Garbage-collected Pool Forest. More...

#include <w_gc_pool_forest.h>

Public Member Functions
	GcPoolForest (const char *debug_name, uint32_t desired_gens, size_t initial_segment_count, gc_offset initial_segment_size)

	~GcPoolForest ()

T *	resolve_pointer (const GcPointer< T > &pointer)

T *	resolve_pointer (gc_pointer_raw pointer)

GcGeneration< T > *	resolve_generation (gc_pointer_raw pointer)

GcGeneration< T > *	resolve_generation (gc_generation gen)

GcSegment< T > *	resolve_segment (gc_pointer_raw pointer)

GcSegment< T > *	resolve_segment (gc_generation gen, gc_segment seg)

T *	allocate (gc_pointer_raw &next, gc_thread_id self)

void	deallocate (T *pointer)

void	deallocate (gc_pointer_raw pointer)

gc_pointer_raw	occupy_segment (gc_thread_id self)

gc_generation	head () const

gc_generation	tail () const

gc_generation	curr () const

size_t	active_generations () const

GcGeneration< T > *	head_generation ()

GcGeneration< T > *	curr_generation ()

bool	is_valid_generation (gc_generation generation) const

bool	advance_generation (lsn_t low_water_mark, lsn_t now, size_t initial_segment_count, gc_offset segment_size)

void	retire_generations (lsn_t low_water_mark, lsn_t recycle_now=lsn_t::null)

void	mfence () const

Static Public Member Functions
static gc_generation	wrap (size_t i)

Public Attributes
const char *	name

uint32_t	head_nowrap

uint32_t	curr_nowrap

uint32_t	tail_nowrap

uint32_t	desired_generations

GcGeneration< T > *	generations [GC_MAX_GENERATIONS]

lsn_t	epochs [GC_MAX_GENERATIONS]

GcWakeupFunctor *	gc_wakeup_functor

Detailed Description

template<class T>
struct GcPoolForest< T >

Garbage-collected Pool Forest.

Template Parameters

T	Type of the managed class/struct. It must have a member "gc_pointer_raw gc_pointer" accessible to this class.

This is a Roll-Your-Own Garbage Collector implementation optimized for long-running services such as filesystems and databases.

Constructor & Destructor Documentation

§ GcPoolForest()

template<class T>

GcPoolForest< T >::GcPoolForest	(	const char *	debug_name,
		uint32_t	desired_gens,
		size_t	initial_segment_count,
		gc_offset	initial_segment_size
	)

inline

§ ~GcPoolForest()

template<class T>

GcPoolForest< T >::~GcPoolForest ( )

inline

Member Function Documentation

§ active_generations()

template<class T>

size_t GcPoolForest< T >::active_generations ( ) const

inline

Returns the number of active generations.

§ advance_generation()

template<class T >

bool GcPoolForest< T >::advance_generation	(	lsn_t	low_water_mark,
		lsn_t	now,
		size_t	initial_segment_count,
		gc_offset	segment_size
	)

inline

Create a new generation for the given starting LSN.

Parameters

[in]	low_water_mark	LSN of the oldest transaction in the system. Used to recycle old generations. lsn_t::null prohibits recycling.
[in]	now	higest LSN as of now, which means every thread that newly allocates from this new generation would have this LSN or higher.

Returns: whether we could advance the generation or there is already a generation for the starting LSN (or more recent). false means too many generations.

§ allocate()

template<class T >

T * GcPoolForest< T >::allocate	(	gc_pointer_raw &	next,
		gc_thread_id	self
	)

inline

Allocate a new object from this pool.

Parameters

[in,out]	next	this is a thread-local hint to allocate from. we also increment or even switch to new segment. the caller probably uses a thread-local for this.
[in]	self	Some ID of the calling thread. eg, pthread_self().

§ curr()

template<class T>

gc_generation GcPoolForest< T >::curr ( ) const

inline

The yougnest active generation in which we should allocate new segments. wrapped.

§ curr_generation()

template<class T>

GcGeneration<T>* GcPoolForest< T >::curr_generation ( )

inline

§ deallocate() [1/2]

template<class T>

void GcPoolForest< T >::deallocate ( T * pointer )

inline

Return an object to this pool.

Parameters

[in] pointer The object to return.

§ deallocate() [2/2]

template<class T>

void GcPoolForest< T >::deallocate ( gc_pointer_raw pointer )

inline

Return an object to this pool.

Parameters

[in] pointer Logical pointer to the object to return.

§ head()

template<class T>

gc_generation GcPoolForest< T >::head ( ) const

inline

The oldest active generation. wrapped.

