Inheritance diagram for H5::File:

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Classes
struct	ProcessInfo
	Information about a process accessing the shared memory (a process means here an instance of a File class) More...

struct	SharedMemObject

Public Types
enum	FileAccess { read , write }

Public Member Functions
	File (const boost::filesystem::path &filename_, FileAccess type_, const std::function< void()> &closeRequestCallback_=std::function< void()>(), const std::function< void()> &refreshCallback_=std::function< void()>())

	~File () override
	Closes the HDF5 file.

void	enableSWMR () override

void	refresh () override
	Refresh the dataset of a reader. More...

void	requestFlush ()

void	flushIfRequested ()

Public Member Functions inherited from H5::GroupBase
template<class T >
Container< Object, GroupBase >::Creator< T >	createChildObject (const std::string &path)

template<class T >
T *	openChildObject (const std::string &path)

Object *	openChildObject (const std::string &name_, ElementType objectType=nullptr, hid_t type=nullptr)

std::list< std::string >	getChildObjectNames ()

Public Member Functions inherited from H5::Object
template<class T >
Creator< T >	createChildAttribute (const std::string &path)

template<class T >
T *	openChildAttribute (const std::string &path)

Attribute *	openChildAttribute (const std::string &name_, ElementType attributeType=nullptr, hid_t type=nullptr)

std::set< std::string >	getChildAttributeNames ()

bool	hasChildAttribute (const std::string &name_)

GroupBase *	getParent ()

File *	getFile ()

std::string	getPath ()

Public Member Functions inherited from H5::Element
hid_t	getID ()
	Note: use the returned hid_t only temporarily since it may get invalid, at least when File::enableSWMR is called.

std::string	getName ()

Static Public Member Functions
static int	getDefaultCompression ()

static void	setDefaultCompression (int comp)

static int	getDefaultChunkSize ()

static void	setDefaultChunkSize (int chunk)

static int	getDefaultCacheSize ()

static void	setDefaultCacheSize (int cache)

static void	dumpSharedMemory (const boost::filesystem::path &filename)

static void	removeSharedMemory (const boost::filesystem::path &filename)
	Internal helper function which removes the shared memory associated with filename, !!!EVEN if other process still use it!!!

Private Types
enum class	WriterState { none , writeRequest , active , swmr }
	A writer can be in the following state:

Private Member Functions
void	close () override

void	openReader ()
	Helper function to open the file as a reader.

void	closeReader ()
	Helper function to close the file as a reader.

void	openWriter ()
	Helper function to open the file as a writer.

void	closeWriter ()
	Helper function to close the file as a writer.

void	wait (Internal::ScopedLock &lock, std::string_view blockingMsg, const std::function< bool()> &pred)

void	stillAlivePing ()

void	listenForRequest ()
	The worker function for the thread listenForRequestThread.

void	initProcessInfo ()
	Write process information of this process to the shared memory.

void	deinitProcessInfo ()
	Remove process information of this process from the shared memory.

void	openOrCreateShm ()
	open or create the shared memory atomically (process with using file lock)

Static Private Member Functions
static std::string	createShmName (const boost::filesystem::path &filename)
	transform filename to a valid boost interprocess name.

Private Attributes
const boost::filesystem::path	filename
	The name of the file.

const FileAccess	type
	Flag if this instance is a writer or reader.

const std::function< void()>	closeRequestCallback
	This callback is called when a writer requested a close of all readers.

const std::function< void()>	refreshCallback
	This callback is called when a writer has flushed.

std::string	shmName
	Name of the shared memory. More...

const boost::uuids::uuid	processUUID

Internal::SharedMemory	shm

boost::interprocess::mapped_region	region

SharedMemObject *	sharedData {nullptr}
	Pointer to the shared memory object.

bool	flushRequested { false }
	True if this reader has requested a flush.

WriterState	lastWriterState { WriterState::none }
	The last wrtierState known by this object.

boost::thread	stillAlivePingThread

std::thread	listenForRequestThread

bool	exitThread { false }
	Flag which is set to true to enforce the thread to exit (on the next condition notify signal)

Static Private Attributes
static int	defaultCompression =1

static int	defaultChunkSize =100

static int	defaultCacheSize =100

static constexpr size_t	MAXREADERS { 100 }
	the maximal number of readers which can access the file simultanously

static constexpr size_t	MAXWRITERS { 10 }
	the maximal number of writers. Just need since only a fixed amount of readers+writers can wait for the ConditionVariable

Friends
class	Internal::ScopedLock

Additional Inherited Members
Protected Member Functions inherited from H5::GroupBase
	GroupBase (int dummy, GroupBase *parent_, const std::string &name_)

	GroupBase (GroupBase *parent_, const std::string &name_)

void	close () override

void	refresh () override

void	flush () override

void	enableSWMR () override

Dataset *	openChildDataset (const std::string &name_, ElementType objectType, hid_t type)

GroupBase *	getFileAsGroup ()

Protected Member Functions inherited from H5::Object
	Object (GroupBase *parent_, const std::string &name_)

void	close () override

void	refresh () override

void	flush () override

void	enableSWMR () override

Object *	getFileAsObject ()

Object *	getAttrParent (const std::string &path, size_t pos)

