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glm/test/external/boost/interprocess/mem_algo/rbtree_best_fit.hpp

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//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2005-2009. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTERPROCESS_MEM_ALGO_RBTREE_BEST_FIT_HPP
#define BOOST_INTERPROCESS_MEM_ALGO_RBTREE_BEST_FIT_HPP
#if (defined _MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif
#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <boost/pointer_to_other.hpp>
#include <boost/interprocess/interprocess_fwd.hpp>
#include <boost/interprocess/mem_algo/detail/mem_algo_common.hpp>
#include <boost/interprocess/containers/allocation_type.hpp>
#include <boost/container/detail/multiallocation_chain.hpp>
#include <boost/interprocess/offset_ptr.hpp>
#include <boost/interprocess/sync/interprocess_mutex.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/detail/utilities.hpp>
#include <boost/interprocess/detail/min_max.hpp>
#include <boost/interprocess/detail/math_functions.hpp>
#include <boost/interprocess/detail/type_traits.hpp>
#include <boost/interprocess/sync/scoped_lock.hpp>
#include <boost/type_traits/type_with_alignment.hpp>
#include <boost/assert.hpp>
#include <boost/static_assert.hpp>
#include <boost/type_traits.hpp>
#include <algorithm>
#include <utility>
#include <climits>
#include <cstring>
#include <iterator>
#include <boost/assert.hpp>
#include <new>
#include <boost/intrusive/set.hpp>
//#define BOOST_INTERPROCESS_RBTREE_BEST_FIT_ABI_V1_HPP
//to maintain ABI compatible with the original version
//ABI had to be updated to fix compatibility issues when
//sharing shared memory between 32 adn 64 bit processes.
//!\file
//!Describes a best-fit algorithm based in an intrusive red-black tree used to allocate
//!objects in shared memory. This class is intended as a base class for single segment
//!and multi-segment implementations.
namespace boost {
namespace interprocess {
//!This class implements an algorithm that stores the free nodes in a red-black tree
//!to have logarithmic search/insert times.
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
class rbtree_best_fit
{
/// @cond
//Non-copyable
rbtree_best_fit();
rbtree_best_fit(const rbtree_best_fit &);
rbtree_best_fit &operator=(const rbtree_best_fit &);
private:
struct block_ctrl;
typedef typename boost::
pointer_to_other<VoidPointer, block_ctrl>::type block_ctrl_ptr;
typedef typename boost::
pointer_to_other<VoidPointer, char>::type char_ptr;
/// @endcond
public:
//!Shared interprocess_mutex family used for the rest of the Interprocess framework
typedef MutexFamily mutex_family;
//!Pointer type to be used with the rest of the Interprocess framework
typedef VoidPointer void_pointer;
typedef boost::container::containers_detail::
basic_multiallocation_chain<VoidPointer> multiallocation_chain;
typedef typename std::iterator_traits<char_ptr>::difference_type difference_type;
typedef typename boost::make_unsigned<difference_type>::type size_type;
/// @cond
private:
typedef typename bi::make_set_base_hook
< bi::void_pointer<VoidPointer>
, bi::optimize_size<true>
, bi::link_mode<bi::normal_link> >::type TreeHook;
struct SizeHolder
{
//!This block's memory size (including block_ctrl
//!header) in Alignment units
size_type m_prev_size : sizeof(size_type)*CHAR_BIT;
size_type m_size : sizeof(size_type)*CHAR_BIT - 2;
size_type m_prev_allocated : 1;
size_type m_allocated : 1;
};
//!Block control structure
struct block_ctrl
: public SizeHolder, public TreeHook
{
block_ctrl()
{ this->m_size = 0; this->m_allocated = 0, this->m_prev_allocated = 0; }
friend bool operator<(const block_ctrl &a, const block_ctrl &b)
{ return a.m_size < b.m_size; }
friend bool operator==(const block_ctrl &a, const block_ctrl &b)
{ return a.m_size == b.m_size; }
};
struct size_block_ctrl_compare
{
bool operator()(size_type size, const block_ctrl &block) const
{ return size < block.m_size; }
bool operator()(const block_ctrl &block, size_type size) const
{ return block.m_size < size; }
};
//!Shared interprocess_mutex to protect memory allocate/deallocate
typedef typename MutexFamily::mutex_type interprocess_mutex;
typedef typename bi::make_multiset
<block_ctrl, bi::base_hook<TreeHook> >::type Imultiset;
typedef typename Imultiset::iterator imultiset_iterator;
//!This struct includes needed data and derives from
//!interprocess_mutex to allow EBO when using null interprocess_mutex
struct header_t : public interprocess_mutex
{
Imultiset m_imultiset;
//!The extra size required by the segment
size_type m_extra_hdr_bytes;
//!Allocated bytes for internal checking
size_type m_allocated;
//!The size of the memory segment
size_type m_size;
} m_header;
friend class ipcdetail::memory_algorithm_common<rbtree_best_fit>;
typedef ipcdetail::memory_algorithm_common<rbtree_best_fit> algo_impl_t;
public:
/// @endcond
//!Constructor. "size" is the total size of the managed memory segment,
//!"extra_hdr_bytes" indicates the extra bytes beginning in the sizeof(rbtree_best_fit)
//!offset that the allocator should not use at all.
rbtree_best_fit (size_type size, size_type extra_hdr_bytes);
//!Destructor.
~rbtree_best_fit();
//!Obtains the minimum size needed by the algorithm
static size_type get_min_size (size_type extra_hdr_bytes);
//Functions for single segment management
//!Allocates bytes, returns 0 if there is not more memory
void* allocate (size_type nbytes);
/// @cond
//Experimental. Dont' use
//!Multiple element allocation, same size
multiallocation_chain allocate_many(size_type elem_bytes, size_type num_elements)
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
return algo_impl_t::allocate_many(this, elem_bytes, num_elements);
}
//!Multiple element allocation, different size
multiallocation_chain allocate_many(const size_type *elem_sizes, size_type n_elements, size_type sizeof_element)
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
return algo_impl_t::allocate_many(this, elem_sizes, n_elements, sizeof_element);
}
//!Multiple element allocation, different size
void deallocate_many(multiallocation_chain chain);
/// @endcond
//!Deallocates previously allocated bytes
void deallocate (void *addr);
//!Returns the size of the memory segment
size_type get_size() const;
//!Returns the number of free bytes of the segment
size_type get_free_memory() const;
//!Initializes to zero all the memory that's not in use.
