diff --git a/src/core/stellar_core.cpp b/src/core/stellar_core.cpp
index eef53c0..e9fd970 100644
--- a/src/core/stellar_core.cpp
+++ b/src/core/stellar_core.cpp
@@ -594,7 +594,7 @@ void stellar_run(struct stellar *st)
         usleep(1000); // 1ms
 
         // only available in dump file mode, automatically exits when all sessions have been released
-        if (packet_io_wait_exit(runtime->packet_io) && all_session_have_freed(runtime, config))
+        if (packet_io_isbreak(runtime->packet_io) && all_session_have_freed(runtime, config))
         {
             stellar_stat_output(runtime->stat); // flush stat
             STELLAR_LOG_STATE("all sessions have been released, notify threads to exit");
diff --git a/src/packet_io/CMakeLists.txt b/src/packet_io/CMakeLists.txt
index b2e55fc..8f07fd7 100644
--- a/src/packet_io/CMakeLists.txt
+++ b/src/packet_io/CMakeLists.txt
@@ -1,4 +1,4 @@
-add_library(packet_io dumpfile_io.cpp marsio_io.cpp lock_free_queue.cpp packet_io.cpp)
+add_library(packet_io dumpfile_io.cpp marsio_io.cpp packet_io.cpp)
 target_include_directories(packet_io PUBLIC ${CMAKE_CURRENT_LIST_DIR})
 target_include_directories(packet_io PUBLIC ${CMAKE_SOURCE_DIR}/src/stellar)
 target_link_libraries(packet_io marsio pcap packet)
\ No newline at end of file
diff --git a/src/packet_io/dumpfile_io.cpp b/src/packet_io/dumpfile_io.cpp
index d19585c..f8fc887 100644
--- a/src/packet_io/dumpfile_io.cpp
+++ b/src/packet_io/dumpfile_io.cpp
@@ -16,7 +16,6 @@
 #include "packet_private.h"
 #include "packet_parser.h"
 #include "packet_dump.h"
-#include "lock_free_queue.h"
 
 #define PACKET_IO_LOG_STATE(format, ...) LOG_STATE("dumpfile", format, ##__VA_ARGS__)
 #define PACKET_IO_LOG_ERROR(format, ...) LOG_ERROR("dumpfile", format, ##__VA_ARGS__)
@@ -30,7 +29,7 @@ struct dumpfile_io
     char dumpfile_path[256];
 
     pcap_t *pcap;
-    struct lock_free_queue *queue[MAX_THREAD_NUM];
+    struct packet_queue *queue[MAX_THREAD_NUM];
     struct packet_io_stat stat[MAX_THREAD_NUM];
     uint64_t io_thread_need_exit;
     uint64_t io_thread_is_runing;
@@ -44,10 +43,93 @@ struct pcap_pkt
 };
 
 /******************************************************************************
- * Private API
+ * Private API -- queue
  ******************************************************************************/
 
-static void pcap_packet_handler(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes)
+struct packet_queue
+{
+    uint64_t *queue;
+    uint32_t size;
+    uint32_t head;
+    uint32_t tail;
+};
+
+static struct packet_queue *packet_queue_new(uint32_t size)
+{
+    struct packet_queue *queue = (struct packet_queue *)calloc(1, sizeof(struct packet_queue));
+    if (queue == NULL)
+    {
+        PACKET_IO_LOG_ERROR("unable to new packet queue");
+        return NULL;
+    }
+
+    queue->queue = (uint64_t *)calloc(size, sizeof(uint64_t));
+    if (queue->queue == NULL)
+    {
+        PACKET_IO_LOG_ERROR("unable to new packet queue");
+        free(queue);
+        return NULL;
+    }
+
+    queue->size = size;
+    queue->head = 0;
+    queue->tail = 0;
+
+    return queue;
+}
+
+static void packet_queue_free(struct packet_queue *queue)
+{
+    if (queue == NULL)
+    {
+        return;
+    }
+
+    if (queue->queue)
+    {
+        free(queue->queue);
+        queue->queue = NULL;
+    }
+
+    free(queue);
+}
+
+static int packet_queue_push(struct packet_queue *queue, void *data)
+{
+    if (__sync_val_compare_and_swap(&queue->queue[queue->tail], 0, data) != 0)
+    {
+        PACKET_IO_LOG_ERROR("packet queue is full, retry later");
+        return -1;
+    }
+
+    queue->tail = (queue->tail + 1) % queue->size;
+    return 0;
+}
+
+static void packet_queue_pop(struct packet_queue *queue, void **data)
+{
+    uint64_t read = ATOMIC_READ(&queue->queue[queue->head]);
+    if (read == 0)
+    {
+        *data = NULL;
+        return;
+    }
+    __sync_val_compare_and_swap(&queue->queue[queue->head], read, 0);
+    *data = (void *)read;
+    queue->head = (queue->head + 1) % queue->size;
+}
+
+static int packet_queue_isempty(struct packet_queue *queue)
+{
+    uint64_t read = ATOMIC_READ(&queue->queue[queue->head]);
+    return read == 0;
+}
+
+/******************************************************************************
+ * Private API -- utils
+ ******************************************************************************/
+
+static void pcap_pkt_handler(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes)
 {
     struct dumpfile_io *handle = (struct dumpfile_io *)user;
 
