making your own malloc function in C

Question

I need your help in this. I have an average knowledge of C and here is the problem. I am about to use some benchmarks to test some computer architecture stuff (branch misses

Answer 1

Trying a thread safe nos answer given above, I am referring his code with some changes as below:

static unsigned char our_memory[1024 * 1024]; //reserve 1 MB for malloc
static size_t next_index = 0;

static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;

void *malloc(size_t sz)
{
    void *mem;
    pthread_mutex_lock(&lock);
    if(sizeof our_memory - next_index < sz){
        pthread_mutex_unlock(&lock);
        return NULL;
    }

    mem = &our_memory[next_index];
    next_index += sz;
    pthread_mutex_unlock(&lock);
    return mem;
}

void free(void *mem)
{
   //we cheat, and don't free anything.
}