1025 lines
36 KiB
C++
Executable File
1025 lines
36 KiB
C++
Executable File
// Copyright (C) 2000, 2001 Stephen Cleary
|
|
//
|
|
// 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 for updates, documentation, and revision history.
|
|
|
|
#ifndef BOOST_POOL_HPP
|
|
#define BOOST_POOL_HPP
|
|
|
|
#include <boost/config.hpp> // for workarounds
|
|
|
|
// std::less, std::less_equal, std::greater
|
|
#include <functional>
|
|
// new[], delete[], std::nothrow
|
|
#include <new>
|
|
// std::size_t, std::ptrdiff_t
|
|
#include <cstddef>
|
|
// std::malloc, std::free
|
|
#include <cstdlib>
|
|
// std::invalid_argument
|
|
#include <exception>
|
|
// std::max
|
|
#include <algorithm>
|
|
|
|
#include <boost/pool/poolfwd.hpp>
|
|
|
|
// boost::integer::static_lcm
|
|
#include <boost/integer/common_factor_ct.hpp>
|
|
// boost::simple_segregated_storage
|
|
#include <boost/pool/simple_segregated_storage.hpp>
|
|
// boost::alignment_of
|
|
#include <boost/type_traits/alignment_of.hpp>
|
|
// BOOST_ASSERT
|
|
#include <boost/assert.hpp>
|
|
|
|
#ifdef BOOST_POOL_INSTRUMENT
|
|
#include <iostream>
|
|
#include<iomanip>
|
|
#endif
|
|
#ifdef BOOST_POOL_VALGRIND
|
|
#include <set>
|
|
#include <valgrind/memcheck.h>
|
|
#endif
|
|
|
|
#ifdef BOOST_NO_STDC_NAMESPACE
|
|
namespace std { using ::malloc; using ::free; }
|
|
#endif
|
|
|
|
// There are a few places in this file where the expression "this->m" is used.
|
|
// This expression is used to force instantiation-time name lookup, which I am
|
|
// informed is required for strict Standard compliance. It's only necessary
|
|
// if "m" is a member of a base class that is dependent on a template
|
|
// parameter.
|
|
// Thanks to Jens Maurer for pointing this out!
|
|
|
|
/*!
|
|
\file
|
|
\brief Provides class \ref pool: a fast memory allocator that guarantees proper alignment of all allocated chunks,
|
|
and which extends and generalizes the framework provided by the simple segregated storage solution.
|
|
Also provides two UserAllocator classes which can be used in conjuction with \ref pool.
|
|
*/
|
|
|
|
/*!
|
|
\mainpage Boost.Pool Memory Allocation Scheme
|
|
|
|
\section intro_sec Introduction
|
|
|
|
Pool allocation is a memory allocation scheme that is very fast, but limited in its usage.
|
|
|
|
This Doxygen-style documentation is complementary to the
|
|
full Quickbook-generated html and pdf documentation at www.boost.org.
|
|
|
|
This page generated from file pool.hpp.
|
|
|
|
*/
|
|
|
|
#ifdef BOOST_MSVC
|
|
#pragma warning(push)
|
|
#pragma warning(disable:4127) // Conditional expression is constant
|
|
#endif
|
|
|
|
namespace boost
|
|
{
|
|
|
|
//! \brief Allocator used as the default template parameter for
|
|
//! a <a href="boost_pool/pool/pooling.html#boost_pool.pool.pooling.user_allocator">UserAllocator</a>
|
|
//! template parameter. Uses new and delete.
|
|
struct default_user_allocator_new_delete
|
|
{
|
|
typedef std::size_t size_type; //!< An unsigned integral type that can represent the size of the largest object to be allocated.
|
|
typedef std::ptrdiff_t difference_type; //!< A signed integral type that can represent the difference of any two pointers.
|
|
|
|
static char * malloc BOOST_PREVENT_MACRO_SUBSTITUTION(const size_type bytes)
|
|
{ //! Attempts to allocate n bytes from the system. Returns 0 if out-of-memory
|
|
return new (std::nothrow) char[bytes];
|
|
}
|
|
static void free BOOST_PREVENT_MACRO_SUBSTITUTION(char * const block)
|
|
{ //! Attempts to de-allocate block.
|
|
//! \pre Block must have been previously returned from a call to UserAllocator::malloc.
|
|
delete [] block;
|
|
}
|
|
};
|
|
|
|
//! \brief <a href="boost_pool/pool/pooling.html#boost_pool.pool.pooling.user_allocator">UserAllocator</a>
|
|
//! used as template parameter for \ref pool and \ref object_pool.
|
|
//! Uses malloc and free internally.
|
|
struct default_user_allocator_malloc_free
|
|
{
|
|
typedef std::size_t size_type; //!< An unsigned integral type that can represent the size of the largest object to be allocated.
|
|
typedef std::ptrdiff_t difference_type; //!< A signed integral type that can represent the difference of any two pointers.
|
|
|
|
static char * malloc BOOST_PREVENT_MACRO_SUBSTITUTION(const size_type bytes)
|
|
{ return static_cast<char *>((std::malloc)(bytes)); }
|
|
static void free BOOST_PREVENT_MACRO_SUBSTITUTION(char * const block)
|
|
{ (std::free)(block); }
|
|
};
|
|
|
|
namespace details
|
|
{ //! Implemention only.
