Exception in code C - C / C++ / MFC Discussion Boards

Have a gander here[^]. Pay particular attention to #11.

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Hi Guys!,

I'm developing a simple tracking game using two haptic devices as controllers.
Haptic rendering is executed in a high priority thread.
During the experiment, force experienced will depends on the position of each player, it's calculated as follows:

C++

coupledForce1 = cMul(Kp, (newPosition2-newPosition1))-(cMul(Kb, (linearVelocity1)));

C++

coupledForce2 = cMul(Kp, (newPosition1-newPosition2))-(cMul(Kb, (linearVelocity2)));

I have 100 trials of tracking tasks and I have to calculate the average interaction force during each trial. How it can be done? my issue is: this manipulation have to be done in a thread with execution rate of around 8KHz

Thanks!

Please don't repost questions. You have already asked this here Calculating average in a thread[^].

my bad!, just removed

Thank you. The problem with duplicate questions is that you may get answers from different users to both questions.

A clarification question to yours: Do you need code to calculate the average?
If so, you may search for "moving average" or "rolling average".

Thank you!. I have already seen some implementation of moving average. But I'm not sure about how to implement for my application. Since it's in a thread which is executing at 8Khz, I'm wondering how to store forces trial by trial and to take avareage?

See this Stackoverflow thread: http://stackoverflow.com/questions/10990618/calculate-rolling-moving-average-in-c-or-c[^].

The fastest solution would be a ring buffer and a total sum variable (untested):

C++

int items = 0;
int ndx = 0;
int buffer[buffer_Size];
// May need floating point here when max. value * buffer_size >= INT_MAX
int sum = 0;

int get_av(int val)
{
    if (items >= buffer_size)
        sum -= buffer[ndx];
    else
        ++items;
    sum += val;
    buffer[ndx] = val;
    if (++ndx >= buffer_size)
        ndx = 0;
    return sum / items;
}

This should be fast enough for your requirements

Hello,
This is my code.
When i compile and execute it i have the following error:

VB

1 [main] test 5952 exception::handle: Exception: STATUS_ACCESS_VIOLATION
    722 [main] test 5952 open_stackdumpfile: Dumping stack trace to test.exe.sta
ckdump

C++

#include <stdio.h>
#include<stdlib.h>
#include<string.h>

typedef struct Date{
int J ;
int M ;
int A ;
} Date;

typedef struct Operation{
char Obj[30];
float Mnt ;
Date Date_Tr ;
int Type_Tr ;
int Etat ;
} Operation;

typedef struct Cellule{
Operation Info ;
struct Cellule *succ ;
} Cellule ;

typedef Cellule * Liste ;

int EgaliteDates(Date d1 , Date d2)
{
    if ((d1.J==d2.J) && (d1.M==d2.M) && (d1.A==d2.A))
    return 0;
    else
    {
        if ((d1.A>d2.A) || ((d1.A==d2.A) && (d1.M>d2.M)) || (((d1.A==d2.A) && (d1.M==d2.A) && (d1.J==d2.J))))
            return 1;
        else
            return 2;
             }
}
Liste InsertionOperation(Liste L , Operation op)
{

		Liste temp;
		Liste pred;
		Liste element;
 		element = malloc(sizeof(Liste));
    	element->Info = op;
    	element->succ = NULL;

    	if(L == NULL)
    	{
			L=element;
    	}
    	else
    	{
        	if (EgaliteDates(L->Info.Date_Tr,op.Date_Tr)==2)
        	{
        		element->succ= L;
        		L=element;
			}
			else
			{
			temp=L;
			pred=L;
        	while((temp->succ != NULL) && (EgaliteDates(temp->Info.Date_Tr,op.Date_Tr)<2))
        	{
        		pred=temp;
            	temp = temp->succ;
        	}
        	element->succ=temp->succ;
        	pred->succ = element;

        	}
    	}
    	return L;
}

void afficherListe(Liste L)
{
    Cellule *tmp = L;
    int i=0;
    while(tmp != NULL)
    {
        i++;
        printf("Objet %d : %s, montant: %f, date : %d %d %d, type: %s\n", i,tmp->Info.Obj,tmp->Info.Mnt,tmp->Info.Date_Tr.J,tmp->Info.Date_Tr.M,tmp->Info.Date_Tr.M,tmp->Info.Type_Tr,tmp->Info.Etat);
        tmp = tmp->succ;
    }
}

void RechercheDate(Liste L, Date minDate , Date maxDate )
{
Cellule *tmp = L;
printf("liste des objets entre %d/%d/%d et %d/%d/%d: \n",minDate.J,minDate.M,minDate.A,maxDate.J,maxDate.M,maxDate.A);
    while(tmp != NULL)
    {
        if ((EgaliteDates(tmp->Info.Date_Tr , maxDate)<2) && (EgaliteDates(minDate,tmp->Info.Date_Tr)<2))
        printf("Objet : %s, montant: %f, date : %d %d %d, type: %s\n",tmp->Info.Obj,tmp->Info.Mnt,tmp->Info.Date_Tr.J,tmp->Info.Date_Tr.M,tmp->Info.Date_Tr.M,tmp->Info.Type_Tr,tmp->Info.Etat);
        tmp = tmp->succ;
    }
}

void ReglerOp(Liste en_cours , Liste reglee, char obj_op[])
{
Cellule *tmp = en_cours;
Cellule *pred = en_cours;
    while((tmp != NULL) && (strcmp(en_cours->Info.Obj,obj_op) != 0))
    {
        pred=tmp;
        tmp = tmp->succ;
    }
    if (tmp==en_cours)
    en_cours=en_cours->succ;
    else
        pred->succ=tmp->succ;
    tmp->Info.Etat=1;
    InsertionOperation(reglee , tmp->Info);
    free(tmp);
}

