mainloop-test: Fix race conditions

* Wait for adder threads before deallocating crawler_array and
  context_array to avoid use after-free and data race.
* Handle spurious wakeups around g_cond_wait.
* Avoid starting recurser_idle without context.

Fixes issue #1530.
This commit is contained in:
Tomasz Miąsko 2018-10-30 00:00:00 +00:00
parent d512c0fe43
commit 88f36a1d6f

View File

@ -263,10 +263,10 @@ adder_response (GIOChannel *source,
return TRUE;
}
static void
static GThread *
create_adder_thread (void)
{
GError *err = NULL;
GThread *thread;
TestData *test_data;
GIOChannel *in_channels[2];
@ -282,13 +282,7 @@ create_adder_thread (void)
sub_channels[0] = in_channels[0];
sub_channels[1] = out_channels[1];
g_thread_create (adder_thread, sub_channels, FALSE, &err);
if (err)
{
g_warning ("Cannot create thread: %s", err->message);
exit (1);
}
thread = g_thread_new ("adder", adder_thread, sub_channels);
test_data = g_new (TestData, 1);
test_data->in = in_channels[1];
@ -299,6 +293,8 @@ create_adder_thread (void)
adder_response, test_data);
do_add (test_data->in, test_data->current_val, INCREMENT);
return thread;
}
static void create_crawler (void);
@ -389,12 +385,15 @@ recurser_start (gpointer data)
GSource *source;
g_mutex_lock (&context_array_mutex);
context = context_array->pdata[g_random_int_range (0, context_array->len)];
source = g_idle_source_new ();
g_source_set_name (source, "Recursing idle source");
g_source_set_callback (source, recurser_idle, context, NULL);
g_source_attach (source, context);
g_source_unref (source);
if (context_array->len > 0)
{
context = context_array->pdata[g_random_int_range (0, context_array->len)];
source = g_idle_source_new ();
g_source_set_name (source, "Recursing idle source");
g_source_set_callback (source, recurser_idle, context, NULL);
g_source_attach (source, context);
g_source_unref (source);
}
g_mutex_unlock (&context_array_mutex);
return TRUE;
@ -405,6 +404,7 @@ main (int argc,
char *argv[])
{
gint i;
GThread *threads[NTHREADS];
context_array = g_ptr_array_new ();
@ -413,13 +413,13 @@ main (int argc,
main_loop = g_main_loop_new (NULL, FALSE);
for (i = 0; i < NTHREADS; i++)
create_adder_thread ();
threads[i] = create_adder_thread ();
/* Wait for all threads to start
*/
g_mutex_lock (&context_array_mutex);
if (context_array->len < NTHREADS)
while (context_array->len < NTHREADS)
g_cond_wait (&context_array_cond, &context_array_mutex);
g_mutex_unlock (&context_array_mutex);
@ -432,6 +432,9 @@ main (int argc,
g_main_loop_run (main_loop);
g_main_loop_unref (main_loop);
for (i = 0; i < NTHREADS; i++)
g_thread_join (threads[i]);
g_ptr_array_unref (crawler_array);
g_ptr_array_unref (context_array);