Bug 71042 – Don't use GOwnPtr for ref-counted objects

• Component: WebKitGTK
• Status: RESOLVED FIXED

[Jonathon Jongsma (jonner)]

Created attachment 112716 [details]
patch to use GRefPtr instead

In a few places in the gstreamer media player implementation, GOwnPtr is used with ref-counted objects (GstElement, etc).  The implementation is basically correct, but the semantics are confusing because a GOwnPtr is meant to indicate exclusive ownership of memory, whereas ref-counted objects have shared ownership by definition.  Changing to use GRefPtr makes things a bit more verbose (due to not having the outPtr() method), but I think it is more correct and less confusing.

[WebKit Review Bot]

Attachment 112716 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/CMakeListsEfl.txt', u'Sourc..." exit_code: 1

Source/WebCore/platform/graphics/gstreamer/GStreamerGWorld.cpp:91:  Declaration has space between type name and * in GstElement *p  [whitespace/declaration] [3]
Source/WebCore/platform/graphics/gstreamer/GStreamerGWorld.cpp:91:  Use 0 instead of NULL.  [readability/null] [5]
Source/WebCore/platform/graphics/gstreamer/GStreamerGWorld.cpp:163:  Declaration has space between type name and * in GstElement *p  [whitespace/declaration] [3]
Source/WebCore/platform/graphics/gstreamer/GStreamerGWorld.cpp:163:  Use 0 instead of NULL.  [readability/null] [5]
Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:1013:  Declaration has space between type name and * in GstElement *p  [whitespace/declaration] [3]
Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:1013:  Use 0 instead of NULL.  [readability/null] [5]
Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:1026:  Declaration has space between type name and * in GstElement *p  [whitespace/declaration] [3]
Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:1026:  Use 0 instead of NULL.  [readability/null] [5]
Source/WebCore/ChangeLog:1:  ChangeLog entry has no bug number  [changelog/bugnumber] [5]
Total errors found: 9 in 3 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Jonathon Jongsma (jonner)]

Created attachment 112723 [details]
[GStreamer] Don't use GOwnPtr for ref-counted objects https://bugs.webkit.org/show_bug.cgi?id=71042

Reviewed by NOBODY (OOPS!).

* CMakeListsEfl.txt:
* GNUmakefile.list.am:
* WebCore.gypi:
* WebCore.pro:
* platform/graphics/gstreamer/GOwnPtrGStreamer.cpp: Removed.
* platform/graphics/gstreamer/GOwnPtrGStreamer.h: Removed.
* platform/graphics/gstreamer/GStreamerGWorld.cpp:
(WebCore::GStreamerGWorld::enterFullscreen):
(WebCore::GStreamerGWorld::exitFullscreen):
* platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::updateAudioSink):
(WebCore::MediaPlayerPrivateGStreamer::sourceChanged):

[Martin Robinson]

Comment on attachment 112723 [details]
[GStreamer] Don't use GOwnPtr for ref-counted objects https://bugs.webkit.org/show_bug.cgi?id=71042

View in context: https://bugs.webkit.org/attachment.cgi?id=112723&action=review

Thanks for the cleanup. Just a nit below.

> Source/WebCore/platform/graphics/gstreamer/GStreamerGWorld.cpp:91
> +    GstElement* p = 0;

We typically use full words for variable names in WebKit. If you want you call this videoSinkPtr or maybe we can consider adding a adoptOutPtr method to GRefPtr.

> Source/WebCore/platform/graphics/gstreamer/GStreamerGWorld.cpp:163
> +    GstElement* p = 0;

Ditto.

> Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:1013
> +    GstElement* p = 0;

Ditto.

> Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:1026
> +    GstElement* p = 0;

Ditto.

[Jonathon Jongsma (jonner)]

(In reply to comment #3)
> We typically use full words for variable names in WebKit. 

Indeed, will fix that.

> If you want you call this videoSinkPtr or maybe we can consider adding a adoptOutPtr method to GRefPtr.

I considered adding a method to GRefPtr but decided against it since it has a lot of potential for misuse.  It would basically only ever be safe to use that method when the GRefPtr is NULL.  so I chose the more verbose approach instead.

[Martin Robinson]

(In reply to comment #4)

> I considered adding a method to GRefPtr but decided against it since it has a lot of potential for misuse.  It would basically only ever be safe to use that method when the GRefPtr is NULL.  so I chose the more verbose approach instead.

This could be handled either via a deref of the old value or an ASSERT, but it's fine to avoid doing that for now, I think.

[Jonathon Jongsma (jonner)]

Created attachment 113078 [details]
Patch

[WebKit Review Bot]

Comment on attachment 113078 [details]
Patch

Clearing flags on attachment: 113078

Committed r98924: <http://trac.webkit.org/changeset/98924>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.