From: igaztanaga_at_[hidden]
Date: 2008-05-23 19:20:34
Author: igaztanaga
Date: 2008-05-23 19:20:33 EDT (Fri, 23 May 2008)
New Revision: 45705
URL: http://svn.boost.org/trac/boost/changeset/45705
Log:
#1912: some copy edits on boost.intrusive
#1932: move semantics for shared objects
#1635: Incomplete include guard in boost/intrusive
Added:
trunk/boost/interprocess/mem_algo/detail/multi_simple_seq_fit.hpp (contents, props changed)
trunk/boost/interprocess/mem_algo/detail/multi_simple_seq_fit_impl.hpp (contents, props changed)
Text files modified:
trunk/boost/interprocess/mem_algo/detail/mem_algo_common.hpp | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
Modified: trunk/boost/interprocess/mem_algo/detail/mem_algo_common.hpp
==============================================================================
--- trunk/boost/interprocess/mem_algo/detail/mem_algo_common.hpp (original)
+++ trunk/boost/interprocess/mem_algo/detail/mem_algo_common.hpp 2008-05-23 19:20:33 EDT (Fri, 23 May 2008)
@@ -406,13 +406,13 @@
if(nbytes > UsableByPreviousChunk)
nbytes -= UsableByPreviousChunk;
- //We can find a aligned portion if we allocate a chunk that has alignment
+ //We can find a aligned portion if we allocate a block that has alignment
//nbytes + alignment bytes or more.
std::size_t minimum_allocation = max_value
(nbytes + alignment, std::size_t(MinBlockUnits*Alignment));
- //Since we will split that chunk, we must request a bit more memory
+ //Since we will split that block, we must request a bit more memory
//if the alignment is near the beginning of the buffer, because otherwise,
- //there is no space for a new chunk before the alignment.
+ //there is no space for a new block before the alignment.
//
// ____ Aligned here
// |
@@ -487,7 +487,7 @@
// | MBU +more | ACB | (3) | BCU |
// -----------------------------------------------------
//This size will be the minimum size to be able to create a
- //new chunk in the end.
+ //new block in the end.
const std::size_t second_min_units = max_value(std::size_t(MinBlockUnits),
ceil_units(nbytes) + AllocatedCtrlUnits );
Added: trunk/boost/interprocess/mem_algo/detail/multi_simple_seq_fit.hpp
==============================================================================
--- (empty file)
+++ trunk/boost/interprocess/mem_algo/detail/multi_simple_seq_fit.hpp 2008-05-23 19:20:33 EDT (Fri, 23 May 2008)
@@ -0,0 +1,61 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2005-2007. 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_MULTI_SIMPLE_SEQ_FIT_HPP
+#define BOOST_INTERPROCESS_MULTI_SIMPLE_SEQ_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/interprocess/interprocess_fwd.hpp>
+#include <boost/interprocess/mem_algo/detail/simple_seq_fit_impl.hpp>
+#include <boost/interprocess/intersegment_ptr.hpp>
+
+/*!\file
+ Describes sequential fit algorithm used to allocate objects in shared memory.
+*/
+
+namespace boost {
+
+namespace interprocess {
+
+/*!This class implements the simple sequential fit algorithm with a simply
+ linked list of free buffers.*/
+template<class MutexFamily, class VoidPtr>
+class multi_simple_seq_fit
+ : public detail::simple_seq_fit_impl<MutexFamily, VoidPtr>
+{
+ typedef detail::simple_seq_fit_impl<MutexFamily, VoidPtr> base_t;
+ public:
+ /*!Constructor. "size" is the total size of the managed memory segment,
+ "extra_hdr_bytes" indicates the extra bytes beginning in the sizeof(multi_simple_seq_fit)
+ offset that the allocator should not use at all.*/
+ multi_simple_seq_fit (std::size_t size, std::size_t extra_hdr_bytes)
+ : base_t(size, extra_hdr_bytes){}
+
+ /*!Allocates bytes from existing segments. If there is no memory, it uses
+ the growing functor associated with the group to allocate a new segment.
