From 91859fc261a2c4f4a3375f51416ea9bd20d67c9c Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Mon, 18 Jan 2021 17:37:02 +0100
Subject: [PATCH] sys/event: add event_wait_timeout_ztimer()

---
 sys/event/event.c   | 40 ++++++++++++++++++++++++++++++++++------
 sys/include/event.h | 25 ++++++++++++++++++++++++-
 2 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/sys/event/event.c b/sys/event/event.c
index cda7ab8021..a4da87c2e8 100644
--- a/sys/event/event.c
+++ b/sys/event/event.c
@@ -29,7 +29,7 @@
 #include "clist.h"
 #include "thread.h"
 
-#ifdef MODULE_XTIMER
+#if IS_USED(MODULE_XTIMER)
 #include "xtimer.h"
 #endif
 
@@ -96,8 +96,8 @@ event_t *event_wait_multi(event_queue_t *queues, size_t n_queues)
     return result;
 }
 
-#ifdef MODULE_XTIMER
-static event_t *_wait_timeout(event_queue_t *queue, xtimer_t *timer)
+#if IS_USED(MODULE_XTIMER) || IS_USED(MODULE_ZTIMER)
+static event_t *_wait_timeout(event_queue_t *queue)
 {
     assert(queue);
     event_t *result;
@@ -106,10 +106,19 @@ static event_t *_wait_timeout(event_queue_t *queue, xtimer_t *timer)
     do {
         result = event_get(queue);
         if (result == NULL) {
-            flags = thread_flags_wait_any(THREAD_FLAG_EVENT | THREAD_FLAG_TIMEOUT);
+            flags = thread_flags_wait_any(THREAD_FLAG_EVENT |
+                                          THREAD_FLAG_TIMEOUT);
         }
     } while ((result == NULL) && (flags & THREAD_FLAG_EVENT));
 
+    return result;
+}
+#endif
+
+#if IS_USED(MODULE_XTIMER)
+static event_t *_wait_timeout_xtimer(event_queue_t *queue, xtimer_t *timer)
+{
+    event_t *result = _wait_timeout(queue);
     if (result) {
         xtimer_remove(timer);
     }
@@ -121,15 +130,34 @@ event_t *event_wait_timeout(event_queue_t *queue, uint32_t timeout)
 {
     xtimer_t timer;
 
+    thread_flags_clear(THREAD_FLAG_TIMEOUT);
     xtimer_set_timeout_flag(&timer, timeout);
-    return _wait_timeout(queue, &timer);
+    return _wait_timeout_xtimer(queue, &timer);
 }
 
 event_t *event_wait_timeout64(event_queue_t *queue, uint64_t timeout)
 {
     xtimer_t timer;
 
+    thread_flags_clear(THREAD_FLAG_TIMEOUT);
     xtimer_set_timeout_flag64(&timer, timeout);
-    return _wait_timeout(queue, &timer);
+    return _wait_timeout_xtimer(queue, &timer);
+}
+#endif
+
+#if IS_USED(MODULE_ZTIMER)
+event_t *event_wait_timeout_ztimer(event_queue_t *queue,
+                                   ztimer_clock_t *clock, uint32_t timeout)
+{
+    ztimer_t timer;
+    event_t *result;
+
+    thread_flags_clear(THREAD_FLAG_TIMEOUT);
+    ztimer_set_timeout_flag(clock, &timer, timeout);
+    result = _wait_timeout(queue);
+    if (result) {
+        ztimer_remove(clock, &timer);
+    }
+    return result;
 }
 #endif
diff --git a/sys/include/event.h b/sys/include/event.h
index 4ce40f6a20..9b9cee4110 100644
--- a/sys/include/event.h
+++ b/sys/include/event.h
@@ -106,6 +106,10 @@
 #include "thread_flags.h"
 #include "ptrtag.h"
 
+#if IS_USED(MODULE_ZTIMER)
+#include "ztimer.h"
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -333,7 +337,7 @@ static inline event_t *event_wait(event_queue_t *queue)
     return event_wait_multi(queue, 1);
 }
 
-#if defined(MODULE_XTIMER) || defined(DOXYGEN)
+#if IS_USED(MODULE_XTIMER) || defined(DOXYGEN)
 /**
  * @brief   Get next event from event queue, blocking until timeout expires
  *
@@ -357,6 +361,25 @@ event_t *event_wait_timeout(event_queue_t *queue, uint32_t timeout);
 event_t *event_wait_timeout64(event_queue_t *queue, uint64_t timeout);
 #endif
 
+#if IS_USED(MODULE_ZTIMER) || defined(DOXYGEN)
+/**
+ * @brief   Get next event from event queue, blocking until timeout expires
+ *
+ * This function is the same as event_wait_timeout() with the difference that it
+ * uses ztimer instead of xtimer as timer backend.
+ *
+ * @param[in]   queue    queue to query for an event
+ * @param[in]   clock    ztimer clock to use
+ * @param[in]   timeout  maximum time to wait for an event, time unit depends
+ *                       on the used ztimer clock
+ *
+ * @return      pointer to next event if event was taken from the queue
+ * @return      NULL if timeout expired before an event was posted
+ */
+event_t *event_wait_timeout_ztimer(event_queue_t *queue,
+                                   ztimer_clock_t *clock, uint32_t timeout);
+#endif
+
 /**
  * @brief   Simple event loop with multiple queues
  *