X-Git-Url: https://pd.if.org/git/?p=nbds;a=blobdiff_plain;f=map%2Flist.c;h=e900f0203229c8d52618b6d2fa1c499b096d0c53;hp=a0f52a57d573a7efb7ce74f32987ce22657a0d8e;hb=d26bac75802a324ed98c8d3d88cfb9eb87b3b35a;hpb=025017478bb385da88a6b185849c8bcffeb2e2aa diff --git a/map/list.c b/map/list.c index a0f52a5..e900f02 100644 --- a/map/list.c +++ b/map/list.c @@ -5,63 +5,71 @@ * Harris-Michael lock-free list-based set * http://www.research.ibm.com/people/m/michael/spaa-2002.pdf */ + #include #include #include "common.h" #include "mlocal.h" -#include "nstring.h" +#include "list.h" #include "mem.h" typedef struct node { - nstring_t *key; + void *key; uint64_t val; struct node *next; } node_t; 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 }; -static node_t *node_alloc (const void *key_data, uint32_t key_len, uint64_t val) { +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)); - memset(item, 0, sizeof(node_t)); - // If is -1 it indicates is an integer and not a pointer - item->key = (key_len == (unsigned)-1) - ? (void *)TAG_VALUE(key_data) - : ns_alloc(key_data, key_len); + item->key = key; item->val = val; return item; } -static void node_free (node_t *item) { - if (!IS_TAGGED(item->key)) { - nbd_free(item->key); - } - nbd_free(item); -} - -static void node_defer_free (node_t *item) { - if (!IS_TAGGED(item->key)) { - nbd_defer_free(item->key); - } - nbd_defer_free(item); -} - -list_t *ll_alloc (void) { +list_t *ll_alloc (const datatype_t *key_type) { list_t *ll = (list_t *)nbd_malloc(sizeof(list_t)); - ll->head = node_alloc(" ", 0, 0); + ll->key_type = key_type; + ll->head = node_alloc(NULL, 0); ll->head->next = NULL; return ll; } void ll_free (list_t *ll) { + node_t *item = ll->head->next; + while (item) { + node_t *next = (node_t *)STRIP_TAG(item->next); + nbd_free(item); + item = next; + } } -static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, const void *key_data, uint32_t key_len, int help_remove) { +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); + } + return count; +} + +static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, void *key, int help_remove) { node_t *pred = ll->head; node_t *item = pred->next; - TRACE("l2", "find_pred: searching for key %p in ll (head is %p)", key_data, pred); + TRACE("l2", "find_pred: searching for key %p in list (head is %p)", key, pred); while (item != NULL) { node_t *next = item->next; @@ -91,12 +99,15 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, const vo TRACE("l3", "find_pred: now current item is %p next is %p", item, next); // The thread that completes the unlink should free the memory. - node_defer_free(other); + if (ll->key_type != NULL) { + nbd_defer_free((void*)other->key); + } + nbd_defer_free(other); } 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)) - return find_pred(pred_ptr, item_ptr, ll, key_data, key_len, help_remove); // retry + return find_pred(pred_ptr, item_ptr, ll, key, help_remove); // retry item = other; if (EXPECT_FALSE(item == NULL)) break; @@ -108,17 +119,13 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, const vo break; TRACE("l3", "find_pred: visiting item %p (next is %p)", item, next); - TRACE("l4", "find_pred: key %p val %p", STRIP_TAG(item->key), item->val); + TRACE("l4", "find_pred: key %p val %p", item->key, item->val); - // A tagged key is an integer, otherwise it is a pointer to a string int d; - if (IS_TAGGED(item->key)) { - d = (STRIP_TAG(item->key) - (uint64_t)key_data); + if (EXPECT_TRUE(ll->key_type == NULL)) { + d = (uint64_t)item->key - (uint64_t)key; } else { - int item_key_len = item->key->len; - int len = (key_len < item_key_len) ? key_len : item_key_len; - d = memcmp(item->key->data, key_data, len); - if (d == 0) { d = item_key_len - key_len; } + d = ll->key_type->cmp(item->key, key); } // If we reached the key (or passed where it should be), we found the right predesssor @@ -131,7 +138,7 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, const vo TRACE("l2", "find_pred: found matching item %p in list, pred is %p", item, pred); return TRUE; } - TRACE("l2", "find_pred: found proper place for key %p in list, pred is %p", key_data, pred); + TRACE("l2", "find_pred: found proper place for key %p in list, pred is %p", key, pred); return FALSE; } @@ -149,10 +156,10 