[PYTHON][RPC] Make rpc proxy jupyter friendly via PopenWorker.

python/tvm/contrib/popen_pool.py

@@ -112,7 +112,10 @@ def kill(self):
             except IOError:
                 pass
             # kill all child processes recurisvely
-            kill_child_processes(self._proc.pid)
+            try:
+                kill_child_processes(self._proc.pid)
+            except TypeError:
+                pass
             try:
                 self._proc.kill()
             except OSError:
@@ -149,6 +152,11 @@ def _start(self):
         self._reader = os.fdopen(main_read, "rb")
         self._writer = os.fdopen(main_write, "wb")
 
+    def join(self):
+        """Join the current process worker before it terminates"""
+        if self._proc:
+            self._proc.wait()
+
     def send(self, fn, args=(), kwargs=None, timeout=None):
         """Send a new function task fn(*args, **kwargs) to the subprocess.
 

python/tvm/exec/popen_worker.py

@@ -22,6 +22,7 @@
 import threading
 import traceback
 import pickle
+import logging
 import cloudpickle
 
 from tvm.contrib.popen_pool import StatusKind
@@ -49,6 +50,8 @@ def main():
         reader = os.fdopen(int(sys.argv[1]), "rb")
         writer = os.fdopen(int(sys.argv[2]), "wb")
 
+    logging.basicConfig(level=logging.INFO)
+
     lock = threading.Lock()
 
     def _respond(ret_value):

python/tvm/exec/rpc_proxy.py

@@ -16,14 +16,10 @@
 # under the License.
 # pylint: disable=redefined-outer-name, invalid-name
 """RPC web proxy, allows redirect to websocket based RPC servers(browsers)"""
-from __future__ import absolute_import
-
 import logging
 import argparse
-import multiprocessing
-import sys
 import os
-from ..rpc.proxy import Proxy
+from tvm.rpc.proxy import Proxy
 
 
 def find_example_resource():
@@ -82,24 +78,6 @@ def main(args):
         "--example-rpc", type=bool, default=False, help="Whether to switch on example rpc mode"
     )
     parser.add_argument("--tracker", type=str, default="", help="Report to RPC tracker")
-    parser.add_argument(
-        "--no-fork",
-        dest="fork",
-        action="store_false",
-        help="Use spawn mode to avoid fork. This option \
-                         is able to avoid potential fork problems with Metal, OpenCL \
-                         and ROCM compilers.",
-    )
-    parser.set_defaults(fork=True)
     args = parser.parse_args()
     logging.basicConfig(level=logging.INFO)
-    if args.fork is False:
-        if sys.version_info[0] < 3:
-            raise RuntimeError("Python3 is required for spawn mode.")
-        multiprocessing.set_start_method("spawn")
-    else:
-        logging.info(
-            "If you are running ROCM/Metal, \
-        fork with cause compiler internal error. Try to launch with arg ```--no-fork```"
-        )
     main(args)

python/tvm/rpc/proxy.py

@@ -22,12 +22,11 @@
 the proxy server will forward the message between the client and server.
 """
 # pylint: disable=unused-variable, unused-argument
-from __future__ import absolute_import
-
 import os
+import asyncio
 import logging
 import socket
-import multiprocessing
+import threading
 import errno
 import struct
 import time
@@ -43,6 +42,7 @@
         "RPCProxy module requires tornado package %s. Try 'pip install tornado'." % error_msg
     )
 
+from tvm.contrib.popen_pool import PopenWorker
 from . import _ffi_api
 from . import base
 from .base import TrackerCode
@@ -261,6 +261,7 @@ def __init__(
                 logging.info(pair)
             self.app = tornado.web.Application(handlers)
             self.app.listen(web_port)
+
         self.sock = sock
         self.sock.setblocking(0)
         self.loop = ioloop.IOLoop.current()
@@ -471,6 +472,7 @@ def _proxy_server(
     index_page,
     resource_files,
 ):
+    asyncio.set_event_loop(asyncio.new_event_loop())
     handler = ProxyServerHandler(
         listen_sock,
         listen_port,
@@ -484,6 +486,87 @@ def _proxy_server(
     handler.run()
 
