This class is used to maintain the list of hazard pointed objects. More...

#include <hazard_pointer.h>

Public Types
enum	SlotID : size_t { SlotID::SHORTUSE = 0, SlotID::SHORTUSE2, SlotID::PROG_ASSUR, SlotID::END }

Public Member Functions
	HazardPointer (int num_threads)

	~HazardPointer ()

void	watch (SlotID slot, void *value)
	This function takes a SlotID and stores the specified value into that the threads alloted slot for that id in the hazard pointer watch list. More...

void	clear_watch (SlotID slot)
	This function takes a SlotID and stores null into that the threads alloted slot for that id in the hazard pointer watch list. More...

bool	contains (void *value)
	This function returns true of the specified value is being watched. More...

	DISALLOW_COPY_AND_ASSIGN (HazardPointer)

Static Public Member Functions
static bool	watch (SlotID slot_id, Element elem, std::atomic< void > address, void expected, HazardPointer *const hazard_pointer=tervel::tl_thread_info->get_hazard_pointer())
	This method is used to achieve a hazard pointer watch on the the based descr. More...

static bool	watch (SlotID slot_id, void value, std::atomic< void > address, void expected, HazardPointer *const hazard_pointer=tervel::tl_thread_info->get_hazard_pointer())
	This method is used to achieve a hazard pointer watch on a memory address. More...

static void	unwatch (SlotID slot_id, HazardPointer *const hazard_pointer=tervel::tl_thread_info->get_hazard_pointer())
	This method is used to remove the hazard pointer watch. More...

static void	unwatch (SlotID slot_id, Element descr, HazardPointer const hazard_pointer=tervel::tl_thread_info->get_hazard_pointer())
	This method is used to remove the hazard pointer watch. More...

static bool	is_watched (Element descr, HazardPointer const hazard_pointer=tervel::tl_thread_info->get_hazard_pointer())
	This method is used to determine if a hazard pointer watch exists on a passed value. More...

static bool	is_watched (void value, HazardPointer const hazard_pointer=tervel::tl_thread_info->get_hazard_pointer())
	This method is used to determine if a hazard pointer watch exists on a passed value. More...

Public Attributes
util::memory::hp::ListManager	hp_list_manager_

Private Member Functions
size_t	get_slot (SlotID id)
	This function calculates a the position of a threads slot for the specified SlotID. More...

Private Attributes
std::unique_ptr< std::atomic< void * >[]>	watches_

const size_t	num_slots_

Detailed Description

This class is used to maintain the list of hazard pointed objects.

Any value can be written into a slot, however we provide special implementation for Elements, in that we call their on_* functions. This allows for more expressive operations to be performed.

If an individual thread requires more than one element to be hazard pointer protected at a single instance, then SlotIDs should be added.

Member Enumeration Documentation

enum tervel::util::memory::hp::HazardPointer::SlotID : size_t

strong

Enumerator
SHORTUSE
SHORTUSE2
PROG_ASSUR
END

Constructor & Destructor Documentation

tervel::util::memory::hp::HazardPointer::HazardPointer ( int num_threads )

explicit

tervel::util::memory::hp::HazardPointer::~HazardPointer ( )

Member Function Documentation

void tervel::util::memory::hp::HazardPointer::clear_watch ( SlotID slot )

inline

This function takes a SlotID and stores null into that the threads alloted slot for that id in the hazard pointer watch list.

Parameters

slot	The id of the slot to watch.

bool tervel::util::memory::hp::HazardPointer::contains ( void * value )

inline

This function returns true of the specified value is being watched.

Parameters

value The value to check.

Returns: true is the table contains the specified value

tervel::util::memory::hp::HazardPointer::DISALLOW_COPY_AND_ASSIGN ( HazardPointer )

size_t tervel::util::memory::hp::HazardPointer::get_slot ( SlotID id )

inlineprivate

This function calculates a the position of a threads slot for the specified SlotID.

Parameters

slot	The slot id to get the position of

static bool tervel::util::memory::hp::HazardPointer::is_watched	(	Element *	descr,
		HazardPointer *const	hazard_pointer = `tervel::tl_thread_info->get_hazard_pointer()`
	)

static

This method is used to determine if a hazard pointer watch exists on a passed value.

If a descr is passed then it will internally call descr->on_is_watched.

Parameters

descr to call on_is_watched on.

static bool tervel::util::memory::hp::HazardPointer::is_watched	(	void *	value,
		HazardPointer *const	hazard_pointer = `tervel::tl_thread_info->get_hazard_pointer()`
	)

static

This method is used to determine if a hazard pointer watch exists on a passed value.

If a descr is passed then it will internally call descr->on_is_watched.

Parameters

value to check if watch

static void tervel::util::memory::hp::HazardPointer::unwatch	(	SlotID	slot_id,
		HazardPointer *const	hazard_pointer = `tervel::tl_thread_info->get_hazard_pointer()`
	)

static

This method is used to remove the hazard pointer watch.

If a descr is passed then it will internally call descr->on_unwatch.

Parameters

slot	the slot to remove the watch

static void tervel::util::memory::hp::HazardPointer::unwatch	(	SlotID	slot_id,
		Element *	descr,
		HazardPointer *const	hazard_pointer = `tervel::tl_thread_info->get_hazard_pointer()`
	)

static

This method is used to remove the hazard pointer watch.

If a descr is passed then it will internally call descr->on_unwatch.

Parameters

slot	the slot to remove the watch
descr	to call on_unwatch on.

static bool tervel::util::memory::hp::HazardPointer::watch	(	SlotID	slot_id,
		Element *	elem,
		std::atomic< void * > *	address,
		void *	expected,
		HazardPointer *const	hazard_pointer = `tervel::tl_thread_info->get_hazard_pointer()`
	)

static

This method is used to achieve a hazard pointer watch on the the based descr.

Internally it will call the descriptors on_watch function.

If after writing descr the object is still at the address (indicated by *a == value), it will call on_watch. If that returns true then it will return true. Otherwise it removes the hazard pointer watch and returns false

Parameters

slot	The position to place the descr value in the watch table.
descr	The descr that is to be watched.
address	The address to check
expected	The value which is to be expected at the address

static bool tervel::util::memory::hp::HazardPointer::watch	(	SlotID	slot_id,
		void *	value,
		std::atomic< void * > *	address,
		void *	expected,
		HazardPointer *const	hazard_pointer = `tervel::tl_thread_info->get_hazard_pointer()`
	)

static

This method is used to achieve a hazard pointer watch on a memory address.

If after writing the value, it is still at the address (indicated by *a == value), will return true. Otherwise it removes the hazard pointer watch and returns false

Parameters

slot	The position to place the value in the watch table.
value	The value that is to be watched.
address	The address to check
expected	The value which is to be expected at the address

void tervel::util::memory::hp::HazardPointer::watch	(	SlotID	slot,
		void *	value
	)

inline

This function takes a SlotID and stores the specified value into that the threads alloted slot for that id in the hazard pointer watch list.

Parameters

slot	The id of the slot to watch.
value	The value to watch

Member Data Documentation

util::memory::hp::ListManager tervel::util::memory::hp::HazardPointer::hp_list_manager_

const size_t tervel::util::memory::hp::HazardPointer::num_slots_

private

std::unique_ptr<std::atomic<void *>[]> tervel::util::memory::hp::HazardPointer::watches_

private

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

tervel/util/memory/hp/hazard_pointer.h

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation