[Ace-users] [ace-users] Strange code in ACE_Hash_Multi_Map_Manager

[Boris Kaminer]

    ACE VERSION: 5.6.1 

    AREA/CLASS/EXAMPLE AFFECTED: ACE_Hash_Multi_Map_Manager

 

    DOES THE PROBLEM AFFECT:

        EXECUTION?  - YES

 

    SYNOPSIS:

Redundant copying in bind_i method

 

    DESCRIPTION:

The code below presented in ACE_Hash_Multi_Map_Manager at least since 5.5.3.

 

template <class EXT_ID, class INT_ID, class HASH_KEY, class COMPARE_KEYS,
class ACE_LOCK> int

ACE_Hash_Multi_Map_Manager<EXT_ID, INT_ID, HASH_KEY, COMPARE_KEYS,
ACE_LOCK>::bind_i (const EXT_ID &ext_id,

 
const INT_ID &int_id,

 
ACE_Hash_Multi_Map_Entry<EXT_ID, INT_ID> *&entry)

{

  size_t loc;

  int result = this->shared_find (ext_id, entry, loc);

 

  ACE_Unbounded_Set<INT_ID> int_id_set;

  if (result == -1)

    {

      void *ptr;

      // Not found.

      ACE_ALLOCATOR_RETURN (ptr,

                            this->entry_allocator_->malloc (sizeof
(ACE_Hash_Multi_Map_Entry<EXT_ID, INT_ID>)),

                            -1);

 

      int_id_set.insert (int_id);

 

      entry = new (ptr) ACE_Hash_Multi_Map_Entry<EXT_ID, INT_ID> (ext_id,

 
int_id_set, ß Unnecessary copying

 
this->table_[loc].next_,

 
&this->table_[loc]);

      this->table_[loc].next_ = entry;

      entry->next_->prev_ = entry;

      this->cur_size_++;

      return 0;

    }

  else

    {

     // Just unbelieveable way of new element inserting

      int_id_set = (*entry).int_id_set_;

 

      if (0 == int_id_set.insert (int_id))

        {

          this->unbind_i (entry);

          return this->bind_i (ext_id, int_id_set);

        }

      else

        return 1;

    }

}

 

    REPEAT BY:

[What you did to get the error; include test program or session

transcript if at all possible.  ]

 

    SAMPLE FIX/WORKAROUND:

This is a straightforward fix, but more correct implementation requires
introducing an additional constructor for ACE_Hash_Multi_Map_Entry without

const ACE_Unbounded_Set<INT_ID> &int_id_set parameter and using it during an
entry creation.

 

template <class EXT_ID, class INT_ID, class HASH_KEY, class COMPARE_KEYS,
class ACE_LOCK> int

ACE_Hash_Multi_Map_Manager<EXT_ID, INT_ID, HASH_KEY, COMPARE_KEYS,
ACE_LOCK>::bind_i (const EXT_ID &ext_id,

 
const INT_ID &int_id,

 
ACE_Hash_Multi_Map_Entry<EXT_ID, INT_ID> *&entry)

{

  size_t loc;

  int result = this->shared_find (ext_id, entry, loc);

 

  if (result == -1)

    {

      void *ptr;

      // Not found.

      ACE_ALLOCATOR_RETURN (ptr,

                            this->entry_allocator_->malloc (sizeof
(ACE_Hash_Multi_Map_Entry<EXT_ID, INT_ID>)),

                            -1);

 

      entry = new (ptr) ACE_Hash_Multi_Map_Entry<EXT_ID, INT_ID> (ext_id,

 
ACE_Unbounded_Set<INT_ID>(), 

 
this->table_[loc].next_,

 
&this->table_[loc]);

      this->table_[loc].next_ = entry;

      entry->next_->prev_ = entry;

    }

 

   if (!(*entry).int_id_set_.insert(int_id)) {

      this->cur_size_++;

      return 0;

   } else

        return 1;

}

 

 

/Boris

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