 
+class PopenProxyServerState(object):
+    """Internal PopenProxy State for Popen"""
+
+    current = None
+
+    def __init__(
+        self,
+        host,
+        port=9091,
+        port_end=9199,
+        web_port=0,
+        timeout_client=600,
+        timeout_server=600,
+        tracker_addr=None,
+        index_page=None,
+        resource_files=None,
+    ):
+
+        sock = socket.socket(base.get_addr_family((host, port)), socket.SOCK_STREAM)
+        self.port = None
+        for my_port in range(port, port_end):
+            try:
+                sock.bind((host, my_port))
+                self.port = my_port
+                break
+            except socket.error as sock_err:
+                if sock_err.errno in [98, 48]:
+                    continue
+                raise sock_err
+        if not self.port:
+            raise ValueError("cannot bind to any port in [%d, %d)" % (port, port_end))
+        logging.info("RPCProxy: client port bind to %s:%d", host, self.port)
+        sock.listen(1)
+        self.thread = threading.Thread(
+            target=_proxy_server,
+            args=(
+                sock,
+                self.port,
+                web_port,
+                timeout_client,
+                timeout_server,
+                tracker_addr,
+                index_page,
+                resource_files,
+            ),
+        )
+        # start the server in a different thread
+        # so we can return the port directly
+        self.thread.start()
+
+
+def _popen_start_server(
+    host,
+    port=9091,
+    port_end=9199,
+    web_port=0,
+    timeout_client=600,
+    timeout_server=600,
+    tracker_addr=None,
+    index_page=None,
+    resource_files=None,
+):
+    # This is a function that will be sent to the
+    # Popen worker to run on a separate process.
+    # Create and start the server in a different thread
+    state = PopenProxyServerState(
+        host,
+        port,
+        port_end,
+        web_port,
+        timeout_client,
+        timeout_server,
+        tracker_addr,
+        index_page,
+        resource_files,
+    )
+    PopenProxyServerState.current = state
+    # returns the port so that the main can get the port number.
+    return state.port
+
+
 class Proxy(object):
     """Start RPC proxy server on a seperate process.
 
@@ -532,43 +615,31 @@ def __init__(
         index_page=None,
         resource_files=None,
     ):
-        sock = socket.socket(base.get_addr_family((host, port)), socket.SOCK_STREAM)
-        self.port = None
-        for my_port in range(port, port_end):
-            try:
-                sock.bind((host, my_port))
-                self.port = my_port
-                break
-            except socket.error as sock_err:
-                if sock_err.errno in [98, 48]:
-                    continue
-                raise sock_err
-        if not self.port:
-            raise ValueError("cannot bind to any port in [%d, %d)" % (port, port_end))
-        logging.info("RPCProxy: client port bind to %s:%d", host, self.port)
-        sock.listen(1)
-        self.proc = multiprocessing.Process(
-            target=_proxy_server,
-            args=(
-                sock,
-                self.port,
+        self.proc = PopenWorker()
+        # send the function
+        self.proc.send(
+            _popen_start_server,
+            [
+                host,
+                port,
+                port_end,
                 web_port,
                 timeout_client,
                 timeout_server,
                 tracker_addr,
                 index_page,
                 resource_files,
-            ),
+            ],
         )
-        self.proc.start()
-        sock.close()
+        # receive the port
+        self.port = self.proc.recv()
         self.host = host
 
     def terminate(self):
         """Terminate the server process"""
         if self.proc:
             logging.info("Terminating Proxy Server...")
-            self.proc.terminate()
+            self.proc.kill()
             self.proc = None
 
     def __del__(self):

tests/python/contrib/test_rpc_proxy.py

@@ -38,20 +38,12 @@ def rpc_proxy_check():
         from tvm.rpc import proxy
 
         web_port = 8888
-        prox = proxy.Proxy("localhost", web_port=web_port)
+        prox = proxy.Proxy("127.0.0.1", web_port=web_port)
 
         def check():
             if not tvm.runtime.enabled("rpc"):
                 return
 
-            @tvm.register_func("rpc.test2.addone")
-            def addone(x):
-                return x + 1
-
-            @tvm.register_func("rpc.test2.strcat")
-            def addone(name, x):
-                return "%s:%d" % (name, x)
-
             server = multiprocessing.Process(
                 target=proxy.websocket_proxy_server, args=("ws://localhost:%d/ws" % web_port, "x1")
             )
@@ -60,10 +52,9 @@ def addone(name, x):
             server.deamon = True
             server.start()
             client = rpc.connect(prox.host, prox.port, key="x1")
-            f1 = client.get_function("rpc.test2.addone")
-            assert f1(10) == 11
-            f2 = client.get_function("rpc.test2.strcat")
-            assert f2("abc", 11) == "abc:11"
+            f1 = client.get_function("testing.echo")
+            assert f1(10) == 10
+            assert f1("xyz") == "xyz"
 
         check()
     except ImportError: