Barrier demo

mikeckennedy · mikeckennedy · commit fa49ef61072c · 2022-12-20T16:40:44.000-08:00
diff --git a/code/ch03-concurrency/in_sync_with_barriers.py b/code/ch03-concurrency/in_sync_with_barriers.py
@@ -0,0 +1,57 @@
+import asyncio
+
+
+def main():
+    print("Running game loop!")
+    print()
+    asyncio.run(game_loop())
+
+
+async def game_loop():
+    barrier = asyncio.Barrier(3)
+
+    while True:
+        print('/////////////// FRAME START ////////////////////////', flush=True)
+        async with asyncio.TaskGroup() as tg:
+            tg.create_task(compute_physics(barrier))
+            tg.create_task(get_input(barrier))
+            tg.create_task(render_scene(barrier))
+
+        print(r'\\\\\\\\\\\\\\\\\\\\\\ FRAME END \\\\\\\\\\\\\\')
+        print()
+
+
+async def render_scene(b: asyncio.Barrier):
+    print("Rendering scene!")
+    # Simulate work ;)
+    await asyncio.sleep(1.5)
+
+    await b.wait()
+
+    # Clean up work after all tasks are done.
+    print("Rendering done.")
+    await asyncio.sleep(.25)
+
+
+async def compute_physics(b: asyncio.Barrier):
+    print("Computing physics!")
+    await asyncio.sleep(.75)
+
+    await b.wait()
+
+    print("Physics done.")
+    await asyncio.sleep(.25)
+
+
+async def get_input(b: asyncio.Barrier):
+    print("Getting input!")
+    await asyncio.sleep(1)
+
+    await b.wait()
+
+    print("Input done.")
+    await asyncio.sleep(.25)
+
+
+if __name__ == '__main__':
+    main()
