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/******************************************************************************
* Copyright (c) 2013-2014, Texas Instruments Incorporated - http://www.ti.com/
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Texas Instruments Incorporated nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*****************************************************************************/
/**************************************************************************//**
*
* @file u_concurrent_map.h
* @brief TI implementation class that implements a thread safe map.
*
******************************************************************************/
#ifndef _U_CONCURRENT_MAP_H_
#define _U_CONCURRENT_MAP_H_
#include <iostream>
#include <map>
#include "u_lockable.h"
/**************************************************************************//**
* @class concurrent_map
*
* @brief A thread safe map implementation
*
* @details This implementation wraps a standard stl map with some locking
* capability to make the member functions mutually exclusive
* regions. In derives from the class Lockable which defines a type
* Lock that can be used to define a type in a scope. The result will
* be that the remainder of the scope (or until unlock is called) is a
* mutex.
*
******************************************************************************/
template<typename I, typename T>
class concurrent_map : public Lockable
{
public:
concurrent_map() : M(), num_elements(0) {}
~concurrent_map() {}
/**********************************************************************//**
* @brief Place an object in the map.
* @param data is the item to psh on the map
***************************************************************************/
void push(I index, T const data)
{
Lock lock(this);
M[index] = data;
num_elements++;
}
/**********************************************************************//**
* @brief How many elements are in the map.
* @returns The number of elements in the map.
***************************************************************************/
int size() const
{
Lock lock(this);
return num_elements;
}
/**********************************************************************//**
* @brief Determine if the map is empty.
* @returns true if the map is empty, otherwise false.
***************************************************************************/
bool empty() const
{
Lock lock(this);
return (num_elements == 0);
}
/**********************************************************************//**
* @brief Attempt to pop an item off the map.
* @param popped_value is an output parameter that contains the object popped
* if the map is successfully popped.
* @returns true if a value is popped, otherwise false
***************************************************************************/
bool try_pop(I idx, T& popped_value)
{
Lock lock(this);
if (num_elements == 0) return false;
typename std::map<I,T>::iterator it = M.find(idx);
if (it != M.end())
{
popped_value = it->second;
M.erase (it);
num_elements--;
return true;
}
return false;
}
void dump()
{
for (typename std::map<I,T>::const_iterator i = M.begin(); i != M.end(); ++i)
std::cout << i->first << " ==> " << i->second << std::endl;
}
/*-------------------------------------------------------------------------
* The class's data
*------------------------------------------------------------------------*/
private:
std::map<I,T> M; //!< standard stl map
int num_elements;
/*-------------------------------------------------------------------------
* Prevent copy construction and assignment
*------------------------------------------------------------------------*/
private:
concurrent_map(const concurrent_map&);
concurrent_map& operator=(const concurrent_map&);
};
#endif //_U_CONCURRENT_MAP_H_
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