+ If this fails, returns 0.*/
+ void* allocate (std::size_t nbytes)
+ { return base_t::multi_allocate(nbytes); }
+};
+
+} //namespace interprocess {
+
+} //namespace boost {
+
+#include <boost/interprocess/detail/config_end.hpp>
+
+#endif //#ifndef BOOST_INTERPROCESS_MULTI_SIMPLE_SEQ_FIT_HPP
+
Added: trunk/boost/interprocess/mem_algo/detail/multi_simple_seq_fit_impl.hpp
==============================================================================
--- (empty file)
+++ trunk/boost/interprocess/mem_algo/detail/multi_simple_seq_fit_impl.hpp 2008-05-23 19:20:33 EDT (Fri, 23 May 2008)
@@ -0,0 +1,973 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2005-2007. 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_DETAIL_SIMPLE_SEQ_FIT_IMPL_HPP
+#define BOOST_INTERPROCESS_MEM_ALGO_DETAIL_SIMPLE_SEQ_FIT_IMPL_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/interprocess/interprocess_fwd.hpp>
+#include <boost/interprocess/allocators/allocation_type.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/multi_segment_services.hpp>
+#include <boost/type_traits/alignment_of.hpp>
+#include <boost/type_traits/type_with_alignment.hpp>
+#include <boost/interprocess/sync/scoped_lock.hpp>
+#include <algorithm>
+#include <utility>
+#include <cstring>
+
+#include <assert.h>
+#include <new>
+
+/*!\file
+ Describes sequential fit algorithm 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 {
+
+namespace detail {
+
+/*!This class implements the simple sequential fit algorithm with a simply
+ linked list of free buffers.
+ This class is intended as a base class for single segment and multi-segment
+ implementations.*/
+template<class MutexFamily, class VoidPointer>
+class simple_seq_fit_impl
+{
+ //Non-copyable
+ simple_seq_fit_impl();
+ simple_seq_fit_impl(const simple_seq_fit_impl &);
+ simple_seq_fit_impl &operator=(const simple_seq_fit_impl &);
+
+ 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;
+
+ private:
+ struct block_ctrl;
+ typedef typename detail::
+ pointer_to_other<void_pointer, block_ctrl>::type block_ctrl_ptr;
+
+ /*!Block control structure*/
+ struct block_ctrl
+ {
+ /*!Offset pointer to the next block.*/
+ block_ctrl_ptr m_next;
+ /*!This block's memory size (including block_ctrl
+ header) in BasicSize units*/
+ std::size_t m_size;
+
+ std::size_t get_user_bytes() const
+ { return this->m_size*Alignment - BlockCtrlBytes; }
+
+ std::size_t get_total_bytes() const
+ { return this->m_size*Alignment; }
+
+ static block_ctrl *get_block_from_addr(void *addr)
+ {
+ return reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(addr) - BlockCtrlBytes);
+ }
+
+ void *get_addr() const
+ {
+ return reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(this) + BlockCtrlBytes);
+ }
+
+ };
+
+ /*!Shared interprocess_mutex to protect memory allocate/deallocate*/
+ typedef typename MutexFamily::mutex_type interprocess_mutex;
+
+ /*!This struct includes needed data and derives from
+ interprocess_mutex to allow EBO when using null interprocess_mutex*/
+ struct header_t : public interprocess_mutex
+ {
+ /*!Pointer to the first free block*/
+ block_ctrl m_root;
+ /*!Allocated bytes for internal checking*/
+ std::size_t m_allocated;
+ /*!The size of the memory segment*/
+ std::size_t m_size;
+ } m_header;
+
+ public:
+ /*!Constructor. "size" is the total size of the managed memory segment,
+ "extra_hdr_bytes" indicates the extra bytes beginning in the sizeof(simple_seq_fit_impl)
+ offset that the allocator should not use at all.*/
+ simple_seq_fit_impl (std::size_t size, std::size_t extra_hdr_bytes);
+ /*!Destructor.*/
+ ~simple_seq_fit_impl();
+ /*!Obtains the minimum size needed by the algorithm*/
+ static std::size_t get_min_size (std::size_t extra_hdr_bytes);
+
+ //Functions for single segment management
+
+ /*!Allocates bytes, returns 0 if there is not more memory*/
+ void* allocate (std::size_t nbytes);
+
+ /*!Deallocates previously allocated bytes*/
+ void deallocate (void *addr);
+
+ /*!Returns the size of the memory segment*/
+ std::size_t get_size() const;
+
+ /*!Increases managed memory in extra_size bytes more*/
+ void grow(std::size_t extra_size);
+
+ /*!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();
+
+ //!Initializes to zero all the memory that's not in use.
