container_of.c

struct my_element
{
    int my_element_data;

    /* Placement of container-specific node data can be easily modified for locality
       optimization */
    struct container__slist_node slist_node;

    /* A single element can be linked into multiple containers */
    struct container__hash_node hash_node;
};

void
InsertElement (...)
{
    struct my_element* el;

    /* Allocate elements using any mechanism desired */
    el = malloc(sizeof(struct my_element));

    el->my_element_data = 42;

    /* Perform locking only during the insertion, allowing potentially costly allocations and
       initializations to occur outside the lock */
    pthread_mutex_lock(&my_slist_lock);

    Container_AddSListHead(&el->slist_node, &my_slist);

    pthread_mutex_unlock(&my_slist_lock);

    /* Easily allow external libraries to operate on the container */
    ExternalLibUpdate(&el->hash_node, &my_hash);
}