tests: update posix_time tests for running with pexpect script

tests/posix_time/Makefile

@@ -4,3 +4,6 @@ include ../Makefile.tests_common
 USEMODULE += posix_time
 
 include $(RIOTBASE)/Makefile.include
+
+test:
+	./tests/01-run.py

tests/posix_time/README.md

+# posix_time test application
+
+This test tests POSIX' `sleep()` and `usleep()`.
+The test script also checks the sanity of the timings by comparing the overall
+run time of the test with the host's time with an expected jitter of 15%.
+
+## Usage
+```
+make flash test
+```

tests/posix_time/main.c

 /*
- * Copyright (C) 2014 Freie Universität Berlin
+ * Copyright (C) 2014-17 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
@@ -14,6 +14,7 @@
  * @brief Posix sleep test application
  *
  * @author Christian Mehlis <mehlis@inf.fu-berlin.de>
+ * @author Martine Lenders <m.lenders@fu-berlin.de>
  *
  * @}
  */
@@ -23,22 +24,21 @@
 
 int main(void)
 {
-    puts("usleep 1 x 1000*1000");
-    for (int i = 0; i < 10; i++) {
-        useconds_t us = i*1000u*1000u;
-        printf("calling usleep(%u)\n", (unsigned int) us);
+    puts("Please hit any key and then ENTER to continue");
+    getchar();
+    puts("5 x usleep(i++ * 500000)");
+    for (unsigned i = 0; i < 5; i++) {
+        useconds_t us = i * 500000u;
         usleep(us);
         puts("wake up");
     }
 
-    puts("sleep 1");
-    for (int i = 0; i < 10; i++) {
-        unsigned int s = i;
-        printf("calling sleep(%u)\n", s);
-        sleep(s);
+    puts("5 x sleep(i++)");
+    for (unsigned i = 0; i < 5; i++) {
+        sleep(i);
         puts("wake up");
     }
 
-    puts("done");
+    puts("DONE");
     return 0;
 }

tests/posix_time/tests/01-run.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
+
+# 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.
+
+import os
+import sys
+import time
+
+sys.path.append(os.path.join(os.environ['RIOTBASE'], 'dist/tools/testrunner'))
+import testrunner
+
+US_PER_SEC = 1000000
+EXTERNAL_JITTER = 0.15
+
+class InvalidTimeout(Exception):
+    pass
+
+def testfunc(child):
+    try:
+        child.expect_exact("Please hit any key and then ENTER to continue")
+        child.sendline("a")
+        start_test = time.time()
+        child.expect_exact("5 x usleep(i++ * 500000)")
+        for i in range(5):
+            child.expect_exact("wake up")
+        child.expect_exact("5 x sleep(i++)")
+        for i in range(5):
+            child.expect_exact("wake up")
+        child.expect_exact("DONE")
+        testtime = (time.time() - start_test) * US_PER_SEC
+        exp = sum(i * 500000 for i in range(5)) + \
+              sum(i * US_PER_SEC for i in range(5))
+        lower_bound = exp - (exp * EXTERNAL_JITTER)
+        upper_bound = exp + (exp * EXTERNAL_JITTER)
+        if not (lower_bound < testtime < upper_bound):
+            raise InvalidTimeout("Host timer measured %d us (client measured %d us)" % \
+                                 (testtime, exp));
+    except InvalidTimeout as e:
+        print(e)
+        sys.exit(1)
+
+if __name__ == "__main__":
+    sys.exit(testrunner.run(testfunc, echo=True))