+ //!This function is normally used for security reasons.
+ void clear_free_memory();
+
+ std::pair<void *, bool>
+ allocation_command (allocation_type command, std::size_t limit_size,
+ std::size_t preferred_size,std::size_t &received_size,
+ void *reuse_ptr = 0, std::size_t backwards_multiple = 1);
+
+ /*!Returns the size of the buffer previously allocated pointed by ptr*/
+ std::size_t size(void *ptr) const;
+
+ /*!Allocates aligned bytes, returns 0 if there is not more memory.
+ Alignment must be power of 2*/
+ void* allocate_aligned (std::size_t nbytes, std::size_t alignment);
+
+ /*!Allocates bytes, if there is no more memory, it executes functor
+ f(std::size_t) to allocate a new segment to manage. The functor returns
+ std::pair<void*, std::size_t> indicating the base address and size of
+ the new segment. If the new segment can't be allocated, allocate
+ it will return 0.*/
+ void* multi_allocate(std::size_t nbytes);
+
+ private:
+ /*!Real allocation algorithm with min allocation option*/
+ std::pair<void *, bool> priv_allocate(allocation_type command
+ ,std::size_t min_size
+ ,std::size_t preferred_size
+ ,std::size_t &received_size
+ ,void *reuse_ptr = 0);
+ /*!Returns next block if it's free.
+ Returns 0 if next block is not free.*/
+ block_ctrl *priv_next_block_if_free(block_ctrl *ptr);
+
+ /*!Returns previous block's if it's free.
+ Returns 0 if previous block is not free.*/
+ std::pair<block_ctrl*, block_ctrl*>priv_prev_block_if_free(block_ctrl *ptr);
+
+ /*!Real expand function implementation*/
+ bool priv_expand(void *ptr
+ ,std::size_t min_size, std::size_t preferred_size
+ ,std::size_t &received_size);
+
+ /*!Real expand to both sides implementation*/
+ void* 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);
+
+ /*!Real shrink function implementation*/
+ bool priv_shrink(void *ptr
+ ,std::size_t max_size, std::size_t preferred_size
+ ,std::size_t &received_size);
+
+ //!Real private aligned allocation function
+ void* priv_allocate_aligned (std::size_t nbytes, std::size_t alignment);
+
+ /*!Checks if block has enough memory and splits/unlinks the block
+ returning the address to the users*/
+ void* priv_check_and_allocate(std::size_t units
+ ,block_ctrl* prev
+ ,block_ctrl* block
+ ,std::size_t &received_size);
+ /*!Real deallocation algorithm*/
+ void priv_deallocate(void *addr);
+
+ /*!Makes a new memory portion available for allocation*/
+ void priv_add_segment(void *addr, std::size_t size);
+
+ enum { Alignment = boost::alignment_of<boost::detail::max_align>::value };
+ enum { BlockCtrlBytes = detail::ct_rounded_size<sizeof(block_ctrl), Alignment>::value };
+ enum { BlockCtrlSize = BlockCtrlBytes/Alignment };
+ enum { MinBlockSize = BlockCtrlSize + Alignment };
+
+ public:
+ enum { PayloadPerAllocation = BlockCtrlBytes };
+};
+
+template<class MutexFamily, class VoidPointer>
+inline simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ simple_seq_fit_impl(std::size_t size, std::size_t extra_hdr_bytes)
+{
+ //Initialize sizes and counters
+ m_header.m_allocated = 0;
+ m_header.m_size = size;
+
+ //Initialize pointers
+ std::size_t block1_off = detail::get_rounded_size(sizeof(*this)+extra_hdr_bytes, Alignment);
+ m_header.m_root.m_next = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(this) + block1_off);
+ m_header.m_root.m_next->m_size = (size - block1_off)/Alignment;
+ m_header.m_root.m_next->m_next = &m_header.m_root;
+}
+
+template<class MutexFamily, class VoidPointer>
+inline simple_seq_fit_impl<MutexFamily, VoidPointer>::~simple_seq_fit_impl()
+{
+ //There is a memory leak!
