将malloc用于结构的指针数组时出现段故障

Question

I'm trying to implement a cache struct with pointers that point to "lower-level" set structs; It's supposed to simulate a cache. When I try to malloc the cache struct in the initCache function I get a seg fault. I've read other posts and I'm pretty sure it's not the syntax, but I'm new to C so I could be using the pointers wrong. I get a warning that L1cache may be uninitialized and I've also checked posts related to that but with no luck, trying what worked for others.

TO be clear the **sets in the cache definition is supposed to be an array of pointers where each pointer in the array points to a struct

The cache struct is defined as:

/* Struct representing the cache */
struct cache{
    set **sets; /* Array of set pointers */
};

initCache is called in main as such:

cache* L1cache;
initCache(L1cache, nSets, setSize);

The code for initCache is:

void initCache(cache* c, int nSets, int setSize){
    int i;

    c->sets=malloc(nSets*sizeof(set*)); /* SEG FAULT HERE malloc space for array of pointers to each set       */

    for(i = 0; i < nSets; i++){
        c->sets[i]=malloc(sizeof(set)); /* malloc space for each set */
    initSet(c->sets[i],setSize);
}

    return;     
}

Answer 1

You need to initialize L1cache :

cache *L1cache = malloc(sizeof (cache));

Or you could just declare it as an ordinary variable:

char L1cache;
initCache(&L1cache, nSets, setSize);