boost/container/detail/pool_resource.hpp
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2015-2015. 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/container for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_CONTAINER_POOL_RESOURCE_HPP
#define BOOST_CONTAINER_POOL_RESOURCE_HPP
#if defined (_MSC_VER)
# pragma once
#endif
#include <boost/container/detail/config_begin.hpp>
#include <boost/container/detail/workaround.hpp>
#include <boost/container/pmr/memory_resource.hpp>
#include <boost/container/detail/block_list.hpp>
#include <boost/container/pmr/pool_options.hpp>
#include <cstddef>
namespace boost {
namespace container {
namespace pmr {
#if !defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
class pool_data_t;
BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_minimum_max_blocks_per_chunk = 1u;
BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_default_max_blocks_per_chunk = 32u;
BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_minimum_largest_required_pool_block =
memory_resource::max_align > 2*sizeof(void*) ? memory_resource::max_align : 2*sizeof(void*);
BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_default_largest_required_pool_block =
pool_options_minimum_largest_required_pool_block > 4096u
? pool_options_minimum_largest_required_pool_block : 4096u;
#endif //BOOST_CONTAINER_DOXYGEN_INVOKED
class pool_resource
{
typedef block_list_base<> block_list_base_t;
pool_options m_options;
memory_resource& m_upstream;
block_list_base_t m_oversized_list;
pool_data_t *m_pool_data;
std::size_t m_pool_count;
static void priv_limit_option(std::size_t &val, std::size_t min, std::size_t max);
static std::size_t priv_pool_index(std::size_t block_size);
static std::size_t priv_pool_block(std::size_t index);
void priv_fix_options();
void priv_init_pools();
void priv_constructor_body();
public:
//! <b>Requires</b>: `upstream` is the address of a valid memory resource.
//!
//! <b>Effects</b>: Constructs a pool resource object that will obtain memory
//! from upstream whenever the pool resource is unable to satisfy a memory
//! request from its own internal data structures. The resulting object will hold
//! a copy of upstream, but will not own the resource to which upstream points.
//! [ Note: The intention is that calls to upstream->allocate() will be
//! substantially fewer than calls to this->allocate() in most cases. - end note
//! The behavior of the pooling mechanism is tuned according to the value of
//! the opts argument.
//!
//! <b>Throws</b>: Nothing unless upstream->allocate() throws. It is unspecified if
//! or under what conditions this constructor calls upstream->allocate().
pool_resource(const pool_options& opts, memory_resource* upstream) BOOST_NOEXCEPT;
//! <b>Effects</b>: Same as
//! `pool_resource(pool_options(), get_default_resource())`.
pool_resource() BOOST_NOEXCEPT;
//! <b>Effects</b>: Same as
//! `pool_resource(pool_options(), upstream)`.
explicit pool_resource(memory_resource* upstream) BOOST_NOEXCEPT;
//! <b>Effects</b>: Same as
//! `pool_resource(opts, get_default_resource())`.
explicit pool_resource(const pool_options& opts) BOOST_NOEXCEPT;
#if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
pool_resource(const pool_resource&) = delete;
pool_resource operator=(const pool_resource&) = delete;
#else
private:
pool_resource (const pool_resource&);
pool_resource operator=(const pool_resource&);
public:
#endif
//! <b>Effects</b>: Calls
//! `this->release()`.
~pool_resource();
//! <b>Effects</b>: Calls Calls `upstream_resource()->deallocate()` as necessary
//! to release all allocated memory. [ Note: memory is released back to
//! `upstream_resource()` even if deallocate has not been called for some
//! of the allocated blocks. - end note ]
void release();
//! <b>Returns</b>: The value of the upstream argument provided to the
//! constructor of this object.
memory_resource* upstream_resource() const;
//! <b>Returns</b>: The options that control the pooling behavior of this resource.
//! The values in the returned struct may differ from those supplied to the pool
//! resource constructor in that values of zero will be replaced with
//! implementation-defined defaults and sizes may be rounded to unspecified granularity.
pool_options options() const;
public: //public so that [un]synchronized_pool_resource can use them
//! <b>Returns</b>: A pointer to allocated storage with a size of at least `bytes`.
//! The size and alignment of the allocated memory shall meet the requirements for
//! a class derived from `memory_resource`.
//!
//! <b>Effects</b>: If the pool selected for a block of size bytes is unable to
//! satisfy the memory request from its own internal data structures, it will call
//! `upstream_resource()->allocate()` to obtain more memory. If `bytes` is larger
//! than that which the largest pool can handle, then memory will be allocated
//! using `upstream_resource()->allocate()`.
//!
//! <b>Throws</b>: Nothing unless `upstream_resource()->allocate()` throws.
void* do_allocate(std::size_t bytes, std::size_t alignment);
//! <b>Effects</b>: Return the memory at p to the pool. It is unspecified if or under
//! what circumstances this operation will result in a call to
//! `upstream_resource()->deallocate()`.
//!
//! <b>Throws</b>: Nothing.
void do_deallocate(void* p, std::size_t bytes, std::size_t alignment);
//Non-standard observers
public:
//! <b>Returns</b>: The number of pools that will be used in the pool resource.
//!
//! <b>Note</b>: Non-standard extension.
std::size_t pool_count() const;
//! <b>Returns</b>: The index of the pool that will be used to serve the allocation of `bytes`.
//! from the pool specified by `pool_index`. Returns `pool_count()` if `bytes` is bigger
//! than `options().largest_required_pool_block` (no pool will be used to serve this).
//!
//! <b>Note</b>: Non-standard extension.
std::size_t pool_index(std::size_t bytes) const;
//! <b>Requires</b>: `pool_idx < pool_index()`
//!
//! <b>Returns</b>: The number blocks that will be allocated in the next chunk
//! from the pool specified by `pool_idx`.
//!
//! <b>Note</b>: Non-standard extension.
std::size_t pool_next_blocks_per_chunk(std::size_t pool_idx) const;
//! <b>Requires</b>: `pool_idx < pool_index()`
//!
//! <b>Returns</b>: The number of bytes of the block that the specified `pool_idx` pool manages.
//!
//! <b>Note</b>: Non-standard extension.
std::size_t pool_block(std::size_t pool_idx) const;
//! <b>Requires</b>: `pool_idx < pool_index()`
//!
//! <b>Returns</b>: The number of blocks that the specified `pool_idx` pool has cached
//! and will be served without calling the upstream_allocator.
//!
//! <b>Note</b>: Non-standard extension.
std::size_t pool_cached_blocks(std::size_t pool_idx) const;
};
} //namespace pmr {
} //namespace container {
} //namespace boost {
#include <boost/container/detail/config_end.hpp>
#endif //BOOST_CONTAINER_POOL_RESOURCE_HPP