1 files changed, 32 insertions, 0 deletions
diff --git a/tests/extmod/uasyncio_fair.py b/tests/extmod/uasyncio_fair.py
new file mode 100644
index 000000000..9b04454bc
--- /dev/null
+++ b/tests/extmod/uasyncio_fair.py
@@ -0,0 +1,32 @@
+# Test fairness of scheduler
+
+try:
+    import uasyncio as asyncio
+except ImportError:
+    try:
+        import asyncio
+    except ImportError:
+        print("SKIP")
+        raise SystemExit
+
+
+async def task(id, t):
+    print("task start", id)
+    while True:
+        if t > 0:
+            print("task work", id)
+        await asyncio.sleep(t)
+
+
+async def main():
+    t1 = asyncio.create_task(task(1, -0.01))
+    t2 = asyncio.create_task(task(2, 0.1))
+    t3 = asyncio.create_task(task(3, 0.2))
+    await asyncio.sleep(0.5)
+    t1.cancel()
+    t2.cancel()
+    t3.cancel()
+    print("finish")
+
+
+asyncio.run(main())