From dcea6780c6b520cdb489b88528d7d5eb570209ae Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Tue, 26 Jan 2016 00:48:12 +0100
Subject: [PATCH] protocols/pipe_ipc: implement AsyncioChildComm for Unix
 (affected by python/asyncio#314)

---
 artiq/protocols/pipe_ipc.py | 46 ++++++++++++++++++++++++------------
 artiq/test/pipe_ipc.py      | 47 +++++++++++++++++++++++++++++++++----
 2 files changed, 74 insertions(+), 19 deletions(-)

diff --git a/artiq/protocols/pipe_ipc.py b/artiq/protocols/pipe_ipc.py
index 085e0eea8..a982bdf9b 100644
--- a/artiq/protocols/pipe_ipc.py
+++ b/artiq/protocols/pipe_ipc.py
@@ -1,5 +1,6 @@
 import os
 import asyncio
+from asyncio.streams import FlowControlMixin
 
 
 class _BaseIO:
@@ -20,6 +21,22 @@ class _BaseIO:
 
 
 if os.name != "nt":
+    async def _fds_to_asyncio(rfd, wfd, loop):
+        reader = asyncio.StreamReader(loop=loop)
+        reader_protocol = asyncio.StreamReaderProtocol(reader, loop=loop)
+
+        wf = open(wfd, "wb", 0)
+        transport, protocol = await loop.connect_write_pipe(
+            FlowControlMixin, wf)
+        writer = asyncio.StreamWriter(transport, protocol,
+                                      None, loop)
+
+        rf = open(rfd, "rb", 0)
+        await loop.connect_read_pipe(lambda: reader_protocol, rf)
+
+        return reader, writer
+
+
     class AsyncioParentComm(_BaseIO):
         def __init__(self):
             self.c_rfd, self.p_wfd = os.pipe()
@@ -35,20 +52,19 @@ if os.name != "nt":
             os.close(self.c_rfd)
             os.close(self.c_wfd)
 
-            pipe = open(self.p_rfd, "rb", 0)
-            self.reader = asyncio.StreamReader(loop=loop)
-            def factory():
-                return asyncio.StreamReaderProtocol(self.reader, loop=loop)
-            await loop.connect_read_pipe(factory, pipe)
+            self.reader, self.writer = await _fds_to_asyncio(
+                self.p_rfd, self.p_wfd, loop)
 
-            pipe = open(self.p_wfd, "wb", 0)
-            transport, protocol = await loop.connect_write_pipe(
-                asyncio.Protocol, pipe)
-            self.writer = asyncio.StreamWriter(transport, protocol,
-                                               None, loop)
 
     class AsyncioChildComm(_BaseIO):
-        pass
+        def __init__(self, address):
+            self.address = address
+
+        async def connect(self):
+            rfd, wfd = self.address.split(",", maxsplit=1)
+            self.reader, self.writer = await _fds_to_asyncio(
+                int(rfd), int(wfd), asyncio.get_event_loop())
+
 
     class ChildComm:
         def __init__(self, address):
@@ -82,10 +98,10 @@ else:  # windows
         async def connect(self):
             loop = asyncio.get_event_loop()
             self.reader = asyncio.StreamReader(loop=loop)
-            def factory():
-                return asyncio.StreamReaderProtocol(self.reader)
-            transport, protocol = await loop.create_pipe_connection(self.address,
-                                                                    factory)
+            reader_protocol = asyncio.StreamReaderProtocol(
+                self.reader, loop=loop)
+            transport, protocol = await loop.create_pipe_connection(
+                self.address, lambda: reader_protocol)
             self.writer = asyncio.StreamWriter(transport, protocol,
                                                self.reader, loop)
 
diff --git a/artiq/test/pipe_ipc.py b/artiq/test/pipe_ipc.py
index 901c49fa6..9614a7431 100644
--- a/artiq/test/pipe_ipc.py
+++ b/artiq/test/pipe_ipc.py
@@ -1,25 +1,31 @@
 import unittest
 import sys
 import asyncio
+import os
 
 from artiq.protocols import pipe_ipc
 
 
 class IPCCase(unittest.TestCase):
     def setUp(self):
-        self.loop = asyncio.new_event_loop()
+        if os.name == "nt":
+            self.loop = asyncio.ProactorEventLoop()
+        else:
+            self.loop = asyncio.new_event_loop()
         asyncio.set_event_loop(self.loop)
 
     def tearDown(self):
         self.loop.close()
 
-    async def _coro_test(self, child_blocking):
+    async def _coro_test(self, child_asyncio):
         ipc = pipe_ipc.AsyncioParentComm()
         await ipc.create_subprocess(sys.executable,
                                     sys.modules[__name__].__file__,
+                                    str(child_asyncio),
                                     ipc.get_address())
         for i in range(10):
             ipc.write("{}\n".format(i).encode())
+            await ipc.drain()
             s = (await ipc.readline()).decode()
             self.assertEqual(int(s), i+1)
         ipc.write(b"-1\n")
@@ -27,16 +33,49 @@ class IPCCase(unittest.TestCase):
         ipc.close()
 
     def test_blocking(self):
+        self.loop.run_until_complete(self._coro_test(False))
+
+    def test_asyncio(self):
         self.loop.run_until_complete(self._coro_test(True))
 
 
-def run_child():
-    child_comm = pipe_ipc.ChildComm(sys.argv[1])
+def run_child_blocking():
+    child_comm = pipe_ipc.ChildComm(sys.argv[2])
     while True:
         x = int(child_comm.readline().decode())
         if x < 0:
             break
         child_comm.write((str(x+1) + "\n").encode())
+    child_comm.close()
+
+
+async def coro_child():
+    child_comm =  pipe_ipc.AsyncioChildComm(sys.argv[2])
+    await child_comm.connect()
+    while True:
+       x = int((await child_comm.readline()).decode())
+       if x < 0:
+           break
+       child_comm.write((str(x+1) + "\n").encode())
+       await child_comm.drain()
+    child_comm.close()
+
+
+def run_child_asyncio():
+    if os.name == "nt":
+        loop = asyncio.ProactorEventLoop()
+        asyncio.set_event_loop(loop)
+    else:
+        loop = asyncio.get_event_loop()
+    loop.run_until_complete(coro_child())
+    loop.close()
+
+
+def run_child():
+    if sys.argv[1] == "True":
+        run_child_asyncio()
+    else:
+        run_child_blocking()
 
 if __name__ == "__main__":
     run_child()