diff --git a/include/ucore/heapsort.h b/include/ucore/heapsort.h
deleted file mode 100644
index c5dbf01..0000000
--- a/include/ucore/heapsort.h
+++ /dev/null
@@ -1,21 +0,0 @@
-#ifndef UC_HEAPSORT_H_
-#define UC_HEAPSORT_H_
-
-#include <stddef.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-///compare function. Needs only to return < 0 if 
-//the first element is less than the second
-typedef int (*uc_hs_cmp)(const void *, const void *);
-
-void
-uc_heapsort(void *base, size_t count, size_t width,
-     uc_hs_cmp cmp);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/include/ucore/htable.h b/include/ucore/htable.h
index e5dc9d1..1702c5f 100644
--- a/include/ucore/htable.h
+++ b/include/ucore/htable.h
@@ -83,7 +83,7 @@ static inline struct UHNode *uc_htable_first_bucket(const struct UHTable *table,
  * Get the next node in the bucket. 
  * @return next node or NULL
  */
-static inline struct UHNode *uc_htable_next_bucket(const struct UHNode *node)
+static inline struct UHNode *uc_htable_next_in_bucket(const struct UHNode *node)
 {
     return node->next;
 }
@@ -112,7 +112,7 @@ static inline struct UHNode *uc_htable_next_hash(const struct UHNode *node)
 
 
 //internal helper
-struct UHNode *uc_htable_iter_hlp(struct UHTable *table, size_t bucket);
+struct UHNode *uc_htable_iter_hlp(struct UHTable *table, size_t start_bucket);
 
 /** Get the first node in the hash table
  *
@@ -151,7 +151,7 @@ void uc_htable_swap(struct UHTable *a, struct UHTable *b);
 #define UC_HTABLE_FOREACH_BUCKET(table, node_iter, hash)\
     for ((node_iter) = uc_htable_first_bucket((table), (hash));\
          (node_iter) != NULL;\
-         (node_iter) = uc_htable_next_bucket((node_iter)))
+         (node_iter) = uc_htable_next_in_bucket((node_iter)))
 
 /**
  * Iterate over all nodes that has the given hash.
diff --git a/include/ucore/logging.h b/include/ucore/logging.h
index bbaebe0..b0a956f 100644
--- a/include/ucore/logging.h
+++ b/include/ucore/logging.h
@@ -239,7 +239,7 @@ void uc_log_destination_set_module_loglevel(
  *  SHORT_NAME_1=LEVEL:SHORT_NAME_2=LEVEL:SHORT_NAME_N=LEVEL
  *
  * The SHORT_NAME_N is the .short_name within a struct uc_log_module
- * LEVEL is one of DEBUG,INFO, WARNING or ERROR
+ * LEVEL is one of DEBUG, INFO, WARNING, ERROR or NONE
  * Example: 
  *  DB=DEBUG:IO=ERROR:POLLER=INFO
  *
@@ -280,8 +280,8 @@ void uc_logf(int log_level, int module, int raw,
 #   define UC_DEBUGFR(mod, fmt, ...)\
         uc_logf(UC_LL_DEBUG, mod,1 , UC_SRC_LOCATION, fmt, ## __VA_ARGS__)
 #else 
-#   define UC_DEBUGF(mod, fmt, ...)
-#   define UC_DEBUGFR(mod, fmt, ...)
+#   define UC_DEBUGF(mod, fmt, ...) do {} while (0)
+#   define UC_DEBUGFR(mod, fmt, ...) do {} while (0)
 #endif
 
