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Fields of a struct gets corrupted while in an ADT module

2017-06-17 18:21 Omer Guttman imported from Stackoverflow

i am try to make an ADT of a set that contains no more then 1 of the same variable, now when i try to send struct to it memebers of the sturct gets corrupted, im guessing there is a problem whith the line s->array = (element*)malloc(setSize*sizeof(element)) ; but im not really sure about it.

this is my main

int main()
{
    student st1;
    st1.age=10;
    st1.id=123;
    st1.name="Erik";
    student st2;
    st2.age=12;
    st1.id=181;
    st1.name="Loren";

    Set studset=setCreate(99,copystud,freestud,compstud);
    if(studset==NULL)
    {
        printf("error");
        exit(-1);
    }
    element* elm;
    Insert(studset,(element)&st1);
    Insert(studset,(element)&st1);
    Insert(studset,(element)&st2);
    printstudents(studset);
    return 1;
}

these are the function i send to setCreate

element copystud(element s)
{
    student* new_s;
    new_s=(student*)malloc(sizeof(student));
    ((student*)new_s)->name = (char*) malloc (strlen(((student*)s)->name) + 1);
    strcpy(((student*)new_s)->name,((student*)s)->name);
    new_s->age=((student*)s)->age;
    new_s->id=((student*)s)->id;
    return new_s;
}

void freestud(element s)
{
    free(((student*)s)->name);
    free(s);
    return;
}

Comparison compstud(element a, element b)
{
    {
        if((((student*)a)->id)<(((student*)b)->id))
            return Smaller;
        if((((student*)a)->id)>(((student*)b)->id))
            return Bigger;

        return Equal;
    }

this is my header:

#ifndef HEADER_H_INCLUDED
#define HEADER_H_INCLUDED
typedef enum {Fail, Success} Result ;
typedef enum {Smaller,Equal,Bigger} Comparison;

typedef void* element;
typedef struct Set* Set;

struct student
{
    char* name;
    int age;
    int id;
};
typedef struct student student;

typedef element (*cpy_func)(element);
typedef void (*free_func)(element);
typedef Comparison (*comp_func)(element,element);
Set setCreate(int setSize,cpy_func copy_elm,free_func free_elm,comp_func comp_elm);
Result Insert(Set s, element elm);
Result removeByIndex (Set mySet, element index); //remove the item at specified index from set
element getByIndex(Set s, element index); //get the value at the current Index, if invalid returns null.
Result pop(Set s);
void setDestroy(Set s);
//
void printstrset(Set s);
void printdoubleset(Set s);
void printstudents(Set s);
void printstud(element s);
#endif // HEADER_H_INCLUDED

and these are the create and insert functions

Set setCreate(int setSize,cpy_func copy_elm,free_func free_elm,comp_func comp_elm)
{
    Set s ;
    if ( setSize <=0 || free_elm==NULL || copy_elm == NULL || comp_elm ==NULL)
        return NULL ;
    s = malloc (sizeof(Set)) ;
    if (s == NULL)
        return NULL;
    s->array = (element*)malloc(setSize*sizeof(element)) ;
    if (s->array == NULL)
    {
        free(s) ;
        return NULL ;
    }
    s->top = 0;
    s->maxCapacity = setSize ;
    s->cp_elm = copy_elm ;
    s->fr_elm = free_elm;
    s->cmp_elm= comp_elm;
    return s ;

}

Result Insert(Set s, element elm)
{
    element tmp = NULL;
    int i;
    if ( s == NULL || elm == NULL || s->top >= s->maxCapacity )
    {
        return Fail;
    }
    for(i=0; i<s->top; i++)
    {
        if(s->cmp_elm(s->array[i],elm) == Equal)
            return Fail;
    }
    //printstud(elm);
    tmp = s->cp_elm(elm);
    if (tmp == NULL)
    {
        return Fail;
    }
    s->array[s->top] = tmp;
    s->top++ ;
    return Success;
}

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typedef unsigned short half;
extern uint16 float2half_impl(float value);
extern float half2float_impl(half value);