//!This function is normally used for security reasons.
void zero_free_memory();
//!Increases managed memory in
//!extra_size bytes more
void grow(size_type extra_size);
//!Decreases managed memory as much as possible
void shrink_to_fit();
//!Returns true if all allocated memory has been deallocated
bool all_memory_deallocated();
//!Makes an internal sanity check
//!and returns true if success
bool check_sanity();
template<class T>
std::pair<T *, bool>
allocation_command (boost::interprocess::allocation_type command, size_type limit_size,
size_type preferred_size,size_type &received_size,
T *reuse_ptr = 0);
std::pair<void *, bool>
raw_allocation_command (boost::interprocess::allocation_type command, size_type limit_object,
size_type preferred_object,size_type &received_object,
void *reuse_ptr = 0, size_type sizeof_object = 1);
//!Returns the size of the buffer previously allocated pointed by ptr
size_type size(const void *ptr) const;
//!Allocates aligned bytes, returns 0 if there is not more memory.
//!Alignment must be power of 2
void* allocate_aligned (size_type nbytes, size_type alignment);
/// @cond
private:
static size_type priv_first_block_offset_from_this(const void *this_ptr, size_type extra_hdr_bytes);
block_ctrl *priv_first_block();
block_ctrl *priv_end_block();
std::pair<void*, bool>
priv_allocation_command(boost::interprocess::allocation_type command, size_type limit_size,
size_type preferred_size,size_type &received_size,
void *reuse_ptr, size_type sizeof_object);
//!Real allocation algorithm with min allocation option
std::pair<void *, bool> priv_allocate(boost::interprocess::allocation_type command
,size_type limit_size
,size_type preferred_size
,size_type &received_size
,void *reuse_ptr = 0
,size_type backwards_multiple = 1);
//!Obtains the block control structure of the user buffer
static block_ctrl *priv_get_block(const void *ptr);
//!Obtains the pointer returned to the user from the block control
static void *priv_get_user_buffer(const block_ctrl *block);
//!Returns the number of total units that a user buffer
//!of "userbytes" bytes really occupies (including header)
static size_type priv_get_total_units(size_type userbytes);
//!Real expand function implementation
bool priv_expand(void *ptr
,const size_type min_size, const size_type preferred_size
,size_type &received_size);
//!Real expand to both sides implementation
void* priv_expand_both_sides(boost::interprocess::allocation_type command
,size_type min_size
,size_type preferred_size
,size_type &received_size
,void *reuse_ptr
,bool only_preferred_backwards
,size_type backwards_multiple);
//!Returns true if the previous block is allocated
bool priv_is_prev_allocated(block_ctrl *ptr);
//!Get a pointer of the "end" block from the first block of the segment
static block_ctrl * priv_end_block(block_ctrl *first_segment_block);
//!Get a pointer of the "first" block from the end block of the segment
static block_ctrl * priv_first_block(block_ctrl *end_segment_block);
//!Get poitner of the previous block (previous block must be free)
static block_ctrl * priv_prev_block(block_ctrl *ptr);
//!Get the size in the tail of the previous block
static block_ctrl * priv_next_block(block_ctrl *ptr);
//!Check if this block is free (not allocated)
bool priv_is_allocated_block(block_ctrl *ptr);
//!Marks the block as allocated
void priv_mark_as_allocated_block(block_ctrl *ptr);
//!Marks the block as allocated
void priv_mark_new_allocated_block(block_ctrl *ptr)
{ return priv_mark_as_allocated_block(ptr); }
//!Marks the block as allocated
void priv_mark_as_free_block(block_ctrl *ptr);
//!Checks if block has enough memory and splits/unlinks the block
//!returning the address to the users
void* priv_check_and_allocate(size_type units
,block_ctrl* block
,size_type &received_size);
//!Real deallocation algorithm
void priv_deallocate(void *addr);
//!Makes a new memory portion available for allocation
void priv_add_segment(void *addr, size_type size);
public:
static const size_type Alignment = !MemAlignment
? size_type(::boost::alignment_of< ::boost::detail::max_align>::value)
: size_type(MemAlignment)
;
private:
//Due to embedded bits in size, Alignment must be at least 4
BOOST_STATIC_ASSERT((Alignment >= 4));
//Due to rbtree size optimizations, Alignment must have at least pointer alignment
BOOST_STATIC_ASSERT((Alignment >= ::boost::alignment_of<void_pointer>::value));
static const size_type AlignmentMask = (Alignment - 1);
static const size_type BlockCtrlBytes = ipcdetail::ct_rounded_size<sizeof(block_ctrl), Alignment>::value;