§ head_generation()

template<class T>

GcGeneration<T>* GcPoolForest< T >::head_generation ( )

inline

§ is_valid_generation()

template<class T>

bool GcPoolForest< T >::is_valid_generation ( gc_generation generation ) const

inline

§ mfence()

template<class T>

void GcPoolForest< T >::mfence ( ) const

inline

full load-store fence.

§ occupy_segment()

template<class T >

gc_pointer_raw GcPoolForest< T >::occupy_segment ( gc_thread_id self )

inline

Occupy a segment in latest generation and return a pointer to its first object.

§ resolve_generation() [1/2]

template<class T>

GcGeneration<T>* GcPoolForest< T >::resolve_generation ( gc_pointer_raw pointer )

inline

§ resolve_generation() [2/2]

template<class T>

GcGeneration<T>* GcPoolForest< T >::resolve_generation ( gc_generation gen )

inline

§ resolve_pointer() [1/2]

template<class T>

T* GcPoolForest< T >::resolve_pointer ( const GcPointer< T > & pointer )

inline

Returns a physical pointer represented by the logical pointer.

§ resolve_pointer() [2/2]

template<class T>

T * GcPoolForest< T >::resolve_pointer ( gc_pointer_raw pointer )

inline

Returns a physical pointer represented by the logical pointer.

§ resolve_segment() [1/2]

template<class T>

GcSegment<T>* GcPoolForest< T >::resolve_segment ( gc_pointer_raw pointer )

inline

§ resolve_segment() [2/2]

template<class T>

GcSegment<T>* GcPoolForest< T >::resolve_segment	(	gc_generation	gen,
		gc_segment	seg
	)

inline

§ retire_generations()

template<class T >

void GcPoolForest< T >::retire_generations	(	lsn_t	low_water_mark,
		lsn_t	recycle_now = `lsn_t::null`
	)

inline

Retire old generations that are no longer needed.

Parameters

[in]	low_water_mark	LSN of the oldest transaction in the system
[in]	recycle_now	higest LSN as of now. This is used to recycle retired generations. lsn_t::null means prohibiting recycle.

§ tail()

template<class T>

gc_generation GcPoolForest< T >::tail ( ) const

inline

The exclusive end of active generations. wrapped.

§ wrap()

template<class T>

static gc_generation GcPoolForest< T >::wrap ( size_t i )

inlinestatic

Member Data Documentation

§ curr_nowrap

template<class T>

uint32_t GcPoolForest< T >::curr_nowrap

The latest active generation. No wrap, so take modulo before use.

§ desired_generations

template<class T>

uint32_t GcPoolForest< T >::desired_generations

Desired number of generations. Don't add more than it unless can't retire old ones.

§ epochs

template<class T>

lsn_t GcPoolForest< T >::epochs[GC_MAX_GENERATIONS]

LSN as of starting each generation.

§ gc_wakeup_functor

template<class T>

GcWakeupFunctor* GcPoolForest< T >::gc_wakeup_functor

Function pointer to wakeup GC when pre-allocation or retiring gets behind.

§ generations

template<class T>

GcGeneration<T>* GcPoolForest< T >::generations[GC_MAX_GENERATIONS]

Active (or being-retired) generation objects.

§ head_nowrap

template<class T>

uint32_t GcPoolForest< T >::head_nowrap

The oldest active generation. No wrap, so take modulo before use.

§ name

template<class T>

const char* GcPoolForest< T >::name

Only used to put the name of this forest in debug print.

§ tail_nowrap

template<class T>

uint32_t GcPoolForest< T >::tail_nowrap

The exclusive end of active generation. No wrap, so take modulo before use.

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

src/common/w_gc_pool_forest.h

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

template<class T> struct GcPoolForest< T >

Constructor & Destructor Documentation

§ GcPoolForest()

§ ~GcPoolForest()

Member Function Documentation

§ active_generations()

§ advance_generation()

§ allocate()

§ curr()

§ curr_generation()

§ deallocate() [1/2]

§ deallocate() [2/2]

§ head()

§ head_generation()

§ is_valid_generation()

§ mfence()

§ occupy_segment()

§ resolve_generation() [1/2]

§ resolve_generation() [2/2]

§ resolve_pointer() [1/2]

§ resolve_pointer() [2/2]

§ resolve_segment() [1/2]

§ resolve_segment() [2/2]

§ retire_generations()

§ tail()

§ wrap()

Member Data Documentation

§ curr_nowrap

§ desired_generations

§ epochs

§ gc_wakeup_functor

§ generations

§ head_nowrap

§ name

§ tail_nowrap

template<class T>
struct GcPoolForest< T >