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float vflt = 3.14;
half vhlf;
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ab_printf("vflt = %f\n", vflt);
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            float xx;
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vflt = 3.140000
vhlf = 4248
bits = 40490000
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TRAP_error(t_NO: 0x80 )  PSR: 0x06401fc6, PC: 0x20001144 

== method 1 == 
vflt = 3.140000
vhlf = 4248
bits = 40490000
bits = 3.140625
received : vflt2 = 1078525952.000000

TRAP_error(t_NO: 0x80 )  PSR: 0x06401fc6, PC: 0x20001144 

== method 2 == 
vflt = 3.140000
vhlf = 4248
bits = 40490000
xx = 3.140625
received : vflt2 = 3.140625

TRAP_error(t_NO: 0x80 )  PSR: 0x06401fc6, PC: 0x20001144 

== method 3 == 
vflt = 3.140000
vhlf = 4248
bits = 40490000
bits = 3.140625
received : vflt2 = 3.140625

TRAP_error(t_NO: 0x80 )  PSR: 0x06401fc6, PC: 0x20001144 

== method 4 == 
vflt = 3.140000
vhlf = 4248
bits = 40490000
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    Some additional code I used for testing:

    C header file ===================

extern __declspec(dllexport) int Test(
    int(*fn1)(double a), int *address1,
    int(*fn2)(double a), int *address2,
    int(*fn3)(double a), int *address3
);

C file ===================

int Test(
    int(*fn1)(double a), int *address1,
    int(*fn2)(double a), int *address2,
    int(*fn3)(double a), int *address3
)
{
    *address1 = (int)fn1;
    *address2 = (int)fn2;
    *address3 = (int)fn3;
    int result = fn1(5538867.0);
    result += 9;
    return result;
}

C# file ===================

class Program
{
    static void Main(string[] args)
    {
        var sc1 = new SomeClass(5538867);
        var sc2 = new SomeClass(-999999);
        var callback1 = new CallbackType(sc1.TheCallback);
        var callback2 = new CallbackType(sc2.TheCallback);
        int called_address1 = 0, called_address2 = 0, called_address3 = 0;

        var result = Test(
            callback1, ref called_address1,
            callback2, ref called_address2,
            callback2, ref called_address3
            );
        // should be 9 or 8
        Console.WriteLine(result);
        Console.WriteLine(called_address1.ToString("x8"));
        Console.WriteLine(called_address2.ToString("x8"));
        Console.WriteLine(called_address3.ToString("x8"));

        result = Test(
            callback1, ref called_address1,
            callback2, ref called_address2,
            callback2, ref called_address3
            );

        Console.WriteLine(result);
        Console.WriteLine(called_address1.ToString("x8"));
        Console.WriteLine(called_address2.ToString("x8"));
        Console.WriteLine(called_address3.ToString("x8"));

        GC.KeepAlive(callback1);
        GC.KeepAlive(callback2);

        Console.ReadKey();
    }

    class SomeClass
    {
        public SomeClass(int i)
        {
            this.i = i;
            this.something_else = "sjdklfjksdf";
        }

        private readonly int i;
        private readonly string something_else;

        public int TheCallback(double something)
        {
            return (int)something - this.i + this.something_else.Length - 11;
        }
    }

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    delegate int CallbackType(double something);

    [DllImport("TestLib.dll", CallingConvention = CallingConvention.Cdecl)]
    extern static int Test(
        CallbackType callback1, ref int called_address1,
        CallbackType callback2, ref int called_address2,
        CallbackType callback3, ref int called_address3
        );
}
  • Function returning a pointer in C

    I solved the next challenge on hacker rank. I searched the internet and found something about function pointers (which I thought will help me to solve the challenge), but I could not solve it. I looked in the discussion on the site and I have found a way to solve the problem. It did not pass all the test cases on the site, but it worked for 5 out of 7. I somehow copied some code, ran it, made some change, ran it and so on until I got the following version. The thing is that I still do not understand how and why does it work and if this approach is the best used in this case. This is my code:

