simple_seq_fit_impl.hpp

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      last  = block;
      block = detail::get_pointer(block->m_next);
   }

   char *last_free_end_address   = reinterpret_cast<char*>(last) + last->m_size*Alignment;
   if(last_free_end_address != (reinterpret_cast<char*>(this) + priv_block_end_offset())){
      //there is an allocated block in the end of this block
      //so no shrinking is possible
      return;
   }

   //Check if have only 1 big free block
   void *unique_block = 0;
   if(!m_header.m_allocated){
      assert(prev == root);
      std::size_t ignore;
      unique_block = priv_allocate(allocate_new, 0, 0, ignore).first;
      if(!unique_block)
         return;
      last = detail::get_pointer(m_header.m_root.m_next);
      assert(last_free_end_address == (reinterpret_cast<char*>(last) + last->m_size*Alignment));
   }
   std::size_t last_units = last->m_size;

   std::size_t received_size;
   void *addr = priv_check_and_allocate(last_units, prev, last, received_size);
   (void)addr;
   assert(addr);
   assert(received_size == last_units*Alignment - AllocatedCtrlBytes);
   
   //Shrink it
   m_header.m_size /= Alignment;
   m_header.m_size -= last->m_size;
   m_header.m_size *= Alignment;
   m_header.m_allocated -= last->m_size*Alignment;

   if(unique_block)
      priv_deallocate(unique_block);
}

template<class MutexFamily, class VoidPointer>
inline void simple_seq_fit_impl<MutexFamily, VoidPointer>::
   priv_mark_new_allocated_block(block_ctrl *new_block)
{
   new_block->m_next = 0;
}

template<class MutexFamily, class VoidPointer>
inline
typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl *
   simple_seq_fit_impl<MutexFamily, VoidPointer>::priv_get_block(const void *ptr)
{
   return const_cast<block_ctrl*>(reinterpret_cast<const block_ctrl*>
      (reinterpret_cast<const char*>(ptr) - AllocatedCtrlBytes));
}

template<class MutexFamily, class VoidPointer>
inline
void *simple_seq_fit_impl<MutexFamily, VoidPointer>::
      priv_get_user_buffer(const typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl *block)
{
   return const_cast<char*>(reinterpret_cast<const char*>(block) + AllocatedCtrlBytes);
}

template<class MutexFamily, class VoidPointer>
inline void simple_seq_fit_impl<MutexFamily, VoidPointer>::priv_add_segment(void *addr, std::size_t size)
{  
   algo_impl_t::assert_alignment(addr);
   //Check size
   assert(!(size < MinBlockSize));
   if(size < MinBlockSize)
      return;
   //Construct big block using the new segment
   block_ctrl *new_block   = static_cast<block_ctrl *>(addr);
   new_block->m_size       = size/Alignment;
   new_block->m_next       = 0;
   //Simulate this block was previously allocated
   m_header.m_allocated   += new_block->m_size*Alignment; 
   //Return block and insert it in the free block list
   this->priv_deallocate(priv_get_user_buffer(new_block));
}

template<class MutexFamily, class VoidPointer>
inline std::size_t simple_seq_fit_impl<MutexFamily, VoidPointer>::get_size()  const
   {  return m_header.m_size;  }

template<class MutexFamily, class VoidPointer>
inline std::size_t simple_seq_fit_impl<MutexFamily, VoidPointer>::get_free_memory()  const
{
   return m_header.m_size - m_header.m_allocated - 
      algo_impl_t::multiple_of_units(sizeof(*this) + m_header.m_extra_hdr_bytes);
}

template<class MutexFamily, class VoidPointer>
inline std::size_t simple_seq_fit_impl<MutexFamily, VoidPointer>::
   get_min_size (std::size_t extra_hdr_bytes)
{
   return detail::get_rounded_size(sizeof(simple_seq_fit_impl),Alignment) +
          detail::get_rounded_size(extra_hdr_bytes,Alignment)
          + MinBlockSize;
}

template<class MutexFamily, class VoidPointer>
inline bool simple_seq_fit_impl<MutexFamily, VoidPointer>::
    all_memory_deallocated()
{
   //-----------------------
   boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
   //-----------------------
   return m_header.m_allocated == 0 &&
          detail::get_pointer(m_header.m_root.m_next->m_next) == &m_header.m_root;
}

template<class MutexFamily, class VoidPointer>
inline void simple_seq_fit_impl<MutexFamily, VoidPointer>::zero_free_memory()
{
   //-----------------------
   boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
   //-----------------------
   block_ctrl *block = detail::get_pointer(m_header.m_root.m_next);

