qcoro · danvratil · Jan 20, 2023 · Jan 20, 2023
diff --git a/docs/reference/core/qtimer.md b/docs/reference/core/qtimer.md
@@ -46,5 +46,38 @@ QCoro::Task<> MyClass::pretendWork() {
 }
 ```
 
+## `QCoro::sleepFor()`
+
+A simple coroutine that will suspend for the specified time duration. Can be quite
+useful especially in unit-tests.
+
+```cpp
+template<typename Rep, Period>
+QCoro::Task<> QCoro::sleepFor(const std::chrono::duration<Rep, Period> &timeout);
+```
+
+## `QCoro::sleepUntil()`
+
+A simple coroutine that will suspend until the specified point in time. Can be useful
+for scheduling tasks.
+
+```cpp
+template<typename Clock, typename Duration>
+QCoro::Task< QCoro::sleepUntil(const std::chrono::time_point<Clock, Duration> &when);
+```
+
+Example:
+
+```cpp
+const auto now = std::chrono::system_clock::now();
+const auto tomorrow_time = std::chrono::system_clock::to_time_t(now + 86400s);
+std::tm *gt = std::gmtime(&tomorrow_time);
+gt.tm_hour = 0;
+gt.tm_min = 0;
+gt.tm_sec = 0;
+const auto tomorrow_midnight = std::mktime(&gt);
+co_await QCoro::sleepUntil(std::chrono::system_clock::from_time_t(tomorrow_midnight));
+```
+
 [qdoc-qtimer]: https://doc.qt.io/qt-5/qtimer.html
 [qdoc-qtimer-timeout]: https://doc.qt.io/qt-5/qtimer.html#timeout
diff --git a/qcoro/core/qcorotimer.h b/qcoro/core/qcorotimer.h
@@ -52,6 +52,26 @@ struct awaiter_type<QTimer> {
 
 } // namespace QCoro::detail
 
+namespace QCoro {
+
+//! A coroutine that suspends for given period of time.
+template<typename Rep, typename Period>
+QCoro::Task<> sleepFor(const std::chrono::duration<Rep, Period> &timeout) {
+    QTimer timer;
+    timer.setSingleShot(true);
+    timer.start(std::chrono::duration_cast<std::chrono::milliseconds>(timeout));
+    co_await timer;
+}
+
+//! A coroutine that suspends until the specified time.
+template<typename Clock, typename Duration>
+QCoro::Task<> sleepUntil(const std::chrono::time_point<Clock, Duration> &when) {
+    const auto tp = when.time_since_epoch() - std::chrono::steady_clock::now().time_since_epoch();
+    return sleepFor(tp);
+}
+
+} // namespace QCoro
+
 /*! \endcond */
 
 //! Returns a coroutine-friendly wrapper for QTimer object.

diff --git a/tests/qtimer.cpp b/tests/qtimer.cpp
@@ -6,6 +6,10 @@
 
 #include "qcorotimer.h"
 
+#include <chrono>
+
+using namespace std::chrono_literals;
+
 class QCoroTimerTest : public QCoro::TestObject<QCoroTimerTest> {
     Q_OBJECT
 
@@ -68,12 +72,28 @@ class QCoroTimerTest : public QCoro::TestObject<QCoroTimerTest> {
         QVERIFY(triggered);
     }
 
+    QCoro::Task<> testSleepFor_coro(QCoro::TestContext) {
+        QElapsedTimer elapsed;
+        elapsed.start();
+        co_await QCoro::sleepFor(100ms);
+        QCORO_VERIFY(elapsed.elapsed() >= 75);
+    }
+
+    QCoro::Task<> testSleepUntil_coro(QCoro::TestContext) {
+        QElapsedTimer elapsed;
+        elapsed.start();
+        co_await QCoro::sleepUntil(std::chrono::steady_clock::now() + 500ms);
+        QCORO_VERIFY(elapsed.elapsed() >= 475);
+    }
+
 private Q_SLOTS:
     addTest(Triggers)
     addTest(QCoroWrapperTriggers)
     addTest(DoesntBlockEventLoop)
     addTest(DoesntCoAwaitInactiveTimer)
     addTest(DoesntCoAwaitNullTimer)
+    addTest(SleepFor)
+    addTest(SleepUntil)
 
     addThenTest(Triggers)
 };