    #include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int* solve(int a0, int a1, int a2, int b0, int b1, int b2, int *result_size){
    static int ar[2] = {0, 0};
    *result_size = 2;
    ar[0] += a0 > b0;
    ar[0] += a1 > b2;
    ar[0] += a2 > b2;
    ar[1] += b0 > a0;
    ar[1] += b1 > a1;
    ar[1] += b2 > a2;
    return ar;
}

int main() {
    int a0; 
    int a1; 
    int a2; 
    scanf("%d %d %d", &a0, &a1, &a2);
    int b0; 
    int b1; 
    int b2; 
    scanf("%d %d %d", &b0, &b1, &b2);
    int result_size;
    int* result = solve(a0, a1, a2, b0, b1, b2, &result_size);
    for(int result_i = 0; result_i < result_size; result_i++) {
        if(result_i) {
            printf(" ");
        }
        printf("%d", result[result_i]);
    }
    puts("");


    return 0;
}

    This is the link to the problem: https://www.hackerrank.com/challenges/compare-the-triplets/problem.

    What I do not understand is that int *solve. How does that work? I read the question about function pointers on SO, but I didn't get it. And why must I use static array? If the array is not static my compiler (gcc) says that I can't return address of local variable. Also in main shouldn't int* solve have memory allocated?

    (Should I add the "text" of the problem here instead of adding the link?)

  • AIR Build Server Setup

    I am at the point where I am running into incredibly long build times for my project and more projects to come. I would like to make a build server but I have not had any experience with them aside from downloading files from them as an end user.

    My ideal setup is this: A GitHub where I can place my .fla file, classes and ANEs. The server sees this, compiles it, and allows me to test it remotely or hook into some debugger that lets me see stack traces and active variables at breakpoints and errors like Adobe Animate or Flash Builder.

    Now I see there are GitHub plugins for Jenkins. I see there are questions referring to how to set one up with Flex/AIR. I come here with a few issues.

    1. I am too far into my project to switch over from using Animate to something like Flash Develop or anything ADT related. The only thing I have found is how to take existing elements from my library in Animate and have them in a .swc for handling. However, this doesn't let me access existing elements in the Timeline and would rather not try to export/position/handle them in code (which is the only workaround that I see if this is not possible)
    2. I run ANEs that are dependent on Google Play services and other Android specific libraries. Thus, I haven't been able to use the standard mobile debug launcher for AIR. I see Jenkins has some specific abilities for Android. Is it possible to somehow use this to give me a proper window for testing? I am thinking that I would need to run their emulator after compiling everything but I am unsure if there is a more efficient method or if it would even work.

    I have never worked with Jenkins before or any other tools capable of automating tasks. Any step by step explanations is appreciated if you have the time.

  • Data structure desgin

    I have a question about designing an ADT for streamingvideo, and here is some of the thoughts:

    public interface StreamingVideo {

/**
 * The abstract methods below are declared as void methods with no
 * parameters. You need to expand each declaration to specify a return type
 * and parameters, as necessary. You also need to include a detailed comment
 * for each abstract method describing its effect, its return value, any
 * corner cases that the client may need to consider, any exceptions the
 * method may throw (including a description of the circumstances under
 * which this will happen), and so on. You should include enough details
 * that a client could use this data structure without ever being surprised
 * or not knowing what will happen, even though they haven't read the
 * implementation.
 */

/**
 * Adds a new video to the system. If the added video
 * that is within the size, then add the video can be successful and 
 * increase the size of per added video. If the size is full, there should 
 * be a private method that to double the size , then video can be 
 * successfully added. And if the added video already exists then it
 * will return false. If the position of a video that was accidentally
 * added to a wrong position (either position -1 or the postion outside
 * the size), then this method will throw an IndexOutOfBoundsExceptrion.
 *
 * @param theVideo video from which the user want to add
 * @throws IndexOutOfBoundsException if the video wants to be added outside
 * the size of bag
 * @throws NullPointerException if either the user or the video is null
 * @throws IllegalArgumentException if the video need to be added is null
 * @return true if the video is added correctly or return false is not 
 */
  public boolean addVideo(Video theVideo);