static const size_type BlockCtrlUnits = BlockCtrlBytes/Alignment;
static const size_type AllocatedCtrlBytes = ipcdetail::ct_rounded_size<sizeof(SizeHolder), Alignment>::value;
static const size_type AllocatedCtrlUnits = AllocatedCtrlBytes/Alignment;
static const size_type EndCtrlBlockBytes = ipcdetail::ct_rounded_size<sizeof(SizeHolder), Alignment>::value;
static const size_type EndCtrlBlockUnits = EndCtrlBlockBytes/Alignment;
static const size_type MinBlockUnits = BlockCtrlUnits;
static const size_type UsableByPreviousChunk = sizeof(size_type);
//Make sure the maximum alignment is power of two
BOOST_STATIC_ASSERT((0 == (Alignment & (Alignment - size_type(1u)))));
/// @endcond
public:
static const size_type PayloadPerAllocation = AllocatedCtrlBytes - UsableByPreviousChunk;
};
/// @cond
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::size_type
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>
::priv_first_block_offset_from_this(const void *this_ptr, size_type extra_hdr_bytes)
{
size_type uint_this = (std::size_t)this_ptr;
size_type main_hdr_end = uint_this + sizeof(rbtree_best_fit) + extra_hdr_bytes;
size_type aligned_main_hdr_end = ipcdetail::get_rounded_size(main_hdr_end, Alignment);
size_type block1_off = aligned_main_hdr_end - uint_this;
algo_impl_t::assert_alignment(aligned_main_hdr_end);
algo_impl_t::assert_alignment(uint_this + block1_off);
return block1_off;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
priv_add_segment(void *addr, size_type size)
{
//Check alignment
algo_impl_t::check_alignment(addr);
//Check size
BOOST_ASSERT(size >= (BlockCtrlBytes + EndCtrlBlockBytes));
//Initialize the first big block and the "end" node
block_ctrl *first_big_block = new(addr)block_ctrl;
first_big_block->m_size = size/Alignment - EndCtrlBlockUnits;
BOOST_ASSERT(first_big_block->m_size >= BlockCtrlUnits);
//The "end" node is just a node of size 0 with the "end" bit set
block_ctrl *end_block = static_cast<block_ctrl*>
(new (reinterpret_cast<char*>(addr) + first_big_block->m_size*Alignment)SizeHolder);
//This will overwrite the prev part of the "end" node
priv_mark_as_free_block (first_big_block);
#ifdef BOOST_INTERPROCESS_RBTREE_BEST_FIT_ABI_V1_HPP
first_big_block->m_prev_size = end_block->m_size =
(reinterpret_cast<char*>(first_big_block) - reinterpret_cast<char*>(end_block))/Alignment;
#else
first_big_block->m_prev_size = end_block->m_size =
(reinterpret_cast<char*>(end_block) - reinterpret_cast<char*>(first_big_block))/Alignment;
#endif
end_block->m_allocated = 1;
first_big_block->m_prev_allocated = 1;
BOOST_ASSERT(priv_next_block(first_big_block) == end_block);
BOOST_ASSERT(priv_prev_block(end_block) == first_big_block);
BOOST_ASSERT(priv_first_block() == first_big_block);
BOOST_ASSERT(priv_end_block() == end_block);
//Some check to validate the algorithm, since it makes some assumptions
//to optimize the space wasted in bookkeeping:
//Check that the sizes of the header are placed before the rbtree
BOOST_ASSERT(static_cast<void*>(static_cast<SizeHolder*>(first_big_block))
< static_cast<void*>(static_cast<TreeHook*>(first_big_block)));
//Insert it in the intrusive containers
m_header.m_imultiset.insert(*first_big_block);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>
::priv_first_block()
{
size_type block1_off = priv_first_block_offset_from_this(this, m_header.m_extra_hdr_bytes);
return reinterpret_cast<block_ctrl *>(reinterpret_cast<char*>(this) + block1_off);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>
::priv_end_block()
{
size_type block1_off = priv_first_block_offset_from_this(this, m_header.m_extra_hdr_bytes);
const size_type original_first_block_size = m_header.m_size/Alignment*Alignment - block1_off/Alignment*Alignment - EndCtrlBlockBytes;
block_ctrl *end_block = reinterpret_cast<block_ctrl*>
(reinterpret_cast<char*>(this) + block1_off + original_first_block_size);
return end_block;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
rbtree_best_fit(size_type size, size_type extra_hdr_bytes)
{
//Initialize the header
m_header.m_allocated = 0;
m_header.m_size = size;
m_header.m_extra_hdr_bytes = extra_hdr_bytes;
//Now write calculate the offset of the first big block that will
//cover the whole segment
BOOST_ASSERT(get_min_size(extra_hdr_bytes) <= size);
size_type block1_off = priv_first_block_offset_from_this(this, extra_hdr_bytes);
priv_add_segment(reinterpret_cast<char*>(this) + block1_off, size - block1_off);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::~rbtree_best_fit()
{
//There is a memory leak!
