class representing a chunk of pages

Author: Manuel Schiller manue.nosp@m.l.sc.nosp@m.hille.nosp@m.r@ni.nosp@m.khef..nosp@m.nl

Date: 2013-07-24

allocating pages from the OS happens in chunks in order to not exhaust the maximum allowed number of memory mappings per process; this class takes care of such a chunk

a page chunk allows callers to obtain or release pages in groups of continuous pages of fixed size

Definition at line 45 of file BidirMMapPipe.h.

Public Types
enum	MMapVariety { Unknown , Copy , FileBacked , DevZero , Anonymous }
	type of mmap support found More...

Public Member Functions
	PageChunk (PagePool *parent, unsigned length, unsigned nPgPerGroup)
	constructor

	~PageChunk ()
	destructor

bool	contains (const Pages &p) const
	return if p is contained in this PageChunk

bool	empty () const
	return true if no used page groups in this chunk

bool	full () const
	return true if no free page groups in this chunk

unsigned	len () const
	return length of chunk

unsigned	nPagesPerGroup () const
	return number of pages per page group

Pages	pop ()
	pop a group of pages off the free list

void	push (const Pages &p)
	push a group of pages onto the free list

void	zap (Pages &p)
	free all pages except for those pointed to by p

Static Public Member Functions
static MMapVariety	mmapVariety ()
	return mmap variety support found

static unsigned	pagesize ()
	return the logical page size

static unsigned	physPgSz ()
	return the physical page size of the system

Private Types
typedef BidirMMapPipeException	Exception
	convenience typedef

Private Member Functions
	PageChunk (const PageChunk &)
	forbid copying

PageChunk &	operator= (const PageChunk &)
	forbid assignment

Static Private Member Functions
static void *	dommap (unsigned len)
	mmap pages, len is length of mmapped area in bytes

static void	domunmap (void *p, unsigned len)
	munmap pages p, len is length of mmapped area in bytes

static unsigned	getPageSize ()
	determine page size at run time

Private Attributes
void *	m_begin
	pointer to start of mmapped area

void *	m_end
	pointer one behind end of mmapped area

std::list< void * >	m_freelist
	free pages list

unsigned	m_nPgPerGrp
	number of pages per group

unsigned	m_nUsedGrp
	number of used page groups

PagePool *	m_parent
	parent page pool

Static Private Attributes
static MMapVariety	s_mmapworks = PageChunk::Unknown
	mmap variety that works on this system

static unsigned	s_pagesize = std::min(PageChunk::s_physpgsz, 16384u)
	logical page size (run-time determined)

static unsigned	s_physpgsz = PageChunk::getPageSize()
	system physical page size

#include </home/sftnight/build/workspace/root-makedoc-v628/rootspi/rdoc/src/v6-28-00-patches/roofit/roofitcore/src/BidirMMapPipe.h>

Member Typedef Documentation

◆ Exception

typedef BidirMMapPipeException RooFit::BidirMMapPipe_impl::PageChunk::Exception

private

convenience typedef

Definition at line 63 of file BidirMMapPipe.h.

Member Enumeration Documentation

◆ MMapVariety

enum RooFit::BidirMMapPipe_impl::PageChunk::MMapVariety

type of mmap support found

Enumerator
Unknown	don't know yet what'll work
Copy	mmap doesn't work, have to copy back and forth
FileBacked	mmapping a temp file works
DevZero	mmapping /dev/zero works
Anonymous	anonymous mmap works

Definition at line 48 of file BidirMMapPipe.h.

Constructor & Destructor Documentation

◆ PageChunk() [1/2]

RooFit::BidirMMapPipe_impl::PageChunk::PageChunk ( const PageChunk & )

inlineprivate

forbid copying

Definition at line 82 of file BidirMMapPipe.h.

◆ PageChunk() [2/2]

RooFit::BidirMMapPipe_impl::PageChunk::PageChunk	(	PagePool *	parent,
		unsigned	length,
		unsigned	nPgPerGroup
	)

constructor

Definition at line 344 of file BidirMMapPipe.cxx.

◆ ~PageChunk()

RooFit::BidirMMapPipe_impl::PageChunk::~PageChunk ( )

destructor

Definition at line 360 of file BidirMMapPipe.cxx.

Member Function Documentation

◆ contains()

bool RooFit::BidirMMapPipe_impl::PageChunk::contains ( const Pages & p ) const

return if p is contained in this PageChunk

Definition at line 366 of file BidirMMapPipe.cxx.

◆ dommap()

void * RooFit::BidirMMapPipe_impl::PageChunk::dommap ( unsigned len )

staticprivate

mmap pages, len is length of mmapped area in bytes

Definition at line 392 of file BidirMMapPipe.cxx.

◆ domunmap()

void RooFit::BidirMMapPipe_impl::PageChunk::domunmap	(	void *	p,
		unsigned	len
	)

staticprivate

munmap pages p, len is length of mmapped area in bytes

Definition at line 532 of file BidirMMapPipe.cxx.

◆ empty()

bool RooFit::BidirMMapPipe_impl::PageChunk::empty ( ) const

inline

return true if no used page groups in this chunk

Definition at line 118 of file BidirMMapPipe.h.

◆ full()

bool RooFit::BidirMMapPipe_impl::PageChunk::full ( ) const

inline

return true if no free page groups in this chunk

Definition at line 121 of file BidirMMapPipe.h.

