typedef struct list {
node_t *head;
- node_t *last;
} list_t;
node_t *node_alloc (uint64_t key, uint64_t value) {
list_t *ll_alloc (void) {
list_t *list = (list_t *)nbd_malloc(sizeof(list_t));
- list->head = node_alloc(0, 0);
- list->last = node_alloc((uint64_t)-1, 0);
- list->head->next = list->last;
+ list->head = node_alloc((uint64_t)-1, 0);
+ list->head->next = NULL;
return list;
}
node_t *pred = list->head;
node_t *item = pred->next;
TRACE("l3", "find_pred: searching for key %p in list (head is %p)", key, pred);
-#ifndef NDEBUG
- int count = 0;
-#endif
- do {
+ while (item != NULL) {
node_t *next = item->next;
TRACE("l3", "find_pred: visiting item %p (next %p)", item, next);
TRACE("l3", "find_pred: key %p", item->key, item->value);
// Skip over partially removed items.
if (!help_remove) {
item = (node_t *)STRIP_TAG(item->next);
+ if (EXPECT_FALSE(item == NULL))
+ break;
next = item->next;
continue;
}
node_t *other;
if ((other = SYNC_CAS(&pred->next, item, STRIP_TAG(next))) == item) {
item = (node_t *)STRIP_TAG(next);
+ if (EXPECT_FALSE(item == NULL))
+ break;
next = item->next;
TRACE("l3", "find_pred: unlinked item %p from pred %p", item, pred);
TRACE("l3", "find_pred: now item is %p next is %p", item, next);
// The thread that completes the unlink should free the memory.
nbd_defer_free(other);
} else {
- TRACE("l3", "find_pred: lost race to unlink item from pred %p; its link changed to %p", pred, other);
+ TRACE("l3", "find_pred: lost race to unlink from pred %p; its link changed to %p", pred, other);
if (IS_TAGGED(other))
return find_pred(pred_ptr, list, key, help_remove); // retry
item = other;
+ if (EXPECT_FALSE(item == NULL))
+ break;
next = item->next;
}
}
+ if (EXPECT_FALSE(item == NULL))
+ break;
+
// If we reached the key (or passed where it should be), we found the right predesssor
if (item->key >= key) {
TRACE("l3", "find_pred: found pred %p item %p", pred, item);
return item;
}
- assert(count++ < 18);
pred = item;
item = next;
- } while (1);
+ }
+
+ // <key> is not in the list.
+ if (pred_ptr != NULL) {
+ *pred_ptr = pred;
+ }
+ return NULL;
}
// Fast find. Do not help unlink partially removed nodes and do not return the found item's predecessor.
node_t *item = find_pred(NULL, list, key, FALSE);
// If we found an <item> matching the <key> return its value.
- return (item->key == key) ? item->value : DOES_NOT_EXIST;
+ return (item && item->key == key) ? item->value : DOES_NOT_EXIST;
}
// Insert the <key>, if it doesn't already exist in the <list>
node_t *next = find_pred(&pred, list, key, TRUE);
// If a node matching <key> already exists in the list, return its value.
- if (next->key == key) {
+ if (next != NULL && next->key == key) {
TRACE("l3", "ll_add: there is already an item %p (value %p) with the same key", next, next->value);
if (EXPECT_FALSE(item != NULL)) { nbd_free(item); }
return next->value;
TRACE("l3", "ll_remove: removing item with key %p from list %p", key, list);
node_t *pred;
node_t *item = find_pred(&pred, list, key, TRUE);
- if (item->key != key) {
+ if (item == NULL || item->key != key) {
TRACE("l3", "ll_remove: remove failed, an item with a matching key does not exist in the list", 0, 0);
return DOES_NOT_EXIST;
}
void ll_print (list_t *list) {
node_t *item;
- item = list->head;
+ item = list->head->next;
while (item) {
printf("0x%llx ", item->key);
fflush(stdout);
static list_t *ll_;
void *worker (void *arg) {
- int id = (int)(size_t)arg;
-
- unsigned int rand_seed = id+1;//rdtsc_l();
// Wait for all the worker threads to be ready.
SYNC_ADD(&wait_, -1);
do {} while (wait_);
for (int i = 0; i < NUM_ITERATIONS/num_threads_; ++i) {
- int n = rand_r(&rand_seed);
- int key = (n & 0xF) + 1;
- if (n & (1 << 8)) {
+ unsigned r = nbd_rand();
+ int key = (r & 0xF);
+ if (r & (1 << 8)) {
ll_add(ll_, key, 1);
} else {
ll_remove(ll_, key);
gettimeofday(&tv2, NULL);
int ms = (int)(1000000*(tv2.tv_sec - tv1.tv_sec) + tv2.tv_usec - tv1.tv_usec) / 1000;
- printf("Th:%ld Time:%dms\n", num_threads_, ms);
ll_print(ll_);
- lwt_dump("lwt.out");
+ printf("Th:%ld Time:%dms\n", num_threads_, ms);
return 0;
}