X-Git-Url: https://pd.if.org/git/?p=nbds;a=blobdiff_plain;f=map%2Flist.c;h=f2e9c82c0e65fe85888721bed1145947af79ef73;hp=f7a9cd43cbaa2da9049be46bc791d11f81e92cda;hb=329b5ab58cde015f4faec1879d3106f635294dd6;hpb=11572afcaf218cfcbb8e9747f22739f75252c4f4 diff --git a/map/list.c b/map/list.c index f7a9cd4..f2e9c82 100644 --- a/map/list.c +++ b/map/list.c @@ -10,27 +10,22 @@ #include #include "common.h" -#include "mlocal.h" +#include "list.h" #include "mem.h" -typedef struct node { +typedef struct ll_iter node_t; + +struct ll_iter { void *key; uint64_t val; - struct node *next; -} node_t; + node_t *next; +}; struct ll { node_t *head; const datatype_t *key_type; }; -static const map_impl_t ll_map_impl = { - (map_alloc_t)ll_alloc, (map_cas_t)ll_cas, (map_get_t)ll_lookup, (map_remove_t)ll_remove, - (map_count_t)ll_count, (map_print_t)ll_print, (map_free_t)ll_free -}; - -const map_impl_t *MAP_TYPE_LIST = &ll_map_impl; - static node_t *node_alloc (void *key, uint64_t val) { node_t *item = (node_t *)nbd_malloc(sizeof(node_t)); item->key = key; @@ -49,7 +44,7 @@ list_t *ll_alloc (const datatype_t *key_type) { void ll_free (list_t *ll) { node_t *item = ll->head->next; while (item) { - node_t *next = (node_t *)STRIP_TAG(item->next); + node_t *next = (node_t *)STRIP_TAG(item->next, TAG1); nbd_free(item); item = next; } @@ -59,8 +54,10 @@ uint64_t ll_count (list_t *ll) { uint64_t count = 0; node_t *item = ll->head->next; while (item) { - count++; - item = (node_t *)STRIP_TAG(item->next); + if (!IS_TAGGED(item->next, TAG1)) { + count++; + } + item = (node_t *)STRIP_TAG(item->next, TAG1); } return count; } @@ -74,11 +71,11 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, void *ke node_t *next = item->next; // A tag means an item is logically removed but not physically unlinked yet. - while (EXPECT_FALSE(IS_TAGGED(next))) { + while (EXPECT_FALSE(IS_TAGGED(next, TAG1))) { // Skip over logically removed items. if (!help_remove) { - item = (node_t *)STRIP_TAG(item->next); + item = (node_t *)STRIP_TAG(item->next, TAG1); if (EXPECT_FALSE(item == NULL)) break; TRACE("l3", "find_pred: skipping marked item %p (next is %p)", item, next); @@ -89,9 +86,9 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, void *ke // Unlink logically removed items. node_t *other; TRACE("l3", "find_pred: unlinking marked item %p next is %p", item, next); - if ((other = SYNC_CAS(&pred->next, item, STRIP_TAG(next))) == item) { + if ((other = SYNC_CAS(&pred->next, item, STRIP_TAG(next, TAG1))) == item) { TRACE("l2", "find_pred: unlinked item %p from pred %p", item, pred); - item = (node_t *)STRIP_TAG(next); + item = (node_t *)STRIP_TAG(next, TAG1); if (EXPECT_FALSE(item == NULL)) break; next = item->next; @@ -105,7 +102,7 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, void *ke } else { TRACE("l2", "find_pred: lost a race to unlink item %p from pred %p", item, pred); TRACE("l2", "find_pred: pred's link changed to %p", other, 0); - if (IS_TAGGED(other)) + if (IS_TAGGED(other, TAG1)) return find_pred(pred_ptr, item_ptr, ll, key, help_remove); // retry item = other; if (EXPECT_FALSE(item == NULL)) @@ -252,22 +249,22 @@ uint64_t ll_remove (list_t *ll, void *key) { return DOES_NOT_EXIST; } - // Mark removed. This must be atomic. If multiple threads try to remove the same item - // only one of them should succeed. + // Mark removed. If multiple threads try to remove the same item only one of them should succeed. node_t *next; node_t *old_next = item->next; do { next = old_next; - old_next = SYNC_CAS(&item->next, next, TAG_VALUE(next)); - if (IS_TAGGED(old_next)) { + old_next = SYNC_CAS(&item->next, next, TAG_VALUE(next, TAG1)); + if (IS_TAGGED(old_next, TAG1)) { TRACE("l1", "ll_remove: lost a race -- %p is already marked for removal by another thread", item, 0); return DOES_NOT_EXIST; } } while (next != old_next); TRACE("l2", "ll_remove: logically removed item %p", item, 0); - ASSERT(IS_TAGGED(item->next)); + ASSERT(IS_TAGGED(item->next, TAG1)); - // This has to be an atomic swap in case another thread is updating the item while we are removing it. + // Atomically swap out the item's value in case another thread is updating the item while we are + // removing it. This establishes which operation occurs first logically, the update or the remove. uint64_t val = SYNC_SWAP(&item->val, DOES_NOT_EXIST); TRACE("l2", "ll_remove: replaced item's val %p with DOES_NOT_EXIT", val, 0); @@ -296,12 +293,12 @@ void ll_print (list_t *ll) { int i = 0; while (item) { node_t *next = item->next; - if (IS_TAGGED(item)) { + if (IS_TAGGED(item, TAG1)) { printf("*"); } printf("%p:%p ", item, item->key); fflush(stdout); - item = (node_t *)STRIP_TAG(next); + item = (node_t *)STRIP_TAG(next, TAG1); if (i++ > 30) { printf("..."); break; @@ -309,3 +306,30 @@ void ll_print (list_t *ll) { } printf("\n"); } + +ll_iter_t *ll_iter_begin (list_t *ll, void *key) { + node_t *iter = node_alloc(0,0); + find_pred(NULL, &iter->next, ll, key, FALSE); + return iter; +} + +uint64_t ll_iter_next (ll_iter_t *iter, void **key_ptr) { + assert(iter); + node_t *item = iter->next; + while (item != NULL && IS_TAGGED(item->next, TAG1)) { + item = (node_t *)STRIP_TAG(item->next, TAG1); + } + if (item == NULL) { + iter->next = NULL; + return DOES_NOT_EXIST; + } + iter->next = item->next; + if (key_ptr != NULL) { + *key_ptr = item->key; + } + return item->val; +} + +void ll_iter_free (ll_iter_t *iter) { + nbd_free(iter); +}