Crashes on gst_bus_add_watch

[Duzy Chan]

Problem solved. Thanks all.


On Fri, Jan 25, 2013 at 7:21 PM, Duzy Chan <geek at duzy.info> wrote:

> And here are some CRITICAL warnings:
>
>   GStreamer-CRITICAL **: gst_poll_get_read_gpollfd: assertion `set !=
> NULL' failed
>   GStreamer-CRITICAL **: gst_bus_create_watch: assertion `bus->priv->poll
> != NULL' failed
>   GLib-CRITICAL **: g_source_set_callback: assertion `source != NULL'
> failed
>
>
>
>
> On Fri, Jan 25, 2013 at 7:09 PM, Duzy Chan <geek at duzy.info> wrote:
>
>> The worker in this case is wrapping a pipeline and watching the bus of
>> the pipeline. And the crash was happened while creating the worker and
>> preparing for further usage.
>>
>> While repeatedly creating many workers and each worker may exist only for
>> a short time (maybe less than 1 second), and then be stopped
>> (gst_element_set_state to null state), and then unref (including the
>> pipeline). After repeat for a while, the problem occurs.
>>
>>
>> On Fri, Jan 25, 2013 at 5:44 PM, Duzy Chan <geek at duzy.info> wrote:
>>
>>> Greeting, all
>>>
>>> I'm currently working on a app. But I'm now confronting a crash
>>> while repeatedly creating a pipeline very quickly. And I found that it was
>>> caused by a gst_bus_add_watch (http://pastebin.com/b2DVmHnQ). The code
>>> in *gst_bus_add_watch_full_unlocked* was trying to creating a new
>>> GSource by calling *gst_bus_create_watch*, yet it turned out a NULL
>>> source. This is the final end point of the cause. And the code in *
>>> gstbus.c* looks like this:
>>>
>>> static guint
>>> *gst_bus_add_watch_full_unlocked* (GstBus * bus, gint priority,
>>>     GstBusFunc func, gpointer user_data, GDestroyNotify notify)
>>> {
>>>   GMainContext *ctx;
>>>   guint id;
>>>   GSource *source;
>>>
>>>   if (bus->priv->watch_id) {
>>>     GST_ERROR_OBJECT (bus,
>>>         "Tried to add new watch while one was already there");
>>>     return 0;
>>>   }
>>>
>>>   *source* = *gst_bus_create_watch* (bus);
>>>
>>>   if (priority != G_PRIORITY_DEFAULT)
>>>     g_source_set_priority (*source*, priority);
>>>
>>>   g_source_set_callback (*source*, (GSourceFunc) func, user_data,
>>> notify);
>>>
>>>   ctx = g_main_context_get_thread_default ();
>>>   id = g_source_attach (source, ctx);
>>>   g_source_unref (source);
>>>
>>>   if (id) {
>>>     bus->priv->watch_id = source;
>>>   }
>>>
>>>   GST_DEBUG_OBJECT (bus, "New source %p with id %u", source, id);
>>>   return id;
>>> }
>>>
>>>
>>> And the client code from my app looks like this:
>>>
>>>   worker->pipeline = workerclass->create_pipeline (worker);
>>>   if (!worker->pipeline)
>>>     goto error_create_pipeline;
>>>
>>>   gst_pipeline_set_auto_flush_bus (GST_PIPELINE (worker->pipeline),
>>> FALSE);
>>>
>>>   worker->bus = gst_pipeline_get_bus (GST_PIPELINE (worker->pipeline));
>>>   worker->watch = *gst_bus_add_watch* (worker->bus, gst_worker_message,
>>> worker);
>>>
>>>
>>> Part of the stack when it crashed is like this:
>>>
>>> #0  0x00007ffff728ef56 in *g_source_attach* () from
>>> /lib/x86_64-linux-gnu/libglib-2.0.so.0
>>> #1  0x00007ffff7b1e228 in *gst_bus_add_watch_full_unlocked*(notify=<optimized out>, user_data=0x7fffc801a0c0, func=0x403d50
>>> <gst_worker_message>, priority=<optimized out>, bus=<optimized out>) at
>>> gstbus.c:867
>>> #2  gst_bus_add_watch_full_unlocked (bus=<optimized out>,
>>> priority=<optimized out>, func=0x403d50 <gst_worker_message>,
>>> user_data=0x7fffc801a0c0, notify=<optimized out>) at gstbus.c:846
>>> #3  0x00007ffff7b1e367 in gst_bus_add_watch_full (bus=0x991c10,
>>> priority=priority at entry=0, func=func at entry=0x403d50
>>> <gst_worker_message>, user_data=user_data at entry=0x7fffc801a0c0,
>>> notify=notify at entry=0x0) at gstbus.c:916
>>> #4  0x00007ffff7b1e390 in *gst_bus_add_watch* (bus=<optimized out>,
>>> func=func at entry=0x403d50 <gst_worker_message>, user_data=user_data at entry=0x7fffc801a0c0)
>>> at gstbus.c:948
>>> #5  0x00000000004041b1 in gst_worker_prepare (worker=0x7fffc801a0c0) at
>>> gstworker.c:480
>>>
>>>
>>> Do you have any ideas about this? I've been tracking on it for long
>>> time, still have no lucks.
>>>
>>> Regards
>>> Duzy Chan
>>>
>>>
>>
>
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