 /** Main macro that should be used for logging.
diff --git a/include/ucore/tailq.h b/include/ucore/tailq.h
new file mode 100644
index 0000000..010fb8a
--- /dev/null
+++ b/include/ucore/tailq.h
@@ -0,0 +1,252 @@
+#ifndef UC_TAILQ_H_
+#define UC_TAILQ_H_
+
+#ifdef __GNUC__
+#define UC_INLINE inline __attribute__((always_inline,flatten))
+#else
+#define UC_INLINE inline
+#endif
+/**
+ * Doubly Linked List.
+ * It is used either as
+ * 1) a linked list "head" - a node serving to hold pointer to the 
+ *                           first and last node in a list
+ * 2) a linked list entry  - a node in the linked list
+ *
+ * This is  variant of sys/queue.h TAILQ which avoids too many conditionals.
+ * The struct TailQ serves both as an entry/node in a linked list,
+ * and as head of a linked list.
+ * 
+ * Note that unlike the sys/queue.h TAILQ, the list does
+ * not begin/end with a NULL pointer. For a entry node, the beginning/end
+ * is a back pointer to the head node.
+ *
+ * Traditional linked list          TailQ
+ * node->prev == NULL               node->prev == head
+ * node->next == NULL               node->next == head
+ *
+ * Do not ever add an entry that's a NULL pointer.
+ *
+ */
+struct TailQ {
+    //pointer to next element, or for a head node,
+    //pointer to the first entry
+    struct TailQ *next;
+    //pointer to previous element, or for a head node,
+    //pointer to the last node
+    struct TailQ *prev;
+};
+
+#define UC_TAILQ_HEAD_INIT(name) {&(name), &(name)}
+
+#define UC_TAILQ_HEAD(name)\
+struct TailQ name = UC_TAILQ_HEAD_INIT(name)
+
+//given 'ptr' as a pointer to a struct 'member',
+//find the struct that ptr is the member of, where
+//'type' is the type of the containing struct
+//This is basically UC_CONTAINER_OF in ucore/utils.h, this is here
+//to make tailq.h a standalone header
+#define UC_TAILQ_CONTAINER(ptr, type, member) ({\
+typeof( ((type *)0)->member ) *__mptr = (ptr);    \
+    (type *)((void *)(unsigned char *)__mptr - offsetof(type, member) ); })
+
+
+static UC_INLINE void uc_tailq_init(struct TailQ *head)
+{
+    head->prev = head;
+    head->next = head;
+}
+
+/** Test if the tailq is empty
+ */
+static UC_INLINE int uc_tailq_empty(const struct TailQ *head)
+{
+    return head->next == head->prev;
+}
+
+/** Insert the entry between prev and next
+ */
+static UC_INLINE void uc_tailq_insert(struct TailQ *entry, 
+                                      struct TailQ *prev,
+                                      struct TailQ *next)
+{
+    entry->prev = prev;
+    prev->next  = entry;
+
+    entry->next = next;
+    next->prev  = entry;
+}
+
+/** Insert entry to the tail(end) of the tailq
+ */
+static UC_INLINE void uc_tailq_insert_tail(struct TailQ *head, struct TailQ *entry)
+{
+    //head becomes entry->next, signalling the end of the tailq
+    uc_tailq_insert(entry, head->prev, head);
+}
+
+/** Insert entry to the head(start) of the tailq
+ */
+static UC_INLINE void uc_tailq_insert_head(struct TailQ *head, struct TailQ *entry)
+{
+    //head becomes entry->prev, signalling the end of the tailq
+    uc_tailq_insert(entry, head, head->next);
+}
+
+/** Link the first and second entry together,
+ */
+static UC_INLINE void uc_tailq_link(struct TailQ *first, struct TailQ *second)
+{
+    first->next = second;
+    second->prev = first;
+}
+
+/** Remove the entry from the tailq it is part of.
+ * (It *must* already be part of a tailq.
+ */
+static UC_INLINE void uc_tailq_remove(struct TailQ *entry)
+{
+    uc_tailq_link(entry->prev, entry->next);
+
+//help catch illegal use:
+    entry->next = (void*)0x101;
+    entry->prev = (void*)0x102;
+}
+
+/** Move entry from its current tailq to the head of another tailq.
+ * (entry must be part of a tailq)
+ */
+static UC_INLINE void uc_tailq_move_head(struct TailQ *entry, struct TailQ *head)
+{
+    uc_tailq_link(entry->prev, entry->next);
+    uc_tailq_insert(entry, head, head->next);
+}
+
+/** Move entry from its current tailq to the tail of another tailq.
+ * (entry must be part of a tailq)
+ */
+static UC_INLINE void uc_tailq_move_tail(struct TailQ *entry, struct TailQ *head)
+{
+    uc_tailq_link(entry->prev, entry->next);
+    uc_tailq_insert(entry, head->prev, head);
+}
+
+//FIRST/NEXT/LAST/PREV macros similar to sys/queue.h 
+//Note that unlike the standard TAILQ, you have to check
+// != head instead of != NULL to determine if the tailq entry
+// exists
+
+#define UC_TAILQ_FIRST(head)\
+((head)->next)
+
+#define UC_TAILQ_NEXT(entry)\
+((entry)->next)
+
+#define UC_TAILQ_LAST(head)\
+((head)->prev)
+
+#define UC_TAILQ_PREV(entry)\
+((entry)->prev)
+