main()
{
    Date d1 = {2,10,2012};
    Date d2 = {2,12,2012};
    Date d3 = {12,10,2012};
    Date d4 = {10,12,2011};
    Date d5 = {2,10,2012};
    Date d6 = {2,10,2012};
    printf("Comapraison %d/%d/%d et %d/%d/%d donne %d\n",d1.J,d1.M,d1.A,d2.J,d2.M,d2.A,EgaliteDates(d1 , d2));
    printf("Comapraison %d/%d/%d et %d/%d/%d donne %d\n",d3.J,d3.M,d3.A,d4.J,d4.M,d4.A,EgaliteDates(d3 , d4));
    printf("Comapraison %d/%d/%d et %d/%d/%d donne %d\n",d5.J,d5.M,d5.A,d6.J,d6.M,d6.A,EgaliteDates(d5 , d6));
    Liste L;
    Operation op1= {"objet1",23.5,{30,3,2012},1,1};
    Operation op2= {"objet2",24.5,{2,2,2012},1,1};
    Operation op3= {"objet3",25.5,{12,4,2013},1,1};
    Operation op4= {"objet4",26.5,{15,10,2014},1,1};
    Operation op5= {"objet5",27.5,{9,8,2014},1,1};
    Operation op6= {"objet6",28.5,{10,11,2015},1,1};
    L=InsertionOperation(L , op1);
    L=InsertionOperation(L , op2);
    L=InsertionOperation(L , op3);
    L=InsertionOperation(L , op4);
    L=InsertionOperation(L , op5);
    L=InsertionOperation(L , op6);
    printf("\n liste réglée \n");
    afficherListe(L);
    Date dmin = {1,1,2014};
    Date dmax = {30,12,2015};
    RechercheDate(L,dmin,dmax);
    Liste en_cours;
    Operation ec1= {"ec1",20.5,{7,2,2012},2,0};
    Operation ec2= {"ec2",33.5,{30,3,2010},2,0};
    Operation ec3= {"ec3",43.5,{9,12,2014},2,0};
    Operation ec4= {"ec4",53.5,{10,10,2013},2,0};
    L=InsertionOperation(en_cours , ec1);
    L=InsertionOperation(en_cours, ec2);
    L=InsertionOperation(en_cours , ec3);
    L=InsertionOperation(en_cours , ec4);
    printf("\n liste en cours \n");
    afficherListe(en_cours);
    ReglerOp(en_cours , L, "ec4");
    ReglerOp(en_cours , L, "ec1");
    printf("\n liste réglée \n");
    afficherListe(L);
    printf("\n liste en cours \n");
    afficherListe(en_cours);

}

So what is wrong with my code and how can i fix it?
Thanks.

You will need to use your debugger to find where the exception occurs, and update the question with that information.

in line 54 i have (Liste InsertionOperation(Liste L , Operation op))
Program received signal SIGSEGV

modified 15-May-15 5:13am.

Where exactly is line 54, and what are the values of the variables that are being referenced?

Single step through the code using the debugger.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

And test one function at a time for each case. Put breakpoint in each branch and ensure you test each one or better yet, make unit test for each one.

Philippe Mori

C++

element = malloc(sizeof(Liste));

should be

C++

element = malloc(sizeof(Cellule));

You are allocating 4 bytes (on 32 bit platform) instead of approximatively 60 bytes.

The following line is also incorrect:

C++

en_cours=en_cours->succ;

Since you are Inside a function, the pointer is passed by value and a change inside the function has no effect outside of it. You need to have a pointer to a pointer to be able to update the pointer at the caller location.

You don't initialized new list to NULL so first insertion might fails because the pointer is garbage.

Philippe Mori

Hi ,

I am using a dialog box and there are some text in the dialog box and want to copy that text from the dialog box .

Just want to know how to do it.

See https://msdn.microsoft.com/en-us/library/windows/desktop/ms645489%28v=vs.85%29.aspx[^]. It really makes life easier if you read the documentation for the controls you use.

Thakur JAI SINGH wrote:
I am using a dialog box...

So the dialog box is created and displayed via your code, or are you wanting to access a dialog box from some other app?

Thakur JAI SINGH wrote:
...and there are some text in the dialog box...

What type of control specifically?

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

@DavidCroww

Dialog box is displayed via my code.

And there are lots of text on my dialog box and I have to copy the whole text available there on the dialog box.

So if the dialog box belongs to your app, and you are populating the controls on it, then don't you already have access to the text?

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

Hi
I am trying to run a Legacy MFC application in Debug buil(earlier it was always built in Release Build (with debug info)). While loading resource using LoadToolBar() funtion ::FindResource fails while it succeeds in the Relase build. Can any body help me with this.

Thanks and Regards

Without seeing the code that is in error it is impossible to guess what the problem may be.

Probably uninitialized variables or invalid/NULL pointers.

Have a look at

Surviving the Release Version[^]

I'd rather be phishing!

This is the opposite problem of what the OP stated.
OP stated: works in release, fails in debug
things you're referring to: work in debug, fail in release

My mistake.

(the linked article can still offer hints and tips).

I'd rather be phishing!

When it comes to resources, it could be any number of things... if you make the call within a dll and not the main application, you have to make sure to have the resources of the main application loaded and not the dll's resources.

In any case, hard to tell without more info and some code.