src/KsPlugins.cpp - pub/scm/utils/trace-cmd/kernel-shark - Git at Google

 // SPDX-License-Identifier: LGPL-2.1

 /*
  * Copyright (C) 2019 VMware Inc, Yordan Karadzhov (VMware) <y.karadz@gmail.com>
  */

 /**
   *  @file    KsPlugins.cpp
   *  @brief   KernelShark C++ plugin declarations.
   */

 // C++
 #include<iostream>
 #include <limits>

 // KernelShark
 #include "KsPlugins.hpp"

 using namespace KsPlot;

 /**
  * A pair of Bin Id and a trace event data field in this bin, that needs to be
  * plotted.
  */
 typedef std::forward_list<std::pair<int, kshark_data_field_int64 *>> PlotPointList;

 //! @cond Doxygen_Suppress

 typedef std::function<void(int, kshark_data_container *, ssize_t,
 			   PlotPointList *)> pushFunc;

 typedef std::function<void(kshark_data_container *, ssize_t,
 			   PlotPointList *)> resolveFunc;

 //! @endcond

 static void pointPlot(KsCppArgV *argvCpp, IsApplicableFunc isApplicable,
 		      pluginShapeFunc makeShape, Color col, float size)
 {
 	int nBins = argvCpp->_graph->size();

 	for (int bin = 0; bin < nBins; ++bin)
 		if (isApplicable(nullptr, bin))
 			argvCpp->_shapes->push_front(makeShape({argvCpp->_graph},
 							       {bin}, {},
 							       col, size));
 }

 static std::pair<ssize_t, ssize_t>
 getRange(kshark_trace_histo *histo, kshark_data_container *data)
 {
 	ssize_t firstEntry, lastEntry;
 	std::pair<ssize_t, ssize_t> err(-1, -2);

 	firstEntry = kshark_find_entry_field_by_time(histo->min,
 						     data->data,
 						     0,
 						     data->size - 1);

 	if (firstEntry == BSEARCH_ALL_SMALLER)
 		return err;

 	if (firstEntry == BSEARCH_ALL_GREATER)
 		firstEntry = 0;

 	lastEntry = kshark_find_entry_field_by_time(histo->max,
 						    data->data,
 						    firstEntry,
 						    data->size - 1);

 	if (lastEntry == BSEARCH_ALL_GREATER)
 		return err;

 	if (lastEntry == BSEARCH_ALL_SMALLER)
 		lastEntry = data->size - 1;

 	return {firstEntry, lastEntry};
 }

 static PlotPointList
 getInBinEvents(kshark_trace_histo *histo,
 	       kshark_data_container *data,
 	       IsApplicableFunc isApplicable,
 	       pushFunc push,
 	       resolveFunc resolve)
 {
 	int bin, lastBin(-1);
 	PlotPointList buffer;

 	auto lamIsOverflow = [] (int bin) {
 		return (bin == UPPER_OVERFLOW_BIN ||
 			bin == LOWER_OVERFLOW_BIN) ? true : false;
 	};

 	auto range = getRange(histo, data);

 	for (ssize_t i = range.second; i >= range.first; --i) {
 		if (isApplicable(data, i)) {
 			bin = ksmodel_get_bin(histo, data->data[i]->entry);
 			if (lamIsOverflow(bin))
 				continue;

 			if (bin != lastBin) {
 				push(bin, data, i, &buffer);
 				lastBin = bin;
 			} else {
 				resolve(data, i, &buffer);
 			}
 		}
 	}

 	return buffer;
 }

 static PlotPointList
 getLastInBinEvents(kshark_trace_histo *histo, kshark_data_container *data,
 		   IsApplicableFunc isApplicable)
 {
 	pushFunc push = [] (int bin, kshark_data_container *data, ssize_t i,
 			    PlotPointList *list) {
 		list->push_front({bin, data->data[i]});
 	};

