Wefts::Stack< T > Class Template Reference
[Advanced Syncronization constructs]

#include <wefts_stack.h>

Collaboration diagram for Wefts::Stack< T >:

[legend]List of all members.

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Detailed Description

template<class T>
class Wefts::Stack< T >

Waitable template LIFO structure.

A Stack, in Wefts++ context, is an Last-in first-out synchronization object, where one or more thread are posting data, and one or more thread are waiting for data to become available to process it. The last data posted will be retreived by the first thread coming in search for data.

Stack is a fast and clean way to pass arbitrary data in a 1:1 scheme from a producer to a consumer (or from a master to a worker) even if there are more producer/masters and consumer/workers running at the same time.

Stacks have not any scheduling poicies; the first thread that is able to wake up will take the first element available.

By default, stacks have infinite size. You can set a maximum length and in that case, a thread willing to post a new data will be blocked until the stack becomes free again, or will immediately return an error (depending on user preferences).

Note:

It is illegal to destroy a Stack while there are threads waiting.

Public Member Functions
	Stack (unsigned int maxLen=0)
	Creates a stack.
bool	push (T elem, const bool wait=false)
	Pushes data in the stack.
bool	pop (T &elem, const bool wait=true)
	Pops data from the stack.
Protected Attributes
FastCondition	m_cond
unsigned long	m_maxLen
std::list< T >	m_list
Private Member Functions
void	p_waitForFree ()
void	p_waitForFull ()

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Constructor & Destructor Documentation

template<class T> Wefts::Stack< T >::Stack (  unsigned int  maxLen = 0  )  [inline]

Creates a stack. If the parameter is zero, the stack will have infinite length; if it is not zero, push() method will block or return immediately false when the maximum length is reached. Parameters: maxLen  maximum length of the stack or 0.

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Member Function Documentation

template<class T> void Wefts::Stack< T >::p_waitForFree (   )  [inline, private]

template<class T> void Wefts::Stack< T >::p_waitForFull (   )  [inline, private]

template<class T> bool Wefts::Stack< T >::pop (  T &  elem, const bool  wait = true )  [inline]

Pops data from the stack. Stacks are LIFO, that is Last in, First out. The last element you push will be served first to the waiters. Note that the default behavior of pop() is to wait until there is some data to be placed in the parameter, but you can also set wait parameter to false to have an immediate return in case of the stack being empty in that moment. A blocking pop() is a cancellation point; be sure you have a proper cleanup scheme set up before to call a blocking pop. Parameters: elem  an element that will receive the popped value. wait  if false, returns immediately if the stack is empty. Returns: true if operation suceeded, false if stack is full and wait parameter is false

template<class T> bool Wefts::Stack< T >::push (  T  elem, const bool  wait = false )  [inline]

Pushes data in the stack. Stacks are LIFO, that is Last in, First out. The last element you push will be served first to the waiters. Parameters: elem  the data to be pushed in the Stack wait  true to wait in case the stack is full, false to return immediately Returns: true if operation suceeded, false if stack is full and wait parameter is false

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Member Data Documentation

template<class T> FastCondition Wefts::Stack< T >::m_cond [protected]

template<class T> std::list<T> Wefts::Stack< T >::m_list [protected]

template<class T> unsigned long Wefts::Stack< T >::m_maxLen [protected]

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

• wefts_stack.h

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