[GStreamer][MSE] Generic main thread notification support

• Component: Platform
• Status: RESOLVED FIXED

[Philippe Normand]

I did this only for the playback pipeline because reusing the player bus like this is not optimal. The same approach could be used in the append pipeline but it's less critical because a new bus is created there.

[Philippe Normand]

Created attachment 347258 [details]
Patch

[Xabier Rodríguez Calvar]

Comment on attachment 347258 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=347258&action=review

> Source/WebCore/platform/graphics/gstreamer/mse/WebKitMediaSourceGStreamer.cpp:126
>          case MediaSourceSeekToTime: {
> -            GstStructure* structure = gst_structure_new_empty("seek-needs-data");
> -            GstMessage* message = gst_message_new_application(GST_OBJECT(appsrc), structure);
> -            gst_bus_post(webKitMediaSrc->priv->bus.get(), message);
> -            GST_TRACE("seek-needs-data message posted to the bus");
> +            webKitMediaSrc->priv->notifier->notify(MSEMainThreadNotification::SeekNeedsData, [webKitMediaSrc] {
> +                seekNeedsDataMainThread(webKitMediaSrc);
> +            });
>              break;
>          }

You don't need to enclose the case in { } anymore since we don't have scoped variables. Please, remove them.

> Source/WebCore/platform/graphics/gstreamer/mse/WebKitMediaSourceGStreamer.cpp:143
>          if (appsrcStream && appsrcStream->type != WebCore::Invalid) {
> -            GstStructure* structure = gst_structure_new("ready-for-more-samples", "appsrc-stream", G_TYPE_POINTER, appsrcStream, nullptr);
> -            GstMessage* message = gst_message_new_application(GST_OBJECT(appsrc), structure);
> -            gst_bus_post(webKitMediaSrc->priv->bus.get(), message);
> -            GST_TRACE("ready-for-more-samples message posted to the bus");
> +
> +            webKitMediaSrc->priv->notifier->notify(MSEMainThreadNotification::ReadyForMoreSamples, [webKitMediaSrc, appsrcStream] {
> +                notifyReadyForMoreSamplesMainThread(webKitMediaSrc, appsrcStream);
> +            });
>          }

You don't need the if { } anymore because there is only one clause in it. Please remove them.

> Source/WebCore/platform/graphics/gstreamer/mse/WebKitMediaSourceGStreamerPrivate.h:100
> +enum MSEMainThreadNotification {

I guess you preprended MSE to this type because it can collide with other types defined inside other other files. In this case I would strongly encourage you to preprend the whole class and name it WebKitMediaSrcMainThreadNotification.

> Source/WebCore/platform/graphics/gstreamer/mse/WebKitMediaSourceGStreamerPrivate.h:102
> +    SeekNeedsData = 1 << 0,
> +    ReadyForMoreSamples = 1 << 1

Longshot nit: I think it would be nicer to, at least, begin with these alphabetically sorted. It is not a requirement, but nice to have :)

[Alicia Boya García]

LGTM too.

[Philippe Normand]

Committed r235110: <https://trac.webkit.org/changeset/235110>

[Radar WebKit Bug Importer]

<rdar://problem/43551293>