 	/*
 	 * Do not resolve. This means that only the very last (in time)
 	 * appearance of the event in the bin will be visualized.
 	 */
 	resolveFunc resolve = [] (kshark_data_container *data, ssize_t i,
 				  PlotPointList *list) {};

 	return getInBinEvents(histo, data, isApplicable, push, resolve);
 }

 static PlotPointList
 getMaxInBinEvents(kshark_trace_histo *histo, kshark_data_container *data,
 		 IsApplicableFunc isApplicable)
 {
 	pushFunc push = [] (int bin, kshark_data_container *data, ssize_t i,
 			    PlotPointList *list) {
 		list->push_front({bin, data->data[i]});
 	};

 	/* Overwrite if bigger. */
 	resolveFunc resolve = [] (kshark_data_container *data, ssize_t i,
 				  PlotPointList *list) {
 		if (list->front().second < data->data[i])
 			list->front().second = data->data[i];
 	};

 	return getInBinEvents(histo, data, isApplicable, push, resolve);
 }


 static PlotPointList
 getMinInBinEvents(kshark_trace_histo *histo, kshark_data_container *data,
 		 IsApplicableFunc isApplicable)
 {
 	pushFunc push = [] (int bin, kshark_data_container *data, ssize_t i,
 			    PlotPointList *list) {
 		list->push_front({bin, data->data[i]});
 	};

 	/* Overwrite if smaller. */
 	resolveFunc resolve = [] (kshark_data_container *data, ssize_t i,
 				  PlotPointList *list) {
 		if (list->front().second > data->data[i])
 			list->front().second = data->data[i];
 	};

 	return getInBinEvents(histo, data, isApplicable, push, resolve);
 }

 //! @cond Doxygen_Suppress

 #define PLUGIN_MIN_BOX_SIZE 4

 //! @endcond

 static void intervalPlot(kshark_trace_histo *histo,
 			 kshark_data_container *dataEvtA,
 			 IsApplicableFunc checkFieldA,
 			 kshark_data_container *dataEvtB,
 			 IsApplicableFunc checkFieldB,
 			 Graph *graph,
 			 PlotObjList *shapes,
 			 pluginShapeFunc makeShape,
 			 Color col,
 			 float size)
 {
 	kshark_data_field_int64 *dataA, *dataB;
 	PlotPointList bufferA, bufferB;
 	int binA, binB;
 	int64_t tsB;

 	auto lamGetBin = [] (auto it) {return (*it).first;};

 	auto lamGetTime = [] (auto it) {return (*it).second->entry->ts;};

 	auto lamGetData = [] (auto it) {return (*it).second;};

 	bufferA = getLastInBinEvents(histo,
 				     dataEvtA,
 				     checkFieldA);

 	bufferB = getLastInBinEvents(histo,
 				     dataEvtB,
 				     checkFieldB);

 	if (bufferA.empty() || bufferB.empty())
 		return;

 	auto itA = bufferA.cbegin();
 	auto itB = bufferB.cbegin();
 	while (itA != bufferA.cend() && itB != bufferB.cend()) {
 		binA = lamGetBin(itA);
 		dataA = lamGetData(itA);

 		/*
 		 * We will draw a shape between "Event A" and "Event B".
 		 * Because the shape starts with "Event A", we will skip all
 		 * "Event B" entries before the "Event A" entry.
 		 */
 		do {
 			dataB = lamGetData(itB);
 			tsB = lamGetTime(itB);
 			binB = lamGetBin(itB);
 			itB++;
 		} while (itB != bufferB.cend() && tsB < lamGetTime(itA));

 		/*
 		 * The shape ends with "Event B" and we already have this
 		 * event. However, we have to make sure that we will start the
 		 * shape from the very last "Event A" entry, which is rigth
 		 * before the "Event B" entry, which we already selected.
 		 */
 		while (itA != bufferA.cend() && lamGetTime(itA) < tsB) {
 			dataA = lamGetData(itA);
 			binA = lamGetBin(itA);
 			itA++;
 		}

 		if (binB - binA >= PLUGIN_MIN_BOX_SIZE)
 			shapes->push_front(makeShape({graph},
 						     {binA, binB},
 						     {dataA, dataB},
 						     col, size));
 	}
 }

