pmem::obj::pool< T > Class Template Reference

PMEMobj pool class. More...

#include <libpmemobj++/pool.hpp>

Public Member Functions
	pool () noexcept=default
	Defaulted constructor.
	pool (const pool &) noexcept=default
	Defaulted copy constructor.
	pool (pool &&) noexcept=default
	Defaulted move constructor.
pool &	operator= (const pool &) noexcept=default
	Defaulted copy assignment operator.
pool &	operator= (pool &&) noexcept=default
	Defaulted move assignment operator.
	~pool () noexcept=default
	Default destructor.
	pool (const pool_base &pb) noexcept
	Defaulted copy constructor.
	pool (pool_base &&pb) noexcept
	Defaulted move constructor.
template<typename M >
M	ctl_get (const std::string &name)
	Query libpmemobj state at pool scope. More...
template<typename M >
M	ctl_set (const std::string &name, M arg)
	Modify libpmemobj state at pool scope. More...
template<typename M >
M	ctl_exec (const std::string &name, M arg)
	Execute function at pool scope. More...
template<typename M >
M	ctl_get (const std::wstring &name)
	Query libpmemobj state at pool scope. More...
template<typename M >
M	ctl_set (const std::wstring &name, M arg)
	Modify libpmemobj state at pool scope. More...
template<typename M >
M	ctl_exec (const std::wstring &name, M arg)
	Execute function at pool scope. More...
persistent_ptr< T >	root ()
	Retrieves pool's root object. More...

Static Public Member Functions
static pool< T >	open (const std::string &path, const std::string &layout)
	Opens an existing object store memory pool. More...
static pool< T >	create (const std::string &path, const std::string &layout, std::size_t size=PMEMOBJ_MIN_POOL, mode_t mode=DEFAULT_MODE)
	Creates a new transactional object store pool. More...
static int	check (const std::string &path, const std::string &layout)
	Checks if a given pool is consistent. More...
static pool< T >	open (const std::wstring &path, const std::wstring &layout)
	Opens an existing object store memory pool. More...
static pool< T >	create (const std::wstring &path, const std::wstring &layout, std::size_t size=PMEMOBJ_MIN_POOL, mode_t mode=DEFAULT_MODE)
	Creates a new transactional object store pool. More...
static int	check (const std::wstring &path, const std::wstring &layout)
	Checks if a given pool is consistent. More...

Detailed Description

template<typename T>
class pmem::obj::pool< T >

PMEMobj pool class.

This class is the pmemobj pool handler. It provides basic primitives for operations on pmemobj pools. The template parameter defines the type of the root object within the pool. This pool class inherits also some methods from the base class: pmem::obj::pool_base.

The typical usage example would be:

#include <fcntl.h>
#include <libpmemobj++/p.hpp>
#include <libpmemobj++/persistent_ptr.hpp>
#include <libpmemobj++/pool.hpp>
 
using namespace pmem::obj;
 
void
pool_example()
{
 
    /* pool root structure */
    struct root {
        p<int> some_array[42];
        p<int> some_other_array[42];
        p<double> some_variable;
    };
 
    /* create a pmemobj pool */
    auto pop = pool<root>::create("poolfile", "layout", PMEMOBJ_MIN_POOL);
 
    /* close a pmemobj pool */
    pop.close();
 
    /* or open a pmemobj pool */
    pop = pool<root>::open("poolfile", "layout");
 
    /* typical usage schemes */
    auto root_obj = pop.root();
 
    /* low-level memory manipulation */
    root_obj->some_variable = 3.2;
    pop.persist(root_obj->some_variable);
 
    pop.memset_persist(root_obj->some_array, 2,
               sizeof(root_obj->some_array));
 
    pop.memcpy_persist(root_obj->some_other_array, root_obj->some_array,
               sizeof(root_obj->some_array));
 
    pop.close();
 
    /* check pool consistency */
    pool<root>::check("poolfile", "layout");
}

This API should not be mixed with C API. For example explicitly calling pmemobj_set_user_data(pop) on pool which is handled by C++ pool object is undefined behaviour.

Member Function Documentation

check() [1/2]

template<typename T >

static int pmem::obj::pool< T >::check ( const std::string &  path, const std::string &  layout  )

inlinestatic

Checks if a given pool is consistent.

Parameters

path	System path to the file containing the memory pool or a pool set.
layout	Unique identifier of the pool as specified at pool creation time.

Returns

-1 on error, 1 if file is consistent, 0 otherwise.

check() [2/2]

template<typename T >

static int pmem::obj::pool< T >::check ( const std::wstring &  path, const std::wstring &  layout  )

inlinestatic

Checks if a given pool is consistent.

Wide string variant. Available only on Windows.

Parameters

path	System path to the file containing the memory pool or a pool set.
layout	Unique identifier of the pool as specified at pool creation time.

Returns

-1 on error, 1 if file is consistent, 0 otherwise.

create() [1/2]

template<typename T >

static pool<T> pmem::obj::pool< T >::create ( const std::string &  path, const std::string &  layout, std::size_t  size = PMEMOBJ_MIN_POOL, mode_t  mode = DEFAULT_MODE  )

inlinestatic

Creates a new transactional object store pool.

