ACE/ace/PI_Malloc.h

   1 // -*- C++ -*-
   2
   3 //==========================================================================
   4 /**
   5  *  @file   PI_Malloc.h
   6  *
   7  *  @author Priyanka Gontla <pgontla@ece.uci.edu>
   8  *  @author Based on code that existed in other ACE files.
   9  */
  10 //==========================================================================
  11
  12 #ifndef ACE_PI_MALLOC_H
  13 #define ACE_PI_MALLOC_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 (ACE_HAS_POSITION_INDEPENDENT_POINTERS == 1)
  24
  25 #include "ace/Malloc.h"
  26 #include "ace/Based_Pointer_T.h"
  27
  28 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  29
  30 // prepare for position independent malloc
  31 /**
  32  * @class ACE_PI_Control_Block
  33  *
  34  * @brief This information is stored in memory allocated by the Memory_Pool.
  35  *
  36  * This class implements the control block structure that can be
  37  * used in a "position independent" fashion, i.e., you don't need to
  38  * "map" the underlying memory pool to the same address in
  39  * processes sharing the memory.  The trade off of this flexibility
  40  * is more expensive malloc/free operations.
  41  */
  42 class ACE_Export ACE_PI_Control_Block
  43 {
  44 public:
  45   class ACE_Malloc_Header;
  46   class ACE_Name_Node;
  47
  48   typedef ACE_Based_Pointer<ACE_Malloc_Header> MALLOC_HEADER_PTR;
  49   typedef ACE_Based_Pointer<ACE_Name_Node> NAME_NODE_PTR;
  50   typedef ACE_Based_Pointer_Basic<char> CHAR_PTR;
  51
  52   /**
  53    * @class ACE_Malloc_Header
  54    *
  55    * @brief This is the control block header.  It's used by ACE_Malloc
  56    * to keep track of each chunk of data when it's in the free
  57    * list or in use.
  58    */
  59   class ACE_Export ACE_Malloc_Header
  60   {
  61   public:
  62     ACE_Malloc_Header ();
  63
  64     /// Points to next block if on free list.
  65     MALLOC_HEADER_PTR next_block_;
  66
  67     /// Initialize a malloc header pointer.
  68     static void init_ptr (MALLOC_HEADER_PTR *ptr,
  69                           ACE_Malloc_Header *init,
  70                           void *base_addr);
  71
  72     /// Size of this header control block.
  73     size_t size_;
  74
  75 # if !defined (ACE_PI_MALLOC_PADDING_SIZE)
  76 #   define ACE_PI_MALLOC_PADDING_SIZE ACE_MALLOC_ROUNDUP (ACE_MALLOC_HEADER_SIZE + sizeof (MALLOC_HEADER_PTR) + sizeof (size_t), ACE_MALLOC_ALIGN) - (sizeof (MALLOC_HEADER_PTR) + sizeof (size_t))
  77 # endif /* !ACE_PI_MALLOC_PADDING_SIZE */
  78     char padding_[(ACE_PI_MALLOC_PADDING_SIZE) ? ACE_PI_MALLOC_PADDING_SIZE : ACE_MALLOC_ALIGN];
  79
  80     /// Dump the state of the object.
  81     void dump () const;
  82
  83   private:
  84     // Disallow copy construction and assignment.
  85     ACE_Malloc_Header (ACE_Malloc_Header const &);
  86     void operator= (ACE_Malloc_Header const &);
  87   };
  88
  89   /**
  90    * @class ACE_Name_Node
  91    *
  92    * @brief This class supports "named memory regions" within ACE_Malloc.
  93    *
  94    * Internally, the named memory regions are stored as a
  95    * doubly-linked list within the Memory_Pool.  This makes
  96    * it easy to iterate over the items in the list in both FIFO
  97    * and LIFO order.
  98    */
  99   class ACE_Export ACE_Name_Node
 100   {
 101   public:
 102     /// Constructor.
 103     ACE_Name_Node (const char *name,
 104                    char *name_ptr,
 105                    char *pointer,
 106                    ACE_Name_Node *head);
 107
 108     /// Copy constructor.