+// assert(m_header.m_allocated == 0);
+// assert(m_header.m_root.m_next->m_next == block_ctrl_ptr(&m_header.m_root));
+}
+
+template<class MutexFamily, class VoidPointer>
+inline void simple_seq_fit_impl<MutexFamily, VoidPointer>::grow(std::size_t extra_size)
+{
+ //Old highest address block's end offset
+ std::size_t old_end = m_header.m_size/Alignment*Alignment;
+
+ //Update managed buffer's size
+ m_header.m_size += extra_size;
+
+ //We need at least MinBlockSize blocks to create a new block
+ if((m_header.m_size - old_end) < MinBlockSize){
+ return;
+ }
+
+ //We'll create a new free block with extra_size bytes
+ block_ctrl *new_block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(this) + old_end);
+
+ new_block->m_next = 0;
+ new_block->m_size = (m_header.m_size - old_end)/Alignment;
+ m_header.m_allocated += new_block->m_size*Alignment;
+ this->priv_deallocate(detail::char_ptr_cast(new_block) + BlockCtrlBytes);
+}
+
+template<class MutexFamily, class VoidPointer>
+inline void simple_seq_fit_impl<MutexFamily, VoidPointer>::priv_add_segment(void *addr, std::size_t size)
+{
+ //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(detail::char_ptr_cast(new_block) + BlockCtrlBytes);
+}
+
+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_min_size (std::size_t extra_hdr_bytes)
+{
+ return detail::get_rounded_size(sizeof(simple_seq_fit_impl)+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>::clear_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( detail::char_ptr_cast(block) + BlockCtrlBytes
+ , 0
+ , block->m_size*Alignment - BlockCtrlBytes);
+ 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
+ do{
+ //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;
+ }
+ while(block != &m_header.m_root);
+
+ //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 priv_allocate_aligned(nbytes, alignment);
+}
+
+template<class MutexFamily, class VoidPointer>
+inline std::pair<void *, bool> simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ allocation_command (allocation_type command, std::size_t min_size,
+ std::size_t preferred_size,std::size_t &received_size,
+ void *reuse_ptr, std::size_t backwards_multiple)
+{
+ //-----------------------
+ boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
+ //-----------------------
+ (void)backwards_multiple;
+ command &= ~expand_bwd;
+ if(!command)
+ return std::pair<void *, bool>(0, false);
+ return priv_allocate(command, min_size, preferred_size, received_size, reuse_ptr);
+}
+
+template<class MutexFamily, class VoidPointer>
+inline std::size_t simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ size(void *ptr) const
+{
+ //We need no synchronization since this block is not going
+ //to be modified
+ //Obtain the real size of the block
+ block_ctrl *block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(ptr) - BlockCtrlBytes);
+ return block->m_size*Alignment - BlockCtrlBytes;
+}
+
+template<class MutexFamily, class VoidPointer>
+inline void* simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ multi_allocate(std::size_t nbytes)
+{
+ //-----------------------
+ boost::interprocess::scoped_lock<interprocess_mutex> guard(m_header);
+ //-----------------------
+ //Multisegment pointer. Let's try first the normal allocation
+ //since it's faster.
+ std::size_t ignore;
+ void *addr = this->priv_allocate(allocate_new, nbytes, nbytes, ignore).first;
+ if(!addr){
+ //If this fails we will try the allocation through the segment
+ //creator.
+ std::size_t group, id;
+ //Obtain the segment group of this segment
+ void_pointer::get_group_and_id(this, group, id);
+ if(group == 0){
+ //Ooops, group 0 is not valid.
+ return 0;
+ }
+ //Now obtain the polymorphic functor that creates
+ //new segments and try to allocate again.
