From 95a339733a6b296d445fa4cb03f6f88b12f415a7 Mon Sep 17 00:00:00 2001
From: Mike Blumenkrantz <zmike@osg.samsung.com>
Date: Fri, 2 Feb 2018 16:59:56 -0500
Subject: [PATCH] eldbus: make connections fork-safe

after a fork, any existing connection objects can no longer be used,
but it's up to the user to destroy them. internally, this prevents
existing connections from ever being returned as valid connections
and creates new ones after a fork

also destroy fd handlers for connections to ensure that no data is
accidentally clobbered before the connections are cleaned up
---
 src/lib/eldbus/eldbus_core.c | 65 +++++++++++++++++++++++++-----------
 1 file changed, 45 insertions(+), 20 deletions(-)

diff --git a/src/lib/eldbus/eldbus_core.c b/src/lib/eldbus/eldbus_core.c
index 91a4021010..ba4a3ba684 100644
--- a/src/lib/eldbus/eldbus_core.c
+++ b/src/lib/eldbus/eldbus_core.c
@@ -85,6 +85,45 @@ static void _eldbus_connection_context_event_cb_del(Eldbus_Connection_Context_Ev
 static void eldbus_dispatch_name_owner_change(Eldbus_Connection_Name *cn, const char *old_id);
 static void _eldbus_connection_free(Eldbus_Connection *conn);
 
+static void
+eldbus_fd_handler_del(Eldbus_Handler_Data *hd)
+{
+   if (!hd->fd_handler) return;
+
+   DBG("free Eldbus_Handler_Data %d", hd->fd);
+   hd->conn->fd_handlers = eina_inlist_remove(hd->conn->fd_handlers,
+                                              EINA_INLIST_GET(hd));
+   if (hd->fd_handler)
+     {
+        ecore_main_fd_handler_del(hd->fd_handler);
+        hd->fd_handler = NULL;
+     }
+
+   free(hd);
+}
+
+static void
+_eldbus_fork_reset()
+{
+   int i;
+
+   for (i =0; i < ELDBUS_CONNECTION_TYPE_LAST - 1; i++)
+     {
+        Eldbus_Connection *conn = shared_connections[i];
+        if (conn)
+          {
+             Eina_Inlist *list;
+             Eldbus_Handler_Data *fd_handler;
+
+             EINA_INLIST_FOREACH_SAFE(conn->fd_handlers, list, fd_handler)
+               dbus_watch_set_data(fd_handler->watch, NULL, NULL);
+          }
+        shared_connections[i] = NULL;
+     }
+   if (address_connections) eina_hash_free(address_connections);
+   address_connections = NULL;
+}
+
 EAPI int
 eldbus_init(void)
 {
@@ -131,7 +170,7 @@ eldbus_init(void)
    if (!eldbus_object_init()) goto object_failed;
    if (!eldbus_proxy_init()) goto proxy_failed;
    if (!eldbus_service_init()) goto service_failed;
-
+   ecore_fork_reset_callback_add(_eldbus_fork_reset, NULL);
    return _eldbus_init_count;
 
 service_failed:
@@ -205,6 +244,7 @@ eldbus_shutdown(void)
    if (--_eldbus_init_count)
      return _eldbus_init_count;
 
+   ecore_fork_reset_callback_del(_eldbus_fork_reset, NULL);
    if (shared_connections[ELDBUS_CONNECTION_TYPE_SESSION - 1])
      {
         CRI("Alive TYPE_SESSION connection");
@@ -548,24 +588,6 @@ eldbus_connection_name_object_get(Eldbus_Connection *conn, const char *name, con
    return eina_hash_find(cn->objects, path);
 }
 
-
-static void
-eldbus_fd_handler_del(Eldbus_Handler_Data *hd)
-{
-   if (!hd->fd_handler) return;
-
-   DBG("free Eldbus_Handler_Data %d", hd->fd);
-   hd->conn->fd_handlers = eina_inlist_remove(hd->conn->fd_handlers,
-                                              EINA_INLIST_GET(hd));
-   if (hd->fd_handler)
-     {
-        ecore_main_fd_handler_del(hd->fd_handler);
-        hd->fd_handler = NULL;
-     }
-
-   free(hd);
-}
-
 static Eina_Bool
 eldbus_fd_handler(void *data, Ecore_Fd_Handler *fd_handler)
 {
@@ -1256,7 +1278,10 @@ _eldbus_connection_free(Eldbus_Connection *conn)
    if (conn->type && conn->shared)
      {
         if (conn->type == ELDBUS_CONNECTION_TYPE_ADDRESS)
-           eina_hash_del_by_data(address_connections, conn);
+           {
+              if (address_connections)
+                eina_hash_del_by_data(address_connections, conn);
+           }
         else if (shared_connections[conn->type - 1] == (void *) conn)
            shared_connections[conn->type - 1] = NULL;
      }