mainloop: detect fork() and abort

Abort if the child process returns to the mainloop after a fork().

https://bugzilla.gnome.org/show_bug.cgi?id=658999
This commit is contained in:
Ryan Lortie 2011-09-13 19:56:22 -04:00
parent 01f9479438
commit 01ed78d525

View File

@ -49,6 +49,7 @@
#ifdef G_OS_UNIX
#include "glib-unix.h"
#include <pthread.h>
#ifdef HAVE_EVENTFD
#include <sys/eventfd.h>
#endif
@ -174,6 +175,10 @@
* <graphic fileref="mainloop-states.gif" format="GIF"></graphic>
* </figure>
* </refsect2>
*
* On Unix, the GLib mainloop is incompatible with fork(). Any program
* using the mainloop must either exec() or exit() from the child
* without returning to the mainloop.
*/
/* Types */
@ -374,6 +379,7 @@ static gboolean g_idle_dispatch (GSource *source,
gpointer user_data);
static GMainContext *glib_worker_context;
static gboolean g_main_context_fork_detected;
G_LOCK_DEFINE_STATIC (main_loop);
static GMainContext *default_main_context;
@ -497,6 +503,14 @@ g_main_context_unref (GMainContext *context)
g_free (context);
}
#ifdef G_OS_UNIX
static void
g_main_context_forked (void)
{
g_main_context_fork_detected = TRUE;
}
#endif
/**
* g_main_context_new:
*
@ -507,25 +521,27 @@ g_main_context_unref (GMainContext *context)
GMainContext *
g_main_context_new (void)
{
static gsize initialised;
GMainContext *context;
g_thread_init_glib ();
context = g_new0 (GMainContext, 1);
if (g_once_init_enter (&initialised))
{
#ifdef G_MAIN_POLL_DEBUG
{
static gboolean beenhere = FALSE;
if (!beenhere)
{
if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
_g_main_poll_debug = TRUE;
beenhere = TRUE;
}
}
if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
_g_main_poll_debug = TRUE;
#endif
#ifdef G_OS_UNIX
pthread_atfork (NULL, NULL, g_main_context_forked);
#endif
g_once_init_leave (&initialised, TRUE);
}
context = g_new0 (GMainContext, 1);
g_static_mutex_init (&context->mutex);
context->owner = NULL;
@ -2976,6 +2992,7 @@ g_main_context_iterate (GMainContext *context,
if (!block)
timeout = 0;
g_assert (!g_main_context_fork_detected);
g_main_context_poll (context, timeout, max_priority, fds, nfds);
some_ready = g_main_context_check (context, max_priority, fds, nfds);