Handles SIGCHLD for remote shell

cloudcontrol/node/host/__init__.py

@@ -90,6 +90,7 @@ class RemoteShell(object):
         self.proto = conn.create_tunnel(endpoint=self.endpoint,
                                         on_shutdown=self.on_tunnel_shutdown)
         self.conn = conn
+        self.child_watcher = None
         try:
             self.process = subprocess.Popen(
                 [exec_], stdout=self.slave,
@@ -104,6 +105,9 @@ class RemoteShell(object):
             # close opened fds
             self.close_cb()
             raise
+        self.child_watcher = conn.loop.child(self.process.pid, False,
+                                             self.child_cb)
+        self.child_watcher.start()
 
     @property
     def label(self):
@@ -121,11 +125,18 @@ class RemoteShell(object):
         self.close()
         logger.debug('Tunnel closed by sjRPC')
 
+    def child_cb(self, watcher, revents):
+        logger.debug('Tunnel closed by process termination')
+        self.process.returncode = watcher.rstatus
+        self.close()
+
     def close(self):
-        if self.process.poll() is None:
+        if self.child_watcher is not None:
+            self.child_watcher.stop()
+            self.child_watcher = None
+        if self.process.returncode is None:
             # process is still alive
             self.process.kill()
-            self.process.wait()
         if self.master is not None:
             try:
                 os.close(self.master)