Use multiprocessing to start multiple servers in tests

Cherrypy uses a bunch of globals, so use multiprocessing to let us
spawn a few that are totally independent.

.gitignore

@@ -7,5 +7,5 @@ build/
 dist/
 *.egg-info/
 .eggs/
-tests/testdb
+tests/testdb*
 MANIFEST

tests/runtests.py

@@ -45,5 +45,6 @@ class JimOrderPlugin(nose.plugins.Plugin):
 # Use setup.cfg for most of the test configuration.  Adding
 # --with-jimorder here means that a normal "nosetests" run will
 # still work, it just won't support test.order.
-nose.main(addplugins = [ JimOrderPlugin() ],
-          argv = sys.argv + ["--with-jimorder"])
+if __name__ == "__main__":
+    nose.main(addplugins = [ JimOrderPlugin() ],
+              argv = sys.argv + ["--with-jimorder"])

tests/test.py

@@ -17,26 +17,48 @@ from nose.tools import assert_raises
 import unittest
 
 from testutil.helpers import *
+import multiprocessing
+import traceback
 
+from urllib.request import urlopen
 from nilmtools.filter import ArgumentError
 
+def run_cherrypy_server(path, port, event):
+    db = nilmdb.utils.serializer_proxy(nilmdb.server.NilmDB)(path)
+    server = nilmdb.server.Server(db, host="127.0.0.1",
+                                  port=port, stoppable=True)
+    server.start(blocking = True, event = event)
+    db.close()
+
 class CommandTester():
 
     url = "http://localhost:32182/"
+    url2 = "http://localhost:32183/"
 
     @classmethod
     def setup_class(cls):
-        path = "tests/testdb"
-        recursive_unlink(path)
-        cls.db = nilmdb.utils.serializer_proxy(nilmdb.server.NilmDB)(path)
-        cls.server = nilmdb.server.Server(cls.db, host="127.0.0.1",
-                                        port=32182, stoppable=True)
-        cls.server.start(blocking=False)
+        # Use multiprocessing with "spawn" method, so that we can
+        # start two fully independent cherrypy instances
+        # (needed for copy-wildcard)
+        multiprocessing.set_start_method('spawn')
+
+        events = []
+        for (path, port) in (("tests/testdb1", 32182),
+                             ("tests/testdb2", 32183)):
+            recursive_unlink(path)
+            event = multiprocessing.Event()
+            proc = multiprocessing.Process(target=run_cherrypy_server,
+                                           args=(path, port, event))
+            proc.start()
+            events.append(event)
+        for event in events:
+            if not event.wait(timeout = 10):
+                raise AssertionError("server didn't start")
 
     @classmethod
     def teardown_class(cls):
-        cls.server.stop()
-        cls.db.close()
+        urlopen("http://127.0.0.1:32182/exit/", timeout = 1)
+        urlopen("http://127.0.0.1:32183/exit/", timeout = 1)
 
     def run(self, arg_string, infile=None, outfile=None):
         """Run a cmdline client with the specified argument string,