+ boost::interprocess::multi_segment_services *p_services =
+ static_cast<boost::interprocess::multi_segment_services*>
+ (void_pointer::find_group_data(group));
+ assert(p_services);
+ std::pair<void *, std::size_t> ret =
+ p_services->create_new_segment(MinBlockSize > nbytes ? MinBlockSize : nbytes);
+ if(ret.first){
+ priv_add_segment(ret.first, ret.second);
+ addr = this->priv_allocate(allocate_new, nbytes, nbytes, ignore).first;
+ }
+ }
+ return addr;
+}
+
+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 = block_ctrl::get_block_from_addr(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){
+ needs_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 *>
+ (detail::char_ptr_cast(reuse) - needs_backwards - BlockCtrlBytes);
+ new_block->m_next = 0;
+ new_block->m_size =
+ BlockCtrlSize + (needs_backwards + extra_forward)/Alignment;
+ prev->m_size =
+ (prev->get_total_bytes() - needs_backwards)/Alignment - BlockCtrlSize;
+ received_size = needs_backwards + extra_forward;
+ m_header.m_allocated += needs_backwards + BlockCtrlBytes;
+ return new_block->get_addr();
+ }
+ 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;
+ return prev->get_addr();
+ }
+ }
+ }
+ return 0;
+}
+
+template<class MutexFamily, class VoidPointer>
+std::pair<void *, bool> simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ priv_allocate(allocation_type command
+ ,std::size_t limit_size
+ ,std::size_t preferred_size
+ ,std::size_t &received_size
+ ,void *reuse_ptr)
+{
+ if(command & shrink_in_place){
+ bool success =
+ this->priv_shrink(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(0, false);
+
+ //Number of units to request (including block_ctrl header)
+ std::size_t nunits = detail::get_rounded_size(preferred_size, Alignment)/Alignment + BlockCtrlSize;
+
+ //Get the root and the first memory block
+ block_ctrl *prev = &m_header.m_root;
+ block_ctrl *block = detail::get_pointer(prev->m_next);
+ block_ctrl *root = &m_header.m_root;
+ block_ctrl *biggest_block = 0;
+ block_ctrl *prev_biggest_block = 0;
+ std::size_t biggest_size = limit_size;
+
+ //Expand in place
+ //reuse_ptr, limit_size, preferred_size, received_size
+ //
+ if(reuse_ptr && (command & (expand_fwd | expand_bwd))){
+ void *ret = priv_expand_both_sides
+ (command, limit_size, preferred_size, received_size, reuse_ptr, true);
+ if(ret)
+ return return_type(ret, true);
+ }
+
+ if(command & allocate_new){
+ received_size = 0;
+ while(block != root){
+ //Update biggest block pointers
+ if(block->m_size > biggest_size){
+ prev_biggest_block = prev;
+ biggest_size = block->m_size;
+ biggest_block = block;
+ }
+ void *addr = this->priv_check_and_allocate(nunits, prev, block, received_size);
+ if(addr) return return_type(addr, false);
+ //Bad luck, let's check next block
+ prev = block;
+ block = detail::get_pointer(block->m_next);
+ }
+
+ //Bad luck finding preferred_size, now if we have any biggest_block
+ //try with this block
+ if(biggest_block){
+ received_size = biggest_block->m_size*Alignment - BlockCtrlSize;
+ nunits = detail::get_rounded_size(limit_size, Alignment)/Alignment + BlockCtrlSize;
+ void *ret = this->priv_check_and_allocate
+ (nunits, prev_biggest_block, biggest_block, received_size);
+ if(ret)
+ return return_type(ret, false);
+ }
+ }
+ //Now try to expand both sides with min size
+ if(reuse_ptr && (command & (expand_fwd | expand_bwd))){
+ return return_type(priv_expand_both_sides
+ (command, limit_size, preferred_size, received_size, reuse_ptr, false), true);
+ }
+ return return_type(0, false);
+}
+
+template<class MutexFamily, class VoidPointer>
+inline typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl *
+ simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ priv_next_block_if_free
+ (typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl *ptr)
+{