@@ -69,8 +151,8 @@ static void pcap_packet_handler(u_char *user, const struct pcap_pkthdr *h, const
     uint64_t hash = packet_ldbc_hash(&pkt, PKT_LDBC_METH_OUTERMOST_INT_EXT_IP, PACKET_DIRECTION_OUTGOING);
 
     // push packet to queue
-    struct lock_free_queue *queue = handle->queue[hash % handle->nr_threads];
-    while (lock_free_queue_push(queue, pcap_pkt) == -1)
+    struct packet_queue *queue = handle->queue[hash % handle->nr_threads];
+    while (packet_queue_push(queue, pcap_pkt) == -1)
     {
         if (ATOMIC_READ(&handle->io_thread_need_exit))
         {
@@ -103,7 +185,7 @@ static int dumpfile_handler(struct dumpfile_io *handle, const char *pcap_file)
         PACKET_IO_LOG_ERROR("unable to open pcap file: %s, %s", resolved_path, pcap_errbuf);
         return -1;
     }
-    pcap_loop(handle->pcap, -1, pcap_packet_handler, (u_char *)handle);
+    pcap_loop(handle->pcap, -1, pcap_pkt_handler, (u_char *)handle);
     pcap_close(handle->pcap);
 
     PACKET_IO_LOG_STATE("dumpfile %s processed", resolved_path)
@@ -115,7 +197,7 @@ static int all_packet_processed(struct dumpfile_io *handle)
 {
     for (uint16_t i = 0; i < handle->nr_threads; i++)
     {
-        if (!lock_free_queue_empty(handle->queue[i]))
+        if (!packet_queue_isempty(handle->queue[i]))
         {
             return 0;
         }
@@ -213,7 +295,7 @@ struct dumpfile_io *dumpfile_io_new(const char *dumpfile_path, enum packet_io_mo
 
     for (uint16_t i = 0; i < handle->nr_threads; i++)
     {
-        handle->queue[i] = lock_free_queue_new(MAX_PACKET_QUEUE_SIZE);
+        handle->queue[i] = packet_queue_new(MAX_PACKET_QUEUE_SIZE);
         if (handle->queue[i] == NULL)
         {
             PACKET_IO_LOG_ERROR("unable to create packet queue");
@@ -249,7 +331,7 @@ void dumpfile_io_free(struct dumpfile_io *handle)
         {
             while (1)
             {
-                lock_free_queue_pop(handle->queue[i], (void **)&pcap_pkt);
+                packet_queue_pop(handle->queue[i], (void **)&pcap_pkt);
                 if (pcap_pkt)
                 {
                     free(pcap_pkt);
@@ -260,14 +342,14 @@ void dumpfile_io_free(struct dumpfile_io *handle)
                 }
             }
 
-            lock_free_queue_free(handle->queue[i]);
+            packet_queue_free(handle->queue[i]);
         }
         free(handle);
         handle = NULL;
     }
 }
 