Protected Member Functions inherited from H5::Element
	Element (std::string name_)

virtual void	close ()

virtual void	refresh ()

virtual void	flush ()

virtual void	enableSWMR ()

Protected Member Functions inherited from H5::Container< Attribute, Object >
void	close ()

void	refresh ()

void	flush ()

void	enableSWMR ()

Creator< T >	createChild (const std::string &name_)

T *	openChild (const std::string &name_)

Protected Member Functions inherited from H5::Container< Object, GroupBase >
void	close ()

void	refresh ()

void	flush ()

void	enableSWMR ()

Creator< T >	createChild (const std::string &name_)

T *	openChild (const std::string &name_)

Protected Attributes inherited from H5::Object
GroupBase *	parent

File *	file

Protected Attributes inherited from H5::Element
ScopedHID	id

std::string	name

Protected Attributes inherited from H5::Container< Attribute, Object >
std::map< std::string, Attribute * >	childs

Protected Attributes inherited from H5::Container< Object, GroupBase >
std::map< std::string, Object * >	childs

Member Enumeration Documentation

◆ FileAccess

enum H5::File::FileAccess

Enumerator
read	open file for reading
write	open file for writing

Constructor & Destructor Documentation

◆ File()

H5::File::File	(	const boost::filesystem::path &	filename_,
		FileAccess	type_,
		const std::function< void()> &	closeRequestCallback_ = `std::function<void()>()`,
		const std::function< void()> &	refreshCallback_ = `std::function<void()>()`
	)

Opens the HDF5 file filename_ as a writer or reader dependent on type_. For a reader closeRequestCallback_ should be set! This callback is called if any writer want to write the file this reader also holds. If this callback is called you should close (destruct) this File object in time. After close (destruct) you can immediately reopen the file by constructing a File object (with the same HDF5 file) again. The inter process communication will ensure the the requested writer does its job before you can reopen the file for reading again. For a reader refreshCallback_ should also be set if the reader will call requestFlush. This this callback is called the reader should call refresh(). Note that both callback functions will be called from of a thread created by this constructor.

Member Function Documentation

◆ close()

void H5::File::close ( )

overrideprivatevirtual

Reimplemented from H5::Element.

◆ dumpSharedMemory()

void H5::File::dumpSharedMemory ( const boost::filesystem::path & filename )

static

Internal helper function which dumps the content of the shared memory associated with filename. !!! Note that the mutex is NOT locked for this operation but the file lock is accquired.

◆ enableSWMR()

void H5::File::enableSWMR ( )

overridevirtual

Switch a writer from dataset creation mode to SWMR. After this call no datasets, groups or attributes can be created anymore and attributes are closed! But readers are no longer blocked and can read the file.

Reimplemented from H5::Element.

◆ flushIfRequested()

void H5::File::flushIfRequested ( )

Flush the file (the dataset) of a writer if this is requested by a reader. Does nothing if no reader has requested a flush. If a flush happend the reades are notified about the flush.

◆ refresh()

void H5::File::refresh ( )

overridevirtual

Refresh the dataset of a reader.

Reimplemented from H5::Element.

◆ requestFlush()

void H5::File::requestFlush ( )

Request a flush of the writer. This is not blocking. If the writer has flushed the refreshCallback is called, see constructor.

◆ wait()

void H5::File::wait	(	Internal::ScopedLock &	lock,
		std::string_view	blockingMsg,
		const std::function< bool()> &	pred
	)

private

Helper function which waits until the condition pred is true. On entry the lock lock is released and re-aquired if waiting ends (the pred() == true). If this call blocks (pred is not already true on entry) then the message blockingMsg is printed (use a empty string to avoid printing)

Member Data Documentation

◆ listenForRequestThread

std::thread H5::File::listenForRequestThread

private

A thread created for a reader to listen when a new writer process requests a write of has flushed the file. boost thread interruption points does not help here since its not working with ConditionVariable -> hence we implement it ourself using the exitThread flag

◆ region

boost::interprocess::mapped_region H5::File::region

private

Memory region holding the shared memory map Access to region (and shm) must bu guarded by locking the boost filelock of filename.

◆ shm

Internal::SharedMemory H5::File::shm

private

Shared memory object holding the shared memory Access to shm (and region) must bu guarded by locking the boost filelock of filename.

◆ shmName

std::string H5::File::shmName

private

Name of the shared memory.

a globally unique identifier for this process

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

/mbsim-env/hdf5serie/hdf5serie/hdf5serie/file.h
/mbsim-env/hdf5serie/hdf5serie/hdf5serie/file.cc

Classes

Public Types

Public Member Functions

Static Public Member Functions

Private Types

Private Member Functions

Static Private Member Functions

Private Attributes

Static Private Attributes

Friends

Additional Inherited Members

Member Enumeration Documentation

◆ FileAccess

Constructor & Destructor Documentation

◆ File()

Member Function Documentation

◆ close()

◆ dumpSharedMemory()

◆ enableSWMR()

◆ flushIfRequested()

◆ refresh()

◆ requestFlush()

◆ wait()

Member Data Documentation

◆ listenForRequestThread

◆ region

◆ shm

◆ shmName