Hi, I need to put in shared memory a list made with object of this structure:
Code:
typedef struct Obj{
char objname[20];
struct Obj *nextObj;
}Object
I've filled my list with (for example) 10 elements, but when i try to put it in shared memory to be read by another process i get segmentation fault after first read record..
I've read in another thread (here ->
dynamic shared memory )that malloc gives sone problems with shared memory
Quote:
|
If you called malloc to create linked_list_header->ptr, then the address returned by malloc is private to the calling (the process that calls malloc) process. Same with NODE->buffer. You will have to allocate these things in shared "by hand" without calling malloc.
|
but i don't understand what i have to do now and how to solve my problem.
i tried to share object in this way:
Code:
Obj *head; //pointer to the head of my FILLED list
int shmid;
Obj *sh;
...
shmid = shmget(SHMKEY,(sizeof(Obj)*10),0666|IPC_CREAT|IPC_EXCL);
...
sh = (Obj *)shmat(shmid, 0, 0666);
...
*sh = *head;
probably I miss something or maybe I'm totally wrong... how can I allocate Obj in shared "by hand" without calling malloc?
Thanks for your support, best regards.
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