kill server on viewer exit to emulate previous behaviour

1 files changed, 30 insertions, 4 deletions

diff --git a/src/jarabe/util/emulator.py b/src/jarabe/util/emulator.py
index 4b3b931..8934f5e 100644
--- a/src/jarabe/util/emulator.py
+++ b/src/jarabe/util/emulator.py
@@ -14,6 +14,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
+import errno
 import os
 import signal
 import subprocess
@@ -27,6 +28,8 @@ from sugar import env
 DEFAULT_DIMENSIONS = (800, 600)
 _DEV_NULL = open(os.devnull, 'w')
 
+server = None
+
 
 def _run_pipe(command, stdin=None):
     """Run a program with optional input and return output.
@@ -103,13 +106,18 @@ def _run_server(display, dpi, dimensions, fullscreen):
 
 
 def _kill_pipe(pipe):
-    """Terminate and wait for child process."""
+    """Terminate and wait for child process (if any)."""
     try:
         os.kill(pipe.pid, signal.SIGTERM)
-    except OSError:
-        pass
+    except OSError, exception:
+        if exception.errno != errno.ESRCH:
+            raise
 
-    pipe.wait()
+    try:
+        pipe.wait()
+    except OSError, exception:
+        if exception.errno != errno.ECHILD:
+            raise
 
 
 def _start_server(dpi, dimensions, fullscreen):
@@ -185,8 +193,24 @@ def _parse_args():
     return parser.parse_args()
 
 
+def _sigchld_handler(number_, frame_):
+    """Kill server when any (direct) child exits.
+
+    So closing the viewer will close the server as well."""
+    if server.returncode is not None:
+        return
+
+    signal.signal(signal.SIGCHLD, signal.SIG_DFL)
+
+    print 'sugar-emulator: Child exited, shutting down server'
+    _kill_pipe(server)
+    return
+
+
 def main():
     """Script-level operations"""
+    global server
+
     options, args = _parse_args()
     display, server = _start_server(options.dpi, options.dimensions,
         options.fullscreen)
@@ -201,6 +225,8 @@ def main():
         _start_window_manager()
         command += args
 
+    signal.signal(signal.SIGCHLD, _sigchld_handler)
     subprocess.call(command, close_fds=True)
+
     _kill_pipe(viewer)
     _kill_pipe(server)