◆ getPageSize()

unsigned RooFit::BidirMMapPipe_impl::PageChunk::getPageSize ( )

staticprivate

determine page size at run time

Definition at line 330 of file BidirMMapPipe.cxx.

◆ len()

unsigned RooFit::BidirMMapPipe_impl::PageChunk::len ( ) const

inline

return length of chunk

Definition at line 109 of file BidirMMapPipe.h.

◆ mmapVariety()

static MMapVariety RooFit::BidirMMapPipe_impl::PageChunk::mmapVariety ( )

inlinestatic

return mmap variety support found

Definition at line 91 of file BidirMMapPipe.h.

◆ nPagesPerGroup()

unsigned RooFit::BidirMMapPipe_impl::PageChunk::nPagesPerGroup ( ) const

inline

return number of pages per page group

Definition at line 115 of file BidirMMapPipe.h.

◆ operator=()

PageChunk & RooFit::BidirMMapPipe_impl::PageChunk::operator= ( const PageChunk & )

inlineprivate

forbid assignment

Definition at line 84 of file BidirMMapPipe.h.

◆ pagesize()

static unsigned RooFit::BidirMMapPipe_impl::PageChunk::pagesize ( )

inlinestatic

return the logical page size

Definition at line 87 of file BidirMMapPipe.h.

◆ physPgSz()

static unsigned RooFit::BidirMMapPipe_impl::PageChunk::physPgSz ( )

inlinestatic

return the physical page size of the system

Definition at line 89 of file BidirMMapPipe.h.

◆ pop()

Pages RooFit::BidirMMapPipe_impl::PageChunk::pop ( )

pop a group of pages off the free list

Definition at line 369 of file BidirMMapPipe.cxx.

◆ push()

void RooFit::BidirMMapPipe_impl::PageChunk::push ( const Pages & p )

push a group of pages onto the free list

Definition at line 378 of file BidirMMapPipe.cxx.

◆ zap()

void RooFit::BidirMMapPipe_impl::PageChunk::zap ( Pages & p )

free all pages except for those pointed to by p

Definition at line 546 of file BidirMMapPipe.cxx.

Member Data Documentation

◆ m_begin

void* RooFit::BidirMMapPipe_impl::PageChunk::m_begin

private

pointer to start of mmapped area

Definition at line 65 of file BidirMMapPipe.h.

◆ m_end

void* RooFit::BidirMMapPipe_impl::PageChunk::m_end

private

pointer one behind end of mmapped area

Definition at line 66 of file BidirMMapPipe.h.

◆ m_freelist

std::list<void*> RooFit::BidirMMapPipe_impl::PageChunk::m_freelist

private

free pages list

Definition at line 69 of file BidirMMapPipe.h.

◆ m_nPgPerGrp

unsigned RooFit::BidirMMapPipe_impl::PageChunk::m_nPgPerGrp

private

number of pages per group

Definition at line 71 of file BidirMMapPipe.h.

◆ m_nUsedGrp

unsigned RooFit::BidirMMapPipe_impl::PageChunk::m_nUsedGrp

private

number of used page groups

Definition at line 72 of file BidirMMapPipe.h.

◆ m_parent

PagePool* RooFit::BidirMMapPipe_impl::PageChunk::m_parent

private

parent page pool

Definition at line 70 of file BidirMMapPipe.h.

◆ s_mmapworks

PageChunk::MMapVariety RooFit::BidirMMapPipe_impl::PageChunk::s_mmapworks = PageChunk::Unknown

staticprivate

mmap variety that works on this system

Definition at line 60 of file BidirMMapPipe.h.

◆ s_pagesize

unsigned RooFit::BidirMMapPipe_impl::PageChunk::s_pagesize = std::min(PageChunk::s_physpgsz, 16384u)

staticprivate

logical page size (run-time determined)

Definition at line 58 of file BidirMMapPipe.h.

◆ s_physpgsz

unsigned RooFit::BidirMMapPipe_impl::PageChunk::s_physpgsz = PageChunk::getPageSize()

staticprivate

system physical page size

Definition at line 57 of file BidirMMapPipe.h.

roofit/roofitcore/src/BidirMMapPipe.h

roofit/roofitcore/src/BidirMMapPipe.cxx

Public Types

Public Member Functions

Static Public Member Functions

Private Types

Private Member Functions

Static Private Member Functions

Private Attributes

Static Private Attributes

Member Typedef Documentation

◆ Exception

Member Enumeration Documentation

◆ MMapVariety

Constructor & Destructor Documentation

◆ PageChunk() [1/2]

◆ PageChunk() [2/2]

◆ ~PageChunk()

Member Function Documentation

◆ contains()

◆ dommap()

◆ domunmap()

◆ empty()

◆ full()

◆ getPageSize()

◆ len()

◆ mmapVariety()

◆ nPagesPerGroup()

◆ operator=()

◆ pagesize()

◆ physPgSz()

◆ pop()

◆ push()

◆ zap()

Member Data Documentation

◆ m_begin

◆ m_end

◆ m_freelist

◆ m_nPgPerGrp

◆ m_nUsedGrp

◆ m_parent

◆ s_mmapworks

◆ s_pagesize

◆ s_physpgsz