+/** Iterate over a tailq. The tailq cannot be altered while iterating.
+ *
+ * @param entry a struct TailQ* to which each element is assigned.
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH(entry, head)\
+    for ((entry) = UC_TAILQ_FIRST(head); \
+         (entry) != (head); \
+         (entry) = UC_TAILQ_NEXT(entry))
+
+/** Iterate over the containing element in a tailq. 
+ *  The tailq cannot be altered while iterating.
+ *
+ * @param ptr a pointer to the struct which the tailq nodes are member of
+ * @param member the member of ptr that is the tailq node
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH_CONTAINER(ptr, member, head)\
+    for ((ptr) = UC_TAILQ_CONTAINER(UC_TAILQ_FIRST(head), typeof(*ptr), member);\
+         &(ptr)->member != (head);\
+        (ptr) = UC_TAILQ_CONTAINER(UC_TAILQ_NEXT(&(ptr)->member), typeof(*ptr), member)) 
+
+/** Iterate over a tailq in reverse order. 
+ * The tailq cannot be altered while iterating.
+ *
+ * @param entry a struct TailQ* to which each element is assigned.
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH_REVERSE(entry, head)\
+    for ((entry) = UC_TAILQ_LAST(entry); \
+         (entry) != (head); \
+         (entry) = UC_TAILQ_PREV(entry)
+
+/** Iterate over the containing element in a tailq in reverse.
+ *  The tailq cannot be altered while iterating.
+ *
+ * @param ptr a pointer to the struct which the tailq nodes are member of
+ * @param member the member of ptr that is the tailq node
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH_REVERSE_CONTAINER(ptr, member, head)\
+    for ((ptr) = UC_TAILQ_CONTAINER(UC_TAILQ_LAST(head), typeof(*ptr), member);\
+         &(ptr)->member != (head);\
+        (ptr) = UC_TAILQ_CONTAINER(UC_TAILQ_PREV(&(ptr)->member), typeof(*ptr), member)) 
+
+/** Iterate over a tailq. safe to remove the entry when iterating.
+ *
+ * @param entry a struct TailQ* to which each element is assigned.
+ * @param nxt a struct TailQ* needed for temporary storage.
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH_SAFE(entry, nxt, head)\
+    for ((entry) = UC_TAILQ_FIRST(head), (nxt) = UC_TAILQ_NEXT(entry); \
+         (entry) != (head); \
+         (entry) = (nxt), (nxt) = UC_TAILQ_NEXT(entry))\
+
+/** Iterate over the containing element in a tailq, safe to remove
+ *  the entry when iterating
+ *
+ * @param ptr a pointer to the struct which the tailq nodes are member of
+ * @param nxt same type as ptr needed for temporary storage.
+ * @param member the member of ptr that is the tailq node
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH_CONTAINER_SAFE(ptr, nxt, member, head)\
+    for ((ptr) = UC_TAILQ_CONTAINER(UC_TAILQ_FIRST(head), typeof(*ptr), member),\
+         (nxt) = UC_TAILQ_CONTAINER(UC_TAILQ_NEXT(&(ptr)->member), typeof(*ptr), member);\
+         &(ptr)->member != (head);\
+        (ptr) = (nxt),\
+        (nxt) = UC_TAILQ_CONTAINER(UC_TAILQ_NEXT(&(ptr)->member), typeof(*ptr), member)) 
+
+/** Iterate over a tailq in reverse order. safe to remove the entry when 
+ *  iterating.
+ *
+ * @param entry a struct TailQ* to which each element is assigned.
+ * @param prv a struct TailQ* needed for temporary storage.
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH_REVERSE_SAFE(entry, prv, head)\
+    for ((entry) = UC_TAILQ_LAST(head), (prv) = UC_TAILQ_PREV(entry); \
+         (entry) != (head); \
+         (entry) = (prv), (prv) = UC_TAILQ_PREV(entry))\
+
+/** Iterate over the containing element in a tailq in reverse order, safe 
+ *  to remove the entry when iterating
+ *
+ * @param ptr a pointer to the struct which the tailq nodes are member of
+ * @param prv same type as ptr needed for temporary storage.
+ * @param member the member of ptr that is the tailq node
+ * @param head the struct TailQ* head of the tailq
+ */
+#define UC_TAILQ_FOREACH_REVERSE_CONTAINER_SAFE(ptr, prv, member, head)\
+    for ((ptr) = UC_TAILQ_CONTAINER(UC_TAILQ_LAST(head), typeof(*ptr), member),\
+         (prv) = UC_TAILQ_CONTAINER(UC_TAILQ_PREV(&(ptr)->member), typeof(*ptr), member);\
+         &(ptr)->member != (head);\
+        (ptr) = (prv),\
+        (prv) = UC_TAILQ_CONTAINER(UC_TAILQ_NEXT(&(ptr)->member), typeof(*ptr), member)) 
+
+#undef UC_INLINE
+
+#endif
diff --git a/include/ucore/utils.h b/include/ucore/utils.h
index 0b2e358..f3bedef 100644
--- a/include/ucore/utils.h
+++ b/include/ucore/utils.h
@@ -60,20 +60,21 @@ const typeof( ((const type *)0)->member ) *__mptr = (ptr);    \
 /**
  * Test if x is a power of 2
  * 
- * @param x value
+ * @param x value, must be an unsigned type
  * @return 1 if x is a power of 20, 0 if it is not
  */
 #define UC_IS_POW2(x) ((x) && !((x) & (x) - 1))
 
