X-Git-Url: https://pd.if.org/git/?p=nbds;a=blobdiff_plain;f=map%2Flist.c;h=04bfd2d02f23c3fae4808665b4d4cd377e22d777;hp=98522c3b1b7f033567a9de274c79f40901865844;hb=HEAD;hpb=4ae7c1069667d8f067258d89676126f9b44226d6

diff --git a/map/list.c b/map/list.c
index 98522c3..04bfd2d 100644
--- a/map/list.c
+++ b/map/list.c
@@ -12,6 +12,11 @@
 #include "common.h"
 #include "list.h"
 #include "mem.h"
+#ifdef LIST_USE_HAZARD_POINTER
+#include "hazard.h"
+#else
+#include "rcu.h"
+#endif
 
 typedef struct node {
     map_key_t  key;
@@ -20,7 +25,7 @@ typedef struct node {
 } node_t;
 
 struct ll_iter {
-    node_t *next;
+    node_t *pred;
 };
 
 struct ll {
@@ -29,13 +34,14 @@ struct ll {
 };
 
 // Marking the <next> field of a node logically removes it from the list
-#define  MARK_NODE(x) TAG_VALUE((markable_t)(x), TAG1)
-#define   HAS_MARK(x) (IS_TAGGED((x), TAG1) == TAG1)
+#define  MARK_NODE(x) TAG_VALUE((markable_t)(x), 0x1)
+#define   HAS_MARK(x) (IS_TAGGED((x), 0x1) == 0x1)
 #define   GET_NODE(x) ((node_t *)(x))
-#define STRIP_MARK(x) ((node_t *)STRIP_TAG((x), TAG1))
+#define STRIP_MARK(x) ((node_t *)STRIP_TAG((x), 0x1))
 
 static node_t *node_alloc (map_key_t key, map_val_t val) {
     node_t *item = (node_t *)nbd_malloc(sizeof(node_t));
+    assert(!HAS_MARK((size_t)item));
     item->key = key;
     item->val = val;
     return item;
@@ -53,6 +59,9 @@ void ll_free (list_t *ll) {
     node_t *item = STRIP_MARK(ll->head->next);
     while (item != NULL) {
         node_t *next = STRIP_MARK(item->next);
+        if (ll->key_type != NULL) {
+            nbd_free((void *)item->key);
+        }
         nbd_free(item);
         item = next;
     }
@@ -70,12 +79,27 @@ size_t ll_count (list_t *ll) {
     return count;
 }
 
+#ifdef LIST_USE_HAZARD_POINTER
+static void nbd_free_node (node_t *x) {
+    nbd_free((void *)x->key);
+    nbd_free(x);
+}
+#endif
+
 static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, map_key_t key, int help_remove) {
     node_t *pred = ll->head;
     node_t *item = GET_NODE(pred->next);
     TRACE("l2", "find_pred: searching for key %p in list (head is %p)", key, pred);
+#ifdef LIST_USE_HAZARD_POINTER
+    haz_t *temp, *hp0 = haz_get_static(0), *hp1 = haz_get_static(1);
+#endif
 
     while (item != NULL) {
+#ifdef LIST_USE_HAZARD_POINTER
+        haz_set(hp0, item);
+        if (STRIP_MARK(pred->next) != item)
+            return find_pred(pred_ptr, item_ptr, ll, key, help_remove); // retry
+#endif
         markable_t next = item->next;
 
         // A mark means the node is logically removed but not physically unlinked yet.
@@ -94,7 +118,7 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, map_key_
             // Unlink logically removed items.
             TRACE("l3", "find_pred: unlinking marked item %p next is %p", item, next);
 
