tests/xtimer_mutex_lock_timeout: minimal xtimer_mutex_lock_timeout test

Adding a first normal test case where the mutex is unlocked and the timeout is long.
The timer will not trigger in this test and instead wil be removed after getting the mutex.

tests/xtimer_mutex_lock_timeout/Makefile

@@ -0,0 +1,8 @@
+include ../Makefile.tests_common
+
+USEMODULE += xtimer
+USEMODULE += shell
+
+TEST_ON_CI_WHITELIST += all
+
+include $(RIOTBASE)/Makefile.include

tests/xtimer_mutex_lock_timeout/main.c

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2019 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       testing xtimer_mutex_lock_timeout function
+ *
+ *
+ * @author      Julian Holzwarth <julian.holzwarth@fu-berlin.de>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "shell.h"
+#include "xtimer.h"
+
+/* timeout at one millisecond (1000 us) to make sure it does not spin. */
+#define LONG_MUTEX_TIMEOUT 1000
+
+/**
+ * Foward declarations
+ */
+static int cmd_test_xtimer_mutex_lock_timeout_long_unlocked(int argc,
+                                                            char **argv);
+
+/**
+ * @brief   List of command for this application.
+ */
+static const shell_command_t shell_commands[] = {
+    { "mutex_timeout_long_unlocked", "unlocked mutex with long timeout",
+      cmd_test_xtimer_mutex_lock_timeout_long_unlocked, },
+    { NULL, NULL, NULL }
+};
+
+/**
+ * @brief   shell command to test xtimer_mutex_lock_timeout
+ *
+ * the mutex is not locked before the function call and
+ * the timer long. Meaning the timer will get removed
+ * before triggering.
+ *
+ * @param[in] argc  Number of arguments
+ * @param[in] argv  Array of arguments
+ *
+ * @return 0 on success
+ */
+static int cmd_test_xtimer_mutex_lock_timeout_long_unlocked(int argc,
+                                                            char **argv)
+{
+    (void)argc;
+    (void)argv;
+    puts("starting test: xtimer mutex lock timeout");
+    mutex_t test_mutex = MUTEX_INIT;
+
+    if (xtimer_mutex_lock_timeout(&test_mutex, LONG_MUTEX_TIMEOUT) == 0) {
+        /* mutex has to be locked */
+        if (mutex_trylock(&test_mutex) == 0) {
+            puts("OK");
+        }
+        else {
+            puts("error mutex not locked");
+        }
+    }
+    else {
+        puts("error: mutex timed out");
+    }
+
+    return 0;
+}
+
+/**
+ * @brief   main function starting shell
+ *
+ * @return 0 on success
+ */
+int main(void)
+{
+    puts("Starting shell...");
+    char line_buf[SHELL_DEFAULT_BUFSIZE];
+    shell_run(shell_commands, line_buf, SHELL_DEFAULT_BUFSIZE);
+
+    return 0;
+}

tests/xtimer_mutex_lock_timeout/tests/01-run.py

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+#!/usr/bin/env python3
+
+#  Copyright (C) 2019 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.
+
+# @author      Julian Holzwarth <julian.holzwarth@fu-berlin.de>
+
+import sys
+import pexpect
+from testrunner import run
+
+
+def testfunc(child):
+    # Try to wait for the shell
+    for _ in range(0, 10):
+        child.sendline("help")
+        if child.expect_exact(["> ", pexpect.TIMEOUT], timeout=1) == 0:
+            break
+    child.sendline("mutex_timeout_long_unlocked")
+    child.expect("starting test: xtimer mutex lock timeout")
+    child.expect("OK")
+    child.expect_exact("> ")
+
+
+if __name__ == "__main__":
+    sys.exit(run(testfunc))