A simple lock-free list implementation to append or erase data of type T. More...

#include <rtt/internal/ListLockFree.hpp>

Inheritance diagram for RTT::internal::ListLockFree< T >:

Public Types
typedef T	value_t
Public Member Functions
	ListLockFree (unsigned int lsize, unsigned int threads=ORONUM_OS_MAX_THREADS)
	Create a lock-free list wich can store lsize elements.
size_t	capacity () const
	Returns the maximum number of elements this list can hold.
size_t	size () const
	Returns the current number of elements in this list.
bool	empty () const
	Returns true if this list is empty.
void	grow (size_t items=1)
	Grow the capacity to contain at least n additional items.
void	shrink (size_t items=1)
	Shrink the capacity with at most n items.
void	reserve (size_t lsize)
	Reserve a capacity for this list.
void	clear ()
	Clears all elements in the list.
bool	append (value_t item)
	Append a single value to the list.
value_t	front () const
	Returns the first element of the list.
value_t	back () const
	Returns the last element of the list.
size_t	append (const std::vector< T > &items)
	Append a sequence of values to the list.
bool	erase (value_t item)
	Erase a value from the list.
template<typename Pred >
bool	delete_if (Pred pred)
	Erase a value from the list.
template<class Function >
void	apply (Function func)
	Apply a function to the elements of the whole list.
template<class Function >
void	apply_and_blank (Function func, value_t blank)
	Apply a function to the non-blanked elements of the list.
bool	erase_and_blank (value_t item, value_t blank)
	Erase an element from the list and blank it if possible.
template<class Function >
value_t	find_if (Function func, value_t blank=value_t())
	Find an item in the list such that func( item ) == true.
Public Attributes
const unsigned int	MAX_THREADS
	The maximum number of threads.

Detailed Description

template<class T>
class RTT::internal::ListLockFree< T >

A simple lock-free list implementation to append or erase data of type T.

If T is a value type, no memory allocation is done during appending or erasing. The maximum number of threads which can access this object is defined by MAX_THREADS.

Parameters:

T	The value type to be stored in the list. If T is a type that does memory allocation or deallocation in copy-constructor or destructor, certain functions of this list will not be real-time. Example : ListLockFree is a list which holds values of type A.

Definition at line 85 of file ListLockFree.hpp.

Constructor & Destructor Documentation

template<class T>

RTT::internal::ListLockFree< T >::ListLockFree	(	unsigned int	lsize,
		unsigned int	threads = `ORONUM_OS_MAX_THREADS`
	)		`[inline]`

Create a lock-free list wich can store lsize elements.

Parameters:

lsize	the capacity of the list.
threads	the number of threads which may concurrently read or write this buffer. Defaults to ORONUM_OS_MAX_THREADS, but you may lower this number in case not all threads will read this buffer. A lower number will consume less memory. '

Definition at line 164 of file ListLockFree.hpp.

Member Function Documentation

template<class T>

bool RTT::internal::ListLockFree< T >::append ( value_t item ) [inline]

Append a single value to the list.

This function calls the copy-constructor of item and may call the destructor of item

Parameters:

item	the value to write

Returns:: false if the list is full.

Note:: This function is only real-time if the destructor or copy-constructor of of T is real-time.

Definition at line 344 of file ListLockFree.hpp.

template<class T>

size_t RTT::internal::ListLockFree< T >::append ( const std::vector< T > & items ) [inline]

Append a sequence of values to the list.

Parameters:

items the values to append.

Returns:: the number of values written (may be less than d.size())

Note:: This function is only real-time if the destructor and copy-constructor of of T is real-time.

Definition at line 401 of file ListLockFree.hpp.

template<class T>

template<class Function >

void RTT::internal::ListLockFree< T >::apply ( Function func ) [inline]

Apply a function to the elements of the whole list.

Parameters:

func	The function to apply.

Note:: Always real-time.

Definition at line 524 of file ListLockFree.hpp.

Referenced by RTT::internal::SignalBase::disconnect().

template<class T>

template<class Function >

void RTT::internal::ListLockFree< T >::apply_and_blank	(	Function	func,
		value_t	blank
	)		`[inline]`

Apply a function to the non-blanked elements of the list.

If during an apply_and_blank, the erase_and_blank function is called, that element will not be subject to func if not yet processed. You must not call this function concurrently from multiple threads.

Parameters:

func	The function to apply.
blank	The 'blank' item. Each item of this list will be compared to this item using operator==(), if it matches, it is considered blank, and func is not applied.

See also:: erase_and_blank

Deprecated:: This complicated function is nowhere used.

Note:: This function is only real-time if the destructor and copy-constructor of of T is real-time.

Definition at line 552 of file ListLockFree.hpp.

template<class T>

size_t RTT::internal::ListLockFree< T >::capacity ( ) const [inline]

Returns the maximum number of elements this list can hold.

Note:: Always real-time.

Definition at line 178 of file ListLockFree.hpp.

Referenced by RTT::internal::ListLockFree< connection_t >::grow(), and RTT::internal::ListLockFree< connection_t >::reserve().

template<class T>

void RTT::internal::ListLockFree< T >::clear ( ) [inline]

Clears all elements in the list.