// BOOST_ASSERT(m_header.m_allocated == 0);
// BOOST_ASSERT(m_header.m_root.m_next->m_next == block_ctrl_ptr(&m_header.m_root));
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::grow(size_type extra_size)
{
//Get the address of the first block
block_ctrl *first_block = priv_first_block();
block_ctrl *old_end_block = priv_end_block();
size_type old_border_offset = (size_type)(reinterpret_cast<char*>(old_end_block) -
reinterpret_cast<char*>(this)) + EndCtrlBlockBytes;
//Update managed buffer's size
m_header.m_size += extra_size;
//We need at least MinBlockUnits blocks to create a new block
if((m_header.m_size - old_border_offset) < MinBlockUnits){
return;
}
//Now create a new block between the old end and the new end
size_type align_offset = (m_header.m_size - old_border_offset)/Alignment;
block_ctrl *new_end_block = reinterpret_cast<block_ctrl*>
(reinterpret_cast<char*>(old_end_block) + align_offset*Alignment);
//the last and first block are special:
//new_end_block->m_size & first_block->m_prev_size store the absolute value
//between them
new_end_block->m_allocated = 1;
#ifdef BOOST_INTERPROCESS_RBTREE_BEST_FIT_ABI_V1_HPP
new_end_block->m_size = (reinterpret_cast<char*>(first_block) -
reinterpret_cast<char*>(new_end_block))/Alignment;
#else
new_end_block->m_size = (reinterpret_cast<char*>(new_end_block) -
reinterpret_cast<char*>(first_block))/Alignment;
#endif
first_block->m_prev_size = new_end_block->m_size;
first_block->m_prev_allocated = 1;
BOOST_ASSERT(new_end_block == priv_end_block());
//The old end block is the new block
block_ctrl *new_block = old_end_block;
new_block->m_size = (reinterpret_cast<char*>(new_end_block) -
reinterpret_cast<char*>(new_block))/Alignment;
BOOST_ASSERT(new_block->m_size >= BlockCtrlUnits);
priv_mark_as_allocated_block(new_block);
BOOST_ASSERT(priv_next_block(new_block) == new_end_block);
m_header.m_allocated += (size_type)new_block->m_size*Alignment;
//Now deallocate the newly created block
this->priv_deallocate(priv_get_user_buffer(new_block));
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::shrink_to_fit()
{
//Get the address of the first block
block_ctrl *first_block = priv_first_block();
algo_impl_t::assert_alignment(first_block);
//block_ctrl *old_end_block = priv_end_block(first_block);
block_ctrl *old_end_block = priv_end_block();
algo_impl_t::assert_alignment(old_end_block);
size_type old_end_block_size = old_end_block->m_size;
void *unique_buffer = 0;
block_ctrl *last_block;
//Check if no memory is allocated between the first and last block
if(priv_next_block(first_block) == old_end_block){
//If so check if we can allocate memory
size_type ignore;
unique_buffer = priv_allocate(boost::interprocess::allocate_new, 0, 0, ignore).first;
//If not, return, we can't shrink
if(!unique_buffer)
return;
//If we can, mark the position just after the new allocation as the new end
algo_impl_t::assert_alignment(unique_buffer);
block_ctrl *unique_block = priv_get_block(unique_buffer);
BOOST_ASSERT(priv_is_allocated_block(unique_block));
algo_impl_t::assert_alignment(unique_block);
last_block = priv_next_block(unique_block);
BOOST_ASSERT(!priv_is_allocated_block(last_block));
algo_impl_t::assert_alignment(last_block);
}
else{
//If memory is allocated, check if the last block is allocated
if(priv_is_prev_allocated(old_end_block))
return;
//If not, mark last block after the free block
last_block = priv_prev_block(old_end_block);
}
size_type last_block_size = last_block->m_size;
//Erase block from the free tree, since we will erase it
m_header.m_imultiset.erase(Imultiset::s_iterator_to(*last_block));
size_type shrunk_border_offset = (size_type)(reinterpret_cast<char*>(last_block) -
reinterpret_cast<char*>(this)) + EndCtrlBlockBytes;
block_ctrl *new_end_block = last_block;
algo_impl_t::assert_alignment(new_end_block);
//Write new end block attributes
#ifdef BOOST_INTERPROCESS_RBTREE_BEST_FIT_ABI_V1_HPP
new_end_block->m_size = first_block->m_prev_size =
(reinterpret_cast<char*>(first_block) - reinterpret_cast<char*>(new_end_block))/Alignment;
#else
new_end_block->m_size = first_block->m_prev_size =
(reinterpret_cast<char*>(new_end_block) - reinterpret_cast<char*>(first_block))/Alignment;
#endif
new_end_block->m_allocated = 1;
(void)last_block_size;
(void)old_end_block_size;
BOOST_ASSERT(new_end_block->m_size == (old_end_block_size - last_block_size));
//Update managed buffer's size
m_header.m_size = shrunk_border_offset;
BOOST_ASSERT(priv_end_block() == new_end_block);
if(unique_buffer)
priv_deallocate(unique_buffer);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::size_type
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::get_size() const
{ return m_header.m_size; }
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::size_type
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::get_free_memory() const
{
return m_header.m_size - m_header.m_allocated -
priv_first_block_offset_from_this(this, m_header.m_extra_hdr_bytes);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::size_type
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
get_min_size (size_type extra_hdr_bytes)
{
return (algo_impl_t::ceil_units(sizeof(rbtree_best_fit)) +
algo_impl_t::ceil_units(extra_hdr_bytes) +
MinBlockUnits + EndCtrlBlockUnits)*Alignment;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline bool rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
all_memory_deallocated()
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
size_type block1_off =
priv_first_block_offset_from_this(this, m_header.m_extra_hdr_bytes);
return m_header.m_allocated == 0 &&
m_header.m_imultiset.begin() != m_header.m_imultiset.end() &&
(++m_header.m_imultiset.begin()) == m_header.m_imultiset.end()
&& m_header.m_imultiset.begin()->m_size ==
(m_header.m_size - block1_off - EndCtrlBlockBytes)/Alignment;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
bool rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
check_sanity()
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
imultiset_iterator ib(m_header.m_imultiset.begin()), ie(m_header.m_imultiset.end());
size_type free_memory = 0;
//Iterate through all blocks obtaining their size
for(; ib != ie; ++ib){
free_memory += (size_type)ib->m_size*Alignment;
algo_impl_t::assert_alignment(&*ib);
if(!algo_impl_t::check_alignment(&*ib))
return false;
}
//Check allocated bytes are less than size
if(m_header.m_allocated > m_header.m_size){
return false;
}
size_type block1_off =
priv_first_block_offset_from_this(this, m_header.m_extra_hdr_bytes);
//Check free bytes are less than size
if(free_memory > (m_header.m_size - block1_off)){
return false;
}
return true;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline void* rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
allocate(size_type nbytes)
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
size_type ignore;
void * ret = priv_allocate(boost::interprocess::allocate_new, nbytes, nbytes, ignore).first;
return ret;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline void* rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
allocate_aligned(size_type nbytes, size_type alignment)
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
return algo_impl_t::allocate_aligned(this, nbytes, alignment);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
template<class T>
inline std::pair<T*, bool> rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
allocation_command (boost::interprocess::allocation_type command, size_type limit_size,
size_type preferred_size,size_type &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 % ::boost::alignment_of<T>::value));
return std::pair<T *, bool>(static_cast<T*>(ret.first), ret.second);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline std::pair<void*, bool> rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
raw_allocation_command (boost::interprocess::allocation_type command, size_type limit_objects,
size_type preferred_objects,size_type &received_objects,
void *reuse_ptr, size_type sizeof_object)
{
if(!sizeof_object)
return std::pair<void *, bool>(static_cast<void*>(0), false);
if(command & boost::interprocess::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, std::size_t MemAlignment>
inline std::pair<void*, bool> rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
priv_allocation_command (boost::interprocess::allocation_type command, size_type limit_size,
size_type preferred_size,size_type &received_size,
void *reuse_ptr, size_type sizeof_object)
{
std::pair<void*, bool> ret;
size_type max_count = m_header.m_size/sizeof_object;
if(limit_size > max_count || preferred_size > max_count){
ret.first = 0; return ret;
}
size_type l_size = limit_size*sizeof_object;
size_type p_size = preferred_size*sizeof_object;
size_type r_size;
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
ret = priv_allocate(command, l_size, p_size, r_size, reuse_ptr, sizeof_object);
}
received_size = r_size/sizeof_object;
return ret;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::size_type
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
size(const void *ptr) const
{
//We need no synchronization since this block's size is not going
//to be modified by anyone else
//Obtain the real size of the block
return ((size_type)priv_get_block(ptr)->m_size - AllocatedCtrlUnits)*Alignment + UsableByPreviousChunk;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::zero_free_memory()
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
imultiset_iterator ib(m_header.m_imultiset.begin()), ie(m_header.m_imultiset.end());
//Iterate through all blocks obtaining their size
while(ib != ie){
//Just clear user the memory part reserved for the user
volatile char *ptr = reinterpret_cast<char*>(&*ib) + BlockCtrlBytes;
size_type s = (size_type)ib->m_size*Alignment - BlockCtrlBytes;
while(s--){
*ptr++ = 0;
}
//This surprisingly is optimized out by Visual C++ 7.1 in release mode!
