Add support for automatically shutdown dbus-daemon after after last client disconnects on Windows.terminate-dbus-after-clients-disconnect

Shutdown the server if the bus is running with an autolaunch meta
transport and the last client has disconnected.

6 files changed, 78 insertions, 4 deletions

diff --git a/bus/bus.c b/bus/bus.c
index b01386643..2ad221c92 100644
--- a/bus/bus.c
+++ b/bus/bus.c
@@ -74,6 +74,7 @@ struct BusContext
   unsigned int allow_anonymous : 1;
   unsigned int systemd_activation : 1;
   dbus_bool_t watches_enabled;
+  int n_connections;
 };
 
 static dbus_int32_t server_data_slot = -1;
@@ -1825,3 +1826,19 @@ bus_context_check_all_watches (BusContext *context)
       _dbus_server_toggle_all_watches (server, enabled);
     }
 }
+
+void bus_context_increment_connections (BusContext *context)
+{
+    context->n_connections++;
+}
+
+void
+bus_context_decrement_connections (BusContext *context)
+{
+    context->n_connections--;
+}
+
+int bus_context_n_connections (BusContext *context)
+{
+    return context->n_connections;
+}
diff --git a/bus/bus.h b/bus/bus.h
index 2e0de8255..55ea7e593 100644
--- a/bus/bus.h
+++ b/bus/bus.h
@@ -145,5 +145,8 @@ dbus_bool_t       bus_context_check_security_policy              (BusContext
                                                                   BusActivationEntry *activation_entry,
                                                                   DBusError        *error);
 void              bus_context_check_all_watches                  (BusContext       *context);
+void              bus_context_increment_connections              (BusContext       *context);
+void              bus_context_decrement_connections              (BusContext       *context);
+int               bus_context_n_connections                      (BusContext       *context);
 
 #endif /* BUS_BUS_H */
diff --git a/bus/connection.c b/bus/connection.c
index 5144218cf..16e29cc81 100644
--- a/bus/connection.c
+++ b/bus/connection.c
@@ -295,6 +295,29 @@ bus_connection_disconnected (DBusConnection *connection)
   
   bus_connection_remove_transactions (connection);
 
+  bus_context_decrement_connections (d->connections->context);
+#ifdef DBUS_WIIN
+  if (bus_context_n_connections (d->connections->context) == 0)
+    {
+      const char *s = bus_context_get_address (d->connections->context);
+      if (strstr (s, "autolaunch"))
+        {
+          if (_dbus_daemon_lock_autolaunch_address ())
+            {
+              DBusLoop *loop = bus_context_get_loop (d->connections->context);
+              _dbus_loop_quit (loop);
+            }
+          else
+            {
+              // Ignore the case that we are not able to lock autolaunch address mutex
+              // because a client tries to fetch autolaunch address as preparation
+              // to connect to the server.
+              _dbus_verbose ("Could not lock autolaunch address - skipping shutdown");
+            }
+        }
+    }
+#endif
+
   if (d->link_in_monitors != NULL)
     {
       BusMatchmaker *mm = d->connections->monitor_matchmaker;
@@ -1582,7 +1605,9 @@ bus_connection_complete (DBusConnection   *connection,
       d->name = NULL;
       return FALSE;
     }
-  
+
+  bus_context_increment_connections(d->connections->context);
+
   if (dbus_connection_get_unix_user (connection, &uid))
     {
       if (!adjust_connections_for_uid (d->connections,
diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
index 39c13360b..259e9723a 100644
--- a/dbus/dbus-sysdeps-unix.c
+++ b/dbus/dbus-sysdeps-unix.c
@@ -4271,6 +4271,12 @@ _dbus_daemon_publish_session_bus_address (const char* addr,
   return TRUE;
 }
 
