path: root/ace/Malloc.h

/* -*- C++ -*- */
// $Id$

// ============================================================================
//
// = LIBRARY
//    ace
//
// = FILENAME
//    Malloc.h
//
// = AUTHOR
//    Doug Schmidt and Irfan Pyarali
//
// ============================================================================

#if !defined (ACE_MALLOC_H)
#define ACE_MALLOC_H

#include "ace/ACE.h"
#include "ace/Malloc_Base.h"

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

#if defined (ACE_HAS_MALLOC_STATS)
#include "ace/Synch_T.h"
#if defined (ACE_HAS_THREADS)
#define ACE_PROCESS_MUTEX ACE_Process_Mutex
#else
#include "ace/SV_Semaphore_Simple.h"
#define ACE_PROCESS_MUTEX ACE_SV_Semaphore_Simple
#endif /* ACE_HAS_THREADS */

typedef ACE_Atomic_Op<ACE_PROCESS_MUTEX, int> ACE_INT;

struct ACE_Export ACE_Malloc_Stats
// TITLE
//    This keeps stats on the usage of the memory manager.
{
  ACE_Malloc_Stats (void);
  void dump (void) const;

  ACE_INT nchunks_;
  // Coarse-grained unit of allocation.

  ACE_INT nblocks_;
  // Fine-grained unit of allocation.

  ACE_INT ninuse_;
  // Number of blocks in use
};
#define AMS(X) X
#else
#define AMS(X)
#endif /* ACE_HAS_MALLOC_STATS */

// ACE_MALLOC_ALIGN allows you to insure that allocated regions are at
// least <ACE_MALLOC_ALIGN> bytes long.  It is especially useful when
// you want areas to be at least a page long, or 32K long, or
// something like that.  It doesn't guarantee alignment to an address
// multiple, like 8-byte data alignment, etc.  The allocated area's
// padding to your selected size is done with an added array of long[]
// and your compiler will decide how to align things in memory.
//
// The default ACE_MALLOC_ALIGN is 'long', which will probably add a
// long of padding - it doesn't have any real affect.  If you want to
// use this feature, define ACE_MALLOC_ALIGN in your config.h file and
// use a signed integer number of bytes you want.  For example:
// #define ACE_MALLOC_ALIGN ((int)4096)

#if !defined (ACE_MALLOC_ALIGN)
#define ACE_MALLOC_ALIGN ((int)(sizeof (long)))
#endif /* ACE_MALLOC_ALIGN */

union ACE_Export ACE_Malloc_Header
{
  // TITLE
  //    This is a block header.

  struct ACE_Malloc_Control_Block
  {
    ACE_Malloc_Header *next_block_;
    // Points to next block if on free list.

    size_t size_;
    // Size of this block.
  } s_;

  long align_[ACE_MALLOC_ALIGN/sizeof (long)];
  // Force alignment.
};

class ACE_Export ACE_Name_Node
{
  // = TITLE
  //    This is stored as a linked list within the Memory_Pool
  //    to allow "named memory chunks."
public:
  // = Initialization methods.
  ACE_Name_Node (const char *name, void *, ACE_Name_Node *);
  ACE_Name_Node (void);
  ~ACE_Name_Node (void);

  char *name_;
  // Name of the Node.

  void *pointer_;
  // Pointer to the contents.

  ACE_Name_Node *next_;
  // Pointer to the next node in the chain.

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

class ACE_Export ACE_Control_Block
{
  // = TITLE
  //    This information is stored in memory allocated by the MEMORY_POOL.
  //
  // = DESCRIPTION
  //    This class should be local to class ACE_Malloc, but cfront and
  //    G++ don't like nested classes in templates...
public:
  ACE_Name_Node *name_head_;
  // Head of the linked list of Name Nodes.

  ACE_Malloc_Header *freep_;
  // Current head of the freelist.

  char lock_name_[MAXNAMELEN];
  // Name of lock thats ensures mutual exclusion.

#if defined (ACE_HAS_MALLOC_STATS)
  // Keep statistics about ACE_Malloc state and performance.
  ACE_Malloc_Stats malloc_stats_;
#define ACE_CONTROL_BLOCK_SIZE ((int)(sizeof (ACE_Name_Node *) \
                                      + sizeof (ACE_Malloc_Header *) \
                                      + MAXNAMELEN  \
                                      + sizeof (ACE_Malloc_Stats)))
#else
#define ACE_CONTROL_BLOCK_SIZE ((int)(sizeof(ACE_Name_Node *) \
                                      + sizeof (ACE_Malloc_Header *) \
                                      + MAXNAMELEN))
#endif /* ACE_HAS_MALLOC_STATS */

// Notice the casting to int for sizeof() otherwise unsigned int
// arithmetic is used and some awful things may happen.
#define ACE_CONTROL_BLOCK_ALIGN_LONGS ((ACE_CONTROL_BLOCK_SIZE % ACE_MALLOC_ALIGN != 0 \
                                        ? ACE_MALLOC_ALIGN - (ACE_CONTROL_BLOCK_SIZE) \
                                        : ACE_MALLOC_ALIGN) / int(sizeof(long)))

  long align_[ACE_CONTROL_BLOCK_ALIGN_LONGS < 1 ? 1 : ACE_CONTROL_BLOCK_ALIGN_LONGS];

  ACE_Malloc_Header base_;
  // Dummy node used to anchor the freelist.