+ //Take the address where the next block should go
+ block_ctrl *next_block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(ptr) + ptr->m_size*Alignment);
+
+ //Check if the adjacent block is in the managed segment
+ std::size_t distance = (detail::char_ptr_cast(next_block) - detail::char_ptr_cast(this))/Alignment;
+ if(distance >= (m_header.m_size/Alignment)){
+ //"next_block" does not exist so we can't expand "block"
+ return 0;
+ }
+
+ if(!next_block->m_next)
+ return 0;
+
+ return next_block;
+}
+
+template<class MutexFamily, class VoidPointer>
+inline
+ std::pair<typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl *
+ ,typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl *>
+ simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ priv_prev_block_if_free
+ (typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl *ptr)
+{
+ typedef std::pair<block_ctrl *, block_ctrl *> prev_pair_t;
+ //Take the address where the previous block should go
+ block_ctrl *root = &m_header.m_root;
+ block_ctrl *prev_2_block = root;
+ block_ctrl *prev_block = detail::get_pointer(root->m_next);
+ while((detail::char_ptr_cast(prev_block) + prev_block->m_size*Alignment)
+ != (detail::char_ptr_cast(ptr))
+ && prev_block != root){
+ prev_2_block = prev_block;
+ prev_block = detail::get_pointer(prev_block->m_next);
+ }
+
+ if(prev_block == root || !prev_block->m_next)
+ return prev_pair_t(0, 0);
+
+ //Check if the previous block is in the managed segment
+ std::size_t distance = (detail::char_ptr_cast(prev_block) - detail::char_ptr_cast(this))/Alignment;
+ if(distance >= (m_header.m_size/Alignment)){
+ //"previous_block" does not exist so we can't expand "block"
+ return prev_pair_t(0, 0);
+ }
+ return prev_pair_t(prev_2_block, prev_block);
+}
+
+
+template<class MutexFamily, class VoidPointer>
+inline bool simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ priv_expand (void *ptr
+ ,std::size_t min_size
+ ,std::size_t preferred_size
+ ,std::size_t &received_size)
+{
+ //Obtain the real size of the block
+ block_ctrl *block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(ptr) - BlockCtrlBytes);
+ std::size_t old_block_size = block->m_size;
+
+ //All used blocks' next is marked with 0 so check it
+ assert(block->m_next == 0);
+
+ //Put this to a safe value
+ received_size = old_block_size*Alignment - BlockCtrlBytes;
+
+ //Now translate it to Alignment units
+ min_size = detail::get_rounded_size(min_size, Alignment)/Alignment;
+ preferred_size = detail::get_rounded_size(preferred_size, Alignment)/Alignment;
+
+ //Some parameter checks
+ if(min_size > preferred_size)
+ return false;
+
+ std::size_t data_size = old_block_size - BlockCtrlSize;
+
+ if(data_size >= min_size)
+ return true;
+
+ block_ctrl *next_block = priv_next_block_if_free(block);
+ if(!next_block){
+ return false;
+ }
+
+ //Is "block" + "next_block" big enough?
+ std::size_t merged_size = old_block_size + next_block->m_size;
+
+ //Now we can expand this block further than before
+ received_size = merged_size*Alignment - BlockCtrlBytes;
+
+ if(merged_size < (min_size + BlockCtrlSize)){
+ return false;
+ }
+
+ //We can fill expand. Merge both blocks,
+ block->m_next = next_block->m_next;
+ block->m_size = merged_size;
+
+ //Find the previous free block of next_block
+ block_ctrl *prev = &m_header.m_root;
+ while(detail::get_pointer(prev->m_next) != next_block){
+ prev = detail::get_pointer(prev->m_next);
+ }
+
+ //Now insert merged block in the free list
+ //This allows reusing allocation logic in this function
+ m_header.m_allocated -= old_block_size*Alignment;
+ prev->m_next = block;
+
+ //Now use check and allocate to do the allocation logic
+ preferred_size += BlockCtrlSize;
+ std::size_t nunits = preferred_size < merged_size ? preferred_size : merged_size;
+
+ //This must success since nunits is less than merged_size!
