[dpdk-dev] [PATCH v1 1/2] examples/l2fwd-keepalive: add graceful exit

[Remy Horton]

The l2fwd-keepalive example has infinite processing loops and as a
result the only way to exit it is via SIGINT/SIGTERM (e.g. Control-C).
The resulting shutdown is unclean, which is fixed by adding a signal
handler that causes the processing loops to break.

Fixes: e64833f2273a ("examples/l2fwd-keepalive: add sample application")

Signed-off-by: Remy Horton <remy.horton at intel.com>
---
 doc/guides/rel_notes/release_17_05.rst |  4 ++++
 examples/l2fwd-keepalive/main.c        | 25 +++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/doc/guides/rel_notes/release_17_05.rst b/doc/guides/rel_notes/release_17_05.rst
index ad20e86..aefa406 100644
--- a/doc/guides/rel_notes/release_17_05.rst
+++ b/doc/guides/rel_notes/release_17_05.rst
@@ -334,6 +334,10 @@ Libraries
 Examples
 ~~~~~~~~
 
+* **l2fwd-keepalive: Fixed unclean shutdowns.**
+
+  Added clean shutdown to l2fwd-keepalive so that it can free up
+  stale resources used for inter-process communication.
 
 Other
 ~~~~~
diff --git a/examples/l2fwd-keepalive/main.c b/examples/l2fwd-keepalive/main.c
index 4623d2a..5fdbdef 100644
--- a/examples/l2fwd-keepalive/main.c
+++ b/examples/l2fwd-keepalive/main.c
@@ -44,6 +44,7 @@
 #include <ctype.h>
 #include <errno.h>
 #include <getopt.h>
+#include <signal.h>
 
 #include <rte_common.h>
 #include <rte_log.h>
@@ -142,6 +143,15 @@ static int64_t check_period = 5; /* default check cycle is 5ms */
 /* Keepalive structure */
 struct rte_keepalive *rte_global_keepalive_info;
 
+/* Termination signalling */
+static int terminate_signal_received;
+
+/* Termination signal handler */
+static void handle_sigterm(__rte_unused int value)
+{
+	terminate_signal_received = 1;
+}
+
 /* Print out statistics on packets dropped */
 static void
 print_stats(__attribute__((unused)) struct rte_timer *ptr_timer,
@@ -251,7 +261,7 @@ l2fwd_main_loop(void)
 	uint64_t tsc_initial = rte_rdtsc();
 	uint64_t tsc_lifetime = (rand()&0x07) * rte_get_tsc_hz();
 
-	while (1) {
+	while (!terminate_signal_received) {
 		/* Keepalive heartbeat */
 		rte_keepalive_mark_alive(rte_global_keepalive_info);
 
@@ -526,6 +536,8 @@ check_all_ports_link_status(uint8_t port_num, uint32_t port_mask)
 static void
 dead_core(__rte_unused void *ptr_data, const int id_core)
 {
+	if (terminate_signal_received)
+		return;
 	printf("Dead core %i - restarting..\n", id_core);
 	if (rte_eal_get_lcore_state(id_core) == FINISHED) {
 		rte_eal_wait_lcore(id_core);
@@ -554,6 +566,15 @@ main(int argc, char **argv)
 	uint8_t portid, last_port;
 	unsigned lcore_id, rx_lcore_id;
 	unsigned nb_ports_in_mask = 0;
+	struct sigaction signal_handler;
+
+	memset(&signal_handler, 0, sizeof(signal_handler));
+	terminate_signal_received = 0;
+	signal_handler.sa_handler = &handle_sigterm;
+	if (sigaction(SIGINT, &signal_handler, NULL) == -1 ||
+			sigaction(SIGTERM, &signal_handler, NULL) == -1)
+		rte_exit(EXIT_FAILURE, "SIGNAL\n");
+
 
 	/* init EAL */
 	ret = rte_eal_init(argc, argv);
@@ -782,7 +803,7 @@ main(int argc, char **argv)
 				lcore_id);
 		}
 	}
-	for (;;) {
+	while (!terminate_signal_received) {
 		rte_timer_manage();
 		rte_delay_ms(5);
 		}
-- 
2.5.5