tests: add test for evtimer underflow

tests/evtimer_underflow/Makefile

+APPLICATION = evtimer_msg
+include ../Makefile.tests_common
+
+BOARD_INSUFFICIENT_MEMORY := nucleo32-f031 nucleo32-f042
+
+USEMODULE += evtimer
+
+include $(RIOTBASE)/Makefile.include
+
+test:
+# `testrunner` calls `make term` recursively, results in duplicated `TERMFLAGS`.
+# So clears `TERMFLAGS` before run.
+	TERMFLAGS= tests/01-run.py

tests/evtimer_underflow/main.c

+/*
+ * Copyright (C) 2017 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup tests
+ * @{
+ *
+ * @file
+ * @brief    evtimer_msg test application
+ *
+ * @author   Martine Lenders <m.lenders@fu-berlin.de>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+
+#include "evtimer_msg.h"
+#include "thread.h"
+#include "msg.h"
+
+#define WORKER_MSG_QUEUE_SIZE   (8)
+
+msg_t worker_msg_queue[WORKER_MSG_QUEUE_SIZE];
+static char worker_stack[THREAD_STACKSIZE_MAIN];
+static evtimer_t evtimer;
+static evtimer_msg_event_t events[] = {
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "1" } } },
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "2" } } },
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "3" } } },
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "4" } } },
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "5" } } },
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "6" } } },
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "7" } } },
+    { .event = { .offset = 0 }, .msg = { .content = { .ptr = "8" } } },
+};
+
+#define NEVENTS (sizeof(events) / sizeof(evtimer_msg_event_t))
+
+/* This thread will print the drift to stdout once per second */
+void *worker_thread(void *arg)
+{
+    (void) arg;
+
+    msg_init_queue(worker_msg_queue, WORKER_MSG_QUEUE_SIZE);
+    while (1) {
+        char *ctx;
+        msg_t m;
+
+        msg_receive(&m);
+        ctx = m.content.ptr;
+        printf("received msg \"%s\"\n", ctx);
+    }
+}
+
+int main(void)
+{
+    evtimer_init_msg(&evtimer);
+
+    /* create worker thread */
+    kernel_pid_t pid = thread_create(worker_stack, sizeof(worker_stack),
+                                     THREAD_PRIORITY_MAIN - 1,
+                                     THREAD_CREATE_STACKTEST,
+                                     worker_thread, NULL, "worker");
+    while (1) {
+        for (unsigned i = 0; i < NEVENTS; i++) {
+            evtimer_add_msg(&evtimer, &events[i], pid);
+        }
+    }
+}

tests/evtimer_underflow/tests/01-run.py

+#!/usr/bin/env python3
+
+# Copyright (C) 2016 Freie Universität Berlin
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+
+from __future__ import print_function
+import os
+import sys
+import time
+
+sys.path.append(os.path.join(os.environ['RIOTBASE'], 'dist/tools/testrunner'))
+import testrunner
+
+how_many = 100
+
+def testfunc(child):
+    for i in range(how_many):
+        for j in range(8):
+            child.expect(r'received msg "%i"' % (j + 1))
+        print(".", end="", flush=True)
+    print("")
+    print("Stopped after %i iterations, but should run forever." % how_many)
+    print("=> All tests successful")
+
+if __name__ == "__main__":
+    sys.exit(testrunner.run(testfunc, echo=False))