+ if(!this->priv_check_and_allocate (nunits, prev, block, received_size)){
+ //Something very ugly is happening here. This is a bug
+ //or there is memory corruption
+ assert(0);
+ return false;
+ }
+ return true;
+}
+
+template<class MutexFamily, class VoidPointer>
+inline bool simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ priv_shrink (void *ptr
+ ,std::size_t max_size
+ ,std::size_t preferred_size
+ ,std::size_t &received_size)
+{
+ //Obtain the real size of the block
+ block_ctrl *block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(ptr) - BlockCtrlBytes);
+ std::size_t block_size = block->m_size;
+
+ //All used blocks' next is marked with 0 so check it
+ assert(block->m_next == 0);
+
+ //Put this to a safe value
+ received_size = block_size*Alignment - BlockCtrlBytes;
+
+ //Now translate it to Alignment units
+ max_size = max_size/Alignment;
+ preferred_size = detail::get_rounded_size(preferred_size, Alignment)/Alignment;
+
+ //Some parameter checks
+ if(max_size < preferred_size)
+ return false;
+
+ std::size_t data_size = block_size - BlockCtrlSize;
+
+ if(data_size < preferred_size)
+ return false;
+
+ if(data_size == preferred_size)
+ return true;
+
+ //We must be able to create at least a new empty block
+ if((data_size - preferred_size) < BlockCtrlSize){
+ return false;
+ }
+
+ //Now we can just rewrite the size of the old buffer
+ block->m_size = preferred_size + BlockCtrlSize;
+
+ //Update new size
+ received_size = preferred_size*Alignment;
+
+ //We create the new block
+ block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(block) + block->m_size*Alignment);
+
+ //Write control data to simulate this new block was previously allocated
+ block->m_next = 0;
+ block->m_size = data_size - preferred_size;
+
+ //Now deallocate the new block to insert it in the free list
+ this->priv_deallocate(detail::char_ptr_cast(block)+BlockCtrlBytes);
+ return true;
+}
+
+template<class MutexFamily, class VoidPointer>
+inline void* simple_seq_fit_impl<MutexFamily, VoidPointer>::
+ priv_allocate_aligned(std::size_t nbytes, std::size_t alignment)
+{
+ //Ensure power of 2
+ if ((alignment & (alignment - std::size_t(1u))) != 0){
+ //Alignment is not power of two
+ assert((alignment & (alignment - std::size_t(1u))) != 0);
+ return 0;
+ }
+
+ std::size_t ignore;
+ if(alignment <= Alignment){
+ return priv_allocate(allocate_new, nbytes, nbytes, ignore).first;
+ }
+
+ std::size_t request =
+ nbytes + alignment + MinBlockSize*Alignment - BlockCtrlBytes;
+ void *buffer = priv_allocate(allocate_new, request, request, ignore).first;
+ if(!buffer)
+ return 0;
+ else if ((((std::size_t)(buffer)) % alignment) == 0)
+ return buffer;
+
+ char *aligned_portion = (char*)
+ ((std::size_t)((char*)buffer + alignment - 1) & -alignment);
+
+ char *pos = ((aligned_portion - (char*)buffer) >= (MinBlockSize*Alignment)) ?
+ aligned_portion : (aligned_portion + alignment);
+
+
+ block_ctrl *first = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(buffer) - BlockCtrlBytes);
+
+ block_ctrl *second = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(pos) - BlockCtrlBytes);
+
+ std::size_t old_size = first->m_size;
+
+ first->m_size = ((char*)second - (char*)first)/Alignment;
+ second->m_size = old_size - first->m_size;
+
+ //Write control data to simulate this new block was previously allocated
+ second->m_next = 0;
+
+ //Now deallocate the new block to insert it in the free list
+ this->priv_deallocate(detail::char_ptr_cast(first) + BlockCtrlBytes);
+ return detail::char_ptr_cast(second) + BlockCtrlBytes;
+}
+
+template<class MutexFamily, class VoidPointer> inline
+void* simple_seq_fit_impl<MutexFamily, VoidPointer>::priv_check_and_allocate
+ (std::size_t nunits
+ ,typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl* prev
+ ,typename simple_seq_fit_impl<MutexFamily, VoidPointer>::block_ctrl* block
+ ,std::size_t &received_size)
+{
+ std::size_t upper_nunits = nunits + BlockCtrlSize;
+ bool found = false;
+
+ if (block->m_size > upper_nunits){
+ //This block is bigger than needed, split it in
+ //two blocks, the first's size will be (block->m_size-units)
+ //the second's size (units)
+ std::size_t total_size = block->m_size;
+ block->m_size = nunits;
+ block_ctrl *new_block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(block) + Alignment*nunits);
+ new_block->m_size = total_size - nunits;
+ new_block->m_next = block->m_next;
+ prev->m_next = new_block;
+ found = true;
+ }
+ else if (block->m_size >= nunits){
+ //This block has exactly the right size with an extra
+ //unusable extra bytes.
