child reports success of load to parent

1 files changed, 11 insertions, 7 deletions

diff --git a/src/userprog/process.c b/src/userprog/process.c
index 437d6c0..5897c84 100644
--- a/src/userprog/process.c
+++ b/src/userprog/process.c
@@ -25,6 +25,9 @@ struct start_process_args
 
     // parent -> child
     char *file_name;
+
+    // child -> parent
+    bool success;
   };
 
 static thread_func start_process NO_RETURN;
@@ -55,11 +58,15 @@ process_execute (const char *file_name)
      If thread_create fails we free and return immediately since we know
      that the thread didn't start.
      Otherwise, the child thread can be scheduled freely so we explicitly
-     wait for the child to signal that it has read the args. Only then can
-     we free resources and return the tid. */
+     wait for the child to signal that it has read from and written to
+     the args. Only then can we free resources and return the tid. */
   tid = thread_create (file_name, PRI_DEFAULT, start_process, &args);
   if (tid != TID_ERROR) {
     sema_down (&args.sema);
+
+    //TODO push to list of children
+    if (!args.success)
+      tid = -1;
   }
   palloc_free_page (args.file_name);
   return tid;
@@ -82,15 +89,12 @@ start_process (void *args_)
   printf("reading\n");
   success = load (args->file_name, &if_.eip, &if_.esp);
 
+  args->success = success;
   sema_up (&args->sema);
 
   /* If load failed, quit. */
-  if (success) {
-    //TODO report success
-  } else {
-    //TODO report failure
+  if (!success)
     thread_exit ();
-  }
 
   /* Start the user process by simulating a return from an
      interrupt, implemented by intr_exit (in