nested structs

[khumo]

Please help...i have the following code:

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <pthread.h>
#include <time.h>
#include <sys/time.h>
#include <string.h>
 
typedef int ProID;
struct proDes {
   struct proDes *next;
   struct proDes *prev;
   char name[10];
   ProID pid;
   int priority;
   long waittime;
   struct intHeap *heap;
   struct LL *inlist;
};
 
struct intHeap{
   struct intHeap *ndata;
   char *dataname;
   int value;
};
 
 
typedef enum{RUNNING, READY, L_DYING} ListType;
struct LL{
   struct proDes *head;
   ListType type;
};

i would like to create a linked-list using the pointer *inlist, how do i access it?
*NB: i have a linked list *lnode and want to sort its elements according to
waittime saving the sorted list in the new linked-list, inlist.


I tried this:

lnode->inlist->head = (struct proDes *)malloc(sizeof(struct proDes));

but it gives me a segmentation fault when i run it.

[Ganon11]

You have a circular pointer embedded in your structure. Your LL struct contains a pointer to the head of a linked list, which is of type proDes. But the proDes struct has a pointer to a LL. Is this necessary?

I'm not sure if this is giving you the error, but it seems a little strange to me as a design point.

[weaknessforcats]

I might suggest that you separate your linked list from your proDes struct on the off chance that you might want a linked list of something else later on and won't be able to reuse any of your code.

That would force rewriting and debugging the linked list all over again.

Do this:

1) Make your node data independent:

struct Node
{
    void* the Data;
    Node* next;
    Node* prev;
};
 

2) Now get your linked list working. Use an int for starters and put the address of the int in the Node as the pointer to theData. This is a C solution. C++ already has the the linked list written for you.

3) Make sure your linked list code is in files that do not contain main(). Otherwise, you won't be able to use the files in another program.

4) Once the linked list works with ints, use the linked list files in anotrher program where you store the address o a proDes variable in the Node.