|
|
|
|
template <typename SizeType>
|
|
class PODptr
|
|
{ //! PODptr is a class that pretends to be a "pointer" to different class types
|
|
//! that don't really exist. It provides member functions to access the "data"
|
|
//! of the "object" it points to. Since these "class" types are of variable
|
|
//! size, and contains some information at the *end* of its memory
|
|
//! (for alignment reasons),
|
|
//! PODptr must contain the size of this "class" as well as the pointer to this "object".
|
|
|
|
/*! \details A PODptr holds the location and size of a memory block allocated from the system.
|
|
Each memory block is split logically into three sections:
|
|
|
|
<b>Chunk area</b>. This section may be different sizes. PODptr does not care what the size of the chunks is,
|
|
but it does care (and keep track of) the total size of the chunk area.
|
|
|
|
<b>Next pointer</b>. This section is always the same size for a given SizeType. It holds a pointer
|
|
to the location of the next memory block in the memory block list, or 0 if there is no such block.
|
|
|
|
<b>Next size</b>. This section is always the same size for a given SizeType. It holds the size of the
|
|
next memory block in the memory block list.
|
|
|
|
The PODptr class just provides cleaner ways of dealing with raw memory blocks.
|
|
|
|
A PODptr object is either valid or invalid. An invalid PODptr is analogous to a null pointer.
|
|
The default constructor for PODptr will result in an invalid object.
|
|
Calling the member function invalidate will result in that object becoming invalid.
|
|
The member function valid can be used to test for validity.
|
|
*/
|
|
public:
|
|
typedef SizeType size_type;
|
|
|
|
private:
|
|
char * ptr;
|
|
size_type sz;
|
|
|
|
char * ptr_next_size() const
|
|
{
|
|
return (ptr + sz - sizeof(size_type));
|
|
}
|
|
char * ptr_next_ptr() const
|
|
{
|
|
return (ptr_next_size() -
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value);
|
|
}
|
|
|
|
public:
|
|
PODptr(char * const nptr, const size_type nsize)
|
|
:ptr(nptr), sz(nsize)
|
|
{
|
|
//! A PODptr may be created to point to a memory block by passing
|
|
//! the address and size of that memory block into the constructor.
|
|
//! A PODptr constructed in this way is valid.
|
|
}
|
|
PODptr()
|
|
: ptr(0), sz(0)
|
|
{ //! default constructor for PODptr will result in an invalid object.
|
|
}
|
|
|
|
bool valid() const
|
|
{ //! A PODptr object is either valid or invalid.
|
|
//! An invalid PODptr is analogous to a null pointer.
|
|
//! \returns true if PODptr is valid, false if invalid.
|
|
return (begin() != 0);
|
|
}
|
|
void invalidate()
|
|
{ //! Make object invalid.
|
|
begin() = 0;
|
|
}
|
|
char * & begin()
|
|
{ //! Each PODptr keeps the address and size of its memory block.
|
|
//! \returns The address of its memory block.
|
|
return ptr;
|
|
}
|
|
char * begin() const
|
|
{ //! Each PODptr keeps the address and size of its memory block.
|
|
//! \return The address of its memory block.
|
|
return ptr;
|
|
}
|
|
char * end() const
|
|
{ //! \returns begin() plus element_size (a 'past the end' value).
|
|
return ptr_next_ptr();
|
|
}
|
|
size_type total_size() const
|
|
{ //! Each PODptr keeps the address and size of its memory block.
|
|
//! The address may be read or written by the member functions begin.
|
|
//! The size of the memory block may only be read,
|
|
//! \returns size of the memory block.
|
|
return sz;
|
|
}
|
|
size_type element_size() const
|
|
{ //! \returns size of element pointer area.
|
|
return static_cast<size_type>(sz - sizeof(size_type) -
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value);
|
|
}
|
|
|
|
size_type & next_size() const
|
|
{ //!
|
|
//! \returns next_size.
|
|
return *(static_cast<size_type *>(static_cast<void*>((ptr_next_size()))));
|
|
}
|
|
char * & next_ptr() const
|
|
{ //! \returns pointer to next pointer area.
|
|
return *(static_cast<char **>(static_cast<void*>(ptr_next_ptr())));
|
|
}
|
|
|
|
PODptr next() const
|
|
{ //! \returns next PODptr.
|
|
return PODptr<size_type>(next_ptr(), next_size());
|
|
}
|
|
void next(const PODptr & arg) const
|
|
{ //! Sets next PODptr.
|
|
next_ptr() = arg.begin();
|
|
next_size() = arg.total_size();
|
|
}
|
|
}; // class PODptr
|
|
} // namespace details
|
|
|
|
#ifndef BOOST_POOL_VALGRIND
|
|
/*!
|
|
\brief A fast memory allocator that guarantees proper alignment of all allocated chunks.
|
|
|
|
\details Whenever an object of type pool needs memory from the system,
|
|
it will request it from its UserAllocator template parameter.
|
|
The amount requested is determined using a doubling algorithm;
|
|
that is, each time more system memory is allocated,
|
|
the amount of system memory requested is doubled.
|
|
|
|
Users may control the doubling algorithm by using the following extensions:
|
|
|
|
Users may pass an additional constructor parameter to pool.
|
|
This parameter is of type size_type,
|
|
and is the number of chunks to request from the system
|
|
the first time that object needs to allocate system memory.