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

class ACE_Export ACE_New_Allocator : public ACE_Allocator
{
  // = TITLE
  //     Defines a class that provided a simple implementation of
  //     memory allocation.
  //
  // = DESCRIPTION
  //     This class uses the new/delete operators to allocate and free
  //     up memory.  Please note that the only methods that are
  //     supported are malloc and free. All other methods are no-ops.
  //     If you require this functionality, please use:
  //     ACE_Allocator_Adapter <ACE_Malloc <ACE_LOCAL_MEMORY_POOL, MUTEX>>
  //     This will allow you to use the added functionality of
  //     bind/find/etc. while using the new/delete operators.
public:
  virtual void *malloc (size_t nbytes);
  virtual void *calloc (size_t nbytes, char initial_value = '\0');
  virtual void free (void *ptr);
  virtual int remove (void);
  virtual int bind (const char *name, void *pointer, int duplicates = 0);
  virtual int trybind (const char *name, void *&pointer);
  virtual int find (const char *name, void *&pointer);
  virtual int find (const char *name);
  virtual int unbind (const char *name);
  virtual int unbind (const char *name, void *&pointer);
  virtual int sync (ssize_t len = -1, int flags = MS_SYNC);
  virtual int sync (void *addr, size_t len, int flags = MS_SYNC);
  virtual int protect (ssize_t len = -1, int prot = PROT_RDWR);
  virtual int protect (void *addr, size_t len, int prot = PROT_RDWR);
#if defined (ACE_HAS_MALLOC_STATS)
  virtual void print_stats (void) const;
#endif /* ACE_HAS_MALLOC_STATS */
  virtual void dump (void) const;

private:
  // DO NOT ADD ANY STATE (DATA MEMBERS) TO THIS CLASS!!!!
  // See the ACE_Allocator::instance () implementation for explanation.
};

class ACE_Export ACE_Static_Allocator_Base : public ACE_Allocator
{
  // = TITLE
  //     Defines a class that provided a highly optimized memory
  //     management scheme for allocating memory statically.
  //
  // = DESCRIPTION
  //     This class manages a fixed-size <POOL_SIZE> of memory.  Every
  //     time <malloc>/<calloc> is called, it simply moves an internal
  //     index forward and returns a pointer to the requested chunk.
  //     All memory is allocated statically (typically via the
  //     <ACE_Static_Allocator> template) and <free> is a no-op.  This
  //     behavior is useful for use-cases where all the memory
  //     allocation needs are known in advance and no deletions ever
  //     occur.
public:
  ACE_Static_Allocator_Base (char *buffer, size_t size);
  virtual void *malloc (size_t nbytes);
  virtual void *calloc (size_t nbytes, char initial_value = '\0');
  virtual void free (void *ptr);
  virtual int remove (void);
  virtual int bind (const char *name, void *pointer, int duplicates = 0);
  virtual int trybind (const char *name, void *&pointer);
  virtual int find (const char *name, void *&pointer);
  virtual int find (const char *name);
  virtual int unbind (const char *name);
  virtual int unbind (const char *name, void *&pointer);
  virtual int sync (ssize_t len = -1, int flags = MS_SYNC);
  virtual int sync (void *addr, size_t len, int flags = MS_SYNC);
  virtual int protect (ssize_t len = -1, int prot = PROT_RDWR);
  virtual int protect (void *addr, size_t len, int prot = PROT_RDWR);
#if defined (ACE_HAS_MALLOC_STATS)
  virtual void print_stats (void) const;
#endif /* ACE_HAS_MALLOC_STATS */
  virtual void dump (void) const;

protected:
  ACE_Static_Allocator_Base (void);
  // Don't allow direct instantiations of this class.

  char *buffer_;
  // Pointer to the buffer.

  size_t size_;
  // Size of the buffer.

  size_t offset_;
  // Pointer to the current offset in the <buffer_>.
};

#if defined (__ACE_INLINE__)
#include "ace/Malloc.i"
#endif /* __ACE_INLINE__ */

// Include the ACE_Malloc templates and ACE_Memory_Pool classes at this point.
#include "ace/Malloc_T.h"
#include "ace/Memory_Pool.h"

#endif /* ACE_MALLOC_H */