Postcondition:: this->empty() == true

Note:: This function is not real-time if the destructor of of T is not real-time.

Definition at line 316 of file ListLockFree.hpp.

template<class T>

template<typename Pred >

bool RTT::internal::ListLockFree< T >::delete_if ( Pred pred ) [inline]

Erase a value from the list.

Parameters:

function each elements for which pred returns true are removed

Returns:: true if at least one element has been removed

Note:: This function is only real-time if the destructor and copy-constructor of of T is real-time.

Definition at line 480 of file ListLockFree.hpp.

template<class T>

bool RTT::internal::ListLockFree< T >::empty ( ) const [inline]

Returns true if this list is empty.

Note:: Always real-time.

Definition at line 206 of file ListLockFree.hpp.

Referenced by RTT::internal::SignalBase::destroy(), and RTT::corba::CorbaDispatcher::loop().

template<class T>

bool RTT::internal::ListLockFree< T >::erase ( value_t item ) [inline]

Erase a value from the list.

Parameters:

item	is to be erased from the list.

Returns:: true if found and erased.

Note:: This function is only real-time if the destructor and copy-constructor of of T is real-time.

Definition at line 438 of file ListLockFree.hpp.

Referenced by RTT::internal::SignalBase::destroy(), RTT::internal::ListLockFree< connection_t >::erase_and_blank(), and RTT::corba::CorbaDispatcher::loop().

template<class T>

bool RTT::internal::ListLockFree< T >::erase_and_blank	(	value_t	item,
		value_t	blank
	)		`[inline]`

Erase an element from the list and blank it if possible.

If during an apply_and_blank, the erase_and_blank function is called, that element will not be subject to func if not yet processed. You may call this function concurrently from multiple threads.

Warning:: It is possible that item is being processed within apply_and_blank. In that case the 'blank' operation has no effect.

Parameters:

item	The item to erase from the list.
blank	The 'blank' item to use to blank item from the list.

See also:: apply_and_blank

Deprecated:: This complicated function is nowhere used.

Note:: This function is only real-time if the destructor and copy-constructor of of T is real-time.

Definition at line 597 of file ListLockFree.hpp.

template<class T>

template<class Function >

value_t RTT::internal::ListLockFree< T >::find_if	(	Function	func,
		value_t	blank = `value_t()`
	)		`[inline]`

Find an item in the list such that func( item ) == true.

Parameters:

blank The value to return if not found.

Returns:: The item that matches func(item) or blank if none matches.

Note:: This function is only real-time if the copy-constructor of of T is real-time.

Definition at line 626 of file ListLockFree.hpp.

template<class T>

value_t RTT::internal::ListLockFree< T >::front ( ) const [inline]

Returns the first element of the list.

Note:: This function is only real-time if the copy-constructor of of T is real-time.

Definition at line 373 of file ListLockFree.hpp.

Referenced by RTT::internal::SignalBase::destroy(), and RTT::corba::CorbaDispatcher::loop().

template<class T>

void RTT::internal::ListLockFree< T >::grow ( size_t items = 1 ) [inline]

Grow the capacity to contain at least n additional items.

This method tries to avoid too much re-allocations, by growing a bit more than required every N invocations and growing nothing in between.

Parameters:

items The number of items to at least additionally reserve.

Note:: Almost never real-time.

Definition at line 224 of file ListLockFree.hpp.

template<class T>

void RTT::internal::ListLockFree< T >::reserve ( size_t lsize ) [inline]

Reserve a capacity for this list.

If you wish to invoke this method concurrently, guard it with a mutex. The other methods may be invoked concurrently with this method.

Parameters:

lsize the minimal number of items this list will be able to hold. Will not drop below the current capacity() and this method will do nothing if lsize < this->capacity(). @ Not real-time if lsize <= this->capacity().

Definition at line 252 of file ListLockFree.hpp.

Referenced by RTT::internal::ListLockFree< connection_t >::grow(), and RTT::internal::SignalBase::reserve().

template<class T>

void RTT::internal::ListLockFree< T >::shrink ( size_t items = 1 ) [inline]

Shrink the capacity with at most n items.

This method does not actually free memory, it just prevents a (number of) subsequent grow() invocations to allocate more memory.

Parameters:

items The number of items to at most remove from the capacity.

Note:: Always real-time.

Definition at line 238 of file ListLockFree.hpp.

template<class T>

size_t RTT::internal::ListLockFree< T >::size ( ) const [inline]

Returns the current number of elements in this list.

Note:: Always real-time.

Definition at line 192 of file ListLockFree.hpp.

Member Data Documentation

template<class T>

const unsigned int RTT::internal::ListLockFree< T >::MAX_THREADS

The maximum number of threads.

The number of threads which may concurrently access this buffer.

Definition at line 93 of file ListLockFree.hpp.

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

rtt/internal/ListLockFree.hpp

Public Types

Public Member Functions

Public Attributes

Detailed Description

template<class T> class RTT::internal::ListLockFree< T >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class T>
class RTT::internal::ListLockFree< T >