I am not getting ref_count to decrease properly for my GMainContext. The example program here is a small version of a large program (which uses threads, hence the need to create a context and push it on the thread).
GMainLoop *loop;
GMainContext *ctx;
struct conn
{
GSocketClient *client;
GSocketConnection *conn;
GInputStream *in;
GOutputStream *out;
gchar data[8192];
unsigned int count;
};
static void
read_done_cb(GObject *source_object, GAsyncResult *res, gpointer user_data)
{
struct conn *c = (struct conn *)user_data;
gssize len = g_input_stream_read_finish(c->in, res, NULL);
g_input_stream_read_async(c->in, c->data, sizeof c->data / sizeof *c->data, G_PRIORITY_DEFAULT, NULL, read_done_cb, c);
if (c->count++ == 1) {
printf("End of life as I know it...\n");
g_main_loop_quit(loop);
}
}
static void
write_done_cb(GObject *source_object, GAsyncResult *res, gpointer user_data)
{
}
static void
connect_done_cb(GObject *source_object, GAsyncResult *res, gpointer user_data)
{
printf("## %s\n", __FUNCTION__);
struct conn *c = (struct conn *)user_data;
c->conn = g_socket_client_connect_to_host_finish(c->client, res, NULL);
c->in = g_io_stream_get_input_stream(G_IO_STREAM(c->conn));
c->out = g_io_stream_get_output_stream(G_IO_STREAM(c->conn));
char *data = "GET /axis-cgi/mjpg/video.cgi HTTP/1.0\r\n\r\n";
g_output_stream_write_async(c->out, data, strlen(data), G_PRIORITY_DEFAULT, NULL, write_done_cb, c);
g_input_stream_read_async(c->in, c->data, sizeof c->data / sizeof *c->data, G_PRIORITY_DEFAULT, NULL, read_done_cb, c);
}
int
main(int argc, char **argv)
{
g_type_init();
struct conn *c = g_malloc0(sizeof *c);
ctx = g_main_context_new();
loop = g_main_loop_new(ctx, FALSE);
g_main_context_push_thread_default(ctx);
c->client = g_socket_client_new();
g_socket_client_connect_to_host_async(c->client, "10.85.25.20", 80, NULL, connect_done_cb, c);
g_main_loop_run(loop);
g_io_stream_close(G_IO_STREAM(c->conn), NULL, NULL);
g_object_unref(c->client);
g_object_unref(c->conn);
g_main_context_pop_thread_default(ctx);
g_main_loop_unref(loop);
g_main_context_unref(ctx);
return 0;
}
Using gdb, inserting breakpoint just before return I can see that ctx still have one ref count:
(gdb) p ctx->ref_count
$2 = 1
If I do another g_main_context_unref(ctx);
everything shuts down as expected. I do not understand where I get this ownership though.
Thanks in advance for your help
I found the error. I read_done_cb
I issued another g_input_stream_read_async
and immediately after quitting the main loop. g_input_stream_read_async
upped the ref_count but GMainLoop
never got a chance to return to my callback (and decreasing the ref_count on my GMainContext
).
Moving the call to g_input_stream_read_async
in my callback to below the if statement
static void
read_done_cb(GObject *source_object, GAsyncResult *res, gpointer user_data)
{
struct conn *c = (struct conn *)user_data;
gssize len = g_input_stream_read_finish(c->in, res, NULL);
if (c->count++ == 1) {
printf("End of life as I know it...\n");
g_main_loop_quit(loop);
}
g_input_stream_read_async(c->in, c->data, sizeof c->data / sizeof *c->data, G_PRIORITY_DEFAULT, NULL, read_done_cb, c);
}
correctly resolved the number of ref counts on my main context.
Silly mistake. Hopefully someone will find some use of my post at least.