Use sigchld instead of polling children

sileht · Jan 16, 2017 · 64fea67 · 64fea67
1 parent ea3b6ae
commit 64fea67
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 6 deletions.
diff --git a/cotyledon/_service_manager.py b/cotyledon/_service_manager.py
@@ -123,6 +123,7 @@ def __init__(self, wait_interval=0.01, graceful_shutdown_timeout=60):
         self._death_detection_pipe = multiprocessing.Pipe(duplex=False)
 
         signal.signal(signal.SIGINT, self._fast_exit)
+        signal.signal(signal.SIGCHLD, self._signal_catcher)
 
     def register_hooks(self, on_terminate=None, on_reload=None,
                        on_new_worker=None):
@@ -203,9 +204,10 @@ def run(self):
         """
 
         self._systemd_notify_once()
+        self._spawn_missing_workers()
         self._wait_forever()
 
-    def _on_wakeup(self):
+    def _spawn_missing_workers(self):
         info = self._get_last_worker_died()
         while info is not None:
             service_id, worker_id = info
@@ -220,6 +222,8 @@ def _on_signal_received(self, sig):
             self._shutdown()
         elif sig == _utils.SIGHUP:
             self._reload()
+        elif sig == signal.SIGCHLD:
+            self._spawn_missing_workers()
         else:
             LOG.debug("unhandled signal %s" % sig)
 

diff --git a/cotyledon/_utils.py b/cotyledon/_utils.py
@@ -110,6 +110,7 @@ def __init__(self, master=False):
         self._signals_received = collections.deque()
 
         signal.signal(signal.SIGINT, signal.SIG_DFL)
+        signal.signal(signal.SIGCHLD, signal.SIG_DFL)
         if os.name == 'posix':
             signal.signal(signal.SIGTERM, self._signal_catcher)
             signal.signal(signal.SIGALRM, self._signal_catcher)
@@ -144,7 +145,6 @@ def _wait_forever(self):
             if os.name == "posix":
                 self._empty_signal_pipe()
             self._run_signal_handlers()
-            self._on_wakeup()
 
             if os.name == "posix":
                 # NOTE(sileht): we cannot use threading.Event().wait(),
@@ -157,7 +157,7 @@ def _wait_forever(self):
                 # That looks perfect to ensure handlers are run and run in the
                 # main thread
                 try:
-                    select.select([self.signal_pipe_r], [], [], 0.5)
+                    select.select([self.signal_pipe_r], [], [])
                 except select.error as e:
                     if e.args[0] != errno.EINTR:
                         raise
@@ -183,8 +183,5 @@ def _run_signal_handlers(self):
                 return
             self._on_signal_received(sig)
 
-    def _on_wakeup(self):
-        pass
-
     def _on_signal_received(self, sig):
         pass