|
|
The default is 32. This parameter may not be 0.
|
|
|
|
Users may also pass an optional third parameter to pool's
|
|
constructor. This parameter is of type size_type,
|
|
and sets a maximum size for allocated chunks. When this
|
|
parameter takes the default value of 0, then there is no upper
|
|
limit on chunk size.
|
|
|
|
Finally, if the doubling algorithm results in no memory
|
|
being allocated, the pool will backtrack just once, halving
|
|
the chunk size and trying again.
|
|
|
|
<b>UserAllocator type</b> - the method that the Pool will use to allocate memory from the system.
|
|
|
|
There are essentially two ways to use class pool: the client can call \ref malloc() and \ref free() to allocate
|
|
and free single chunks of memory, this is the most efficient way to use a pool, but does not allow for
|
|
the efficient allocation of arrays of chunks. Alternatively, the client may call \ref ordered_malloc() and \ref
|
|
ordered_free(), in which case the free list is maintained in an ordered state, and efficient allocation of arrays
|
|
of chunks are possible. However, this latter option can suffer from poor performance when large numbers of
|
|
allocations are performed.
|
|
|
|
*/
|
|
template <typename UserAllocator>
|
|
class pool: protected simple_segregated_storage < typename UserAllocator::size_type >
|
|
{
|
|
public:
|
|
typedef UserAllocator user_allocator; //!< User allocator.
|
|
typedef typename UserAllocator::size_type size_type; //!< An unsigned integral type that can represent the size of the largest object to be allocated.
|
|
typedef typename UserAllocator::difference_type difference_type; //!< A signed integral type that can represent the difference of any two pointers.
|
|
|
|
private:
|
|
BOOST_STATIC_CONSTANT(size_type, min_alloc_size =
|
|
(::boost::integer::static_lcm<sizeof(void *), sizeof(size_type)>::value) );
|
|
BOOST_STATIC_CONSTANT(size_type, min_align =
|
|
(::boost::integer::static_lcm< ::boost::alignment_of<void *>::value, ::boost::alignment_of<size_type>::value>::value) );
|
|
|
|
//! \returns 0 if out-of-memory.
|
|
//! Called if malloc/ordered_malloc needs to resize the free list.
|
|
void * malloc_need_resize(); //! Called if malloc needs to resize the free list.
|
|
void * ordered_malloc_need_resize(); //! Called if ordered_malloc needs to resize the free list.
|
|
|
|
protected:
|
|
details::PODptr<size_type> list; //!< List structure holding ordered blocks.
|
|
|
|
simple_segregated_storage<size_type> & store()
|
|
{ //! \returns pointer to store.
|
|
return *this;
|
|
}
|
|
const simple_segregated_storage<size_type> & store() const
|
|
{ //! \returns pointer to store.
|
|
return *this;
|
|
}
|
|
const size_type requested_size;
|
|
size_type next_size;
|
|
size_type start_size;
|
|
size_type max_size;
|
|
|
|
//! finds which POD in the list 'chunk' was allocated from.
|
|
details::PODptr<size_type> find_POD(void * const chunk) const;
|
|
|
|
// is_from() tests a chunk to determine if it belongs in a block.
|
|
static bool is_from(void * const chunk, char * const i,
|
|
const size_type sizeof_i)
|
|
{ //! \param chunk chunk to check if is from this pool.
|
|
//! \param i memory chunk at i with element sizeof_i.
|
|
//! \param sizeof_i element size (size of the chunk area of that block, not the total size of that block).
|
|
//! \returns true if chunk was allocated or may be returned.
|
|
//! as the result of a future allocation.
|
|
//!
|
|
//! Returns false if chunk was allocated from some other pool,
|
|
//! or may be returned as the result of a future allocation from some other pool.
|
|
//! Otherwise, the return value is meaningless.
|
|
//!
|
|
//! Note that this function may not be used to reliably test random pointer values.
|
|
|
|
// We use std::less_equal and std::less to test 'chunk'
|
|
// against the array bounds because standard operators
|
|
// may return unspecified results.
|
|
// This is to ensure portability. The operators < <= > >= are only
|
|
// defined for pointers to objects that are 1) in the same array, or
|
|
// 2) subobjects of the same object [5.9/2].
|
|
// The functor objects guarantee a total order for any pointer [20.3.3/8]
|
|
std::less_equal<void *> lt_eq;
|
|
std::less<void *> lt;
|
|
return (lt_eq(i, chunk) && lt(chunk, i + sizeof_i));
|
|
}
|
|
|
|
size_type alloc_size() const
|
|
{ //! Calculated size of the memory chunks that will be allocated by this Pool.
|
|
//! \returns allocated size.
|
|
// For alignment reasons, this used to be defined to be lcm(requested_size, sizeof(void *), sizeof(size_type)),
|
|
// but is now more parsimonious: just rounding up to the minimum required alignment of our housekeeping data
|
|
// when required. This works provided all alignments are powers of two.
|
|
size_type s = (std::max)(requested_size, min_alloc_size);
|
|
size_type rem = s % min_align;
|
|
if(rem)
|
|
s += min_align - rem;
|
|
BOOST_ASSERT(s >= min_alloc_size);
|
|
BOOST_ASSERT(s % min_align == 0);
|
|
return s;
|
|
}
|
|
|
|
static void * & nextof(void * const ptr)
|
|
{ //! \returns Pointer dereferenced.