   //Iterate through all free portions
   do{
      //Just clear user the memory part reserved for the user      
      std::memset( priv_get_user_buffer(block)
                 , 0
                 , block->get_user_bytes());
      block = detail::get_pointer(block->m_next);
   }
   while(block != &m_header.m_root);
}

template<class MutexFamily, class VoidPointer>
inline bool simple_seq_fit_impl<MutexFamily, VoidPointer>::
    check_sanity()
{
   //-----------------------
   boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
   //-----------------------
   block_ctrl *block = detail::get_pointer(m_header.m_root.m_next);

   std::size_t free_memory = 0;

   //Iterate through all blocks obtaining their size
   while(block != &m_header.m_root){
      algo_impl_t::assert_alignment(block);
      if(!algo_impl_t::check_alignment(block))
         return false;
      //Free blocks's next must be always valid
      block_ctrl *next = detail::get_pointer(block->m_next);
      if(!next){
         return false;
      }
      free_memory += block->m_size*Alignment;
      block = next;
   }

   //Check allocated bytes are less than size
   if(m_header.m_allocated > m_header.m_size){
      return false;
   }

   //Check free bytes are less than size
   if(free_memory > m_header.m_size){
      return false;
   }
   return true;
}

template<class MutexFamily, class VoidPointer>
inline void* simple_seq_fit_impl<MutexFamily, VoidPointer>::
   allocate(std::size_t nbytes)
{
   //-----------------------
   boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
   //-----------------------
   std::size_t ignore;
   return priv_allocate(allocate_new, nbytes, nbytes, ignore).first;
}

template<class MutexFamily, class VoidPointer>
inline void* simple_seq_fit_impl<MutexFamily, VoidPointer>::
   allocate_aligned(std::size_t nbytes, std::size_t alignment)
{  
   //-----------------------
   boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
   //-----------------------
   return algo_impl_t::
      allocate_aligned(this, nbytes, alignment); 
}

template<class MutexFamily, class VoidPointer>
template<class T>
inline std::pair<T*, bool> simple_seq_fit_impl<MutexFamily, VoidPointer>::
   allocation_command  (allocation_type command,   std::size_t limit_size,
                        std::size_t preferred_size,std::size_t &received_size, 
                        T *reuse_ptr)
{
   std::pair<void*, bool> ret = priv_allocation_command
      (command, limit_size, preferred_size, received_size, static_cast<void*>(reuse_ptr), sizeof(T));

   BOOST_ASSERT(0 == ((std::size_t)ret.first % detail::alignment_of<T>::value));
   return std::pair<T *, bool>(static_cast<T*>(ret.first), ret.second);
}

template<class MutexFamily, class VoidPointer>
inline std::pair<void*, bool> simple_seq_fit_impl<MutexFamily, VoidPointer>::
   raw_allocation_command  (allocation_type command,   std::size_t limit_objects,
                        std::size_t preferred_objects,std::size_t &received_objects, 
                        void *reuse_ptr, std::size_t sizeof_object)
{
   if(!sizeof_object)
      return std::pair<void *, bool>(static_cast<void*>(0), 0);
   if(command & try_shrink_in_place){
      bool success = algo_impl_t::try_shrink
         ( this, reuse_ptr, limit_objects*sizeof_object
         , preferred_objects*sizeof_object, received_objects);
      received_objects /= sizeof_object;
      return std::pair<void *, bool> ((success ? reuse_ptr : 0), true);
   }
   return priv_allocation_command
      (command, limit_objects, preferred_objects, received_objects, reuse_ptr, sizeof_object);
}

template<class MutexFamily, class VoidPointer>
inline std::pair<void*, bool> simple_seq_fit_impl<MutexFamily, VoidPointer>::
   priv_allocation_command (allocation_type command,   std::size_t limit_size,
                       std::size_t preferred_size, std::size_t &received_size, 
                       void *reuse_ptr, std::size_t sizeof_object)
{
   command &= ~expand_bwd;
   if(!command)   return std::pair<void *, bool>(static_cast<void*>(0), false);

   std::pair<void*, bool> ret;
   std::size_t max_count = m_header.m_size/sizeof_object;
   if(limit_size > max_count || preferred_size > max_count){
      ret.first = 0; return ret;
   }
   std::size_t l_size = limit_size*sizeof_object;
   std::size_t p_size = preferred_size*sizeof_object;
   std::size_t r_size;
   {
      //-----------------------
      boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
      //-----------------------
      ret = priv_allocate(command, l_size, p_size, r_size, reuse_ptr);
   }
   received_size = r_size/sizeof_object;
   return ret;
}