 /**
  * @brief Generic plotting method for plugins. To be used for visualizing
  *	  a trace events.
  *
  * @param argvCpp: The C++ arguments of the drawing function of the plugin.
  * @param isApplicable: Check function used to select events from data
  *		       container A.
  * @param makeShape: Input location for a function pointer used to generate
  *		     the shape to be plotted.
  * @param col: The color of the shape to be plotted.
  * @param size: The size of the shape to be plotted.
  */
 void eventPlot(KsCppArgV *argvCpp,
 	       IsApplicableFunc isApplicable,
 	       pluginShapeFunc makeShape,
 	       Color col,
 	       float size)
 {
 	try {
 		pointPlot(argvCpp, isApplicable, makeShape, col, size);
 	} catch (const std::exception &exc) {
 		std::cerr << "Exception in eventPlot\n"
 			  << exc.what() << std::endl;
 	}
 }

 //! @cond Doxygen_Suppress

 enum class PlotWath {
 	Maximum,
 	Minimum,
 };

 //! @endcond

 static void eventFieldPlot(KsCppArgV *argvCpp,
 		    kshark_data_container *dataEvt,
 		    IsApplicableFunc checkField,
 		    PlotWath s,
 		    pluginShapeFunc makeShape,
 		    KsPlot::Color col,
 		    float size)
 {
 	PlotPointList buffer;

 	if (dataEvt->size == 0)
 		return;

 	if (!dataEvt->sorted)
 		kshark_data_container_sort(dataEvt);

 	try {
 		if (s == PlotWath::Maximum)
 			buffer = getMaxInBinEvents(argvCpp->_histo,
 						   dataEvt, checkField);

 		if  (s == PlotWath::Minimum)
 			buffer = getMinInBinEvents(argvCpp->_histo,
 						   dataEvt, checkField);

 		for (auto const &i: buffer) {
 			argvCpp->_shapes->push_front(makeShape({argvCpp->_graph},
 							       {i.first},
 							       {i.second},
 							       col, size));
 		}
 	} catch (const std::exception &exc) {
 		std::cerr << "Exception in eventFieldPlot\n"
 			  << exc.what() << std::endl;
 	}
 }

 /**
  * @brief Generic plotting method for plugins. To be used for visualizing
  *	  the value of a data fiels trace events.
  *
  * @param argvCpp: The C++ arguments of the drawing function of the plugin.
  * @param dataEvt: Input location for the container of the Evant's data.
  * @param checkField: Check function used to select events from data
  *		       container.
  * @param makeShape: Input location for a function pointer used to generate
  *		     the shape to be plotted.
  * @param col: The color of the shape to be plotted.
  * @param size: The size of the shape to be plotted.
  */
 void eventFieldPlotMax(KsCppArgV *argvCpp,
 		       kshark_data_container *dataEvt,
 		       IsApplicableFunc checkField,
 		       pluginShapeFunc makeShape,
 		       KsPlot::Color col,
 		       float size)
 {
 	eventFieldPlot(argvCpp, dataEvt, checkField,
 		       PlotWath::Maximum,
 		       makeShape, col, size);
 }

 /**
  * @brief Generic plotting method for plugins. To be used for visualizing
  *	  the value of a data fiels trace events.
  *
  * @param argvCpp: The C++ arguments of the drawing function of the plugin.
  * @param dataEvt: Input location for the container of the Evant's data.
  * @param checkField: check function used to select events from data
  *		       container.
  * @param makeShape: Input location for a function pointer used to generate
  *		     the shape to be plotted.
  * @param col: The color of the shape to be plotted.
  * @param size: The size of the shape to be plotted.
  */
 void eventFieldPlotMin(KsCppArgV *argvCpp,
 		       kshark_data_container *dataEvt,
 		       IsApplicableFunc checkField,
 		       pluginShapeFunc makeShape,
 		       KsPlot::Color col,
 		       float size)
 {
 	eventFieldPlot(argvCpp, dataEvt, checkField,
 		       PlotWath::Minimum,
 		       makeShape, col, size);
 }

