tests: xtimer_usleep: remove timer testing in pexpect

As with #7816: testing timings over the UART doesn't make much sense.
This PR removes those timer testing in `pexpect` for
`tests/xtimer_usleep` and simplifies and cleans-up a lot of code overall
(converting counting while-loops to for-loops, syncing iterations of
the test etc.)

tests/xtimer_usleep/main.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2017 Inria
+ *               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
@@ -14,35 +15,44 @@
  * @brief       xtimer_usleep test application
  *
  * @author      Francisco Acosta <francisco.acosta@inria.fr>
+ * @author      Martine Lenders <m.lenders@fu-berlin.de>
  * @}
  */
 
+#include <inttypes.h>
 #include <stdio.h>
 
 #include "xtimer.h"
 #include "timex.h"
 
-#define ONE_SEC_SLEEP     (1 * US_PER_SEC)
-#define FIVE_SEC_SLEEP    (5 * US_PER_SEC)
-#define TEN_SEC_SLEEP     (10 * US_PER_SEC)
+#define RUNS                (5U)
+#define SLEEP_TIMES_NUMOF   (sizeof(sleep_times) / sizeof(sleep_times[0]))
+
+static const uint32_t sleep_times[] = { 10000, 50000, 100000 };
 
 int main(void)
 {
-    int t = 9;
-
-    printf("This test will print \"Slept for X sec...\" every 1, 5 and 10 seconds.\n");
-    printf("\n<======== If using pyterm, this is the time when started.\n\n");
-
-    while (t) {
-        xtimer_usleep(ONE_SEC_SLEEP);
-        printf("Slept for 1 sec...\n");
-        xtimer_usleep(FIVE_SEC_SLEEP);
-        printf("Slept for 5 sec...\n");
-        xtimer_usleep(TEN_SEC_SLEEP);
-        printf("Slept for 10 sec...\n");
-        t--;
+    uint32_t start_test, testtime;
+
+    printf("Running test %u times with %u distinct sleep times\n", RUNS,
+           (unsigned)SLEEP_TIMES_NUMOF);
+    puts("Please hit any key and then ENTER to continue");
+    getchar();
+    start_test = xtimer_now_usec();
+    for (unsigned m = 0; m < RUNS; m++) {
+        for (unsigned n = 0;
+             n < sizeof(sleep_times) / sizeof(sleep_times[0]);
+             n++) {
+            uint32_t diff, start;
+            start = xtimer_now_usec();
+            xtimer_usleep(sleep_times[n]);
+            diff = xtimer_now_usec() - start;
+            printf("Slept for %" PRIu32 " us (expected: %" PRIu32 " us)\n",
+                   diff, sleep_times[n]);
+        }
     }
-    printf("Test end.\n");
+    testtime = xtimer_now_usec() - start_test;
+    printf("Test ran for %" PRIu32 " us\n", testtime);
 
     return 0;
 }

tests/xtimer_usleep/tests/01-run.py

@@ -1,55 +1,56 @@
 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
 
 # Copyright (C) 2017 Francisco Acosta <francisco.acosta@inria.fr>
+#               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
 
-from datetime import datetime
+US_PER_SEC = 1000000
+INTERNAL_JITTER = 0.05
+EXTERNAL_JITTER = 0.15
 
 class InvalidTimeout(Exception):
     pass
 
 def testfunc(child):
-    exp_diff1 = 1000000
-    exp_diff5 = 5000000
-    exp_diff10 = 10000000
-    child.expect(u"This test will print \"Slept for X sec...\" every 1, 5 and 10 seconds.\r\n")
-    child.expect(u"\r\n")
-    child.expect(u"<======== If using pyterm, this is the time when started.")
-    child.expect(u"\r\n")
-    m = 9
-    while (m):
-        n = 3
-        while (n):
-            if n == 3:
-                exp_diff = exp_diff1
-            if n == 2:
-                exp_diff = exp_diff5
-            elif n == 1:
-                exp_diff = exp_diff10
-            start = datetime.now()
-            child.expect(u"Slept for \\d+ sec...", timeout=11)
-            stop = datetime.now()
-            diff = (stop - start)
-            diff = (diff.seconds * 1000000) + diff.microseconds
-            # fail within 5% of expected
-            if diff > (exp_diff + (exp_diff1 * 0.05)) or \
-               diff < (exp_diff - (exp_diff1 * 0.05)):
-                raise InvalidTimeout("Invalid timeout %d (expected %d)" % (diff, exp_diff));
-            else:
-                print("Timed out correctly: %d (expected %d)" % (diff, exp_diff))
-            n = n - 1
-        m = m -1
-
-    child.expect(u"Test end.", timeout=15)
+    child.expect(u"Running test (\\d+) times with (\\d+) distinct sleep times")
+    RUNS = int(child.match.group(1))
+    SLEEP_TIMES_NUMOF = int(child.match.group(2))
+    try:
+        child.expect_exact(u"Please hit any key and then ENTER to continue")
+        child.sendline(u"a")
+        start_test = time.time()
+        for m in range(RUNS):
+            for n in range(SLEEP_TIMES_NUMOF):
+                child.expect(u"Slept for (\\d+) us \\(expected: (\\d+) us\\)")
+                sleep_time = int(child.match.group(1))
+                exp = int(child.match.group(2))
+                lower_bound = exp - (exp * INTERNAL_JITTER)
+                upper_bound = exp + (exp * INTERNAL_JITTER)
+                if not (lower_bound < sleep_time < upper_bound):
+                    raise InvalidTimeout("Invalid timeout %d (expected %d)" % (sleep_time, exp));
+        testtime = (time.time() - start_test) * US_PER_SEC
+        child.expect(u"Test ran for (\\d+) us")
+        exp = int(child.match.group(1))
+        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))
+    sys.exit(testrunner.run(testfunc, echo=True))