-int dumpfile_io_wait_exit(struct dumpfile_io *handle)
+int dumpfile_io_isbreak(struct dumpfile_io *handle)
 {
     return ATOMIC_READ(&handle->io_thread_wait_exit);
 }
@@ -277,17 +359,17 @@ int dumpfile_io_init(struct dumpfile_io *handle __attribute__((unused)), uint16_
     return 0;
 }
 
-int dumpfile_io_ingress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+uint16_t dumpfile_io_ingress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
-    struct lock_free_queue *queue = handle->queue[thr_idx];
+    struct packet_queue *queue = handle->queue[thr_idx];
     struct packet_io_stat *stat = &handle->stat[thr_idx];
     struct pcap_pkt *pcap_pkt = NULL;
     struct packet *pkt;
-    int nr_parsed = 0;
+    uint16_t nr_parsed = 0;
 
-    for (int i = 0; i < nr_pkts; i++)
+    for (uint16_t i = 0; i < nr_pkts; i++)
     {
-        lock_free_queue_pop(queue, (void **)&pcap_pkt);
+        packet_queue_pop(queue, (void **)&pcap_pkt);
         if (pcap_pkt == NULL)
         {
             break;
@@ -312,13 +394,13 @@ int dumpfile_io_ingress(struct dumpfile_io *handle, uint16_t thr_idx, struct pac
     return nr_parsed;
 }
 
-void dumpfile_io_egress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+void dumpfile_io_egress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     int len;
     struct packet *pkt = NULL;
     struct packet_io_stat *stat = &handle->stat[thr_idx];
 
-    for (int i = 0; i < nr_pkts; i++)
+    for (uint16_t i = 0; i < nr_pkts; i++)
     {
         pkt = &pkts[i];
         len = packet_get_raw_len(pkt);
@@ -338,12 +420,12 @@ void dumpfile_io_egress(struct dumpfile_io *handle, uint16_t thr_idx, struct pac
     }
 }
 
-void dumpfile_io_drop(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+void dumpfile_io_drop(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     struct packet *pkt = NULL;
     struct packet_io_stat *stat = &handle->stat[thr_idx];
 
-    for (int i = 0; i < nr_pkts; i++)
+    for (uint16_t i = 0; i < nr_pkts; i++)
     {
         pkt = &pkts[i];
         struct pcap_pkt *pcap_pkt = (struct pcap_pkt *)packet_get_origin_ctx(pkt);
@@ -357,7 +439,7 @@ void dumpfile_io_drop(struct dumpfile_io *handle, uint16_t thr_idx, struct packe
     }
 }
 
-int dumpfile_io_inject(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+uint16_t dumpfile_io_inject(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     uint16_t len;
     struct packet *pkt = NULL;
@@ -368,7 +450,7 @@ int dumpfile_io_inject(struct dumpfile_io *handle, uint16_t thr_idx, struct pack
     char src_addr[INET6_ADDRSTRLEN] = {0};
     char dst_addr[INET6_ADDRSTRLEN] = {0};
 
-    for (int i = 0; i < nr_pkts; i++)
+    for (uint16_t i = 0; i < nr_pkts; i++)
     {
         pkt = &pkts[i];
         len = packet_get_raw_len(pkt);
diff --git a/src/packet_io/dumpfile_io.h b/src/packet_io/dumpfile_io.h
index 7f76ddb..25d6ccc 100644
--- a/src/packet_io/dumpfile_io.h
+++ b/src/packet_io/dumpfile_io.h
@@ -10,13 +10,13 @@ extern "C"
 struct dumpfile_io;
 struct dumpfile_io *dumpfile_io_new(const char *dumpfile_path, enum packet_io_mode mode, uint16_t nr_threads);
 void dumpfile_io_free(struct dumpfile_io *handle);
-int dumpfile_io_wait_exit(struct dumpfile_io *handle);
+int dumpfile_io_isbreak(struct dumpfile_io *handle);
 