//std::memset( reinterpret_cast<char*>(&*ib) + BlockCtrlBytes
// , 0
// , ib->m_size*Alignment - BlockCtrlBytes);
++ib;
}
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
void* rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
priv_expand_both_sides(boost::interprocess::allocation_type command
,size_type min_size
,size_type preferred_size
,size_type &received_size
,void *reuse_ptr
,bool only_preferred_backwards
,size_type backwards_multiple)
{
algo_impl_t::assert_alignment(reuse_ptr);
if(command & boost::interprocess::expand_fwd){
if(priv_expand(reuse_ptr, min_size, preferred_size, received_size))
return reuse_ptr;
}
else{
received_size = this->size(reuse_ptr);
if(received_size >= preferred_size || received_size >= min_size)
return reuse_ptr;
}
if(backwards_multiple){
BOOST_ASSERT(0 == (min_size % backwards_multiple));
BOOST_ASSERT(0 == (preferred_size % backwards_multiple));
}
if(command & boost::interprocess::expand_bwd){
//Obtain the real size of the block
block_ctrl *reuse = priv_get_block(reuse_ptr);
//Sanity check
//BOOST_ASSERT(reuse->m_size == priv_tail_size(reuse));
algo_impl_t::assert_alignment(reuse);
block_ctrl *prev_block;
//If the previous block is not free, there is nothing to do
if(priv_is_prev_allocated(reuse)){
return 0;
}
prev_block = priv_prev_block(reuse);
BOOST_ASSERT(!priv_is_allocated_block(prev_block));
//Some sanity checks
BOOST_ASSERT(prev_block->m_size == reuse->m_prev_size);
algo_impl_t::assert_alignment(prev_block);
size_type needs_backwards_aligned;
size_type lcm;
if(!algo_impl_t::calculate_lcm_and_needs_backwards_lcmed
( backwards_multiple
, received_size
, only_preferred_backwards ? preferred_size : min_size
, lcm, needs_backwards_aligned)){
return 0;
}
//Check if previous block has enough size
if(size_type(prev_block->m_size*Alignment) >= needs_backwards_aligned){
//Now take all next space. This will succeed
if(command & boost::interprocess::expand_fwd){
size_type received_size2;
if(!priv_expand(reuse_ptr, received_size, received_size, received_size2)){
BOOST_ASSERT(0);
}
BOOST_ASSERT(received_size = received_size2);
}
//We need a minimum size to split the previous one
if(prev_block->m_size >= (needs_backwards_aligned/Alignment + BlockCtrlUnits)){
block_ctrl *new_block = reinterpret_cast<block_ctrl *>
(reinterpret_cast<char*>(reuse) - needs_backwards_aligned);
//Free old previous buffer
new_block->m_size =
AllocatedCtrlUnits + (needs_backwards_aligned + (received_size - UsableByPreviousChunk))/Alignment;
BOOST_ASSERT(new_block->m_size >= BlockCtrlUnits);
priv_mark_as_allocated_block(new_block);
prev_block->m_size = (reinterpret_cast<char*>(new_block) -
reinterpret_cast<char*>(prev_block))/Alignment;
BOOST_ASSERT(prev_block->m_size >= BlockCtrlUnits);
priv_mark_as_free_block(prev_block);
//Update the old previous block in the free blocks tree
//If the new size fulfills tree invariants do nothing,
//otherwise erase() + insert()
{
imultiset_iterator prev_block_it(Imultiset::s_iterator_to(*prev_block));
imultiset_iterator was_smaller_it(prev_block_it);
if(prev_block_it != m_header.m_imultiset.begin() &&
(--(was_smaller_it = prev_block_it))->m_size > prev_block->m_size){
m_header.m_imultiset.erase(prev_block_it);
m_header.m_imultiset.insert(m_header.m_imultiset.begin(), *prev_block);
}
}
received_size = needs_backwards_aligned + received_size;
m_header.m_allocated += needs_backwards_aligned;
//Check alignment
algo_impl_t::assert_alignment(new_block);
//If the backwards expansion has remaining bytes in the
//first bytes, fill them with a pattern
void *p = priv_get_user_buffer(new_block);
void *user_ptr = reinterpret_cast<char*>(p);
BOOST_ASSERT((static_cast<char*>(reuse_ptr) - static_cast<char*>(user_ptr)) % backwards_multiple == 0);
algo_impl_t::assert_alignment(user_ptr);
return user_ptr;
}
//Check if there is no place to create a new block and
//the whole new block is multiple of the backwards expansion multiple
else if(prev_block->m_size >= needs_backwards_aligned/Alignment &&
0 == ((prev_block->m_size*Alignment) % lcm)) {
//Erase old previous block, since we will change it
m_header.m_imultiset.erase(Imultiset::s_iterator_to(*prev_block));
//Just merge the whole previous block
//prev_block->m_size*Alignment is multiple of lcm (and backwards_multiple)
received_size = received_size + (size_type)prev_block->m_size*Alignment;
m_header.m_allocated += (size_type)prev_block->m_size*Alignment;
//Now update sizes
prev_block->m_size = prev_block->m_size + reuse->m_size;
BOOST_ASSERT(prev_block->m_size >= BlockCtrlUnits);
priv_mark_as_allocated_block(prev_block);
//If the backwards expansion has remaining bytes in the
//first bytes, fill them with a pattern
void *user_ptr = priv_get_user_buffer(prev_block);
BOOST_ASSERT((static_cast<char*>(reuse_ptr) - static_cast<char*>(user_ptr)) % backwards_multiple == 0);
algo_impl_t::assert_alignment(user_ptr);
return user_ptr;
}
else{
//Alignment issues
}
}
}
return 0;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
deallocate_many(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::multiallocation_chain chain)
{
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
algo_impl_t::deallocate_many(this, boost::interprocess::move(chain));
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
std::pair<void *, bool> rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
