app: write test output directly to files

There is no sense to wait for the process termination or timeout.

It allows to see the output as the file's content during a test
execution.

lib/app_server.py

@@ -33,17 +33,14 @@ def timeout_handler(server_process, test_timeout):
 
 def run_server(execs, cwd, server, logfile, retval, test_id):
     os.putenv("LISTEN", server.listen_uri)
-    server.process = Popen(execs, stdout=PIPE, stderr=PIPE, cwd=cwd)
+    with open(logfile, 'ab') as f:
+        server.process = Popen(execs, stdout=sys.stdout, stderr=f, cwd=cwd)
     sampler.register_process(server.process.pid, test_id, server.name)
     test_timeout = Options().args.test_timeout
     timer = Timer(test_timeout, timeout_handler, (server.process, test_timeout))
     timer.start()
-    stdout, stderr = server.process.communicate()
-    timer.cancel()
-    sys.stdout.write_bytes(stdout)
-    with open(logfile, 'ab') as f:
-        f.write(stderr)
     retval['returncode'] = server.process.wait()
+    timer.cancel()
     server.process = None
 
 

lib/test.py

@@ -91,6 +91,10 @@ def close(self):
     def flush(self):
         self.stream.flush()
 
+    def fileno(self):
+        """ May be used for direct writting. Discards any filters.
+        """
+        return self.stream.fileno()
 
 def get_filename_by_test(postfix, test_name):
     """For <..>/<name>_test.* or <..>/<name>.test.* return <name> + postfix