 int dumpfile_io_init(struct dumpfile_io *handle, uint16_t thr_idx);
-int dumpfile_io_ingress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-void dumpfile_io_egress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-void dumpfile_io_drop(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-int dumpfile_io_inject(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
+uint16_t dumpfile_io_ingress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+void dumpfile_io_egress(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+void dumpfile_io_drop(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+uint16_t dumpfile_io_inject(struct dumpfile_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
 void dumpfile_io_yield(struct dumpfile_io *handle, uint16_t thr_idx, uint64_t timeout_ms);
 struct packet_io_stat *dumpfile_io_stat(struct dumpfile_io *handle, uint16_t thr_idx);
 
diff --git a/src/packet_io/lock_free_queue.cpp b/src/packet_io/lock_free_queue.cpp
deleted file mode 100644
index b3d60c1..0000000
--- a/src/packet_io/lock_free_queue.cpp
+++ /dev/null
@@ -1,90 +0,0 @@
-#include <pthread.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdint.h>
-
-#include "log.h"
-#include "utils.h"
-#include "lock_free_queue.h"
-
-#define LOCK_FREE_QUEUE_LOG_ERROR(format, ...) LOG_ERROR("lock free queue", format, ##__VA_ARGS__)
-#define LOCK_FREE_QUEUE_LOG_DEBUG(format, ...) LOG_DEBUG("lock free queue", format, ##__VA_ARGS__)
-
-struct lock_free_queue
-{
-    uint64_t *queue;
-    uint32_t size;
-    uint32_t head;
-    uint32_t tail;
-};
-
-struct lock_free_queue *lock_free_queue_new(uint32_t size)
-{
-    struct lock_free_queue *queue = (struct lock_free_queue *)calloc(1, sizeof(struct lock_free_queue));
-    if (queue == NULL)
-    {
-        LOCK_FREE_QUEUE_LOG_ERROR("unable to new lock free queue");
-        return NULL;
-    }
-
-    queue->queue = (uint64_t *)calloc(size, sizeof(uint64_t));
-    if (queue->queue == NULL)
-    {
-        LOCK_FREE_QUEUE_LOG_ERROR("unable to new lock free queue");
-        free(queue);
-        return NULL;
-    }
-
-    queue->size = size;
-    queue->head = 0;
-    queue->tail = 0;
-
-    return queue;
-}
-
-void lock_free_queue_free(struct lock_free_queue *queue)
-{
-    if (queue == NULL)
-    {
-        return;
-    }
-
-    if (queue->queue)
-    {
-        free(queue->queue);
-        queue->queue = NULL;
-    }
-
-    free(queue);
-}
-
-int lock_free_queue_push(struct lock_free_queue *queue, void *data)
-{
-    if (__sync_val_compare_and_swap(&queue->queue[queue->tail], 0, data) != 0)
-    {
-        LOCK_FREE_QUEUE_LOG_ERROR("lock free queue is full, retry later");
-        return -1;
-    }
-
-    queue->tail = (queue->tail + 1) % queue->size;
-    return 0;
-}
-
-void lock_free_queue_pop(struct lock_free_queue *queue, void **data)
-{
-    uint64_t read = ATOMIC_READ(&queue->queue[queue->head]);
-    if (read == 0)
-    {
-        *data = NULL;
-        return;
-    }
-    __sync_val_compare_and_swap(&queue->queue[queue->head], read, 0);
-    *data = (void *)read;
-    queue->head = (queue->head + 1) % queue->size;
-}
-
-int lock_free_queue_empty(struct lock_free_queue *queue)
-{
-    uint64_t read = ATOMIC_READ(&queue->queue[queue->head]);
-    return read == 0;
-}
\ No newline at end of file
diff --git a/src/packet_io/lock_free_queue.h b/src/packet_io/lock_free_queue.h
deleted file mode 100644
index 7acbc62..0000000
--- a/src/packet_io/lock_free_queue.h
+++ /dev/null
@@ -1,19 +0,0 @@
-#pragma once
-
-#ifdef __cplusplus
-extern "C"
-{
-#endif
-
-struct lock_free_queue;
-
-struct lock_free_queue *lock_free_queue_new(uint32_t size);
-void lock_free_queue_free(struct lock_free_queue *queue);
-int lock_free_queue_empty(struct lock_free_queue *queue);
-
-int lock_free_queue_push(struct lock_free_queue *queue, void *data);
-void lock_free_queue_pop(struct lock_free_queue *queue, void **data);
-
-#ifdef __cplusplus
-}
-#endif
diff --git a/src/packet_io/marsio_io.cpp b/src/packet_io/marsio_io.cpp
index 3fce3d8..89f8b26 100644
--- a/src/packet_io/marsio_io.cpp
+++ b/src/packet_io/marsio_io.cpp
@@ -256,21 +256,20 @@ int marsio_io_init(struct marsio_io *handle, uint16_t thr_idx __attribute__((unu
     return 0;
 }
 
