Fix HTTP for kernel < 4.16

tools/rosgraph/src/rosgraph/xmlrpc.py

@@ -44,6 +44,7 @@
 
 import errno
 import logging
+import platform
 import select
 import socket
 
@@ -76,9 +77,40 @@ def isstring(s):
     except NameError:
         return isinstance(s, str)
 
-class SilenceableXMLRPCRequestHandler(SimpleXMLRPCRequestHandler):
 
-    protocol_version = 'HTTP/1.1'
+def _support_http_1_1():
+    """Linux kernels 4.15 and older encounter performance issues with HTTP/1.1
+    This function returns true if the Linux kernel version is greater than the
+    input or if the platform is not Linux.
+    """
+    # HTTP/1.1 performance issue only detected on Linux
+    if platform.system() != 'Linux':
+        return True
+
+    release = platform.release().split('.')
+
+    major = 4
+    minor = 15
+
+    platform_major = int(release[0])
+    platform_minor = int(release[1])
+
+    if platform_major > major:
+        return True
+    elif platform_major < major:
+        return False
+
+    if platform_minor > minor:
+        return True
+    elif platform_minor < minor:
+        return False
+
+    return False
+
+
+class SilenceableXMLRPCRequestHandler(SimpleXMLRPCRequestHandler):
+    if _support_http_1_1:
+        protocol_version = 'HTTP/1.1'
 
     def log_message(self, format, *args):
         if 0:
@@ -90,7 +122,8 @@ class ThreadingXMLRPCServer(socketserver.ThreadingMixIn, SimpleXMLRPCServer):
     requests via threading. Also makes logging toggleable.
     """
 
-    daemon_threads = True
+    if _support_http_1_1:
+        daemon_threads = True
 
     def __init__(self, addr, log_requests=1):
         """