|
|
//! (Provided and used for the sake of code readability :)
|
|
return *(static_cast<void **>(ptr));
|
|
}
|
|
|
|
public:
|
|
// pre: npartition_size != 0 && nnext_size != 0
|
|
explicit pool(const size_type nrequested_size,
|
|
const size_type nnext_size = 32,
|
|
const size_type nmax_size = 0)
|
|
:
|
|
list(0, 0), requested_size(nrequested_size), next_size(nnext_size), start_size(nnext_size),max_size(nmax_size)
|
|
{ //! Constructs a new empty Pool that can be used to allocate chunks of size RequestedSize.
|
|
//! \param nrequested_size Requested chunk size
|
|
//! \param nnext_size parameter is of type size_type,
|
|
//! is the number of chunks to request from the system
|
|
//! the first time that object needs to allocate system memory.
|
|
//! The default is 32. This parameter may not be 0.
|
|
//! \param nmax_size is the maximum number of chunks to allocate in one block.
|
|
}
|
|
|
|
~pool()
|
|
{ //! Destructs the Pool, freeing its list of memory blocks.
|
|
purge_memory();
|
|
}
|
|
|
|
// Releases memory blocks that don't have chunks allocated
|
|
// pre: lists are ordered
|
|
// Returns true if memory was actually deallocated
|
|
bool release_memory();
|
|
|
|
// Releases *all* memory blocks, even if chunks are still allocated
|
|
// Returns true if memory was actually deallocated
|
|
bool purge_memory();
|
|
|
|
size_type get_next_size() const
|
|
{ //! Number of chunks to request from the system the next time that object needs to allocate system memory. This value should never be 0.
|
|
//! \returns next_size;
|
|
return next_size;
|
|
}
|
|
void set_next_size(const size_type nnext_size)
|
|
{ //! Set number of chunks to request from the system the next time that object needs to allocate system memory. This value should never be set to 0.
|
|
//! \returns nnext_size.
|
|
next_size = start_size = nnext_size;
|
|
}
|
|
size_type get_max_size() const
|
|
{ //! \returns max_size.
|
|
return max_size;
|
|
}
|
|
void set_max_size(const size_type nmax_size)
|
|
{ //! Set max_size.
|
|
max_size = nmax_size;
|
|
}
|
|
size_type get_requested_size() const
|
|
{ //! \returns the requested size passed into the constructor.
|
|
//! (This value will not change during the lifetime of a Pool object).
|
|
return requested_size;
|
|
}
|
|
|
|
// Both malloc and ordered_malloc do a quick inlined check first for any
|
|
// free chunks. Only if we need to get another memory block do we call
|
|
// the non-inlined *_need_resize() functions.
|
|
// Returns 0 if out-of-memory
|
|
void * malloc BOOST_PREVENT_MACRO_SUBSTITUTION()
|
|
{ //! Allocates a chunk of memory. Searches in the list of memory blocks
|
|
//! for a block that has a free chunk, and returns that free chunk if found.
|
|
//! Otherwise, creates a new memory block, adds its free list to pool's free list,
|
|
//! \returns a free chunk from that block.
|
|
//! If a new memory block cannot be allocated, returns 0. Amortized O(1).
|
|
// Look for a non-empty storage
|
|
if (!store().empty())
|
|
return (store().malloc)();
|
|
return malloc_need_resize();
|
|
}
|
|
|
|
void * ordered_malloc()
|
|
{ //! Same as malloc, only merges the free lists, to preserve order. Amortized O(1).
|
|
//! \returns a free chunk from that block.
|
|
//! If a new memory block cannot be allocated, returns 0. Amortized O(1).
|
|
// Look for a non-empty storage
|
|
if (!store().empty())
|
|
return (store().malloc)();
|
|
return ordered_malloc_need_resize();
|
|
}
|
|
|
|
// Returns 0 if out-of-memory
|
|
// Allocate a contiguous section of n chunks
|
|
void * ordered_malloc(size_type n);
|
|
//! Same as malloc, only allocates enough contiguous chunks to cover n * requested_size bytes. Amortized O(n).
|
|
//! \returns a free chunk from that block.
|
|
//! If a new memory block cannot be allocated, returns 0. Amortized O(1).
|
|
|
|
// pre: 'chunk' must have been previously
|
|
// returned by *this.malloc().
|
|
void free BOOST_PREVENT_MACRO_SUBSTITUTION(void * const chunk)
|
|
{ //! Deallocates a chunk of memory. Note that chunk may not be 0. O(1).
|
|
//!
|
|
//! Chunk must have been previously returned by t.malloc() or t.ordered_malloc().
|
|
//! Assumes that chunk actually refers to a block of chunks
|
|
//! spanning n * partition_sz bytes.
|
|
//! deallocates each chunk in that block.
|
|
//! Note that chunk may not be 0. O(n).
|
|
(store().free)(chunk);
|
|
}
|
|
|
|
// pre: 'chunk' must have been previously
|
|
// returned by *this.malloc().
|
|
void ordered_free(void * const chunk)
|
|
{ //! Same as above, but is order-preserving.
|
|
//!
|
|
//! Note that chunk may not be 0. O(N) with respect to the size of the free list.
|
|
//! chunk must have been previously returned by t.malloc() or t.ordered_malloc().
|
|
store().ordered_free(chunk);
|
|
}
|
|
|
|
// pre: 'chunk' must have been previously
|
|
// returned by *this.malloc(n).