template<class MutexFamily, class VoidPointer>
inline std::size_t simple_seq_fit_impl<MutexFamily, VoidPointer>::
   size(const void *ptr) const
{
   //We need no synchronization since this block is not going
   //to be modified
   //Obtain the real size of the block
   const block_ctrl *block = static_cast<const block_ctrl*>(priv_get_block(ptr));
   return block->get_user_bytes();
}

template<class MutexFamily, class VoidPointer>
void* simple_seq_fit_impl<MutexFamily, VoidPointer>::
   priv_expand_both_sides(allocation_type command
                         ,std::size_t min_size
                         ,std::size_t preferred_size
                         ,std::size_t &received_size
                         ,void *reuse_ptr
                         ,bool only_preferred_backwards)
{
   typedef std::pair<block_ctrl *, block_ctrl *> prev_block_t;
   block_ctrl *reuse = priv_get_block(reuse_ptr);
   received_size = 0;

   if(this->size(reuse_ptr) > min_size){
      received_size = this->size(reuse_ptr);
      return reuse_ptr;
   }

   if(command & expand_fwd){
      if(priv_expand(reuse_ptr, min_size, preferred_size, received_size))
         return reuse_ptr;
   }
   else{
      received_size = this->size(reuse_ptr);
   }
   if(command & expand_bwd){
      std::size_t extra_forward = !received_size ? 0 : received_size + BlockCtrlBytes;
      prev_block_t prev_pair = priv_prev_block_if_free(reuse);
      block_ctrl *prev = prev_pair.second;
      if(!prev){
         return 0;
      }

      std::size_t needs_backwards = 
         detail::get_rounded_size(preferred_size - extra_forward, Alignment);
   
      if(!only_preferred_backwards){
            max_value(detail::get_rounded_size(min_size - extra_forward, Alignment)
                     ,min_value(prev->get_user_bytes(), needs_backwards));
      }

      //Check if previous block has enough size
      if((prev->get_user_bytes()) >=  needs_backwards){
         //Now take all next space. This will succeed
         if(!priv_expand(reuse_ptr, received_size, received_size, received_size)){
            assert(0);
         }
         
         //We need a minimum size to split the previous one
         if((prev->get_user_bytes() - needs_backwards) > 2*BlockCtrlBytes){
             block_ctrl *new_block = reinterpret_cast<block_ctrl*>
                  (reinterpret_cast<char*>(reuse) - needs_backwards - BlockCtrlBytes);

            new_block->m_next = 0;
            new_block->m_size = 
               BlockCtrlUnits + (needs_backwards + extra_forward)/Alignment;
            prev->m_size = 
               (prev->get_total_bytes() - needs_backwards)/Alignment - BlockCtrlUnits;
            received_size = needs_backwards + extra_forward;
            m_header.m_allocated += needs_backwards + BlockCtrlBytes;
            return priv_get_user_buffer(new_block);
         }
         else{
            //Just merge the whole previous block
            block_ctrl *prev_2_block = prev_pair.first;
            //Update received size and allocation
            received_size = extra_forward + prev->get_user_bytes();
            m_header.m_allocated += prev->get_total_bytes();
            //Now unlink it from previous block
            prev_2_block->m_next = prev->m_next;
            prev->m_size = reuse->m_size + prev->m_size;
            prev->m_next = 0;
            priv_get_user_buffer(prev);
         }
      }
   }
   return 0;
}

template<class MutexFamily, class VoidPointer>
inline typename simple_seq_fit_impl<MutexFamily, VoidPointer>::multiallocation_iterator
   simple_seq_fit_impl<MutexFamily, VoidPointer>::
   allocate_many(std::size_t elem_bytes, std::size_t num_elements)
{
   //-----------------------
   boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
   //-----------------------
   return algo_impl_t::
      allocate_many(this, elem_bytes, num_elements);
}

template<class MutexFamily, class VoidPointer>
inline void simple_seq_fit_impl<MutexFamily, VoidPointer>::
   deallocate_many(typename simple_seq_fit_impl<MutexFamily, VoidPointer>::multiallocation_iterator it)
{
   //-----------------------
   boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
   //-----------------------
   while(it){
      void *addr = &*it;
      ++it;
      this->priv_deallocate(addr);
   }
}

template<class MutexFamily, class VoidPointer>
inline typename simple_seq_fit_impl<MutexFamily, VoidPointer>::multiallocation_iterator
   simple_seq_fit_impl<MutexFamily, VoidPointer>::
   allocate_many(const std::size_t *elem_sizes, std::size_t n_elements, std::size_t sizeof_element)
{