+ prev->m_next = block->m_next;
+ found = true;
+ }
+
+ if(found){
+ //We need block_ctrl for deallocation stuff, so
+ //return memory user can overwrite
+ m_header.m_allocated += block->m_size*Alignment;
+ received_size = block->m_size*Alignment - BlockCtrlBytes;
+ //Mark the block as allocated
+ block->m_next = 0;
+ //Check alignment
+ assert(((detail::char_ptr_cast(block) - detail::char_ptr_cast(this))
+ % Alignment) == 0 );
+ return detail::char_ptr_cast(block)+BlockCtrlBytes;
+ }
+ return 0;
+}
+
+template<class MutexFamily, class VoidPointer>
+void simple_seq_fit_impl<MutexFamily, VoidPointer>::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>
+void simple_seq_fit_impl<MutexFamily, VoidPointer>::priv_deallocate(void* addr)
+{
+ if(!addr) return;
+
+ //Let's get free block list. List is always sorted
+ //by memory address to allow block merging.
+ //Pointer next always points to the first
+ //(lower address) block
+ block_ctrl_ptr prev = &m_header.m_root;
+ block_ctrl_ptr pos = m_header.m_root.m_next;
+ block_ctrl_ptr block = reinterpret_cast<block_ctrl*>
+ (detail::char_ptr_cast(addr) - BlockCtrlBytes);
+
+ //All used blocks' next is marked with 0 so check it
+ assert(block->m_next == 0);
+
+ //Check if alignment and block size are right
+ assert((detail::char_ptr_cast(addr) - detail::char_ptr_cast(this))
+ % Alignment == 0 );
+
+ std::size_t total_size = Alignment*block->m_size;
+ assert(m_header.m_allocated >= total_size);
+
+ //Update used memory count
+ m_header.m_allocated -= total_size;
+
+ //Let's find the previous and the next block of the block to deallocate
+ //This ordering comparison must be done with original pointers
+ //types since their mapping to raw pointers can be different
+ //in each process
+ while((detail::get_pointer(pos) != &m_header.m_root) && (block > pos)){
+ prev = pos;
+ pos = pos->m_next;
+ }
+
+ //Try to combine with upper block
+ if ((detail::char_ptr_cast(detail::get_pointer(block))
+ + Alignment*block->m_size) ==
+ detail::char_ptr_cast(detail::get_pointer(pos))){
+
+ block->m_size += pos->m_size;
+ block->m_next = pos->m_next;
+ }
+ else{
+ block->m_next = pos;
+ }
+
+ //Try to combine with lower block
+ if ((detail::char_ptr_cast(detail::get_pointer(prev))
+ + Alignment*prev->m_size) ==
+ detail::char_ptr_cast(detail::get_pointer(block))){
+ prev->m_size += block->m_size;
+ prev->m_next = block->m_next;
+ }
+ else{
+ prev->m_next = block;
+ }
+}
+
+} //namespace detail {
+
+} //namespace interprocess {
+
+} //namespace boost {
+
+#include <boost/interprocess/detail/config_end.hpp>
+
+#endif //#ifndef BOOST_INTERPROCESS_MEM_ALGO_DETAIL_SIMPLE_SEQ_FIT_IMPL_HPP
+