pool now uses a queue kinda behaviour when getting/inserting data through poolbuckets.

src/util-pool.c

@@ -168,6 +168,9 @@ Pool *PoolInit(uint32_t size, uint32_t prealloc_size, uint32_t elt_size,  void *
 
             pb->next = p->alloc_list;
             p->alloc_list = pb;
+            if (p->alloc_list_tail == NULL) {
+                p->alloc_list_tail = pb;
+            }
             p->alloc_list_size++;
         } else {
             PoolBucket *pb = p->empty_list;
@@ -188,6 +191,9 @@ Pool *PoolInit(uint32_t size, uint32_t prealloc_size, uint32_t elt_size,  void *
 
             pb->next = p->alloc_list;
             p->alloc_list = pb;
+            if (p->alloc_list_tail == NULL) {
+                p->alloc_list_tail = pb;
+            }
             p->alloc_list_size++;
         }
     }
@@ -222,6 +228,7 @@ void PoolFree(Pool *p) {
             SCFree(pb);
         }
     }
+    p->alloc_list_tail = NULL;
 
     while (p->empty_list != NULL) {
         PoolBucket *pb = p->empty_list;
@@ -262,6 +269,8 @@ void *PoolGet(Pool *p) {
     if (pb != NULL) {
         /* pull from the alloc list */
         p->alloc_list = pb->next;
+        if (pb->next == NULL)
+            p->alloc_list_tail = NULL;
         p->alloc_list_size--;
 
         /* put in the empty list */
@@ -331,8 +340,13 @@ void PoolReturn(Pool *p, void *data) {
     p->empty_list_size--;
 
     /* put in the alloc list */
-    pb->next = p->alloc_list;
-    p->alloc_list = pb;
+    pb->next = NULL;
+    if (p->alloc_list_tail == NULL) {
+        p->alloc_list = pb;
+    } else {
+        p->alloc_list_tail->next = pb;
+    }
+    p->alloc_list_tail = pb;
     p->alloc_list_size++;
 
     pb->data = data;

src/util-pool.h

@@ -46,6 +46,7 @@ typedef struct Pool_ {
     uint32_t allocated;
 
     PoolBucket *alloc_list;
+    PoolBucket *alloc_list_tail;
     uint32_t alloc_list_size;
 
     PoolBucket *empty_list;