-int marsio_io_ingress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+uint16_t marsio_io_ingress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     struct packet *pkt;
     marsio_buff_t *mbuff;
     marsio_buff_t *rx_buffs[RX_BURST_MAX];
     struct packet_io_stat *stat = &handle->stat[thr_idx];
-    int nr_recv;
-    int nr_parsed = 0;
+    uint16_t nr_parsed = 0;
     int len;
     char *data;
 
-    nr_recv = marsio_recv_burst(handle->mr_dev, thr_idx, rx_buffs, MIN(RX_BURST_MAX, nr_pkts));
+    int nr_recv = marsio_recv_burst(handle->mr_dev, thr_idx, rx_buffs, MIN(RX_BURST_MAX, nr_pkts));
     if (nr_recv <= 0)
     {
-        return 0;
+        return nr_parsed;
     }
 
     for (int i = 0; i < nr_recv; i++)
@@ -294,10 +293,9 @@ int marsio_io_ingress(struct marsio_io *handle, uint16_t thr_idx, struct packet
             continue;
         }
 
-        pkt = &pkts[nr_parsed];
+        pkt = &pkts[nr_parsed++];
         packet_parse(pkt, data, len);
         metadata_from_mbuff_to_packet(mbuff, pkt);
-        nr_parsed++;
 
         if (marsio_buff_is_ctrlbuf(mbuff))
         {
@@ -314,14 +312,14 @@ int marsio_io_ingress(struct marsio_io *handle, uint16_t thr_idx, struct packet
     return nr_parsed;
 }
 
-void marsio_io_egress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+void marsio_io_egress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     struct packet *pkt;
     marsio_buff_t *mbuff;
     struct packet_io_stat *stat = &handle->stat[thr_idx];
     int len;
 
-    for (int i = 0; i < nr_pkts; i++)
+    for (uint16_t i = 0; i < nr_pkts; i++)
     {
         pkt = &pkts[i];
         len = packet_get_raw_len(pkt);
@@ -349,13 +347,13 @@ void marsio_io_egress(struct marsio_io *handle, uint16_t thr_idx, struct packet
     }
 }
 
-void marsio_io_drop(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+void marsio_io_drop(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     struct packet *pkt;
     marsio_buff_t *mbuff;
     struct packet_io_stat *stat = &handle->stat[thr_idx];
 
-    for (int i = 0; i < nr_pkts; i++)
+    for (uint16_t i = 0; i < nr_pkts; i++)
     {
         pkt = &pkts[i];
         mbuff = (marsio_buff_t *)packet_get_origin_ctx(pkt);
@@ -369,16 +367,16 @@ void marsio_io_drop(struct marsio_io *handle, uint16_t thr_idx, struct packet *p
     }
 }
 
-int marsio_io_inject(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+uint16_t marsio_io_inject(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     int len;
-    int nr_inject = 0;
     char *ptr;
+    uint16_t nr_inject = 0;
     struct packet *pkt;
     marsio_buff_t *mbuff;
     struct packet_io_stat *stat = &handle->stat[thr_idx];
 
