demos enhanced during workshop at Garoa

Author: ramalho

concurrency/Concurrency.mm

@@ -0,0 +1,12 @@
+<map version="0.9.0">
+<!-- To view this file, download free mind mapping software FreeMind from http://freemind.sourceforge.net -->
+<node CREATED="1421704544481" ID="ID_1903556943" MODIFIED="1421714803674" TEXT="Concurrency">
+<node CREATED="1421704705118" ID="ID_598225085" MODIFIED="1421714763865" POSITION="left" TEXT="threading"/>
+<node CREATED="1421704717848" ID="ID_1699689274" MODIFIED="1421704738402" POSITION="left" TEXT="multiprocessing"/>
+<node CREATED="1421704568997" ID="ID_48551069" MODIFIED="1421714690188" POSITION="left" TEXT="parallelism"/>
+<node CREATED="1421705811900" ID="ID_740158806" MODIFIED="1421714796092" POSITION="right" TEXT="event-based">
+<node CREATED="1421706014013" ID="ID_1223527993" MODIFIED="1421706021925" TEXT="callbacks"/>
+<node CREATED="1421706028536" ID="ID_151937226" MODIFIED="1421706038694" TEXT="coroutines"/>
+</node>
+</node>
+</map>

concurrency/http_charserver.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+import sys
 import asyncio
 from aiohttp import web
 
@@ -55,26 +56,28 @@ def handle(request):
                       for word in sorted(EXAMPLE_WORDS, key=str.upper))
     text = PAGE_TPL.format(query=query, result=res,
                            message=msg, links=links)
+    print('Sending {} results'.format(len(lines)))
     return web.Response(content_type=CONTENT_TYPE, text=text)
 
 
 @asyncio.coroutine
-def init(loop):
+def init(loop, address, port):
     app = web.Application(loop=loop)
     app.router.add_route('GET', '/', handle)
 
     server = yield from loop.create_server(app.make_handler(),
-                                           '127.0.0.1', 8080)
+                                           address, port)
     host = server.sockets[0].getsockname()
     print('Serving on {}. Hit CTRL-C to stop.'.format(host))
 
 
-def main():
+def main(address="127.0.0.1", port=8888):
+    port = int(port)
     loop = asyncio.get_event_loop()
-    loop.run_until_complete(init(loop))
+    loop.run_until_complete(init(loop, address, port))
     loop.run_forever()
 
-
+    
 if __name__ == '__main__':
     index = UnicodeNameIndex()
-    main()
+    main(*sys.argv[1:])

concurrency/tcp_charserver.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+import sys
 import asyncio
 
 from charfinder import UnicodeNameIndex
@@ -13,8 +14,8 @@
 @asyncio.coroutine
 def handle_queries(reader, writer):
     while True:
-        writer.write(PROMPT)
-        yield from writer.drain()
+        writer.write(PROMPT)  # can't yield from!
+        yield from writer.drain()  # must yield from!
         data = yield from reader.readline()
         try:
             query = data.decode().strip()
@@ -29,15 +30,18 @@ def handle_queries(reader, writer):
             if lines:
                 writer.writelines(line.encode() + CRLF for line in lines)
             writer.write(index.status(query, len(lines)).encode() + CRLF)
+    
             yield from writer.drain()
+            print('Sent {} results'.format(len(lines)))
 
     print('Close the client socket')
     writer.close()
 
 
-def main():
+def main(address='127.0.0.1', port=8888):
+    port = int(port)
     loop = asyncio.get_event_loop()
-    coro = asyncio.start_server(handle_queries, '127.0.0.1', 8888, loop=loop)
+    coro = asyncio.start_server(handle_queries, address, port, loop=loop)
     server = loop.run_until_complete(coro)
 
     host = server.sockets[0].getsockname()
@@ -54,4 +58,4 @@ def main():
 
 if __name__ == '__main__':
     index = UnicodeNameIndex()
-    main()
+    main(*sys.argv[1:])

concurrency/timer.py

@@ -2,11 +2,9 @@
 
 @asyncio.coroutine
 def show_remaining():
-    remaining = 5
-    while remaining:
+    for remaining in range(5, 0, -1):
         print('Remaining: ', remaining)
         yield from asyncio.sleep(1)
-        remaining -= 1
 
 def main():
     loop = asyncio.get_event_loop()

concurrency/timer_clo.py

@@ -0,0 +1,29 @@
+import sys
+import asyncio
+
+def make_show_remaining(seconds):
+    remaining = seconds
+
+    def show_remaining(loop):
+        nonlocal remaining
+        print('Remaining: ', remaining)
+        remaining -= 1
+        if remaining:
+            loop.call_later(1, show_remaining, loop)
+        else:
+            loop.stop()
+
+    return show_remaining
+    
+    
+def main(seconds=5):
+    seconds = int(seconds)
+    loop = asyncio.get_event_loop()
+    try:
+        loop.call_soon(make_show_remaining(seconds), loop)
+        loop.run_forever()
+    finally:
+        loop.close()
+
+if __name__ == '__main__':
+    main(*sys.argv[1:])

concurrency/timer_seq.py

@@ -0,0 +1,8 @@
+import time
+
+def main():
+    for remaining in range(5, 0, -1):
+	    print('Remaining: ', remaining) 
+
+if __name__ == '__main__':
+    main()