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, const vo } // Fast find. Do not help unlink partially removed nodes and do not return the found item's predecessor. -uint64_t ll_lookup (list_t *ll, const void *key_data, uint32_t key_len) { - TRACE("l1", "ll_lookup: searching for key %p in list %p", key_data, ll); +uint64_t ll_lookup (list_t *ll, void *key) { + TRACE("l1", "ll_lookup: searching for key %p in list %p", key, ll); node_t *item; - int found = find_pred(NULL, &item, ll, key_data, key_len, FALSE); + int found = find_pred(NULL, &item, ll, key, FALSE); // If we found an matching the key return its value. if (found) { @@ -167,14 +174,15 @@ uint64_t ll_lookup (list_t *ll, const void *key_data, uint32_t key_len) { return DOES_NOT_EXIST; } -uint64_t ll_cas (list_t *ll, const void *key_data, uint32_t key_len, uint64_t expectation, uint64_t new_val) { - TRACE("l1", "ll_cas: key %p list %p", key_data, ll); +uint64_t ll_cas (list_t *ll, void *key, uint64_t expectation, uint64_t new_val) { + TRACE("l1", "ll_cas: key %p list %p", key, ll); TRACE("l1", "ll_cas: expectation %p new value %p", expectation, new_val); ASSERT((int64_t)new_val > 0); do { node_t *pred, *old_item; - if (!find_pred(&pred, &old_item, ll, key_data, key_len, TRUE)) { + int found = find_pred(&pred, &old_item, ll, key, TRUE); + if (!found) { // There was not an item in the list that matches the key. if (EXPECT_FALSE((int64_t)expectation > 0 || expectation == CAS_EXPECT_EXISTS)) { @@ -186,7 +194,8 @@ uint64_t ll_cas (list_t *ll, const void *key_data, uint32_t key_len, uint64_t ex // Create a new item and insert it into the list. TRACE("l2", "ll_cas: attempting to insert item between %p and %p", pred, pred->next); - node_t *new_item = node_alloc(key_data, key_len, new_val); + void *new_key = (ll->key_type == NULL) ? key : ll->key_type->clone(key); + node_t *new_item = node_alloc(new_key, new_val); node_t *next = new_item->next = old_item; node_t *other = SYNC_CAS(&pred->next, next, new_item); if (other == next) { @@ -196,7 +205,10 @@ uint64_t ll_cas (list_t *ll, const void *key_data, uint32_t key_len, uint64_t ex // Lost a race. Failed to insert the new item into the list. TRACE("l1", "ll_cas: lost a race. CAS failed. expected pred's link to be %p but found %p", next, other); - node_free(new_item); + if (ll->key_type != NULL) { + nbd_free(new_key); + } + nbd_free(new_item); continue; // retry } @@ -231,18 +243,17 @@ uint64_t ll_cas (list_t *ll, const void *key_data, uint32_t key_len, uint64_t ex } while (1); } -uint64_t ll_remove (list_t *ll, const void *key_data, uint32_t key_len) { - TRACE("l1", "ll_remove: removing item with key %p from list %p", key_data, ll); +uint64_t ll_remove (list_t *ll, void *key) { + TRACE("l1", "ll_remove: removing item with key %p from list %p", key, ll); node_t *pred; node_t *item; - int found = find_pred(&pred, &item, ll, key_data, key_len, TRUE); + int found = find_pred(&pred, &item, ll, key, TRUE); if (!found) { TRACE("l1", "ll_remove: remove failed, an item with a matching key does not exist in the list", 0, 0); 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 { @@ -256,7 +267,8 @@ uint64_t ll_remove (list_t *ll, const void *key_data, uint32_t key_len) { TRACE("l2", "ll_remove: logically removed item %p", item, 0); ASSERT(IS_TAGGED(item->next)); - // 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); @@ -271,7 +283,10 @@ uint64_t ll_remove (list_t *ll, const void *key_data, uint32_t key_len) { } // The thread that completes the unlink should free the memory. - node_defer_free(item); + if (ll->key_type != NULL) { + nbd_defer_free(item->key); + } + nbd_defer_free(item); TRACE("l1", "ll_remove: successfully unlinked item %p from the list", item, 0); return val; } @@ -279,19 +294,19 @@ uint64_t ll_remove (list_t *ll, const void *key_data, uint32_t key_len) { void ll_print (list_t *ll) { node_t *item; item = ll->head->next; + int i = 0; while (item) { node_t *next = item->next; if (IS_TAGGED(item)) { printf("*"); } - printf("%p:", item); - if (IS_TAGGED(item->key)) { - printf("0x%llx ", STRIP_TAG(item->key)); - } else { - printf("%s ", (char *)item->key->data); - } + printf("%p:%p ", item, item->key); fflush(stdout); item = (node_t *)STRIP_TAG(next); + if (i++ > 30) { + printf("..."); + break; + } } printf("\n"); }