+dbus_bool_t
+_dbus_daemon_lock_autolaunch_address ()
+{
+  return FALSE;
+}
+
 //PENDING(kdab) docs
 void
 _dbus_daemon_unpublish_session_bus_address (void)
diff --git a/dbus/dbus-sysdeps-win.c b/dbus/dbus-sysdeps-win.c
index e321168bc..3e6e0cc4f 100644
--- a/dbus/dbus-sysdeps-win.c
+++ b/dbus/dbus-sysdeps-win.c
@@ -2859,6 +2859,25 @@ _dbus_daemon_is_session_bus_address_published (const char *scope)
   return FALSE;
 }
 
+/**
+ * Lock access to autolaunched address
+ *
+ * This function is called to prevent client from accessing
+ * autolaunch address in shared memory segment as preparation
+ * to shutdown server
+ * @return TRUE lock has been gotten
+ * @return FALSE lock has not been gotten
+ */
+dbus_bool_t
+_dbus_daemon_lock_autolaunch_address ()
+{
+  HANDLE lock;
+
+  // sync _dbus_daemon_publish_session_bus_address, _dbus_daemon_unpublish_session_bus_address,
+  // _dbus_daemon_already_runs and _dbus_daemon_lock_autolaunch_address
+  return _dbus_global_lock (cUniqueDBusInitMutex) != FALSE;
+}
+
 dbus_bool_t
 _dbus_daemon_publish_session_bus_address (const char* address, const char *scope)
 {
@@ -2876,7 +2895,8 @@ _dbus_daemon_publish_session_bus_address (const char* address, const char *scope
       return FALSE;
     }
 
-  // sync _dbus_daemon_publish_session_bus_address, _dbus_daemon_unpublish_session_bus_address and _dbus_daemon_already_runs
+  // sync _dbus_daemon_publish_session_bus_address, _dbus_daemon_unpublish_session_bus_address,
+  // _dbus_daemon_already_runs and _dbus_daemon_lock_autolaunch_address
   lock = _dbus_global_lock( cUniqueDBusInitMutex );
 
   if (!hDBusDaemonMutex)
@@ -2929,7 +2949,8 @@ _dbus_daemon_unpublish_session_bus_address (void)
 {
   HANDLE lock;
 
-  // sync _dbus_daemon_publish_session_bus_address, _dbus_daemon_unpublish_session_bus_address and _dbus_daemon_already_runs
+  // sync _dbus_daemon_publish_session_bus_address, _dbus_daemon_unpublish_session_bus_address,
+  // _dbus_daemon_already_runs and _dbus_daemon_lock_autolaunch_address
   lock = _dbus_global_lock( cUniqueDBusInitMutex );
 
   CloseHandle( hDBusSharedMem );
@@ -2996,7 +3017,8 @@ _dbus_daemon_already_runs (DBusString *address, DBusString *shm_name, const char
       return FALSE;
     }
 
-  // sync _dbus_daemon_publish_session_bus_address, _dbus_daemon_unpublish_session_bus_address and _dbus_daemon_already_runs
+  // sync _dbus_daemon_publish_session_bus_address, _dbus_daemon_unpublish_session_bus_address,
+  // _dbus_daemon_already_runs and _dbus_daemon_lock_autolaunch_address
   lock = _dbus_global_lock( cUniqueDBusInitMutex );
 
   // do checks
diff --git a/dbus/dbus-sysdeps.h b/dbus/dbus-sysdeps.h
index 5ed4c45ed..0a03253da 100644
--- a/dbus/dbus-sysdeps.h
+++ b/dbus/dbus-sysdeps.h
@@ -610,6 +610,7 @@ void _dbus_logv (DBusSystemLogSeverity  severity,
       _DBUS_BYTE_OF_PRIMITIVE (a, 6) == _DBUS_BYTE_OF_PRIMITIVE (b, 6) &&       \
       _DBUS_BYTE_OF_PRIMITIVE (a, 7) == _DBUS_BYTE_OF_PRIMITIVE (b, 7))
 
+dbus_bool_t _dbus_daemon_lock_autolaunch_address();
 dbus_bool_t _dbus_get_autolaunch_address (const char *scope,
                                           DBusString *address,
 					                      DBusError  *error);