|
|
void free BOOST_PREVENT_MACRO_SUBSTITUTION(void * const chunks, const size_type n)
|
|
{ //! Assumes that chunk actually refers to a block of chunks.
|
|
//!
|
|
//! chunk must have been previously returned by t.ordered_malloc(n)
|
|
//! spanning n * partition_sz bytes.
|
|
//! Deallocates each chunk in that block.
|
|
//! Note that chunk may not be 0. O(n).
|
|
const size_type partition_size = alloc_size();
|
|
const size_type total_req_size = n * requested_size;
|
|
const size_type num_chunks = total_req_size / partition_size +
|
|
((total_req_size % partition_size) ? true : false);
|
|
|
|
store().free_n(chunks, num_chunks, partition_size);
|
|
}
|
|
|
|
// pre: 'chunk' must have been previously
|
|
// returned by *this.malloc(n).
|
|
void ordered_free(void * const chunks, const size_type n)
|
|
{ //! Assumes that chunk actually refers to a block of chunks spanning n * partition_sz bytes;
|
|
//! deallocates each chunk in that block.
|
|
//!
|
|
//! Note that chunk may not be 0. Order-preserving. O(N + n) where N is the size of the free list.
|
|
//! chunk must have been previously returned by t.malloc() or t.ordered_malloc().
|
|
|
|
const size_type partition_size = alloc_size();
|
|
const size_type total_req_size = n * requested_size;
|
|
const size_type num_chunks = total_req_size / partition_size +
|
|
((total_req_size % partition_size) ? true : false);
|
|
|
|
store().ordered_free_n(chunks, num_chunks, partition_size);
|
|
}
|
|
|
|
// is_from() tests a chunk to determine if it was allocated from *this
|
|
bool is_from(void * const chunk) const
|
|
{ //! \returns Returns true if chunk was allocated from u or
|
|
//! may be returned as the result of a future allocation from u.
|
|
//! Returns false if chunk was allocated from some other pool or
|
|
//! may be returned as the result of a future allocation from some other pool.
|
|
//! Otherwise, the return value is meaningless.
|
|
//! Note that this function may not be used to reliably test random pointer values.
|
|
return (find_POD(chunk).valid());
|
|
}
|
|
};
|
|
|
|
#ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
|
|
template <typename UserAllocator>
|
|
typename pool<UserAllocator>::size_type const pool<UserAllocator>::min_alloc_size;
|
|
template <typename UserAllocator>
|
|
typename pool<UserAllocator>::size_type const pool<UserAllocator>::min_align;
|
|
#endif
|
|
|
|
template <typename UserAllocator>
|
|
bool pool<UserAllocator>::release_memory()
|
|
{ //! pool must be ordered. Frees every memory block that doesn't have any allocated chunks.
|
|
//! \returns true if at least one memory block was freed.
|
|
|
|
// ret is the return value: it will be set to true when we actually call
|
|
// UserAllocator::free(..)
|
|
bool ret = false;
|
|
|
|
// This is a current & previous iterator pair over the memory block list
|
|
details::PODptr<size_type> ptr = list;
|
|
details::PODptr<size_type> prev;
|
|
|
|
// This is a current & previous iterator pair over the free memory chunk list
|
|
// Note that "prev_free" in this case does NOT point to the previous memory
|
|
// chunk in the free list, but rather the last free memory chunk before the
|
|
// current block.
|
|
void * free_p = this->first;
|
|
void * prev_free_p = 0;
|
|
|
|
const size_type partition_size = alloc_size();
|
|
|
|
// Search through all the all the allocated memory blocks
|
|
while (ptr.valid())
|
|
{
|
|
// At this point:
|
|
// ptr points to a valid memory block
|
|
// free_p points to either:
|
|
// 0 if there are no more free chunks
|
|
// the first free chunk in this or some next memory block
|
|
// prev_free_p points to either:
|
|
// the last free chunk in some previous memory block
|
|
// 0 if there is no such free chunk
|
|
// prev is either:
|
|
// the PODptr whose next() is ptr
|
|
// !valid() if there is no such PODptr
|
|
|
|
// If there are no more free memory chunks, then every remaining
|
|
// block is allocated out to its fullest capacity, and we can't
|
|
// release any more memory
|
|
if (free_p == 0)
|
|
break;
|
|
|
|
// We have to check all the chunks. If they are *all* free (i.e., present
|
|
// in the free list), then we can free the block.
|
|
bool all_chunks_free = true;
|
|
|
|
// Iterate 'i' through all chunks in the memory block
|
|
// if free starts in the memory block, be careful to keep it there
|
|
void * saved_free = free_p;
|
|
for (char * i = ptr.begin(); i != ptr.end(); i += partition_size)
|
|
{
|
|
// If this chunk is not free
|
|
if (i != free_p)
|
|
{
|
|
// We won't be able to free this block
|
|
all_chunks_free = false;
|
|
|
|
// free_p might have travelled outside ptr
|
|
free_p = saved_free;
|
|
// Abort searching the chunks; we won't be able to free this
|
|
// block because a chunk is not free.
