1 files changed, 31 insertions, 0 deletions
diff --git a/tests/extmod/asyncio_fair.py b/tests/extmod/asyncio_fair.py
new file mode 100644
index 000000000..43076fef1
--- /dev/null
+++ b/tests/extmod/asyncio_fair.py
@@ -0,0 +1,31 @@
+# Test fairness of scheduler
+
+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, 0.18))
+    t4 = asyncio.create_task(task(4, -100))
+    await asyncio.sleep(0.5)
+    t1.cancel()
+    t2.cancel()
+    t3.cancel()
+    t4.cancel()
+    print("finish")
+
+
+asyncio.run(main())