native: Handle gracefully SIGTERM and SIGINT

When SIGTERM or SIGINT are received handle them
by gracefully exiting the program.

Fixes #5477

Signed-off-by: Alberto Escolar Piedras <alpi@oticon.com>

arch/posix/CMakeLists.txt

@@ -20,7 +20,7 @@ zephyr_link_libraries_ifdef(CONFIG_COVERAGE
 	-lgcov
 	)
 
-zephyr_compile_definitions(_POSIX_C_SOURCE=199309)
+zephyr_compile_definitions(_POSIX_C_SOURCE=200809)
 
 zephyr_ld_options(
   -ldl

boards/posix/native_posix/hw_models_top.c

@@ -5,10 +5,13 @@
  */
 
 /**
- * Barebones HW model sufficient to run some of the sample apps
+ * Bare-bones HW model sufficient to run some of the sample apps
+ * and regression tests
  */
 
 #include <stdint.h>
+#include <signal.h>
+#include <stddef.h>
 #include "hw_models_top.h"
 #include "timer_model.h"
 #include "irq_ctrl.h"
@@ -33,6 +36,56 @@ static u64_t *Timer_list[NUMBER_OF_TIMERS] = {
 
 static u64_t next_timer_time;
 
+/* Have we received a SIGTERM or SIGINT */
+static volatile sig_atomic_t signaled_end;
+
+
+/**
+ * Handler for SIGTERM and SIGINT
+ */
+void hwm_signal_end_handler(int sig)
+{
+	signaled_end = 1;
+}
+
+/**
+ * Set the handler for SIGTERM and SIGINT which will cause the
+ * program to exit gracefully when they are received the 1st time
+ *
+ * Note that our handler only sets a variable indicating the signal was
+ * received, and in each iteration of the hw main loop this variable is
+ * evaluated.
+ * If for some reason (the program is stuck) we never evaluate it, the program
+ * would never exit.
+ * Therefore we set SA_RESETHAND: This way, the 2nd time the signal is received
+ * the default handler would be called to terminate the program no matter what.
+ *
+ * Note that SA_RESETHAND requires either _POSIX_C_SOURCE>=200809 or
+ * _XOPEN_SOURCE>=500
+ */
+void hwm_set_sig_handler(void)
+{
+	struct sigaction act;
+	int e;
+
+	act.sa_handler = hwm_signal_end_handler;
+	e = sigemptyset(&act.sa_mask);
+	if (e) {
+		posix_print_error_and_exit("Error on sigemptyset()\n");
+	}
+
+	act.sa_flags = SA_RESETHAND;
+
+	e = sigaction(SIGTERM, &act, NULL);
+	if (e) {
+		posix_print_error_and_exit("Error on sigaction()\n");
+	}
+	e = sigaction(SIGINT, &act, NULL);
+	if (e) {
+		posix_print_error_and_exit("Error on sigaction()\n");
+	}
+}
+
 
 static void hwm_sleep_until_next_timer(void)
 {
@@ -46,9 +99,9 @@ static void hwm_sleep_until_next_timer(void)
 				next_timer_index);
 	}
 
-	if (device_time >= end_of_time) {
-		posix_print_trace("\n\n\n\n\n\nAutostopped after %.3Lfs\n",
-				((long double)end_of_time)/1.0e6);
+	if (signaled_end || (device_time >= end_of_time)) {
+		posix_print_trace("\nStopped after %.3Lfs\n",
+				((long double)device_time)/1.0e6);
 
 		main_clean_up(0);
 	}
@@ -120,6 +173,7 @@ u64_t hwm_get_time(void)
  */
 void hwm_init(void)
 {
+	hwm_set_sig_handler();
 	hwtimer_init();
 	hw_irq_ctrl_init();
 

boards/posix/native_posix/main.c

@@ -6,7 +6,7 @@
 
 /*
  * The basic principle of operation is:
- *   No asynchronous behavior, no undeterminism.
+ *   No asynchronous behavior, no indeterminism.
  *   If you run the same thing 20 times, you get exactly the same result 20
  *   times.
  *   It does not matter if you are running from console, or in a debugger
@@ -15,7 +15,7 @@
  * This is achieved as follows:
  * The HW models run in their own simulated time. We do really not attempt
  * to link ourselves to the actual real time / wall time of the machine as this
- * would make execution undeterministic and debugging or instrumentation not
+ * would make execution indeterministic and debugging or instrumentation not
  * really possible. Although we may slow the run to real time.
  */
 
@@ -42,12 +42,13 @@ void main_clean_up(int exit_code)
 	exit(exit_code);
 }
 
+
 /**
  * This is the actual main for the Linux process,
  * the Zephyr application main is renamed something else thru a define.
  *
  * Note that normally one wants to use this POSIX arch to be part of a
- * simulation engine, with some proper HW models and whatnot
+ * simulation engine, with some proper HW models and what not
  *
  * This is just a very simple demo which is able to run some of the sample
  * apps (hello world, synchronization, philosophers) and run the sanity-check

boards/posix/native_posix/timer_model.c

@@ -76,11 +76,7 @@ static void hwtimer_tick_timer_reached(void)
 		requested_time.tv_sec  = diff / 1e6;
 		requested_time.tv_nsec = (diff - requested_time.tv_sec*1e6)*1e3;
 
-		int s = nanosleep(&requested_time, &remaining);
-
-		if (s == -1) {
-			posix_print_trace("Interrupted or error\n");
-		}
+		nanosleep(&requested_time, &remaining);
 	}
 #endif