* [[inferior events] partial cleanup for copy_py_list
@ 2010-12-14 21:41 Tom Tromey
2010-12-15 15:57 ` sami wagiaalla
0 siblings, 1 reply; 3+ messages in thread
From: Tom Tromey @ 2010-12-14 21:41 UTC (permalink / raw)
To: Project Archer
This fixes some issues in copy_py_list, but not all.
The patch changes it to check PyList_Append.
I think it should probably use an iterator to go through the list.
Otherwise it is susceptible to a bug where another thread changes the
list while we are iterating over it.
Still, ok to push in this form?
Tom
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 7c686d3..34e5bf8 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -163,10 +163,11 @@ compute_python_string (struct command_line *l)
}
/* Returns a a copy of the give LIST.
- Creates a new reference which must be handeld by the caller. */
+ Creates a new reference which must be handled by the caller. */
PyObject *
-copy_py_list (PyObject *list){
+copy_py_list (PyObject *list)
+{
int i;
PyObject *new_list = PyList_New (0);
@@ -174,7 +175,11 @@ copy_py_list (PyObject *list){
return NULL;
for (i = 0; i < PyList_Size (list); i++)
- PyList_Append (new_list, PyList_GET_ITEM (list, i));
+ if (PyList_Append (new_list, PyList_GET_ITEM (list, i)) < 0)
+ {
+ Py_DECREF (new_list);
+ return NULL;
+ }
return new_list;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [[inferior events] partial cleanup for copy_py_list
2010-12-14 21:41 [[inferior events] partial cleanup for copy_py_list Tom Tromey
@ 2010-12-15 15:57 ` sami wagiaalla
2010-12-15 16:42 ` Tom Tromey
0 siblings, 1 reply; 3+ messages in thread
From: sami wagiaalla @ 2010-12-15 15:57 UTC (permalink / raw)
To: Tom Tromey; +Cc: Project Archer
On 12/14/2010 04:41 PM, Tom Tromey wrote:
> This fixes some issues in copy_py_list, but not all.
>
> The patch changes it to check PyList_Append.
>
> I think it should probably use an iterator to go through the list.
> Otherwise it is susceptible to a bug where another thread changes the
> list while we are iterating over it.
>
Hmm I did not know we had the option of using a safe iterator. If we do
then that eliminates the need for copy_py_list in the first place;
copy_py_list is used to make the call back of listeners safe against one
listener editing the list during the iteration by removing an element.
> Still, ok to push in this form?
>
Yes. And thanks for the cleanups.
Sami
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [[inferior events] partial cleanup for copy_py_list
2010-12-15 15:57 ` sami wagiaalla
@ 2010-12-15 16:42 ` Tom Tromey
0 siblings, 0 replies; 3+ messages in thread
From: Tom Tromey @ 2010-12-15 16:42 UTC (permalink / raw)
To: sami wagiaalla; +Cc: Project Archer
Tom> I think it should probably use an iterator to go through the list.
Tom> Otherwise it is susceptible to a bug where another thread changes the
Tom> list while we are iterating over it.
Sami> Hmm I did not know we had the option of using a safe iterator. If we
Sami> do then that eliminates the need for copy_py_list in the first place;
Sami> copy_py_list is used to make the call back of listeners safe against
Sami> one listener editing the list during the iteration by removing an
Sami> element.
TBH, I am not totally sure how things work in this area.
One option would be to use the existing convenience function
PyList_AsTuple, and just trust the Python core to get it right.
Tom
^ permalink raw reply [flat|nested] 3+ messages in thread
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2010-12-14 21:41 [[inferior events] partial cleanup for copy_py_list Tom Tromey
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