Fix closes issue #11109 - socketserver.ForkingMixIn leaves zombies, also fails to reap all zombies in one pass.
A new method called service_action is made available in BaseServer, called by
serve_forever loop. This useful in cases where Mixins can use it for cleanup
action. ForkingMixin class uses service_action to collect the zombie child
processes. Initial Patch by Justin Wark.
diff --git a/Lib/socketserver.py b/Lib/socketserver.py
index 7389608..a2f0f39 100644
--- a/Lib/socketserver.py
+++ b/Lib/socketserver.py
@@ -82,7 +82,7 @@
data is stored externally (e.g. in the file system), a synchronous
class will essentially render the service "deaf" while one request is
being handled -- which may be for a very long time if a client is slow
-to reqd all the data it has requested. Here a threading or forking
+to recv all the data it has requested. Here a threading or forking
server is appropriate.
In some cases, it may be appropriate to process part of a request
@@ -170,6 +170,7 @@
- process_request(request, client_address)
- shutdown_request(request)
- close_request(request)
+ - service_actions()
- handle_error()
Methods for derived classes:
@@ -225,6 +226,8 @@
r, w, e = select.select([self], [], [], poll_interval)
if self in r:
self._handle_request_noblock()
+
+ self.service_actions()
finally:
self.__shutdown_request = False
self.__is_shut_down.set()
@@ -239,6 +242,14 @@
self.__shutdown_request = True
self.__is_shut_down.wait()
+ def service_actions(self):
+ """Called by the serve_forever() loop.
+
+ May be overridden by a subclass / Mixin to implement any code that
+ needs to be run during the loop.
+ """
+ pass
+
# The distinction between handling, getting, processing and
# finishing a request is fairly arbitrary. Remember:
#
@@ -539,9 +550,15 @@
"""
self.collect_children()
+ def service_actions(self):
+ """Collect the zombie child processes regularly in the ForkingMixin.
+
+ service_actions is called in the BaseServer's serve_forver loop.
+ """
+ self.collect_children()
+
def process_request(self, request, client_address):
"""Fork a new subprocess to process the request."""
- self.collect_children()
pid = os.fork()
if pid:
# Parent process
@@ -549,6 +566,7 @@
self.active_children = []
self.active_children.append(pid)
self.close_request(request)
+ return
else:
# Child process.
# This must never return, hence os._exit()!