 /**
  * @brief Generic plotting method for plugins. To be used for visualizing
  *	  the correlation between two trace events.
  *
  * @param argvCpp: The C++ arguments of the drawing function of the plugin.
  * @param dataEvtA: Input location for the container of the Evant A data.
  * @param checkFieldA: Check function used to select events from data
  *		       container A.
  * @param dataEvtB: Input location for the container of the Evant B data.
  * @param checkFieldB: Check function used to select events from data
  *		       container B.
  * @param makeShape: Input location for a function pointer used to generate
  *		     the shape to be plotted.
  * @param col: The color of the shape to be plotted.
  * @param size: The size of the shape to be plotted.
  */
 void eventFieldIntervalPlot(KsCppArgV *argvCpp,
 			    kshark_data_container *dataEvtA,
 			    IsApplicableFunc checkFieldA,
 			    kshark_data_container *dataEvtB,
 			    IsApplicableFunc checkFieldB,
 			    pluginShapeFunc makeShape,
 			    KsPlot::Color col,
 			    float size)
 {
 	if (dataEvtA->size == 0 || dataEvtB->size == 0)
 		return;

 	if (!dataEvtA->sorted)
 		kshark_data_container_sort(dataEvtA);

 	if (!dataEvtB->sorted)
 		kshark_data_container_sort(dataEvtB);

 	try {
 		intervalPlot(argvCpp->_histo,
 			     dataEvtA, checkFieldA,
 			     dataEvtB, checkFieldB,
 			     argvCpp->_graph,
 			     argvCpp->_shapes,
 			     makeShape, col, size);
 	} catch (const std::exception &exc) {
 		std::cerr << "Exception in eventFieldIntervalPlot\n"
 			  << exc.what() << std::endl;
 	}
 }

 /**
  * @brief Distance between the click and the shape. Used to decide if
  *	  the double click action must be executed.
  *
  * @param x: X coordinate of the click.
  * @param y: Y coordinate of the click.
  *
  * @returns If the click is inside the box, the distance is zero.
  *	    Otherwise infinity.
  */
 double LatencyBox::distance(int x, int y) const
 {
 	if (x < pointX(0) || x > pointX(2))
 		return std::numeric_limits<double>::max();

 	if (y < pointY(0) || y > pointY(1))
 		return std::numeric_limits<double>::max();

 	return 0;
 }
	// SPDX-License-Identifier: LGPL-2.1

	/*
	* Copyright (C) 2019 VMware Inc, Yordan Karadzhov (VMware) <y.karadz@gmail.com>
	*/

	/**
	* @file KsPlugins.cpp
	* @brief KernelShark C++ plugin declarations.
	*/

	// C++
	#include<iostream>
	#include <limits>

	// KernelShark
	#include "KsPlugins.hpp"

	using namespace KsPlot;

	/**
	* A pair of Bin Id and a trace event data field in this bin, that needs to be
	* plotted.
	*/
	typedef std::forward_list<std::pair<int, kshark_data_field_int64 *>> PlotPointList;

	//! @cond Doxygen_Suppress

	typedef std::function<void(int, kshark_data_container *, ssize_t,
	PlotPointList *)> pushFunc;

	typedef std::function<void(kshark_data_container *, ssize_t,
	PlotPointList *)> resolveFunc;

