lbann::thread_safe_queue< T > Class Template Reference

A queue that is safe for multiple threads to push to or pull from "simultaneously". More...

#include <thread_safe_queue.hpp>

Collaboration diagram for lbann::thread_safe_queue< T >:

Classes
class	_Node
	A data value in the thread-safe FIFO queue. More...

Public Member Functions
	thread_safe_queue ()
	Default constructor; creates an empty queue. More...
void	push (T value)
	Adds a value to back of the queue. More...
void	wake_all (bool stop=false)
void	set_stop_threads (bool flag)
	Allow the thread pool to set / reset the flags. More...
std::unique_ptr< T >	try_pop ()
	Try to remove the first value from the queue. More...
std::unique_ptr< T >	wait_and_pop ()
	Wait for data and then return it. More...
bool	empty () const
	Check if queue is empty. More...

Private Member Functions
_Node *	do_get_tail_ () const
	Get the tail pointer. More...

Private Attributes
std::mutex	head_mtx_
	The mutex protecting the head of the list. More...
std::mutex	tail_mtx_
	The mutex protecting the tail of the list. More...
std::unique_ptr< _Node >	head_
	The first node in the list. More...
_Node *	tail_
	The last node in the list. More...
std::condition_variable	data_available_
	Condition variable tripped when data added. More...
bool	m_stop_threads

Detailed Description

template<typename T>
class lbann::thread_safe_queue< T >

A queue that is safe for multiple threads to push to or pull from "simultaneously".

This version uses locks.

This is essentially a fancy linked-list implementation that enables finer-grained locks than simply wrapping an std::queue. The trade-off is two locks, one for the front and one for the back of the list.

Template Parameters

T	A move- or copy-constructible type

Definition at line 51 of file thread_safe_queue.hpp.

Constructor & Destructor Documentation

thread_safe_queue()

template<typename T>

lbann::thread_safe_queue< T >::thread_safe_queue ( )

inline

Default constructor; creates an empty queue.

Definition at line 65 of file thread_safe_queue.hpp.

Member Function Documentation

do_get_tail_()

template<typename T>

_Node* lbann::thread_safe_queue< T >::do_get_tail_ ( ) const

inlineprivate

Get the tail pointer.

Definition at line 147 of file thread_safe_queue.hpp.

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empty()

template<typename T>

bool lbann::thread_safe_queue< T >::empty ( ) const

inline

Check if queue is empty.

Definition at line 139 of file thread_safe_queue.hpp.

push()

template<typename T>

void lbann::thread_safe_queue< T >::push ( T  value )

inline

Adds a value to back of the queue.

Definition at line 70 of file thread_safe_queue.hpp.

set_stop_threads()

template<typename T>

void lbann::thread_safe_queue< T >::set_stop_threads ( bool  flag )

inline

Allow the thread pool to set / reset the flags.

Definition at line 98 of file thread_safe_queue.hpp.

try_pop()

template<typename T>

std::unique_ptr<T> lbann::thread_safe_queue< T >::try_pop ( )

inline

Try to remove the first value from the queue.

Returns

nullptr if empty(); otherwise return a value

Definition at line 104 of file thread_safe_queue.hpp.

wait_and_pop()

template<typename T>

std::unique_ptr<T> lbann::thread_safe_queue< T >::wait_and_pop ( )

inline

Wait for data and then return it.

Definition at line 118 of file thread_safe_queue.hpp.

wake_all()

template<typename T>

void lbann::thread_safe_queue< T >::wake_all ( bool  stop = false )

inline

Definition at line 87 of file thread_safe_queue.hpp.

Member Data Documentation

data_available_

template<typename T>

std::condition_variable lbann::thread_safe_queue< T >::data_available_

private

Condition variable tripped when data added.

Definition at line 167 of file thread_safe_queue.hpp.

head_

template<typename T>

std::unique_ptr<_Node> lbann::thread_safe_queue< T >::head_

private

The first node in the list.

Definition at line 161 of file thread_safe_queue.hpp.

head_mtx_

template<typename T>

std::mutex lbann::thread_safe_queue< T >::head_mtx_

mutableprivate

The mutex protecting the head of the list.

Definition at line 155 of file thread_safe_queue.hpp.

m_stop_threads

template<typename T>

bool lbann::thread_safe_queue< T >::m_stop_threads

private

Definition at line 169 of file thread_safe_queue.hpp.

tail_

template<typename T>

_Node* lbann::thread_safe_queue< T >::tail_

private

The last node in the list.

Definition at line 164 of file thread_safe_queue.hpp.

tail_mtx_

template<typename T>

std::mutex lbann::thread_safe_queue< T >::tail_mtx_

mutableprivate

The mutex protecting the tail of the list.

Definition at line 158 of file thread_safe_queue.hpp.

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

• thread_safe_queue.hpp