 /**
- *  * Expands @x and turns it into a string.
- *   */
+ * Expands @x and turns it into a string.
+ */
 #define UC_STRINGIFY(x) UC_STRINGIFY_HLP(x)
 #define UC_STRINGIFY_HLP(x) #x
 
 /** Macro that expands to a string for the current file:line
  */
 #define UC_SRC_LOCATION __FILE__ ":" UC_STRINGIFY(__LINE__)
+
 /** 
  * assert() that is not affected by NDEBUG define
  */
diff --git a/src/heapsort.c b/src/heapsort.c
deleted file mode 100644
index e291c89..0000000
--- a/src/heapsort.c
+++ /dev/null
@@ -1,41 +0,0 @@
-#include <string.h>
-#include "ucore/heapsort.h"
-
-static void
-uc_sift(unsigned char *base, size_t start, size_t count, size_t width,
-     uc_hs_cmp cmp)
-{
-    size_t root = start, child;
-
-    while ((root * 2 + 1) < count) {
-        child = root * 2 + 1;
-        if (child < (count - 1)
-            && cmp(&base[child * width], &base[(child + 1) * width]) < 0)
-            child++;
-
-        if (cmp(&base[root * width], &base[child * width]) < 0) {
-            memcpy(base + root * width, base + child * width, width);
-            root = child;
-        } else
-            return;
-    }
-}
-
-void
-uc_heapsort(void *base_, size_t count, size_t width,
-     uc_hs_cmp cmp)
-{
-    int start = count / 2 - 1, end = count - 1;
-    unsigned char *base = base_;
-
-    while (start >= 0) {
-        uc_sift(base, start, count, width, cmp);
-        start--;
-    }
-
-    while (end > 0) {
-        memcpy(base + end * width, base, width);
-        uc_sift(base, 0, end, width, cmp);
-        end--;
-    }
-}
diff --git a/src/htable.c b/src/htable.c
index 02fc876..51db6ae 100644
--- a/src/htable.c
+++ b/src/htable.c
@@ -50,13 +50,13 @@ struct UHNode *uc_htable_next_hash_hlp(struct UHNode *next, size_t hash)
 }
 
 //find a node, starting at bucket
-struct UHNode *uc_htable_iter_hlp(struct UHTable *table, size_t bucket)
+struct UHNode *uc_htable_iter_hlp(struct UHTable *table, size_t start_bucket)
 {
     size_t i;
     struct UHNode *found = NULL;
 
