *backing_store_name = 0,
  55                         const OPTIONS *options = 0);
  56
  57   virtual ~ACE_Sbrk_Memory_Pool ();
  58
  59   // = Implementor operations.
  60   /// Ask system for initial chunk of local memory.
  61   virtual void *init_acquire (size_t nbytes,
  62                               size_t &rounded_bytes,
  63                               int &first_time);
  64
  65   /// Acquire at least @a nbytes from the memory pool. @a rounded_bytes is
  66   /// the actual number of bytes allocated.
  67   virtual void *acquire (size_t nbytes,
  68                          size_t &rounded_bytes);
  69
  70   /// Instruct the memory pool to release all of its resources.
  71   virtual int release (int destroy = 1);
  72
  73   /**
  74    * Sync @a len bytes of the memory region to the backing store
  75    * starting at @c this->base_addr_.  If @a len == -1 then sync the
  76    * whole region.
  77    */
  78   virtual int sync (ssize_t len = -1, int flags = MS_SYNC);
  79
  80   /// Sync @a len bytes of the memory region to the backing store
  81   /// starting at @a addr.
  82   virtual int sync (void *addr, size_t len, int flags = MS_SYNC);
  83
  84   /**
  85    * Change the protection of the pages of the mapped region to @a prot
  86    * starting at @c this->base_addr_ up to @a len bytes.  If @a len == -1
  87    * then change protection of all pages in the mapped region.
  88    */
  89   virtual int protect (ssize_t len = -1, int prot = PROT_RDWR);
  90
  91   /// Change the protection of the pages of the mapped region to @a prot
  92   /// starting at @a addr up to @a len bytes.
  93   virtual int protect (void *addr, size_t len, int prot = PROT_RDWR);
  94
  95   /// Dump the state of an object.
  96   virtual void dump () const;
  97
  98   /// Return the base address of this memory pool, 0 if base_addr
  99   /// never changes.
 100   virtual void *base_addr () const;
 101
 102   /// Declare the dynamic allocation hooks.
 103   ACE_ALLOC_HOOK_DECLARE;
 104
 105 protected:
 106   /// Implement the algorithm for rounding up the request to an
 107   /// appropriate chunksize.
 108   virtual size_t round_up (size_t nbytes);
 109 };
 110
 111 ACE_END_VERSIONED_NAMESPACE_DECL
 112
 113 #endif /* !ACE_LACKS_SBRK */
 114
 115 #include /**/ "ace/post.h"
 116 #endif /* ACE_SBRK_MEMORY_POOL_H */