 109     ACE_Name_Node (const ACE_Name_Node &);
 110
 111     /// Constructor.
 112     ACE_Name_Node ();
 113
 114     /// Constructor.
 115     ~ACE_Name_Node ();
 116
 117     /// Initialize a name node pointer.
 118     static void init_ptr (NAME_NODE_PTR *ptr,
 119                           ACE_Name_Node *init,
 120                           void *base_addr);
 121
 122     /// Return a pointer to the name of this node.
 123     const char *name () const;
 124
 125     /// Assign a name;
 126     void name (const char *);
 127
 128     /// Name of the Node.
 129     CHAR_PTR name_;
 130
 131     /// Pointer to the contents.
 132     CHAR_PTR pointer_;
 133
 134     /// Pointer to the next node in the doubly-linked list.
 135     NAME_NODE_PTR next_;
 136
 137     /// Pointer to the previous node in the doubly-linked list.
 138     NAME_NODE_PTR prev_;
 139
 140     /// Dump the state of the object.
 141     void dump () const;
 142
 143   private:
 144     // Disallow assignment.
 145     void operator= (const ACE_Name_Node &);
 146   };
 147
 148   /// Print out a bunch of size info for debugging.
 149   static void print_alignment_info ();
 150
 151   /// Reference counter.
 152   int ref_counter_;
 153
 154   /// Head of the linked list of Name Nodes.
 155   NAME_NODE_PTR name_head_;
 156
 157   /// Current head of the freelist.
 158   MALLOC_HEADER_PTR freep_;
 159
 160   /// Name of lock thats ensures mutual exclusion.
 161   char lock_name_[MAXNAMELEN];
 162
 163 #if defined (ACE_HAS_MALLOC_STATS)
 164   /// Keep statistics about ACE_Malloc state and performance.
 165   ACE_Malloc_Stats malloc_stats_;
 166 #define ACE_PI_CONTROL_BLOCK_SIZE ((int)(sizeof (NAME_NODE_PTR) \
 167                                          + sizeof (MALLOC_HEADER_PTR) \
 168                                          + sizeof (int) \
 169                                          + MAXNAMELEN  \
 170                                          + sizeof (ACE_Malloc_Stats)))
 171 #else
 172 #define ACE_PI_CONTROL_BLOCK_SIZE ((int)(sizeof (NAME_NODE_PTR) \
 173                                          + sizeof (MALLOC_HEADER_PTR) \
 174                                          + sizeof (int) \
 175                                          + MAXNAMELEN))
 176 #endif /* ACE_HAS_MALLOC_STATS */
 177
 178 # if !defined (ACE_PI_CONTROL_BLOCK_ALIGN_BYTES)
 179 #   define ACE_PI_CONTROL_BLOCK_ALIGN_BYTES \
 180         ACE_MALLOC_ROUNDUP (ACE_PI_CONTROL_BLOCK_SIZE, ACE_MALLOC_ALIGN) - ACE_PI_CONTROL_BLOCK_SIZE
 181 # endif /* !ACE_PI_CONTROL_BLOCK_ALIGN_LONGS */
 182   /// Force alignment.
 183   char align_[(ACE_PI_CONTROL_BLOCK_ALIGN_BYTES) ? ACE_PI_CONTROL_BLOCK_ALIGN_BYTES : ACE_MALLOC_ALIGN];
 184
 185   /// Dummy node used to anchor the freelist.  This needs to come last...
 186   ACE_Malloc_Header base_;
 187
 188   /// Dump the state of the object.
 189   void dump () const;
 190
 191 private:
 192   void operator= (const ACE_Control_Block &) = delete;
 193 };
 194
 195 ACE_END_VERSIONED_NAMESPACE_DECL
 196
 197 #if defined (__ACE_INLINE__)
 198 #include "ace/PI_Malloc.inl"
 199 #endif /* __ACE_INLINE__ */
 200
 201 #endif /* ACE_HAS_POSITION_INDEPENDENT_POINTERS == 1 */
 202
 203 #include /**/ "ace/post.h"
 204
 205 #endif /* ACE_PI_MALLOC_H */