LockedPageManagerBase< Locker > Class Template Reference

Thread-safe class to keep track of locked (ie, non-swappable) memory pages. More...

#include <allocators.h>

Collaboration diagram for LockedPageManagerBase< Locker >:

Public Member Functions
	LockedPageManagerBase (size_t page_size)
void	LockRange (void *p, size_t size)
void	UnlockRange (void *p, size_t size)
int	GetLockedPageCount ()

Private Types
typedef std::map< size_t, int >	Histogram

Private Attributes
Locker	locker
boost::mutex	mutex
size_t	page_size
size_t	page_mask
Histogram	histogram

Detailed Description

template<class Locker>
class LockedPageManagerBase< Locker >

Thread-safe class to keep track of locked (ie, non-swappable) memory pages.

Memory locks do not stack, that is, pages which have been locked several times by calls to mlock() will be unlocked by a single call to munlock(). This can result in keying material ending up in swap when those functions are used naively. This class simulates stacking memory locks by keeping a counter per page.

Note

By using a map from each page base address to lock count, this class is optimized for small objects that span up to a few pages, mostly smaller than a page. To support large allocations, something like an interval tree would be the preferred data structure.

Definition at line 45 of file allocators.h.

Member Typedef Documentation

template<class Locker>

typedef std::map<size_t,int> LockedPageManagerBase< Locker >::Histogram

private

Definition at line 114 of file allocators.h.

Constructor & Destructor Documentation

template<class Locker>

LockedPageManagerBase< Locker >::LockedPageManagerBase ( size_t  page_size )

inline

Definition at line 48 of file allocators.h.

Member Function Documentation

template<class Locker>

int LockedPageManagerBase< Locker >::GetLockedPageCount ( )

inline

Definition at line 103 of file allocators.h.

template<class Locker>

void LockedPageManagerBase< Locker >::LockRange ( void *  p, size_t  size  )

inline

Definition at line 57 of file allocators.h.

template<class Locker>

void LockedPageManagerBase< Locker >::UnlockRange ( void *  p, size_t  size  )

inline

Definition at line 80 of file allocators.h.

Member Data Documentation

template<class Locker>

Histogram LockedPageManagerBase< Locker >::histogram

private

Definition at line 115 of file allocators.h.

template<class Locker>

Locker LockedPageManagerBase< Locker >::locker

private

Definition at line 110 of file allocators.h.

template<class Locker>

boost::mutex LockedPageManagerBase< Locker >::mutex

private

Definition at line 111 of file allocators.h.

template<class Locker>

size_t LockedPageManagerBase< Locker >::page_mask

private

Definition at line 112 of file allocators.h.

template<class Locker>

size_t LockedPageManagerBase< Locker >::page_size

private

Definition at line 112 of file allocators.h.

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

• src/allocators.h