Fields of a struct gets corrupted while in an ADT module

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• recoding malloc with mmap strange segfault

  I am actually recoding malloc using mmap function, the problem is i am getting a segfault largely before the end of the allocated memory. I can't find where is the problem in my code.

  The init() function is called at the first call of my malloc, then the search_for_free_space() is called instead.

  I am allocating 409600 bytes with mmap (100 pages), but the code is getting segfault after using only 26000 bytes without reason.

  When i'm multiplying the size of my mmap by 10 the segfault appears later, but i verified that the size given to my mmap is well 409600 and not less.

  The segfault should appear only after using all memory as i have not done the next part of the code but it appear too early.

  code (you can run it):

  #include <sys/mman.h>
  #include <unistd.h>
  #include <stdio.h>
  
  # define PAGE_SIZE getpagesize()
  
  typedef struct  s_zone
  {
      int             size;
      int             free;
      struct s_zone   *next;
  }               t_zone;
  
  typedef struct  s_e
  {
      t_zone  *tiny;
  }               t_e;
  
  static t_e  g_e;
  
  void    *allocate(size_t size)
  {
      printf("%s", "allocated memory: ");
      printf("%d\n", (int)size);
      return (mmap(NULL, size, PROT_READ | PROT_WRITE,
          MAP_PRIVATE | MAP_ANON, -1, 0));
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  void    *init_tiny(size_t size)
  {
      g_e.tiny = (t_zone*)allocate((PAGE_SIZE * 100));
      g_e.tiny->size = size;
      g_e.tiny->free = 0;
      g_e.tiny->next = g_e.tiny + sizeof(t_zone) + size;
      g_e.tiny->next->size = PAGE_SIZE;
      g_e.tiny->next->free = 1;
      g_e.tiny->next->next = NULL;
      return (g_e.tiny + sizeof(t_zone));
  }
  
  void    *search_for_free_space(size_t size, t_zone *zone)
  {
      size_t  i;
  
      while (zone->free != 1 || zone->size < size)
          zone = zone->next;
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      zone->next = zone + sizeof(t_zone) + size;
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  void    *malloc2(size_t size)
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      if (g_e.tiny == NULL)
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  int     main(void)
  {
      int     i;
  
      i = 0;
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          malloc2(2000);
          i++;
          printf("%s", "used memory: ");
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      }
      return (0);
  }
  
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  A txt file is read in binary mode and stored in a buffer (I'm writing a HEX editor so it's important that files are read in binary mode):

  

  The following code removes any new lines and prints the txt to the console:

  #include <stdio.h>
  #include <stdlib.h>
  #include <windows.h>
  
  FILE *fileptr;
  unsigned char *buffer;
  long filelen;
  
  int main(int argc, char* argv[]){
  
      fileptr = fopen(argv[1], "rb");
      fseek(fileptr, 0, SEEK_END);
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      rewind(fileptr);
  
      buffer = (char *)malloc((filelen+1)*sizeof(char));
      fread(buffer, filelen, 1, fileptr);
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      for (int i = 0; i < filelen; i++){
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          }else{
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  This is the intended output, what we want:

  This is the actual output, not what we want:

  When a sleep(); command is added this is what seems to be occurring(Second line highlighted in green for clarity):

  

  The first line prints fine, then the new line is reached, this is where the error is occurring the new line seems to be removed, only the cursor jumps back to the beginning of the line, this behavior is not expected nor is it wanted.
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  I tried using LIBS= [ 'abc' ] but getting a linker error, cannot find the library however if i rename libabc.so.10 to libabc.so, it works fine and I am able to get the executable but when i run the executable it, get error as below

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  package main
  
  import "fmt"
  
  type Golang struct {
      SessionCounter int
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  I'm trying to use the pointer toRender to store the address of the closest triangle in my raycasting program. My first print statement indicates that it's working: printing out 1, which is the correct value for toRender->color.x for the closest triangle. However, once the program gets to the next print statement, it prints 0 for toRender->color.x. This is the color value for another triangle, but importantly, that triangle was not intersected for this pixel (this iteration of an outer loop), and the first cout didn't print 0 for this pixel. When I debugged the code, the address assigned to toRender remained the same, despite toRender->color.x giving different values at the two print statements. I don't know how to account for this.

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  I am integrating API and parsing its response in a structure. For this I need to declare field name as type as API's response contains key named type. But when I declare type in field name it gives me error:

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  I have structs in a C library that are like this. The function pointers in DataFn point to static functions.

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  struct Data {
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  typedef struct {
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      ....
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  extern DataFn const DATAFUNC
  

  Using objdump, the table only contains DATAFUNC and a few other things from gcc.

