diff --git a/src/app-layer-parser.c b/src/app-layer-parser.c
index 250500a38c..4c6beea200 100644
--- a/src/app-layer-parser.c
+++ b/src/app-layer-parser.c
@@ -20,7 +20,19 @@
 
 #include "util-debug.h"
 
+static uint16_t app_layer_sid = 0;
+static AppLayerProto al_proto_table[ALPROTO_MAX];
+
+#define MAX_PARSERS 100
+static AppLayerParserTableElement al_parser_table[MAX_PARSERS];
+static uint16_t al_max_parsers = 0; /* incremented for every registered parser */
+
 static Pool *al_result_pool = NULL;
+static SCMutex al_result_pool_mutex = PTHREAD_MUTEX_INITIALIZER;
+#ifdef DEBUG
+static uint32_t al_result_pool_elmts = 0;
+#endif /* DEBUG */
+
 
 /** \brief Alloc a AppLayerParserResultElmt func for the pool */
 static void *AlpResultElmtPoolAlloc(void *null)
@@ -32,6 +44,11 @@ static void *AlpResultElmtPoolAlloc(void *null)
     }
 
     memset(e, 0, sizeof(AppLayerParserResultElmt));
+
+#ifdef DEBUG
+    al_result_pool_elmts++;
+    SCLogDebug("al_result_pool_elmts %"PRIu32"", al_result_pool_elmts);
+#endif /* DEBUG */
     return e;
 }
 
@@ -44,11 +61,19 @@ static void AlpResultElmtPoolFree(void *e)
             free(re->data_ptr);
     }
     free(re);
+
+#ifdef DEBUG
+    al_result_pool_elmts--;
+    SCLogDebug("al_result_pool_elmts %"PRIu32"", al_result_pool_elmts);
+#endif /* DEBUG */
 }
 
 static AppLayerParserResultElmt *AlpGetResultElmt(void)
 {
+    SCMutexLock(&al_result_pool_mutex);
     AppLayerParserResultElmt *e = (AppLayerParserResultElmt *)PoolGet(al_result_pool);
+    SCMutexUnlock(&al_result_pool_mutex);
+
     if (e == NULL) {
         return NULL;
     }
@@ -67,7 +92,9 @@ static void AlpReturnResultElmt(AppLayerParserResultElmt *e)
     e->data_len = 0;
     e->next = NULL;
 
+    SCMutexLock(&al_result_pool_mutex);
     PoolReturn(al_result_pool, (void *)e);
+    SCMutexUnlock(&al_result_pool_mutex);
 }
 
 static void AlpAppendResultElmt(AppLayerParserResult *r, AppLayerParserResultElmt *e)
@@ -426,13 +453,6 @@ int AlpParseFieldByDelimiter(AppLayerParserResult *output, AppLayerParserState *
     SCReturnInt(0);
 }
 
-static uint16_t app_layer_sid = 0;
-static AppLayerProto al_proto_table[ALPROTO_MAX];
-
-#define MAX_PARSERS 100
-static AppLayerParserTableElement al_parser_table[MAX_PARSERS];
-static uint16_t al_max_parsers = 0; /* incremented for every registered parser */
-
 /** \brief Get the Parsers id for storing the parser state.
  *
  * \retval Parser subsys id
diff --git a/src/flow.c b/src/flow.c
index 907a65e9bc..16e6160ceb 100644
--- a/src/flow.c
+++ b/src/flow.c
@@ -203,9 +203,9 @@ static int FlowPrune (FlowQueue *q, struct timeval *ts)
 
     /* remove from the hash */
     if (f->hprev)
-            f->hprev->hnext = f->hnext;
+        f->hprev->hnext = f->hnext;
     if (f->hnext)
-            f->hnext->hprev = f->hprev;
+        f->hnext->hprev = f->hprev;
     if (f->fb->f == f)
         f->fb->f = f->hnext;
 
@@ -249,9 +249,7 @@ static int FlowUpdateSpareFlows(void) {
     uint32_t toalloc = 0, tofree = 0, len;
 
     SCMutexLock(&flow_spare_q.mutex_q);
-
     len = flow_spare_q.len;
-
     SCMutexUnlock(&flow_spare_q.mutex_q);
 
     if (len < flow_config.prealloc) {
@@ -272,6 +270,7 @@ static int FlowUpdateSpareFlows(void) {
 
         uint32_t i;
         for (i = 0; i < tofree; i++) {
+            /* FlowDequeue locks the queue */
             Flow *f = FlowDequeue(&flow_spare_q);
             if (f == NULL)
                 return 1;
diff --git a/src/stream-tcp-reassemble.c b/src/stream-tcp-reassemble.c
index 951d7a919d..9476f56dd2 100644
--- a/src/stream-tcp-reassemble.c
+++ b/src/stream-tcp-reassemble.c
@@ -75,7 +75,8 @@ void *TcpSegmentPoolAlloc(void *payload_len) {
 #ifdef DEBUG
     SCMutexLock(&segment_pool_memuse_mutex);
     segment_pool_memuse += seg->payload_len;
-    segment_pool_memcnt ++;
+    segment_pool_memcnt++;
+    SCLogDebug("segment_pool_memcnt %"PRIu64"", segment_pool_memcnt);
     SCMutexUnlock(&segment_pool_memuse_mutex);
 #endif
     return seg;
@@ -89,6 +90,14 @@ void TcpSegmentPoolFree(void *ptr) {
     TcpSegment *seg = (TcpSegment *) ptr;
     free(seg->payload);
     free(seg);
+
+#ifdef DEBUG
+    SCMutexLock(&segment_pool_memuse_mutex);
+    segment_pool_memuse -= seg->payload_len;
+    segment_pool_memcnt--;
+    SCLogDebug("segment_pool_memcnt %"PRIu64"", segment_pool_memcnt);
+    SCMutexUnlock(&segment_pool_memuse_mutex);
+#endif
     return;
 }