/**
 * Removes an existing video from the system. If there exists the video that
 * need to be removed, then the video will be removed and rest of videos would
 * not to be changed, and if there does not exist such a video,(do not exist or
 * nothing in the system) then this method will thourgh an IllegalArgumentException. 
 *
 * @param theVideo video from which the user want to remove
 * @throws IllegalArguementException if the user want to remove a non exist video
 * @return true is the removal is successful or false when it is not
 */
  public boolean removeVideo(Video theVideo);

/**
 * Adds an existing television episode to an existing television series.
 */
  void addToSeries();

/**
 * Removes a television episode from a television series.
 */
  void removeFromSeries();

/**
 * Sets a user's rating for a video, as either "like" or "dislike".
 */
  public boolean rateVideo(User theUser);

/**
 * Clears a user's rating on a video. If this user has rated this video and
 * the rating has not already been cleared, then the rating is cleared and
 * the state will appear as if the rating was never made. If there is no
 * such rating on record (either because this user has not rated this video,
 * or because the rating has already been cleared), then this method will
 * throw an IllegalArgumentException.
 *
 * @param theUser user whose rating should be cleared
 * @param theVideo video from which the user's rating should be cleared
 * @throws IllegalArgumentException if the user does not currently have a
 * rating on record for the video
 * @throws NullPointerException if either the user or the video is null
 */
  public void clearRating(User theUser, Video theVideo);

/**
 * Predicts whether a user will like or dislike a video (that they have not
 * yet rated). If there is no video exists then this method will throw an 
 * IllegalArgumentException. If this user has already liked or disliked the
 * video, then the video will return null. If there exists the video, then the
 * video will be predicted that if the user would like or not. 
 *
 * @param theUser user who will be predicted his or her preference towards video
 * @param theVideo video from which the user's preference that should be predicted
 * @throws IllegalargumnetException if the user does not currently have a rating on
 * record for the video
 * @throws NullPointerException is either the user or the video is null
 */
  public void predictRating(User theUser, Video theVideo);

/**
 * Suggests a video for a user that they are predicted to like. If there is any
 * video that user will like then return the video. If there is no such a like
 * video then return null. If there is no such prediction on record, then this 
 * method will throw an IllegalArguementException
 *
 * @param theUser user who should be suggest the video
 * @param theVideo video from which should be liked by user
 * @throws IllegalArgumentException if ther user does not currently have a
 * like or dislike video on the record
 * @throws NullPointerException if either the user or the video is null
 */
  public void suggestVideo(User theUser, Video theVideo);
}






 /**
 * A user of the streaming video service.
 */
public interface User {

}
/**
 * A TV episode, which can be used in the video streaming service.
 */
public interface TvEpisode extends Video {

}
/**
 * A film, which can be used in the video streaming service.
 */
public interface Film extends Video {

}
/**
 * A TV series in the video streaming service.
 */
public interface TvSeries {

}
/**
 * A video, which can be used in the video streaming service.
 */
public interface Video {

}

    To develop an ADT without implementing the data structure. I was required to write javadoc style comment for each method in streamingVideo.java. Basically, decide the modifiers, return types and parameters for these methods inStreamingVideo and describes what every method should including corner cases that will throw proper exceptions. The Only thing I know is that the set of users and television series are fixed, so no changes need for those collections. Really not sure how should I write those comments nor how to decide the return types and parameters in each methods, especially for the rateVideo and the predictRating methods.

  • ADT eclipse and SDK Folder

    to clarify, the problem is ADT doesnt install the sdk folder anymore, and also, doesnt support any of the sdk manager above their last version... you can try to look up a sdk manager version that suits ADT, but good look with that. The only way to use eclipse with android sdk is to copy another eclipse well configured with de sdk manager folder, from another pc... now my question is, they (google) dont think about this problem, i mean i work with this shit, not with android studio, i need eclipse... is there something i am missing?