CHOP-661: add and use code to listen on next available server port.

In indra/llmessage/tests/testrunner.py, introduce new freeport() function to
try a caller-specified expression (such as instantiating an object that will
listen on a server port) with a range of candidate port numbers until the
expression produces a value instead of EADDRINUSE exception.
Change test_llsdmessage_peer.py and test_llxmlrpc_peer.py to use freeport() to
construct their server class inline BEFORE launching the thread that will run
it, then pass that server's serve_forever method to daemon thread. Also set
os.environ["PORT"] to selected environment variable before running subject
test program.
In indra/llmessage/tests/commtest.h, introduce commtest_data::getport() to
read port number from specified environment variable, throwing exception if
variable not set or non-numeric. Construct default LLHost from getport("PORT")
instead of hardcoded constant.
Change indra/newview/tests/llxmlrpclistener_test.cpp to use commtest_data::
getport("PORT") instead of hardcoded constant. Also use LLSD::with() rather
than older LLSD::insert() syntax.
HOWEVER -- I am irritated to discover that llxmlrpclistener_test IS NOT RUN or
even built by newview/CMakeLists.txt! It's not even commented out -- it's
entirely deleted! I am determined to restore this test. However, as it will
take some fiddling with new link-time dependencies, that will be a separate
commit.

1 files changed, 13 insertions, 8 deletions

diff --git a/indra/newview/tests/test_llxmlrpc_peer.py b/indra/newview/tests/test_llxmlrpc_peer.py
index 1c7204a6b6..281b72a058 100644
--- a/indra/newview/tests/test_llxmlrpc_peer.py
+++ b/indra/newview/tests/test_llxmlrpc_peer.py
@@ -37,7 +37,7 @@ from SimpleXMLRPCServer import SimpleXMLRPCServer
 mydir = os.path.dirname(__file__)       # expected to be .../indra/newview/tests/
 sys.path.insert(0, os.path.join(mydir, os.pardir, os.pardir, "lib", "python"))
 sys.path.insert(1, os.path.join(mydir, os.pardir, os.pardir, "llmessage", "tests"))
-from testrunner import run, debug
+from testrunner import freeport, run, debug
 
 class TestServer(SimpleXMLRPCServer):
     def _dispatch(self, method, params):
@@ -66,11 +66,16 @@ class TestServer(SimpleXMLRPCServer):
         # Suppress error output as well
         pass
 
-class ServerRunner(Thread):
-    def run(self):
-        server = TestServer(('127.0.0.1', 8000))
-        debug("Starting XMLRPC server...\n")
-        server.serve_forever()
-
 if __name__ == "__main__":
-    sys.exit(run(server=ServerRunner(name="xmlrpc"), *sys.argv[1:]))
+    # Instantiate a TestServer on the first free port in the specified port
+    # range. Doing this inline is better than in a daemon thread: if it blows
+    # up here, we'll get a traceback. If it blew up in some other thread, the
+    # traceback would get eaten and we'd run the subject test program anyway.
+    xmlrpcd, port = freeport(xrange(8000, 8020),
+                             lambda port: TestServer(('127.0.0.1', port)))
+    # Pass the selected port number to the subject test program via the
+    # environment. We don't want to impose requirements on the test program's
+    # command-line parsing -- and anyway, for C++ integration tests, that's
+    # performed in TUT code rather than our own.
+    os.environ["PORT"] = str(port)
+    sys.exit(run(server=Thread(name="xmlrpc", target=xmlrpcd.serve_forever), *sys.argv[1:]))