-            markable_t other = SYNC_CAS(&pred->next, item, STRIP_MARK(next));
+            markable_t other = SYNC_CAS(&pred->next, (markable_t)item, (markable_t)STRIP_MARK(next));
             if (other == (markable_t)item) {
                 TRACE("l2", "find_pred: unlinked item %p from pred %p", item, pred);
                 item = STRIP_MARK(next);
@@ -102,11 +126,15 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, map_key_
                 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_t *unlinked = GET_NODE(other);
+#ifdef LIST_USE_HAZARD_POINTER
+                free_t free_ = (ll->key_type != NULL ? (free_t)nbd_free_node : nbd_free);
+                haz_defer_free(GET_NODE(other), free_);
+#else
                 if (ll->key_type != NULL) {
-                    nbd_defer_free((void *)unlinked->key);
+                    rcu_defer_free((void *)GET_NODE(other)->key);
                 }
-                nbd_defer_free(unlinked);
+                rcu_defer_free(GET_NODE(other));
+#endif
             } 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);
@@ -130,17 +158,14 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, map_key_
             d = ll->key_type->cmp((void *)item->key, (void *)key);
         }
 
-        if (next != DOES_NOT_EXIST && GET_NODE(next)->key < item->key) {
-            lwt_halt();
-            assert(0);
-        }
-
         // If we reached the key (or passed where it should be), we found the right predesssor
         if (d >= 0) {
             if (pred_ptr != NULL) {
                 *pred_ptr = pred;
             }
-            *item_ptr = item;
+            if (item_ptr != NULL) {
+                *item_ptr = item;
+            }
             if (d == 0) {
                 TRACE("l2", "find_pred: found matching item %p in list, pred is %p", item, pred);
                 return TRUE;
@@ -150,6 +175,9 @@ static int find_pred (node_t **pred_ptr, node_t **item_ptr, list_t *ll, map_key_
         }
 
         pred = item;
+#ifdef LIST_USE_HAZARD_POINTER
+        temp = hp0; hp0 = hp1; hp1 = temp;
+#endif
         item = GET_NODE(next);
     }
 
@@ -192,19 +220,17 @@ map_val_t ll_cas (list_t *ll, map_key_t key, map_val_t expectation, map_val_t ne
         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)) {
+            if (EXPECT_FALSE(expectation != CAS_EXPECT_DOES_NOT_EXIST && expectation != CAS_EXPECT_WHATEVER)) {
                 TRACE("l1", "ll_cas: the expectation was not met, the list was not changed", 0, 0);
                 return DOES_NOT_EXIST; // failure
             }
 
-            ASSERT(expectation == CAS_EXPECT_DOES_NOT_EXIST || expectation == CAS_EXPECT_WHATEVER);
-
             // 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);
             map_key_t new_key = ll->key_type == NULL ? key : (map_key_t)ll->key_type->clone((void *)key);
             node_t *new_item = node_alloc(new_key, new_val);
             markable_t next = new_item->next = (markable_t)old_item;
-            markable_t other = SYNC_CAS(&pred->next, next, new_item);
+            markable_t other = SYNC_CAS(&pred->next, (markable_t)next, (markable_t)new_item);
             if (other == next) {
                 TRACE("l1", "ll_cas: successfully inserted new item %p", new_item, 0);
                 return DOES_NOT_EXIST; // success
@@ -272,7 +298,7 @@ map_val_t ll_remove (list_t *ll, map_key_t key) {
         }
     } while (next != old_next);
     TRACE("l2", "ll_remove: logically removed item %p", item, 0);
-    ASSERT(HAS_MARK(((volatile node_t *)item)->next));
+    ASSERT(HAS_MARK(VOLATILE_DEREF(item).next));
 
     // 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. 
@@ -284,64 +310,92 @@ map_val_t ll_remove (list_t *ll, map_key_t key) {
     // item earlier, we logically removed it. 
     TRACE("l2", "ll_remove: unlink the item by linking its pred %p to its successor %p", pred, next);
     markable_t other;
-    if ((other = SYNC_CAS(&pred->next, item, next)) != (markable_t)item) {
+    if ((other = SYNC_CAS(&pred->next, (markable_t)item, next)) != (markable_t)item) {
         TRACE("l1", "ll_remove: unlink failed; pred's link changed from %p to %p", item, other);
         return val;
     } 
 