|
|
break;
|
|
}
|
|
|
|
// We do not increment prev_free_p because we are in the same block
|
|
free_p = nextof(free_p);
|
|
}
|
|
|
|
// post: if the memory block has any chunks, free_p points to one of them
|
|
// otherwise, our assertions above are still valid
|
|
|
|
const details::PODptr<size_type> next = ptr.next();
|
|
|
|
if (!all_chunks_free)
|
|
{
|
|
if (is_from(free_p, ptr.begin(), ptr.element_size()))
|
|
{
|
|
std::less<void *> lt;
|
|
void * const end = ptr.end();
|
|
do
|
|
{
|
|
prev_free_p = free_p;
|
|
free_p = nextof(free_p);
|
|
} while (free_p && lt(free_p, end));
|
|
}
|
|
// This invariant is now restored:
|
|
// free_p points to the first free chunk in some next memory block, or
|
|
// 0 if there is no such chunk.
|
|
// prev_free_p points to the last free chunk in this memory block.
|
|
|
|
// We are just about to advance ptr. Maintain the invariant:
|
|
// prev is the PODptr whose next() is ptr, or !valid()
|
|
// if there is no such PODptr
|
|
prev = ptr;
|
|
}
|
|
else
|
|
{
|
|
// All chunks from this block are free
|
|
|
|
// Remove block from list
|
|
if (prev.valid())
|
|
prev.next(next);
|
|
else
|
|
list = next;
|
|
|
|
// Remove all entries in the free list from this block
|
|
if (prev_free_p != 0)
|
|
nextof(prev_free_p) = free_p;
|
|
else
|
|
this->first = free_p;
|
|
|
|
// And release memory
|
|
(UserAllocator::free)(ptr.begin());
|
|
ret = true;
|
|
}
|
|
|
|
// Increment ptr
|
|
ptr = next;
|
|
}
|
|
|
|
next_size = start_size;
|
|
return ret;
|
|
}
|
|
|
|
template <typename UserAllocator>
|
|
bool pool<UserAllocator>::purge_memory()
|
|
{ //! pool must be ordered.
|
|
//! Frees every memory block.
|
|
//!
|
|
//! This function invalidates any pointers previously returned
|
|
//! by allocation functions of t.
|
|
//! \returns true if at least one memory block was freed.
|
|
|
|
details::PODptr<size_type> iter = list;
|
|
|
|
if (!iter.valid())
|
|
return false;
|
|
|
|
do
|
|
{
|
|
// hold "next" pointer
|
|
const details::PODptr<size_type> next = iter.next();
|
|
|
|
// delete the storage
|
|
(UserAllocator::free)(iter.begin());
|
|
|
|
// increment iter
|
|
iter = next;
|
|
} while (iter.valid());
|
|
|
|
list.invalidate();
|
|
this->first = 0;
|
|
next_size = start_size;
|
|
|
|
return true;
|
|
}
|
|
|
|
template <typename UserAllocator>
|
|
void * pool<UserAllocator>::malloc_need_resize()
|
|
{ //! No memory in any of our storages; make a new storage,
|
|
//! Allocates chunk in newly malloc aftert resize.
|
|
//! \returns pointer to chunk.
|
|
size_type partition_size = alloc_size();
|
|
size_type POD_size = static_cast<size_type>(next_size * partition_size +
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value + sizeof(size_type));
|
|
char * ptr = (UserAllocator::malloc)(POD_size);
|
|
if (ptr == 0)
|
|
{
|
|
if(next_size > 4)
|
|
{
|
|
next_size >>= 1;
|
|
partition_size = alloc_size();
|
|
POD_size = static_cast<size_type>(next_size * partition_size +
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value + sizeof(size_type));
|
|
ptr = (UserAllocator::malloc)(POD_size);
|
|
}
|
|
if(ptr == 0)
|
|
return 0;
|
|
}
|
|
const details::PODptr<size_type> node(ptr, POD_size);
|
|
|
|
BOOST_USING_STD_MIN();
|
|
if(!max_size)
|
|
next_size <<= 1;
|
|
else if( next_size*partition_size/requested_size < max_size)
|
|
next_size = min BOOST_PREVENT_MACRO_SUBSTITUTION(next_size << 1, max_size*requested_size/ partition_size);
|
|
|
|
// initialize it,
|
|
store().add_block(node.begin(), node.element_size(), partition_size);
|
|
|
|
// insert it into the list,
|
|
node.next(list);
|
|
list = node;
|
|
|
|
// and return a chunk from it.
|
|
return (store().malloc)();
|
|
}
|
|
|
|
template <typename UserAllocator>
|
|
void * pool<UserAllocator>::ordered_malloc_need_resize()
|
|
{ //! No memory in any of our storages; make a new storage,
|
|
//! \returns pointer to new chunk.