  This is fine in C where calling fn1 would go like DATAFUNC.fn1(..., ...), but how would something like this be wrapped around so fn1 can be called in python w/ ctypes?

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  results in <_FuncPtr object at 0x6ffffcd7430>

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• How to create an add func to an ordered set ADT?

  I'm trying to implement an ordered set ADT, but I'm having some trouble with the add function, as my tests show that I'm not adding anything. Does anyone have any suggestions as to why this happens? Here is the full code

  struct set_iter
  {
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  };
  
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  {
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    int size;
    cmpfunc_t cmpfunc;
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    {
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• QuickSort - trouble implementing quick sort in my SET ADT

  I am trying to implement QuickSort on my set ADT and am running into an issue where I cannot figure out how to implement the quickSort function in my main

  I ran gcc -w after my seg. fault and am getting the following error:

  table.c:232:24: error: invalid operands to binary / (have ‘int’ and ‘void *’)
       int n = sp->length / sp->data[0];
  

  I also am getting the following error when I run GDB:

  (.text+0x20): undefined reference to `main' collect2: error: ld returned 1 exit status
  

  I think that the errors are coming from how I have referenced the SET *sp in the functions: partition, *quickSort, *getElements, printArray, and main

  Any help is appreciated. Thank you for your time!

  Code:

  #include <stdlib.h>
  #include <assert.h>
  #include <stdio.h>
  #include <stdbool.h>
  #define EMPTY 0
  #define FILLED 1
  #define DELETED 2
  
  struct set
  {
      int count;    /*number of elements*/
      int length; /*length of array */
      void **data; /*array of strings */
      char* flags; /*array of flags */
      int (*compare)(); /* a compare function in the set */
      unsigned(*hash)(); /* equivalent of strhash stored in the set */
  };
  typedef struct set SET;
  
  static int search(SET *sp, void *elt, bool *found);        /* prototyping the search function */
  

  . . .

  // simple pointer swap function
  void swap(int* a, int* b)
  {
      int t = *a;
      *a = *b;
      *b = t;
  }
  
  
  // Big O:
  int partition (SET *sp, int low, int high)
  {
      int j;
      int pivot = sp->data[high];    // pivot position
      int i = (low - 1);  // Index of smaller element
      char **arr = sp->data;
  
      for (j = low; j <= high- 1; j++)
      {
          // current element <= pivot
          if (arr[j] <= pivot)
          {
              i++;
              swap(&arr[i], &arr[j]);
          }
      }
      swap(&arr[i + 1], &arr[high]);
      return (i + 1);
  }
  
  
  // implements QuickSort
  // arr[] --> Array to be sorted,
  // low  --> Starting index,
  // high  --> Ending index
  void *quickSort(SET *sp, int low, int high)
  {
      if (low < high)
      {
          // pi = partitioning index, arr[p] is now at right place
          int pi = partition(sp, low, high);
  
          // sort before and after partition
          quickSort(sp, low, pi - 1);
          quickSort(sp, pi + 1, high);
      }
  }
  
  
  // Runtime: O(n)
  void *getElements(SET *sp)
  {
      assert(sp!=NULL);
  
      char **arr;
      int i;
      int lastIndex = 0;
      int n = sizeof(arr)/sizeof(arr[0]);
  
      arr = malloc(sizeof(void*)*sp->count);        // declare array and allocate memory to be size of the number of elements
  
      for (i = 0; i < sp->length; i++)
      {
          if (sp->flags[i] == FILLED)               // we only want an array of elements and not the entire thing so check if FILLED
          {
              arr[lastIndex]=sp->data[i];           // copy the data
              lastIndex++;
          }
      }
      quickSort(sp, 0, n-1);
  }
  
  
  /* Function to print an array */
  void printArray(SET *sp)
  {
      int i;
      for (i=0; i < sp->length; i++)
      printf("%d \n", sp->data);
      printf("n");
  }
  
  // Driver program to test above functions
  int main(SET *sp)
  {
      char arr = sp->data;
      int n = sp->length / sp->data[0];
      quickSort(sp, 0, n-1);
      printf("Sorted array: n");
      printArray(sp);
      return 0;
  }
  
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  Connected my Chromebook to the development mashine (Windows 10). Used adb connect for it. Created several bat files:

  screenshot.bat:

  adb connect <ip_address>
  adb shell screencap -p /sdcard/1.png
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  read.bat:

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  log.bat:

  adb connect <ip_address>
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  pause
  

  Three the first screenshot.bat, record.bat and read.bat work properly, but log.bat doesn't work. I get error:

  already connected to 192.168.0.107:5555
  adb bugreport  1>/sdcard/log.txt
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  What is wrong here?