     // The thread that completes the unlink should free the memory.
+#ifdef LIST_USE_HAZARD_POINTER
+    free_t free_ = (ll->key_type != NULL ? (free_t)nbd_free_node : nbd_free);
+    haz_defer_free(GET_NODE(item), free_);
+#else
     if (ll->key_type != NULL) {
-        nbd_defer_free((void *)item->key);
+        rcu_defer_free((void *)item->key);
     }
-    nbd_defer_free(item);
+    rcu_defer_free(item);
+#endif
     TRACE("l1", "ll_remove: successfully unlinked item %p from the list", item, 0);
     return val;
 }
 
-void ll_print (list_t *ll) {
-    markable_t next = ll->head->next;
-    int i = 0;
-    while (next != DOES_NOT_EXIST) {
-        if (HAS_MARK(next)) {
-            printf("*");
-        }
-        node_t *item = STRIP_MARK(next);
-        if (item == NULL)
-            break;
-        printf("%p:0x%llx ", item, item->key);
-        fflush(stdout);
-        if (i++ > 30) {
-            printf("...");
-            break;
+void ll_print (list_t *ll, int verbose) {
+    if (verbose) {
+        markable_t next = ll->head->next;
+        int i = 0;
+        while (next != DOES_NOT_EXIST) {
+            node_t *item = STRIP_MARK(next);
+            if (item == NULL)
+                break;
+            printf("%s%p:0x%llx ", HAS_MARK(item->next) ? "*" : "", item, (uint64_t)item->key);
+            fflush(stdout);
+            if (i++ > 30) {
+                printf("...");
+                break;
+            }
+            next = item->next;
         }
-        next = item->next;
+        printf("\n");
     }
-    printf("\n");
+    printf("count:%llu\n", (uint64_t)ll_count(ll));
 }
 
 ll_iter_t *ll_iter_begin (list_t *ll, map_key_t key) {
     ll_iter_t *iter = (ll_iter_t *)nbd_malloc(sizeof(ll_iter_t));
-    find_pred(NULL, &iter->next, ll, key, FALSE);
+    if (key != DOES_NOT_EXIST) {
+        find_pred(&iter->pred, NULL, ll, key, FALSE);
+    } else {
+        iter->pred = ll->head;
+    }
+#ifdef LIST_USE_HAZARD_POINTER
+    haz_register_dynamic((void **)&iter->pred);
+#endif
     return iter;
 }
 
 map_val_t ll_iter_next (ll_iter_t *iter, map_key_t *key_ptr) {
     assert(iter);
-    node_t *item = iter->next;
-    while (item != NULL && HAS_MARK(item->next)) {
-        item = STRIP_MARK(item->next);
-    }
-    if (item == NULL) {
-        iter->next = NULL;
+    if (iter->pred == NULL)
         return DOES_NOT_EXIST;
-    }
-    iter->next = STRIP_MARK(item->next);
+
+    // advance iterator to next item; skip items that have been removed
+    markable_t item;
+#ifdef LIST_USE_HAZARD_POINTER 
+    haz_t *hp0 = haz_get_static(0);
+#endif
+    do {
+#ifndef LIST_USE_HAZARD_POINTER 
+        item = iter->pred->next;
+#else //LIST_USE_HAZARD_POINTER 
+        do {
+            item = iter->pred->next;
+            haz_set(hp0, STRIP_MARK(item));
+        } while (item != VOLATILE_DEREF(iter->pred).next);
+#endif//LIST_USE_HAZARD_POINTER
+        iter->pred = STRIP_MARK(item);
+        if (iter->pred == NULL)
+            return DOES_NOT_EXIST;
+    } while (HAS_MARK(item));
+
     if (key_ptr != NULL) {
-        *key_ptr = item->key;
+        *key_ptr = GET_NODE(item)->key;
     }
-    return item->val;
+    return GET_NODE(item)->val;
 }
 
 void ll_iter_free (ll_iter_t *iter) {
+#ifdef LIST_USE_HAZARD_POINTER
+    haz_unregister_dynamic((void **)&iter->pred);
+#endif
     nbd_free(iter);
 }