	//! @endcond

	static void pointPlot(KsCppArgV *argvCpp, IsApplicableFunc isApplicable,
	pluginShapeFunc makeShape, Color col, float size)
	{
	int nBins = argvCpp->_graph->size();

	for (int bin = 0; bin < nBins; ++bin)
	if (isApplicable(nullptr, bin))
	argvCpp->_shapes->push_front(makeShape({argvCpp->_graph},
	{bin}, {},
	col, size));
	}

	static std::pair<ssize_t, ssize_t>
	getRange(kshark_trace_histo histo, kshark_data_container data)
	{
	ssize_t firstEntry, lastEntry;
	std::pair<ssize_t, ssize_t> err(-1, -2);

	firstEntry = kshark_find_entry_field_by_time(histo->min,
	data->data,
	0,
	data->size - 1);

	if (firstEntry == BSEARCH_ALL_SMALLER)
	return err;

	if (firstEntry == BSEARCH_ALL_GREATER)
	firstEntry = 0;

	lastEntry = kshark_find_entry_field_by_time(histo->max,
	data->data,
	firstEntry,
	data->size - 1);

	if (lastEntry == BSEARCH_ALL_GREATER)
	return err;

	if (lastEntry == BSEARCH_ALL_SMALLER)
	lastEntry = data->size - 1;

	return {firstEntry, lastEntry};
	}

	static PlotPointList
	getInBinEvents(kshark_trace_histo *histo,
	kshark_data_container *data,
	IsApplicableFunc isApplicable,
	pushFunc push,
	resolveFunc resolve)
	{
	int bin, lastBin(-1);
	PlotPointList buffer;

	auto lamIsOverflow = [] (int bin) {
	return (bin == UPPER_OVERFLOW_BIN \|\|
	bin == LOWER_OVERFLOW_BIN) ? true : false;
	};

	auto range = getRange(histo, data);

	for (ssize_t i = range.second; i >= range.first; --i) {
	if (isApplicable(data, i)) {
	bin = ksmodel_get_bin(histo, data->data[i]->entry);
	if (lamIsOverflow(bin))
	continue;

	if (bin != lastBin) {
	push(bin, data, i, &buffer);
	lastBin = bin;
	} else {
	resolve(data, i, &buffer);
	}
	}
	}

	return buffer;
	}

	static PlotPointList
	getLastInBinEvents(kshark_trace_histo histo, kshark_data_container data,
	IsApplicableFunc isApplicable)
	{
	pushFunc push = [] (int bin, kshark_data_container *data, ssize_t i,
	PlotPointList *list) {
	list->push_front({bin, data->data[i]});
	};

	/*
	* Do not resolve. This means that only the very last (in time)
	* appearance of the event in the bin will be visualized.
	*/
	resolveFunc resolve = [] (kshark_data_container *data, ssize_t i,
	PlotPointList *list) {};

	return getInBinEvents(histo, data, isApplicable, push, resolve);
	}

	static PlotPointList
	getMaxInBinEvents(kshark_trace_histo histo, kshark_data_container data,
	IsApplicableFunc isApplicable)
	{
	pushFunc push = [] (int bin, kshark_data_container *data, ssize_t i,
	PlotPointList *list) {
	list->push_front({bin, data->data[i]});
	};

	/* Overwrite if bigger. */
	resolveFunc resolve = [] (kshark_data_container *data, ssize_t i,
	PlotPointList *list) {
	if (list->front().second < data->data[i])
	list->front().second = data->data[i];
	};

	return getInBinEvents(histo, data, isApplicable, push, resolve);
	}


	static PlotPointList
	getMinInBinEvents(kshark_trace_histo histo, kshark_data_container data,
	IsApplicableFunc isApplicable)
	{
	pushFunc push = [] (int bin, kshark_data_container *data, ssize_t i,
	PlotPointList *list) {
	list->push_front({bin, data->data[i]});
	};

	/* Overwrite if smaller. */
	resolveFunc resolve = [] (kshark_data_container *data, ssize_t i,
	PlotPointList *list) {
	if (list->front().second > data->data[i])
	list->front().second = data->data[i];
	};

	return getInBinEvents(histo, data, isApplicable, push, resolve);
	}

	//! @cond Doxygen_Suppress

	#define PLUGIN_MIN_BOX_SIZE 4

	//! @endcond

	static void intervalPlot(kshark_trace_histo *histo,
	kshark_data_container *dataEvtA,
	IsApplicableFunc checkFieldA,
	kshark_data_container *dataEvtB,
	IsApplicableFunc checkFieldB,
	Graph *graph,
	PlotObjList *shapes,
	pluginShapeFunc makeShape,
	Color col,
	float size)
	{
	kshark_data_field_int64 dataA, dataB;
	PlotPointList bufferA, bufferB;
	int binA, binB;
	int64_t tsB;

