tests/kernel: fifo_timeout: Remove wake-up order checking

There is no guarantee of wake-up order when multiple threads
are woken up on the same tick. Hence, modified the tests
accordingly.

Fixes #8159.

Signed-off-by: Rajavardhan Gundi <[email protected]>

Author: rgundi

tests/kernel/fifo/fifo_timeout/src/main.c

@@ -135,7 +135,8 @@ static void test_thread_pend_and_timeout(void *p1, void *p2, void *p3)
 static int test_multiple_threads_pending(struct timeout_order_data *test_data,
 					 int test_data_size)
 {
-	int ii;
+	int ii, j;
+	u32_t diff_ms;
 
 	for (ii = 0; ii < test_data_size; ii++) {
 		tid[ii] = k_thread_create(&ttdata[ii], ttstack[ii], TSTACK_SIZE,
@@ -144,6 +145,14 @@ static int test_multiple_threads_pending(struct timeout_order_data *test_data,
 				FIFO_THREAD_PRIO, K_INHERIT_PERMS, 0);
 	}
 
+	/* In general, there is no guarantee of wakeup order when multiple
+	 * threads are woken up on the same tick. This can especially happen
+	 * when the system is loaded. However, in this particular test, we
+	 * are controlling the system state and hence we can make a reasonable
+	 * estimation of a timeout occurring with the max deviation of an
+	 * additional tick. Hence the timeout order may slightly be different
+	 * from what we normally expect.
+	 */
 	for (ii = 0; ii < test_data_size; ii++) {
 		struct timeout_order_data *data =
 			k_fifo_get(&timeout_order_fifo, K_FOREVER);
@@ -152,9 +161,31 @@ static int test_multiple_threads_pending(struct timeout_order_data *test_data,
 			TC_PRINT(" thread (q order: %d, t/o: %d, fifo %p)\n",
 				data->q_order, data->timeout, data->fifo);
 		} else {
-			TC_ERROR(" *** thread %d woke up, expected %d\n",
-						data->timeout_order, ii);
-			return TC_FAIL;
+			/* Get the index of the thread which should have
+			 * actually timed out.
+			 */
+			for (j = 0; j < test_data_size; j++) {
+				if (test_data[j].timeout_order == ii) {
+					break;
+				}
+			}
+
+			if (data->timeout > test_data[j].timeout) {
+				diff_ms = data->timeout - test_data[j].timeout;
+			} else {
+				diff_ms = test_data[j].timeout - data->timeout;
+			}
+
+			if (_ms_to_ticks(diff_ms) == 1) {
+				TC_PRINT(
+				" thread (q order: %d, t/o: %d, fifo %p)\n",
+				data->q_order, data->timeout, data->fifo);
+			} else {
+				TC_ERROR(
+				" *** thread %d woke up, expected %d\n",
+				data->timeout_order, ii);
+				return TC_FAIL;
+			}
 		}
 	}