X-Git-Url: https://pd.if.org/git/?p=nbds;a=blobdiff_plain;f=map%2Flist.c;h=e900f0203229c8d52618b6d2fa1c499b096d0c53;hp=f7a9cd43cbaa2da9049be46bc791d11f81e92cda;hb=d26bac75802a324ed98c8d3d88cfb9eb87b3b35a;hpb=4d8c8b76b77d3c4966361ad78b08d9ba2d90318a

diff --git a/map/list.c b/map/list.c
index f7a9cd4..e900f02 100644
--- a/map/list.c
+++ b/map/list.c
@@ -11,6 +11,7 @@
 
 #include "common.h"
 #include "mlocal.h"
+#include "list.h"
 #include "mem.h"
 
 typedef struct node {
@@ -252,8 +253,7 @@ uint64_t ll_remove (list_t *ll, void *key) {
         return DOES_NOT_EXIST;
     }
 
-    // Mark <item> removed. This must be atomic. If multiple threads try to remove the same item
-    // only one of them should succeed.
+    // Mark <item> 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 {
@@ -267,7 +267,8 @@ uint64_t ll_remove (list_t *ll, void *key) {
     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);