priv_allocate(boost::interprocess::allocation_type command
,size_type limit_size
,size_type preferred_size
,size_type &received_size
,void *reuse_ptr
,size_type backwards_multiple)
{
//Remove me. Forbid backwards allocation
//command &= (~boost::interprocess::expand_bwd);
if(command & boost::interprocess::shrink_in_place){
bool success =
algo_impl_t::shrink(this, reuse_ptr, limit_size, preferred_size, received_size);
return std::pair<void *, bool> ((success ? reuse_ptr : 0), true);
}
typedef std::pair<void *, bool> return_type;
received_size = 0;
if(limit_size > preferred_size)
return return_type(static_cast<void*>(0), false);
//Number of units to request (including block_ctrl header)
size_type preferred_units = priv_get_total_units(preferred_size);
//Number of units to request (including block_ctrl header)
size_type limit_units = priv_get_total_units(limit_size);
//Expand in place
if(reuse_ptr && (command & (boost::interprocess::expand_fwd | boost::interprocess::expand_bwd))){
void *ret = priv_expand_both_sides
(command, limit_size, preferred_size, received_size, reuse_ptr, true, backwards_multiple);
if(ret)
return return_type(ret, true);
}
if(command & boost::interprocess::allocate_new){
size_block_ctrl_compare comp;
imultiset_iterator it(m_header.m_imultiset.lower_bound(preferred_units, comp));
if(it != m_header.m_imultiset.end()){
return return_type(this->priv_check_and_allocate
(preferred_units, ipcdetail::get_pointer(&*it), received_size), false);
}
if(it != m_header.m_imultiset.begin()&&
(--it)->m_size >= limit_units){
return return_type(this->priv_check_and_allocate
(it->m_size, ipcdetail::get_pointer(&*it), received_size), false);
}
}
//Now try to expand both sides with min size
if(reuse_ptr && (command & (boost::interprocess::expand_fwd | boost::interprocess::expand_bwd))){
return return_type(priv_expand_both_sides
(command, limit_size, preferred_size, received_size, reuse_ptr, false, backwards_multiple), true);
}
return return_type(static_cast<void*>(0), false);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::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, std::size_t MemAlignment>
inline
void *rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
priv_get_user_buffer(const typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *block)
{ return const_cast<char*>(reinterpret_cast<const char*>(block) + AllocatedCtrlBytes); }
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
inline typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::size_type
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
priv_get_total_units(size_type userbytes)
{
if(userbytes < UsableByPreviousChunk)
userbytes = UsableByPreviousChunk;
size_type units = ipcdetail::get_rounded_size(userbytes - UsableByPreviousChunk, Alignment)/Alignment + AllocatedCtrlUnits;
if(units < BlockCtrlUnits) units = BlockCtrlUnits;
return units;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
bool rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::
priv_expand (void *ptr
,const size_type min_size
,const size_type preferred_size
,size_type &received_size)
{
//Obtain the real size of the block
block_ctrl *block = priv_get_block(ptr);
size_type old_block_units = block->m_size;
//The block must be marked as allocated and the sizes must be equal
BOOST_ASSERT(priv_is_allocated_block(block));
//BOOST_ASSERT(old_block_units == priv_tail_size(block));
//Put this to a safe value
received_size = (old_block_units - AllocatedCtrlUnits)*Alignment + UsableByPreviousChunk;
if(received_size >= preferred_size || received_size >= min_size)
return true;
//Now translate it to Alignment units
const size_type min_user_units = algo_impl_t::ceil_units(min_size - UsableByPreviousChunk);
const size_type preferred_user_units = algo_impl_t::ceil_units(preferred_size - UsableByPreviousChunk);
//Some parameter checks
BOOST_ASSERT(min_user_units <= preferred_user_units);
block_ctrl *next_block;
if(priv_is_allocated_block(next_block = priv_next_block(block))){
return received_size >= min_size ? true : false;
}
algo_impl_t::assert_alignment(next_block);
//Is "block" + "next_block" big enough?
const size_type merged_units = old_block_units + (size_type)next_block->m_size;
//Now get the expansion size
const size_type merged_user_units = merged_units - AllocatedCtrlUnits;
if(merged_user_units < min_user_units){
received_size = merged_units*Alignment - UsableByPreviousChunk;
return false;
}
//Now get the maximum size the user can allocate
size_type intended_user_units = (merged_user_units < preferred_user_units) ?
merged_user_units : preferred_user_units;
//These are total units of the merged block (supposing the next block can be split)
const size_type intended_units = AllocatedCtrlUnits + intended_user_units;
//Check if we can split the next one in two parts
if((merged_units - intended_units) >= BlockCtrlUnits){
//This block is bigger than needed, split it in
//two blocks, the first one will be merged and
//the second's size will be the remaining space
BOOST_ASSERT(next_block->m_size == priv_next_block(next_block)->m_prev_size);
const size_type rem_units = merged_units - intended_units;
//Check if we we need to update the old next block in the free blocks tree
//If the new size fulfills tree invariants, we just need to replace the node
//(the block start has been displaced), otherwise erase() + insert().
