update from Atlas with major reorg

attic/concurrency/timer2.py

@@ -0,0 +1,30 @@
+import asyncio
+import sys
+import contextlib
+
+@asyncio.coroutine
+def show_remaining(dots_task):
+    remaining = 5
+    while remaining:
+        print('Remaining: ', remaining)
+        sys.stdout.flush()
+        yield from asyncio.sleep(1)
+        remaining -= 1
+    dots_task.cancel()
+    print()
+
+@asyncio.coroutine
+def dots():
+    while True:
+        print('.', sep='', end='')
+        sys.stdout.flush()
+        yield from asyncio.sleep(.1)
+
+def main():
+    with contextlib.closing(asyncio.get_event_loop()) as loop:
+        dots_task = asyncio.Task(dots())
+        coros = [show_remaining(dots_task), dots_task]
+        loop.run_until_complete(asyncio.wait(coros))
+
+if __name__ == '__main__':
+    main()