Re: [PATCH] Make "backtrace" doesn't print python stack if init python dir get fail

[Tom Tromey <tromey@redhat.com>]

>>>>> "Hui" == Hui Zhu <hui_zhu@mentor.com> writes:

>> Two other approaches are possible here instead.  One, change
>> finish_python_initialization to do the needed bit of locking by handy,
>> not using ensure_python_env.  Or, two, don't release the GIL until
>> somewhere in finish_python_initialization, and then it doesn't need
>> to call ensure_python_env at all.

Hui> I think the first way is better than second way because
Hui> ensure_python_env has relationship with current_arch and
Hui> current_language.  So I make a patch according the first way.

After seeing the patch I think it is probably preferable to do the
second route -- move the GIL releasing to finish_python_initialization.

Can you try the appended?

Tom

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 35a1d73..6554be2 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2013-12-11  Tom Tromey  <tromey@redhat.com>
+
+	* python/python.c (_initialize_python): Don't release the GIL or
+	set gdb_python_initialized.
+	(release_gil): New function.
+	(finish_python_initialization): Use release_gil.  Don't call
+	ensure_python_env.  Set gdb_python_initialized.
+
 2013-12-11  Sergio Durigan Junior  <sergiodj@redhat.com>
 
 	* break-catch-throw.c (fetch_probe_arguments): Pass selected frame
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 1873936..ddf8a1a 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1711,18 +1711,12 @@ message == an error message without a stack will be printed."),
   if (gdbpy_value_cst == NULL)
     goto fail;
 
-  /* Release the GIL while gdb runs.  */
-  PyThreadState_Swap (NULL);
-  PyEval_ReleaseLock ();
-
   make_final_cleanup (finalize_python, NULL);
 
-  gdb_python_initialized = 1;
   return;
 
  fail:
   gdbpy_print_stack ();
-  /* Do not set 'gdb_python_initialized'.  */
   return;
 
 #endif /* HAVE_PYTHON */
@@ -1730,6 +1724,15 @@ message == an error message without a stack will be printed."),
 
 #ifdef HAVE_PYTHON
 
+/* A cleanup function that releases the GIL.  */
+
+static void
+release_gil (void *ignore)
+{
+  PyThreadState_Swap (NULL);
+  PyEval_ReleaseLock ();
+}
+
 /* Perform the remaining python initializations.
    These must be done after GDB is at least mostly initialized.
    E.g., The "info pretty-printer" command needs the "info" prefix
@@ -1743,7 +1746,8 @@ finish_python_initialization (void)
   PyObject *sys_path;
   struct cleanup *cleanup;
 
-  cleanup = ensure_python_env (get_current_arch (), current_language);
+  /* Release the GIL while gdb runs.  */
+  cleanup = make_cleanup (release_gil, NULL);
 
   /* Add the initial data-directory to sys.path.  */
 
@@ -1807,12 +1811,16 @@ finish_python_initialization (void)
      variable.  */
 
   do_cleanups (cleanup);
+
+  gdb_python_initialized = 1;
+
   return;
 
  fail:
   gdbpy_print_stack ();
   warning (_("internal error: Unhandled Python exception"));
   do_cleanups (cleanup);
+  /* Do not set 'gdb_python_initialized'.  */
 }
 
 #endif /* HAVE_PYTHON */