1 From 5dfd206b09f91cba45fa8e2b66e1b57aafe30868 Mon Sep 17 00:00:00 2001
2 From: Kristian Rietveld <kris@lanedo.com>
3 Date: Mon, 8 Jul 2013 12:02:00 +0200
4 Subject: [PATCH] Make g_main_context_iterate resilient to recursion in poll
6 On OS X, main loop recursion may happen during the call the poll.
7 As a result, the allocated poll array may be re-allocated (note that
8 it is always enlarged, never shrunk). By always using cached_poll_array
9 after the poll function, reads from bad memory are avoided.
11 glib/gmain.c | 28 +++++++++++++++-------------
12 1 file changed, 15 insertions(+), 13 deletions(-)
14 diff --git a/glib/gmain.c b/glib/gmain.c
15 index 077a935..529f2b6 100644
18 @@ -3065,8 +3065,7 @@ g_main_context_iterate (GMainContext *context,
22 - gint nfds, allocated_nfds;
23 - GPollFD *fds = NULL;
26 UNLOCK_CONTEXT (context);
28 @@ -3095,29 +3094,32 @@ g_main_context_iterate (GMainContext *context,
29 context->cached_poll_array = g_new (GPollFD, context->n_poll_records);
32 - allocated_nfds = context->cached_poll_array_size;
33 - fds = context->cached_poll_array;
35 UNLOCK_CONTEXT (context);
37 g_main_context_prepare (context, &max_priority);
39 - while ((nfds = g_main_context_query (context, max_priority, &timeout, fds,
40 - allocated_nfds)) > allocated_nfds)
41 + while ((nfds = g_main_context_query (context, max_priority, &timeout,
42 + context->cached_poll_array,
43 + context->cached_poll_array_size))
44 + > context->cached_poll_array_size)
46 LOCK_CONTEXT (context);
48 - context->cached_poll_array_size = allocated_nfds = nfds;
49 - context->cached_poll_array = fds = g_new (GPollFD, nfds);
50 + g_free (context->cached_poll_array);
51 + context->cached_poll_array_size = nfds;
52 + context->cached_poll_array = g_new (GPollFD, nfds);
53 UNLOCK_CONTEXT (context);
59 - g_main_context_poll (context, timeout, max_priority, fds, nfds);
61 - some_ready = g_main_context_check (context, max_priority, fds, nfds);
62 + g_main_context_poll (context, timeout, max_priority,
63 + context->cached_poll_array,
66 + some_ready = g_main_context_check (context, max_priority,
67 + context->cached_poll_array,
71 g_main_context_dispatch (context);