	auto lamGetBin = [] (auto it) {return (*it).first;};

	auto lamGetTime = [] (auto it) {return (*it).second->entry->ts;};

	auto lamGetData = [] (auto it) {return (*it).second;};

	bufferA = getLastInBinEvents(histo,
	dataEvtA,
	checkFieldA);

	bufferB = getLastInBinEvents(histo,
	dataEvtB,
	checkFieldB);

	if (bufferA.empty() \|\| bufferB.empty())
	return;

	auto itA = bufferA.cbegin();
	auto itB = bufferB.cbegin();
	while (itA != bufferA.cend() && itB != bufferB.cend()) {
	binA = lamGetBin(itA);
	dataA = lamGetData(itA);

	/*
	* We will draw a shape between "Event A" and "Event B".
	* Because the shape starts with "Event A", we will skip all
	* "Event B" entries before the "Event A" entry.
	*/
	do {
	dataB = lamGetData(itB);
	tsB = lamGetTime(itB);
	binB = lamGetBin(itB);
	itB++;
	} while (itB != bufferB.cend() && tsB < lamGetTime(itA));

	/*
	* The shape ends with "Event B" and we already have this
	* event. However, we have to make sure that we will start the
	* shape from the very last "Event A" entry, which is rigth
	* before the "Event B" entry, which we already selected.
	*/
	while (itA != bufferA.cend() && lamGetTime(itA) < tsB) {
	dataA = lamGetData(itA);
	binA = lamGetBin(itA);
	itA++;
	}

	if (binB - binA >= PLUGIN_MIN_BOX_SIZE)
	shapes->push_front(makeShape({graph},
	{binA, binB},
	{dataA, dataB},
	col, size));
	}
	}

	/**
	* @brief Generic plotting method for plugins. To be used for visualizing
	* a trace events.
	*
	* @param argvCpp: The C++ arguments of the drawing function of the plugin.
	* @param isApplicable: Check function used to select events from data
	* container A.
	* @param makeShape: Input location for a function pointer used to generate
	* the shape to be plotted.
	* @param col: The color of the shape to be plotted.
	* @param size: The size of the shape to be plotted.
	*/
	void eventPlot(KsCppArgV *argvCpp,
	IsApplicableFunc isApplicable,
	pluginShapeFunc makeShape,
	Color col,
	float size)
	{
	try {
	pointPlot(argvCpp, isApplicable, makeShape, col, size);
	} catch (const std::exception &exc) {
	std::cerr << "Exception in eventPlot\n"
	<< exc.what() << std::endl;
	}
	}

	//! @cond Doxygen_Suppress

	enum class PlotWath {
	Maximum,
	Minimum,
	};

	//! @endcond

	static void eventFieldPlot(KsCppArgV *argvCpp,
	kshark_data_container *dataEvt,
	IsApplicableFunc checkField,
	PlotWath s,
	pluginShapeFunc makeShape,
	KsPlot::Color col,
	float size)
	{
	PlotPointList buffer;

	if (dataEvt->size == 0)
	return;

	if (!dataEvt->sorted)
	kshark_data_container_sort(dataEvt);

	try {
	if (s == PlotWath::Maximum)
	buffer = getMaxInBinEvents(argvCpp->_histo,
	dataEvt, checkField);

	if (s == PlotWath::Minimum)
	buffer = getMinInBinEvents(argvCpp->_histo,
	dataEvt, checkField);

	for (auto const &i: buffer) {
	argvCpp->_shapes->push_front(makeShape({argvCpp->_graph},
	{i.first},
	{i.second},
	col, size));
	}
	} catch (const std::exception &exc) {
	std::cerr << "Exception in eventFieldPlot\n"
	<< exc.what() << std::endl;
	}
	}

