Merge pull request #4272 from OlegHahm/xtimer_msg_receive_timeout

xtimer: implement missing msg receive timeout

sys/xtimer/xtimer.c

@@ -159,22 +159,44 @@ void xtimer_now_timex(timex_t *out)
     out->microseconds = now - (out->seconds * SEC_IN_USEC);
 }
 
-int xtimer_msg_receive_timeout64(msg_t *m, uint64_t timeout) {
-    msg_t tmsg;
-    tmsg.type = MSG_XTIMER;
-    tmsg.content.ptr = (char *) &tmsg;
+/* Prepares the message to trigger the timeout.
+ * Additionally, the xtimer_t struct gets initialized.
+ */
+static void _setup_timer_msg(msg_t *m, xtimer_t *t)
+{
+    m->type = MSG_XTIMER;
+    m->content.ptr = (char *) m;
 
-    xtimer_t t;
-    t.target = t.long_target = 0;
-    xtimer_set_msg64(&t, timeout, &tmsg, sched_active_pid);
+    t->target = t->long_target = 0;
+}
 
+/* Waits for incoming message or timeout. */
+static int _msg_wait(msg_t *m, msg_t *tmsg, xtimer_t *t)
+{
     msg_receive(m);
-    if (m->type == MSG_XTIMER && m->content.ptr == (char *) &tmsg) {
+    if (m->type == MSG_XTIMER && m->content.ptr == (char *) tmsg) {
         /* we hit the timeout */
         return -1;
     }
     else {
-        xtimer_remove(&t);
+        xtimer_remove(t);
         return 1;
     }
 }
+
+int xtimer_msg_receive_timeout64(msg_t *m, uint64_t timeout) {
+    msg_t tmsg;
+    xtimer_t t;
+    _setup_timer_msg(&tmsg, &t);
+    xtimer_set_msg64(&t, timeout, &tmsg, sched_active_pid);
+    return _msg_wait(m, &tmsg, &t);
+}
+
+int xtimer_msg_receive_timeout(msg_t *msg, uint32_t us)
+{
+    msg_t tmsg;
+    xtimer_t t;
+    _setup_timer_msg(&tmsg, &t);
+    xtimer_set_msg(&t, us, &tmsg, sched_active_pid);
+    return _msg_wait(msg, &tmsg, &t);
+}

tests/xtimer_msg_receive_timeout/Makefile

@@ -0,0 +1,7 @@
+APPLICATION = xtimer_msg_receive_timeout
+include ../Makefile.tests_common
+
+FEATURES_REQUIRED += periph_timer
+USEMODULE += xtimer
+
+include $(RIOTBASE)/Makefile.include

tests/xtimer_msg_receive_timeout/main.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2015 INRIA
+ *
+ * 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       test application for xtimer_msg_receive_timeout()
+ *
+ * @author      Oliver Hahm <oliver.hahm@inria.fr>
+ *
+ * @}
+ */
+
+#include "thread.h"
+#include "msg.h"
+#include "xtimer.h"
+#include "timex.h"
+
+int main(void)
+{
+    msg_t m, tmsg;
+    xtimer_t t;
+    int64_t offset = -1000;
+    tmsg.type = 44;
+
+    for (int i = 0; i < 10; i++) {
+        xtimer_set_msg(&t, SEC_IN_USEC + offset, &tmsg, sched_active_pid);
+        if (xtimer_msg_receive_timeout(&m, SEC_IN_USEC) < 0) {
+            puts("Timeout!");
+        }
+        else {
+            printf("Message received: %" PRIu16 "\n", m.type);
+        }
+        offset = (offset < 0) ? 1000 : -1000;
+    }
+    return 0;
+}

tests/xtimer_msg_receive_timeout/tests/01-run.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+
+# Copyright (C) 2015 INRIA
+#
+# 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, signal, sys
+from pexpect import TIMEOUT, EOF
+if sys.version_info[0] == 2:
+    from pexpect import spawn
+else:
+    from pexpect import spawnu as spawn
+
+DEFAULT_TIMEOUT = 2
+
+def main():
+    p = None
+
+    try:
+        p = spawn("make term", timeout=DEFAULT_TIMEOUT)
+        p.logfile = sys.stdout
+
+        for i in range(10):
+            p.expect("Message received: 44")
+            p.expect("Timeout")
+    except TIMEOUT as exc:
+        print(exc)
+        return 1
+    finally:
+        if p and not p.terminate():
+            print("SUCCESS")
+            os.killpg(p.pid, signal.SIGKILL)
+
+    return 0
+
+if __name__ == "__main__":
+    sys.exit(main())