|
|
size_type partition_size = alloc_size();
|
|
size_type POD_size = static_cast<size_type>(next_size * partition_size +
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value + sizeof(size_type));
|
|
char * ptr = (UserAllocator::malloc)(POD_size);
|
|
if (ptr == 0)
|
|
{
|
|
if(next_size > 4)
|
|
{
|
|
next_size >>= 1;
|
|
partition_size = alloc_size();
|
|
POD_size = static_cast<size_type>(next_size * partition_size +
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value + sizeof(size_type));
|
|
ptr = (UserAllocator::malloc)(POD_size);
|
|
}
|
|
if(ptr == 0)
|
|
return 0;
|
|
}
|
|
const details::PODptr<size_type> node(ptr, POD_size);
|
|
|
|
BOOST_USING_STD_MIN();
|
|
if(!max_size)
|
|
next_size <<= 1;
|
|
else if( next_size*partition_size/requested_size < max_size)
|
|
next_size = min BOOST_PREVENT_MACRO_SUBSTITUTION(next_size << 1, max_size*requested_size/ partition_size);
|
|
|
|
// initialize it,
|
|
// (we can use "add_block" here because we know that
|
|
// the free list is empty, so we don't have to use
|
|
// the slower ordered version)
|
|
store().add_ordered_block(node.begin(), node.element_size(), partition_size);
|
|
|
|
// insert it into the list,
|
|
// handle border case
|
|
if (!list.valid() || std::greater<void *>()(list.begin(), node.begin()))
|
|
{
|
|
node.next(list);
|
|
list = node;
|
|
}
|
|
else
|
|
{
|
|
details::PODptr<size_type> prev = list;
|
|
|
|
while (true)
|
|
{
|
|
// if we're about to hit the end or
|
|
// if we've found where "node" goes
|
|
if (prev.next_ptr() == 0
|
|
|| std::greater<void *>()(prev.next_ptr(), node.begin()))
|
|
break;
|
|
|
|
prev = prev.next();
|
|
}
|
|
|
|
node.next(prev.next());
|
|
prev.next(node);
|
|
}
|
|
// and return a chunk from it.
|
|
return (store().malloc)();
|
|
}
|
|
|
|
template <typename UserAllocator>
|
|
void * pool<UserAllocator>::ordered_malloc(const size_type n)
|
|
{ //! Gets address of a chunk n, allocating new memory if not already available.
|
|
//! \returns Address of chunk n if allocated ok.
|
|
//! \returns 0 if not enough memory for n chunks.
|
|
|
|
const size_type partition_size = alloc_size();
|
|
const size_type total_req_size = n * requested_size;
|
|
const size_type num_chunks = total_req_size / partition_size +
|
|
((total_req_size % partition_size) ? true : false);
|
|
|
|
void * ret = store().malloc_n(num_chunks, partition_size);
|
|
|
|
#ifdef BOOST_POOL_INSTRUMENT
|
|
std::cout << "Allocating " << n << " chunks from pool of size " << partition_size << std::endl;
|
|
#endif
|
|
if ((ret != 0) || (n == 0))
|
|
return ret;
|
|
|
|
#ifdef BOOST_POOL_INSTRUMENT
|
|
std::cout << "Cache miss, allocating another chunk...\n";
|
|
#endif
|
|
|
|
// Not enough memory in our storages; make a new storage,
|
|
BOOST_USING_STD_MAX();
|
|
next_size = max BOOST_PREVENT_MACRO_SUBSTITUTION(next_size, num_chunks);
|
|
size_type POD_size = static_cast<size_type>(next_size * partition_size +
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value + sizeof(size_type));
|
|
char * ptr = (UserAllocator::malloc)(POD_size);
|
|
if (ptr == 0)
|
|
{
|
|
if(num_chunks < next_size)
|
|
{
|
|
// Try again with just enough memory to do the job, or at least whatever we
|
|
// allocated last time:
|
|
next_size >>= 1;
|
|
next_size = max BOOST_PREVENT_MACRO_SUBSTITUTION(next_size, num_chunks);
|
|
POD_size = static_cast<size_type>(next_size * partition_size +
|
|
integer::static_lcm<sizeof(size_type), sizeof(void *)>::value + sizeof(size_type));
|
|
ptr = (UserAllocator::malloc)(POD_size);
|
|
}
|
|
if(ptr == 0)
|
|
return 0;
|
|
}
|
|
const details::PODptr<size_type> node(ptr, POD_size);
|
|
|
|
// Split up block so we can use what wasn't requested.
|
|
if (next_size > num_chunks)
|
|
store().add_ordered_block(node.begin() + num_chunks * partition_size,
|
|
node.element_size() - num_chunks * partition_size, partition_size);
|
|
|
|
BOOST_USING_STD_MIN();
|
|
if(!max_size)
|
|
next_size <<= 1;
|
|
else if( next_size*partition_size/requested_size < max_size)
|
|
next_size = min BOOST_PREVENT_MACRO_SUBSTITUTION(next_size << 1, max_size*requested_size/ partition_size);
|
|
|
|
// insert it into the list,
|
|
// handle border case.
|
|
if (!list.valid() || std::greater<void *>()(list.begin(), node.begin()))
|
|
{
|
|
node.next(list);
|
|
list = node;
|
|
}
|
|
else
|
|
{
|
|
details::PODptr<size_type> prev = list;
|
|
|
|
while (true)
|
|
{
|
|
// if we're about to hit the end, or if we've found where "node" goes.
|
|
if (prev.next_ptr() == 0
|
|
|| std::greater<void *>()(prev.next_ptr(), node.begin()))
|
|
break;
|
|
|
|
prev = prev.next();
|
|
}
|
|
|
|
node.next(prev.next());
|
|
prev.next(node);
|
|
}
|
|
|
|
// and return it.
|
|
return node.begin();
|
|
}
|
|
|
|
template <typename UserAllocator>
|
|
details::PODptr<typename pool<UserAllocator>::size_type>
|
|
pool<UserAllocator>::find_POD(void * const chunk) const
|
|
{ //! find which PODptr storage memory that this chunk is from.
|
|
//! \returns the PODptr that holds this chunk.
