protocols/pipe_ipc: Windows support

artiq/protocols/pipe_ipc.py

@@ -3,6 +3,9 @@ import asyncio
 from asyncio.streams import FlowControlMixin
 
 
+__all__ = ["AsyncioParentComm", "AsyncioChildComm", "ChildComm"]
+
+
 class _BaseIO:
     def write(self, data):
         self.writer.write(data)
@@ -92,11 +95,79 @@ if os.name != "nt":
 
 
 else:  # windows
-    class AsyncioParentComm(_BaseIO):
+    import itertools
+
+
+    _pipe_count = itertools.count()
+
+
+    class AsyncioParentComm:
+        """Requires ProactorEventLoop"""
+        def __init__(self):
+            # We cannot use anonymous pipes on Windows, because we do not know
+            # in advance if the child process wants a handle open in overlapped
+            # mode or not.
+            self.address = "\\\\.\\pipe\\artiq-{}-{}".format(os.getpid(),
+                                                             next(_pipe_count))
+            self.server = None
+            self.ready = asyncio.Event()
+            self.write_buffer = b""
+
+        def get_address(self):
+            return self.address
+
         async def _autoclose(self):
             await self.process.wait()
+            if self.server is not None:
+                self.server[0].close()
+                self.server = None
+            if self.ready.is_set():
                 self.writer.close()
 
+        async def create_subprocess(self, *args, **kwargs):
+            loop = asyncio.get_event_loop()
+
+            def factory():
+                reader = asyncio.StreamReader(loop=loop)
+                protocol = asyncio.StreamReaderProtocol(reader,
+                                                self._child_connected,
+                                                loop=loop)
+                return protocol
+            self.server = await loop.start_serving_pipe(
+                factory, self.address)
+
+            self.process = await asyncio.create_subprocess_exec(
+                *args, **kwargs)
+            asyncio.ensure_future(self._autoclose())
+
+        def _child_connected(self, reader, writer):
+            self.server[0].close()
+            self.server = None
+            self.reader = reader
+            self.writer = writer
+            if self.write_buffer:
+                self.writer.write(self.write_buffer)
+                self.write_buffer = b""
+            self.ready.set()
+
+        def write(self, data):
+            if self.ready.is_set():
+                self.writer.write(data)
+            else:
+                self.write_buffer += data
+
+        async def drain(self):
+            await self.ready.wait()
+            await self.writer.drain()
+
+        async def readline(self):
+            await self.ready.wait()
+            return await self.reader.readline()
+
+        async def read(self, n):
+            await self.ready.wait()
+            return await self.reader.read(n)
+
 
     class AsyncioChildComm(_BaseIO):
         """Requires ProactorEventLoop"""
@@ -109,9 +180,26 @@ else:  # windows
             reader_protocol = asyncio.StreamReaderProtocol(
                 self.reader, loop=loop)
             transport, _ = await loop.create_pipe_connection(
-                self.address, lambda: reader_protocol)
+                lambda: reader_protocol, self.address)
             self.writer = asyncio.StreamWriter(transport, reader_protocol,
                                                self.reader, loop)
 
+        def close(self):
+            self.writer.close()
+
+
     class ChildComm:
-        pass
+        def __init__(self, address):
+            self.f = open(address, "a+b", 0)
+
+        def read(self, n):
+            return self.f.read(n)
+
+        def readline(self):
+            return self.f.readline()
+
+        def write(self, data):
+            return self.f.write(data)
+
+        def close(self):
+            self.f.close()