-    for (int i = 0; i < nr_pkts; i++)
+    for (uint16_t i = 0; i < nr_pkts; i++)
     {
         pkt = &pkts[i];
         len = packet_get_raw_len(pkt);
diff --git a/src/packet_io/marsio_io.h b/src/packet_io/marsio_io.h
index 0bd0ba5..45d6cd8 100644
--- a/src/packet_io/marsio_io.h
+++ b/src/packet_io/marsio_io.h
@@ -12,10 +12,10 @@ struct marsio_io *marsio_io_new(const char *app_symbol, const char *dev_symbol,
 void marsio_io_free(struct marsio_io *handle);
 
 int marsio_io_init(struct marsio_io *handle, uint16_t thr_idx);
-int marsio_io_ingress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-void marsio_io_egress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-void marsio_io_drop(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-int marsio_io_inject(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
+uint16_t marsio_io_ingress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+void marsio_io_egress(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+void marsio_io_drop(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+uint16_t marsio_io_inject(struct marsio_io *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
 void marsio_io_yield(struct marsio_io *handle, uint16_t thr_idx, uint64_t timeout_ms);
 struct packet_io_stat *marsio_io_stat(struct marsio_io *handle, uint16_t thr_idx);
 
diff --git a/src/packet_io/packet_io.cpp b/src/packet_io/packet_io.cpp
index b1049b7..b1fa2f3 100644
--- a/src/packet_io/packet_io.cpp
+++ b/src/packet_io/packet_io.cpp
@@ -57,7 +57,7 @@ void packet_io_free(struct packet_io *packet_io)
     }
 }
 
-int packet_io_wait_exit(struct packet_io *packet_io) // used for dumpfile mode
+int packet_io_isbreak(struct packet_io *packet_io) // used for dumpfile mode
 {
     if (likely(packet_io->mode == PACKET_IO_MARSIO))
     {
@@ -65,7 +65,7 @@ int packet_io_wait_exit(struct packet_io *packet_io) // used for dumpfile mode
     }
     else
     {
-        return dumpfile_io_wait_exit(packet_io->dumpfile);
+        return dumpfile_io_isbreak(packet_io->dumpfile);
     }
 }
 
@@ -81,7 +81,7 @@ int packet_io_init(struct packet_io *packet_io, uint16_t thr_idx)
     }
 }
 
-int packet_io_ingress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+uint16_t packet_io_ingress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     if (likely(packet_io->mode == PACKET_IO_MARSIO))
     {
@@ -93,7 +93,7 @@ int packet_io_ingress(struct packet_io *packet_io, uint16_t thr_idx, struct pack
     }
 }
 
-void packet_io_egress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+void packet_io_egress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     if (likely(packet_io->mode == PACKET_IO_MARSIO))
     {
@@ -105,7 +105,7 @@ void packet_io_egress(struct packet_io *packet_io, uint16_t thr_idx, struct pack
     }
 }
 
-void packet_io_drop(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+void packet_io_drop(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     if (likely(packet_io->mode == PACKET_IO_MARSIO))
     {
@@ -117,7 +117,7 @@ void packet_io_drop(struct packet_io *packet_io, uint16_t thr_idx, struct packet
     }
 }
 
-int packet_io_inject(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts)
+uint16_t packet_io_inject(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
 {
     if (likely(packet_io->mode == PACKET_IO_MARSIO))
     {
diff --git a/src/packet_io/packet_io.h b/src/packet_io/packet_io.h
index ef1a16f..c04d79b 100644
--- a/src/packet_io/packet_io.h
+++ b/src/packet_io/packet_io.h
@@ -71,13 +71,13 @@ struct packet_io_options
 struct packet_io;
 struct packet_io *packet_io_new(struct packet_io_options *opts);
 void packet_io_free(struct packet_io *packet_io);
-int packet_io_wait_exit(struct packet_io *packet_io); // used for dumpfile mode
+int packet_io_isbreak(struct packet_io *packet_io); // used for dumpfile mode
 
 int packet_io_init(struct packet_io *packet_io, uint16_t thr_idx);
-int packet_io_ingress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-void packet_io_egress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-void packet_io_drop(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
-int packet_io_inject(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, int nr_pkts);
+uint16_t packet_io_ingress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+void packet_io_egress(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+void packet_io_drop(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
+uint16_t packet_io_inject(struct packet_io *packet_io, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts);
 void packet_io_yield(struct packet_io *packet_io, uint16_t thr_idx, uint64_t timeout_ms);
 struct packet_io_stat *packet_io_stat(struct packet_io *packet_io, uint16_t thr_idx);