     //search through buckets until a node is found
-    for (i = bucket; i < table->cnt_buckets; i++) {
+    for (i = start_bucket; i < table->cnt_buckets; i++) {
         found = uc_htable_first_bucket(table, i);
         if (found != NULL) {
             break;
@@ -69,7 +69,7 @@ struct UHNode *uc_htable_next(struct UHTable *table, struct UHNode *node)
 {
     struct UHNode *found;
     
-    found = uc_htable_next_bucket(node);
+    found = uc_htable_next_in_bucket(node);
     if (found == NULL) {
         size_t current_bucket = uc_htable_bucket(table, node->hash);
         found = uc_htable_iter_hlp(table, current_bucket + 1);
diff --git a/src/logging.c b/src/logging.c
index 248e548..24445cd 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -75,6 +75,7 @@ static const char *const g_log_levels[] = {
     "WARNING",
     "UNKNOWN_6",
     "ERROR",
+    "UNKNOWN_8",
     "NONE"
 };
 
diff --git a/test/tailq_example.c b/test/tailq_example.c
new file mode 100644
index 0000000..e91609f
--- /dev/null
+++ b/test/tailq_example.c
@@ -0,0 +1,97 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ucore/tailq.h>
+#include <ucore/utils.h>
+
+struct Block {
+    char text[64];
+    struct TailQ blocks;
+};
+
+struct File {
+   char name[128];
+   struct TailQ head;
+};
+
+void add_block(struct File *f, const char *txt)
+{
+   struct Block *b = malloc(sizeof *b);
+   strcpy(b->text,txt); 
+   uc_tailq_insert_tail(&f->head, &b->blocks);
+}
+
+void print_file(struct File *f)
+{
+    struct Block *entry;
+    printf("File: %s\n", f->name);
+    UC_TAILQ_FOREACH_CONTAINER(entry, blocks, &f->head) {
+        printf("Block: %s\n", entry->text);
+    }
+}
+
+void print_file_reverse(struct File *f)
+{
+    struct Block *entry;
+    printf("File: %s\n", f->name);
+    UC_TAILQ_FOREACH_REVERSE_CONTAINER(entry, blocks, &f->head) {
+        printf("Block: %s\n", entry->text);
+    }
+}
+
+void delete_block(struct File *f, const char *txt)
+{
+    struct Block *entry, *next;
+    UC_TAILQ_FOREACH_CONTAINER_SAFE(entry, next, blocks, &f->head) {
+        if (strcmp(txt, entry->text) == 0) {
+            uc_tailq_remove(&entry->blocks);
+            free(entry);
+        }
+    }
+}
+
+void delete_all_blocks(struct File *f)
+{
+    struct Block *entry, *next;
+    UC_TAILQ_FOREACH_CONTAINER_SAFE(entry, next, blocks, &f->head) {
+        free(entry);
+    }
+    uc_tailq_init(&f->head);
+}
+
+int main(void)
+{
+    struct File f;
+    uc_tailq_init(&f.head);
+    printf("Is Empty: %d\n", uc_tailq_empty(&f.head));
+    strcpy(f.name,"Test.f");
+    add_block(&f,"one");
+    add_block(&f,"two");
+    add_block(&f,"three");
+
+    print_file(&f);
+    printf("Is Empty: %d\n", uc_tailq_empty(&f.head));
+
+    puts("\nDeleting three");
+    delete_block(&f, "three");
+    print_file(&f);
+
+    puts("\nAdding 2 blocks");
+    add_block(&f,"three");
+    add_block(&f,"three");
+    print_file(&f);
+    puts("\nReverse order:");
+    print_file_reverse(&f);
+
+    puts("\nDeleting three");
+    delete_block(&f, "three");
+    print_file(&f);
+
+    delete_all_blocks(&f);
+    printf("Is Empty: %d\n", uc_tailq_empty(&f.head));
+
+
+    return 0;
+}
+
+
diff --git a/test/udp_heartbeat.c b/test/udp_heartbeat.c
index 4eb3847..f964bca 100644
--- a/test/udp_heartbeat.c
+++ b/test/udp_heartbeat.c
@@ -102,6 +102,7 @@ void peer_add_addr(struct HBContext *ctx, const struct sockaddr_in *addr)
 
     peer->timer.callback = peer_timer_cb;
     peer->timer.cookie_ptr = ctx;
+    peer->state = PeerUnknown;
 
     sec = rand() % PEER_HB_SEC;
     usec = rand() % 1000000;