Add ff_stop_run to stop the poll loop

doc/F-Stack_API_Reference.md

@@ -49,6 +49,12 @@ However, it is  supported only before F-Stack is started.
   The ioctl() function manipulates the underlying device parameters of special files.
   more info see man ioctl.
 
+#### ff_stop_run
+
+	void ff_stop_run();
+
+  Stop the infinite poll loop started by `ff_run`.
+
 ### Network API
 
 #### ff_socket

lib/ff_api.h

@@ -55,6 +55,8 @@ int ff_init(int argc, char * const argv[]);
 
 void ff_run(loop_func_t loop, void *arg);
 
+void ff_stop_run(void);
+
 /* POSIX-LIKE api begin */
 
 int ff_fcntl(int fd, int cmd, ...);

lib/ff_dpdk_if.c

@@ -80,6 +80,7 @@ static int numa_on;
 static unsigned idle_sleep;
 static unsigned pkt_tx_delay;
 static uint64_t usr_cb_tsc;
+static int stop_loop;
 
 static struct rte_timer freebsd_clock;
 
@@ -2005,6 +2006,11 @@ main_loop(void *arg)
     qconf = &lcore_conf;
 
     while (1) {
+
+        if (unlikely(stop_loop)) {
+            break;
+        }
+
         cur_tsc = rte_rdtsc();
         if (unlikely(freebsd_clock.expire < cur_tsc)) {
             rte_timer_manage();
@@ -2136,6 +2142,7 @@ void
 ff_dpdk_run(loop_func_t loop, void *arg) {
     struct loop_routine *lr = rte_malloc(NULL,
         sizeof(struct loop_routine), 0);
+    stop_loop = 0;
     lr->loop = loop;
     lr->arg = arg;
     rte_eal_mp_remote_launch(main_loop, lr, CALL_MAIN);
@@ -2143,6 +2150,11 @@ ff_dpdk_run(loop_func_t loop, void *arg) {
     rte_free(lr);
 }
 
+void
+ff_dpdk_stop(void) {
+    stop_loop = 1;
+}
+
 void
 ff_dpdk_pktmbuf_free(void *m)
 {

lib/ff_dpdk_if.h

@@ -39,6 +39,7 @@ struct loop_routine {
 int ff_dpdk_init(int argc, char **argv);
 int ff_dpdk_if_up(void);
 void ff_dpdk_run(loop_func_t loop, void *arg);
+void ff_dpdk_stop(void);
 
 struct ff_dpdk_if_context;
 struct ff_port_cfg;

lib/ff_init.c

@@ -61,3 +61,9 @@ ff_run(loop_func_t loop, void *arg)
     ff_dpdk_run(loop, arg);
 }
 
+void
+ff_stop_run(void)
+{
+    ff_dpdk_stop();
+}
+