tests/bench_mutex_pingpong: initial commit

tests/bench_mutex_pingpong/Makefile

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+include ../Makefile.tests_common
+
+BOARD_INSUFFICIENT_MEMORY := nucleo-f031k6
+
+USEMODULE += xtimer
+
+TEST_ON_CI_WHITELIST += all
+
+include $(RIOTBASE)/Makefile.include
+
+test:
+	tests/01-run.py

tests/bench_mutex_pingpong/README.md

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+# About
+
+In this test, one thread will repeatedly lock a mutex, while another thread
+will unlock it.  The result is the number of unlocks done in an interval of one
+second, which amounts to half the number of incurred context switches.
+
+This test application intentionally duplicates code with some similar benchmark
+applications in order to be able to compare code sizes.

tests/bench_mutex_pingpong/main.c

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+/*
+ * Copyright (C) 2017 Kaspar Schleiser <kaspar@schleiser.de>
+ *
+ * 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       Mutex context switch benchmark
+ *
+ * @author      Kaspar Schleiser <kaspar@schleiser.de>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+
+#include "mutex.h"
+#include "thread.h"
+#include "xtimer.h"
+
+#ifndef TEST_DURATION
+#define TEST_DURATION       (1000000U)
+#endif
+
+volatile unsigned _flag = 0;
+static char _stack[THREAD_STACKSIZE_MAIN];
+static mutex_t _mutex = MUTEX_INIT;
+
+static void _timer_callback(void*arg)
+{
+    (void)arg;
+
+    _flag = 1;
+}
+
+
+static void *_second_thread(void *arg)
+{
+    (void)arg;
+
+    while(1) {
+        mutex_lock(&_mutex);
+    }
+
+    return NULL;
+}
+
+int main(void)
+{
+    printf("main starting\n");
+
+    thread_create(_stack,
+                  sizeof(_stack),
+                  THREAD_PRIORITY_MAIN - 1,
+                  THREAD_CREATE_WOUT_YIELD | THREAD_CREATE_STACKTEST,
+                  _second_thread,
+                  NULL,
+                  "second_thread");
+
+    /* lock the mutex, then yield to second_thread */
+    mutex_lock(&_mutex);
+    thread_yield_higher();
+
+    xtimer_t timer;
+    timer.callback = _timer_callback;
+
+    uint32_t n = 0;
+
+    xtimer_set(&timer, TEST_DURATION);
+    while(!_flag) {
+        mutex_unlock(&_mutex);
+        n++;
+    }
+
+    printf("{ \"result\" : %"PRIu32" }\n", n);
+
+    return 0;
+}

tests/bench_mutex_pingpong/tests/01-run.py

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+#!/usr/bin/env python3
+
+# Copyright (C) 2018 Kaspar Schleiser <kaspar@schleiser.de>
+#               2017 Sebastian Meiling <s@mlng.net>
+#
+# 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
+
+
+def testfunc(child):
+    child.expect(r"{ \"result\" : \d+ }")
+
+
+if __name__ == "__main__":
+    sys.path.append(os.path.join(os.environ['RIOTTOOLS'], 'testrunner'))
+    from testrunner import run
+    sys.exit(run(testfunc))