	/**
	* @brief Generic plotting method for plugins. To be used for visualizing
	* the value of a data fiels trace events.
	*
	* @param argvCpp: The C++ arguments of the drawing function of the plugin.
	* @param dataEvt: Input location for the container of the Evant's data.
	* @param checkField: Check function used to select events from data
	* container.
	* @param makeShape: Input location for a function pointer used to generate
	* the shape to be plotted.
	* @param col: The color of the shape to be plotted.
	* @param size: The size of the shape to be plotted.
	*/
	void eventFieldPlotMax(KsCppArgV *argvCpp,
	kshark_data_container *dataEvt,
	IsApplicableFunc checkField,
	pluginShapeFunc makeShape,
	KsPlot::Color col,
	float size)
	{
	eventFieldPlot(argvCpp, dataEvt, checkField,
	PlotWath::Maximum,
	makeShape, col, size);
	}

	/**
	* @brief Generic plotting method for plugins. To be used for visualizing
	* the value of a data fiels trace events.
	*
	* @param argvCpp: The C++ arguments of the drawing function of the plugin.
	* @param dataEvt: Input location for the container of the Evant's data.
	* @param checkField: check function used to select events from data
	* container.
	* @param makeShape: Input location for a function pointer used to generate
	* the shape to be plotted.
	* @param col: The color of the shape to be plotted.
	* @param size: The size of the shape to be plotted.
	*/
	void eventFieldPlotMin(KsCppArgV *argvCpp,
	kshark_data_container *dataEvt,
	IsApplicableFunc checkField,
	pluginShapeFunc makeShape,
	KsPlot::Color col,
	float size)
	{
	eventFieldPlot(argvCpp, dataEvt, checkField,
	PlotWath::Minimum,
	makeShape, col, size);
	}

	/**
	* @brief Generic plotting method for plugins. To be used for visualizing
	* the correlation between two trace events.
	*
	* @param argvCpp: The C++ arguments of the drawing function of the plugin.
	* @param dataEvtA: Input location for the container of the Evant A data.
	* @param checkFieldA: Check function used to select events from data
	* container A.
	* @param dataEvtB: Input location for the container of the Evant B data.
	* @param checkFieldB: Check function used to select events from data
	* container B.
	* @param makeShape: Input location for a function pointer used to generate
	* the shape to be plotted.
	* @param col: The color of the shape to be plotted.
	* @param size: The size of the shape to be plotted.
	*/
	void eventFieldIntervalPlot(KsCppArgV *argvCpp,
	kshark_data_container *dataEvtA,
	IsApplicableFunc checkFieldA,
	kshark_data_container *dataEvtB,
	IsApplicableFunc checkFieldB,
	pluginShapeFunc makeShape,
	KsPlot::Color col,
	float size)
	{
	if (dataEvtA->size == 0 \|\| dataEvtB->size == 0)
	return;

	if (!dataEvtA->sorted)
	kshark_data_container_sort(dataEvtA);

	if (!dataEvtB->sorted)
	kshark_data_container_sort(dataEvtB);

	try {
	intervalPlot(argvCpp->_histo,
	dataEvtA, checkFieldA,
	dataEvtB, checkFieldB,
	argvCpp->_graph,
	argvCpp->_shapes,
	makeShape, col, size);
	} catch (const std::exception &exc) {
	std::cerr << "Exception in eventFieldIntervalPlot\n"
	<< exc.what() << std::endl;
	}
	}

	/**
	* @brief Distance between the click and the shape. Used to decide if
	* the double click action must be executed.
	*
	* @param x: X coordinate of the click.
	* @param y: Y coordinate of the click.
	*
	* @returns If the click is inside the box, the distance is zero.
	* Otherwise infinity.
	*/
	double LatencyBox::distance(int x, int y) const
	{
	if (x < pointX(0) \|\| x > pointX(2))
	return std::numeric_limits<double>::max();

	if (y < pointY(0) \|\| y > pointY(1))
	return std::numeric_limits<double>::max();

	return 0;
	}