//
//This fixup must be done in two parts, because the new next block might
//overwrite the tree hook of the old next block. So we first erase the
//old if needed and we'll insert the new one after creating the new next
imultiset_iterator old_next_block_it(Imultiset::s_iterator_to(*next_block));
const bool size_invariants_broken =
(next_block->m_size - rem_units ) < BlockCtrlUnits ||
(old_next_block_it != m_header.m_imultiset.begin() &&
(--imultiset_iterator(old_next_block_it))->m_size > rem_units);
if(size_invariants_broken){
m_header.m_imultiset.erase(old_next_block_it);
}
//This is the remaining block
block_ctrl *rem_block = new(reinterpret_cast<block_ctrl*>
(reinterpret_cast<char*>(block) + intended_units*Alignment))block_ctrl;
rem_block->m_size = rem_units;
algo_impl_t::assert_alignment(rem_block);
BOOST_ASSERT(rem_block->m_size >= BlockCtrlUnits);
priv_mark_as_free_block(rem_block);
//Now the second part of the fixup
if(size_invariants_broken)
m_header.m_imultiset.insert(m_header.m_imultiset.begin(), *rem_block);
else
m_header.m_imultiset.replace_node(old_next_block_it, *rem_block);
//Write the new length
block->m_size = intended_user_units + AllocatedCtrlUnits;
BOOST_ASSERT(block->m_size >= BlockCtrlUnits);
m_header.m_allocated += (intended_units - old_block_units)*Alignment;
}
//There is no free space to create a new node: just merge both blocks
else{
//Now we have to update the data in the tree
m_header.m_imultiset.erase(Imultiset::s_iterator_to(*next_block));
//Write the new length
block->m_size = merged_units;
BOOST_ASSERT(block->m_size >= BlockCtrlUnits);
m_header.m_allocated += (merged_units - old_block_units)*Alignment;
}
priv_mark_as_allocated_block(block);
received_size = ((size_type)block->m_size - AllocatedCtrlUnits)*Alignment + UsableByPreviousChunk;
return true;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_prev_block
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *ptr)
{
BOOST_ASSERT(!ptr->m_prev_allocated);
return reinterpret_cast<block_ctrl *>
(reinterpret_cast<char*>(ptr) - ptr->m_prev_size*Alignment);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_end_block
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *first_segment_block)
{
//The first block's logic is different from the rest of blocks: stores in m_prev_size the absolute
//distance with the end block
BOOST_ASSERT(first_segment_block->m_prev_allocated);
block_ctrl *end_block = reinterpret_cast<block_ctrl *>
(reinterpret_cast<char*>(first_segment_block) + first_segment_block->m_prev_size*Alignment);
(void)end_block;
BOOST_ASSERT(end_block->m_allocated == 1);
BOOST_ASSERT(end_block->m_size == first_segment_block->m_prev_size);
BOOST_ASSERT(end_block > first_segment_block);
return end_block;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_first_block
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *end_segment_block)
{
//The first block's logic is different from the rest of blocks: stores in m_prev_size the absolute
//distance with the end block
BOOST_ASSERT(end_segment_block->m_allocated);
block_ctrl *first_block = reinterpret_cast<block_ctrl *>
(reinterpret_cast<char*>(end_segment_block) - end_segment_block->m_size*Alignment);
(void)first_block;
BOOST_ASSERT(first_block->m_prev_allocated == 1);
BOOST_ASSERT(first_block->m_prev_size == end_segment_block->m_size);
BOOST_ASSERT(end_segment_block > first_block);
return first_block;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *
rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_next_block
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *ptr)
{
return reinterpret_cast<block_ctrl *>
(reinterpret_cast<char*>(ptr) + ptr->m_size*Alignment);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
bool rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_is_allocated_block
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *block)
{
bool allocated = block->m_allocated != 0;
#ifndef NDEBUG
if(block != priv_end_block()){
block_ctrl *next_block = reinterpret_cast<block_ctrl *>
(reinterpret_cast<char*>(block) + block->m_size*Alignment);
bool next_block_prev_allocated = next_block->m_prev_allocated != 0;
(void)next_block_prev_allocated;
BOOST_ASSERT(allocated == next_block_prev_allocated);
}
else{
block = block;
}
#endif
return allocated;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
bool rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_is_prev_allocated
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *block)
{
if(block->m_prev_allocated){
return true;
}
else{
#ifndef NDEBUG
if(block != priv_first_block()){
block_ctrl *prev = priv_prev_block(block);
(void)prev;
BOOST_ASSERT(!prev->m_allocated);
}
else{
block = block;
}
#endif
return false;
}
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_mark_as_allocated_block
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *block)
{
block->m_allocated = 1;
reinterpret_cast<block_ctrl *>
(reinterpret_cast<char*>(block)+ block->m_size*Alignment)->m_prev_allocated = 1;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_mark_as_free_block
(typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl *block)
{
block->m_allocated = 0;
block_ctrl *next_block = priv_next_block(block);
next_block->m_prev_allocated = 0;
next_block->m_prev_size = block->m_size;
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment> inline
void* rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_check_and_allocate
(size_type nunits
,typename rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::block_ctrl* block
,size_type &received_size)
{
size_type upper_nunits = nunits + BlockCtrlUnits;
imultiset_iterator it_old = Imultiset::s_iterator_to(*block);
algo_impl_t::assert_alignment(block);
if (block->m_size >= upper_nunits){
//This block is bigger than needed, split it in
//two blocks, the first's size will be "units" and
//the second's size "block->m_size-units"
size_type block_old_size = block->m_size;
block->m_size = nunits;
BOOST_ASSERT(block->m_size >= BlockCtrlUnits);
//This is the remaining block
block_ctrl *rem_block = new(reinterpret_cast<block_ctrl*>
(reinterpret_cast<char*>(block) + Alignment*nunits))block_ctrl;
algo_impl_t::assert_alignment(rem_block);
rem_block->m_size = block_old_size - nunits;
BOOST_ASSERT(rem_block->m_size >= BlockCtrlUnits);
priv_mark_as_free_block(rem_block);
imultiset_iterator it_hint;
if(it_old == m_header.m_imultiset.begin()
|| (--imultiset_iterator(it_old))->m_size < rem_block->m_size){
//option a: slow but secure
//m_header.m_imultiset.insert(m_header.m_imultiset.erase(it_old), *rem_block);
//option b: Construct an empty node and swap
//Imultiset::init_node(*rem_block);
//block->swap_nodes(*rem_block);
//option c: replace the node directly
m_header.m_imultiset.replace_node(Imultiset::s_iterator_to(*it_old), *rem_block);
}
else{
//Now we have to update the data in the tree
m_header.m_imultiset.erase(it_old);
m_header.m_imultiset.insert(m_header.m_imultiset.begin(), *rem_block);
}
}
else if (block->m_size >= nunits){
m_header.m_imultiset.erase(it_old);
}
else{
BOOST_ASSERT(0);
return 0;
}
//We need block_ctrl for deallocation stuff, so
//return memory user can overwrite
m_header.m_allocated += (size_type)block->m_size*Alignment;
received_size = ((size_type)block->m_size - AllocatedCtrlUnits)*Alignment + UsableByPreviousChunk;
//Mark the block as allocated
priv_mark_as_allocated_block(block);
//Clear the memory occupied by the tree hook, since this won't be
//cleared with zero_free_memory
TreeHook *t = static_cast<TreeHook*>(block);
//Just clear the memory part reserved for the user
std::size_t tree_hook_offset_in_block = (char*)t - (char*)block;
//volatile char *ptr =
char *ptr = reinterpret_cast<char*>(block)+tree_hook_offset_in_block;
const std::size_t s = BlockCtrlBytes - tree_hook_offset_in_block;
std::memset(ptr, 0, s);
this->priv_next_block(block)->m_prev_size = 0;
return priv_get_user_buffer(block);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::deallocate(void* addr)
{
if(!addr) return;
//-----------------------
boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
//-----------------------
return this->priv_deallocate(addr);
}
template<class MutexFamily, class VoidPointer, std::size_t MemAlignment>
void rbtree_best_fit<MutexFamily, VoidPointer, MemAlignment>::priv_deallocate(void* addr)
{
if(!addr) return;
block_ctrl *block = priv_get_block(addr);
//The blocks must be marked as allocated and the sizes must be equal
BOOST_ASSERT(priv_is_allocated_block(block));
// BOOST_ASSERT(block->m_size == priv_tail_size(block));
//Check if alignment and block size are right
algo_impl_t::assert_alignment(addr);
size_type block_old_size = Alignment*(size_type)block->m_size;
BOOST_ASSERT(m_header.m_allocated >= block_old_size);
//Update used memory count
m_header.m_allocated -= block_old_size;
//The block to insert in the tree
block_ctrl *block_to_insert = block;
//Get the next block
block_ctrl *next_block = priv_next_block(block);
bool merge_with_prev = !priv_is_prev_allocated(block);
bool merge_with_next = !priv_is_allocated_block(next_block);
//Merge logic. First just update block sizes, then fix free blocks tree
if(merge_with_prev || merge_with_next){
//Merge if the previous is free
if(merge_with_prev){
//Get the previous block
block_ctrl *prev_block = priv_prev_block(block);
prev_block->m_size += block->m_size;
BOOST_ASSERT(prev_block->m_size >= BlockCtrlUnits);
block_to_insert = prev_block;
}
//Merge if the next is free
if(merge_with_next){
block_to_insert->m_size += next_block->m_size;
BOOST_ASSERT(block_to_insert->m_size >= BlockCtrlUnits);
if(merge_with_prev)
m_header.m_imultiset.erase(Imultiset::s_iterator_to(*next_block));
}
bool only_merge_next = !merge_with_prev && merge_with_next;
imultiset_iterator free_block_to_check_it
(Imultiset::s_iterator_to(only_merge_next ? *next_block : *block_to_insert));
imultiset_iterator was_bigger_it(free_block_to_check_it);
//Now try to shortcut erasure + insertion (O(log(N))) with
//a O(1) operation if merging does not alter tree positions
if(++was_bigger_it != m_header.m_imultiset.end() &&
block_to_insert->m_size > was_bigger_it->m_size ){
m_header.m_imultiset.erase(free_block_to_check_it);
m_header.m_imultiset.insert(m_header.m_imultiset.begin(), *block_to_insert);
}
else if(only_merge_next){
m_header.m_imultiset.replace_node(free_block_to_check_it, *block_to_insert);
}
}
else{
m_header.m_imultiset.insert(m_header.m_imultiset.begin(), *block_to_insert);
}
priv_mark_as_free_block(block_to_insert);
}
/// @endcond
} //namespace interprocess {
} //namespace boost {
#include <boost/interprocess/detail/config_end.hpp>
#endif //#ifndef BOOST_INTERPROCESS_MEM_ALGO_RBTREE_BEST_FIT_HPP