Parameters

path	System path to the file to be created. If exists the pool can be created in-place depending on the size parameter. Existing file must be zeroed.
layout	Unique identifier of the pool, can be a null-terminated string.
size	Size of the pool in bytes. If zero and the file exists the pool is created in-place.
mode	File mode for the new file.

Returns

handle to the created pool.

Exceptions

pmem::pool_error

when an error during creation occurs.

create() [2/2]

template<typename T >

static pool<T> pmem::obj::pool< T >::create ( const std::wstring &  path, const std::wstring &  layout, std::size_t  size = PMEMOBJ_MIN_POOL, mode_t  mode = DEFAULT_MODE  )

inlinestatic

Creates a new transactional object store pool.

Wide string variant. Available only on Windows.

Parameters

path	System path to the file to be created. If exists the pool can be created in-place depending on the size parameter. Existing file must be zeroed.
layout	Unique identifier of the pool, can be a null-terminated string.
size	Size of the pool in bytes. If zero and the file exists the pool is created in-place.
mode	File mode for the new file.

Returns

handle to the created pool.

Exceptions

pmem::pool_error

when an error during creation occurs.

ctl_exec() [1/2]

template<typename T >

template<typename M >

M pmem::obj::pool< T >::ctl_exec ( const std::string &  name, M  arg  )

inline

Execute function at pool scope.

Parameters

[in]	name	name of entry point
[in]	arg	extra argument

Returns

copy of arg, possibly modified by query

For more details, see: https://pmem.io/pmdk/manpages/linux/master/libpmemobj/pmemobj_ctl_get.3

ctl_exec() [2/2]

template<typename T >

template<typename M >

M pmem::obj::pool< T >::ctl_exec ( const std::wstring &  name, M  arg  )

inline

Execute function at pool scope.

Parameters

[in]	name	name of entry point
[in]	arg	extra argument

Returns

copy of arg, possibly modified by query

For more details, see: https://pmem.io/pmdk/manpages/linux/master/libpmemobj/pmemobj_ctl_get.3

ctl_get() [1/2]

template<typename T >

template<typename M >

M pmem::obj::pool< T >::ctl_get ( const std::string &  name )

inline

Query libpmemobj state at pool scope.

Parameters

[in]

name

name of entry point

Returns

variable representing internal state

For more details, see: https://pmem.io/pmdk/manpages/linux/master/libpmemobj/pmemobj_ctl_get.3

ctl_get() [2/2]

template<typename T >

template<typename M >

M pmem::obj::pool< T >::ctl_get ( const std::wstring &  name )

inline

Query libpmemobj state at pool scope.

Parameters

[in]

name

name of entry point

Returns

variable representing internal state

For more details, see: https://pmem.io/pmdk/manpages/linux/master/libpmemobj/pmemobj_ctl_get.3

ctl_set() [1/2]

template<typename T >

template<typename M >

M pmem::obj::pool< T >::ctl_set ( const std::string &  name, M  arg  )

inline

Modify libpmemobj state at pool scope.

Parameters

[in]	name	name of entry point
[in]	arg	extra argument

Returns

copy of arg, possibly modified by query

For more details, see: https://pmem.io/pmdk/manpages/linux/master/libpmemobj/pmemobj_ctl_get.3

ctl_set() [2/2]

template<typename T >

template<typename M >

M pmem::obj::pool< T >::ctl_set ( const std::wstring &  name, M  arg  )

inline

Modify libpmemobj state at pool scope.

Parameters

[in]	name	name of entry point
[in]	arg	extra argument

Returns

copy of arg, possibly modified by query

For more details, see: https://pmem.io/pmdk/manpages/linux/master/libpmemobj/pmemobj_ctl_get.3

open() [1/2]

template<typename T >

static pool<T> pmem::obj::pool< T >::open ( const std::string &  path, const std::string &  layout  )

inlinestatic

Opens an existing object store memory pool.

Parameters

path	System path to the file containing the memory pool or a pool set.
layout	Unique identifier of the pool as specified at pool creation time.

Returns

handle to the opened pool.

Exceptions

pmem::pool_error

when an error during opening occurs.

open() [2/2]

template<typename T >

static pool<T> pmem::obj::pool< T >::open ( const std::wstring &  path, const std::wstring &  layout  )

inlinestatic

Opens an existing object store memory pool.

Wide string variant. Available only on Windows.

Parameters

path	System path to the file containing the memory pool or a pool set.
layout	Unique identifier of the pool as specified at pool creation time.

Returns

handle to the opened pool.

Exceptions

pmem::pool_error

when an error during opening occurs.

root()

template<typename T >

persistent_ptr<T> pmem::obj::pool< T >::root ( )

inline

Retrieves pool's root object.

Returns

persistent pointer to the root object.

Exceptions

pmem::pool_error

when pool handle is incorrect.

---

The documentation for this class was generated from the following files:

• libpmemobj++/persistent_ptr.hpp
• libpmemobj++/pool.hpp