|
|
// Iterate down list to find which storage this chunk is from.
|
|
details::PODptr<size_type> iter = list;
|
|
while (iter.valid())
|
|
{
|
|
if (is_from(chunk, iter.begin(), iter.element_size()))
|
|
return iter;
|
|
iter = iter.next();
|
|
}
|
|
|
|
return iter;
|
|
}
|
|
|
|
#else // BOOST_POOL_VALGRIND
|
|
|
|
template<typename UserAllocator>
|
|
class pool
|
|
{
|
|
public:
|
|
// types
|
|
typedef UserAllocator user_allocator; // User allocator.
|
|
typedef typename UserAllocator::size_type size_type; // An unsigned integral type that can represent the size of the largest object to be allocated.
|
|
typedef typename UserAllocator::difference_type difference_type; // A signed integral type that can represent the difference of any two pointers.
|
|
|
|
// construct/copy/destruct
|
|
explicit pool(const size_type s, const size_type = 32, const size_type m = 0) : chunk_size(s), max_alloc_size(m) {}
|
|
~pool()
|
|
{
|
|
purge_memory();
|
|
}
|
|
|
|
bool release_memory()
|
|
{
|
|
bool ret = free_list.empty() ? false : true;
|
|
for(std::set<void*>::iterator pos = free_list.begin(); pos != free_list.end(); ++pos)
|
|
{
|
|
(user_allocator::free)(static_cast<char*>(*pos));
|
|
}
|
|
free_list.clear();
|
|
return ret;
|
|
}
|
|
bool purge_memory()
|
|
{
|
|
bool ret = free_list.empty() && used_list.empty() ? false : true;
|
|
for(std::set<void*>::iterator pos = free_list.begin(); pos != free_list.end(); ++pos)
|
|
{
|
|
(user_allocator::free)(static_cast<char*>(*pos));
|
|
}
|
|
free_list.clear();
|
|
for(std::set<void*>::iterator pos = used_list.begin(); pos != used_list.end(); ++pos)
|
|
{
|
|
(user_allocator::free)(static_cast<char*>(*pos));
|
|
}
|
|
used_list.clear();
|
|
return ret;
|
|
}
|
|
size_type get_next_size() const
|
|
{
|
|
return 1;
|
|
}
|
|
void set_next_size(const size_type){}
|
|
size_type get_max_size() const
|
|
{
|
|
return max_alloc_size;
|
|
}
|
|
void set_max_size(const size_type s)
|
|
{
|
|
max_alloc_size = s;
|
|
}
|
|
size_type get_requested_size() const
|
|
{
|
|
return chunk_size;
|
|
}
|
|
void * malloc BOOST_PREVENT_MACRO_SUBSTITUTION()
|
|
{
|
|
void* ret;
|
|
if(free_list.empty())
|
|
{
|
|
ret = (user_allocator::malloc)(chunk_size);
|
|
VALGRIND_MAKE_MEM_UNDEFINED(ret, chunk_size);
|
|
}
|
|
else
|
|
{
|
|
ret = *free_list.begin();
|
|
free_list.erase(free_list.begin());
|
|
VALGRIND_MAKE_MEM_UNDEFINED(ret, chunk_size);
|
|
}
|
|
used_list.insert(ret);
|
|
return ret;
|
|
}
|
|
void * ordered_malloc()
|
|
{
|
|
return (this->malloc)();
|
|
}
|
|
void * ordered_malloc(size_type n)
|
|
{
|
|
if(max_alloc_size && (n > max_alloc_size))
|
|
return 0;
|
|
void* ret = (user_allocator::malloc)(chunk_size * n);
|
|
used_list.insert(ret);
|
|
return ret;
|
|
}
|
|
void free BOOST_PREVENT_MACRO_SUBSTITUTION(void *const chunk)
|
|
{
|
|
BOOST_ASSERT(used_list.count(chunk) == 1);
|
|
BOOST_ASSERT(free_list.count(chunk) == 0);
|
|
used_list.erase(chunk);
|
|
free_list.insert(chunk);
|
|
VALGRIND_MAKE_MEM_NOACCESS(chunk, chunk_size);
|
|
}
|
|
void ordered_free(void *const chunk)
|
|
{
|
|
return (this->free)(chunk);
|
|
}
|
|
void free BOOST_PREVENT_MACRO_SUBSTITUTION(void *const chunk, const size_type)
|
|
{
|
|
BOOST_ASSERT(used_list.count(chunk) == 1);
|
|
BOOST_ASSERT(free_list.count(chunk) == 0);
|
|
used_list.erase(chunk);
|
|
(user_allocator::free)(static_cast<char*>(chunk));
|
|
}
|
|
void ordered_free(void *const chunk, const size_type n)
|
|
{
|
|
(this->free)(chunk, n);
|
|
}
|
|
bool is_from(void *const chunk) const
|
|
{
|
|
return used_list.count(chunk) || free_list.count(chunk);
|
|
}
|
|
|
|
protected:
|
|
size_type chunk_size, max_alloc_size;
|
|
std::set<void*> free_list, used_list;
|
|
};
|
|
|
|
#endif
|
|
|
|
} // namespace boost
|
|
|
|
#ifdef BOOST_MSVC
|
|
#pragma warning(pop)
|
|
#endif
|
|
|
|
#endif // #ifdef BOOST_POOL_HPP
|
|
|