RFR: 8258754: Gracefully fallback to the OpenGL rendering pipeline if Metal rendering pipeline initialization fails

[Prasanta Sadhukhan]

On 08-Jan-21 1:33 PM, Jayathirth D V wrote:
> On Wed, 6 Jan 2021 11:05:56 GMT, Ajit Ghaisas <aghaisas at openjdk.org> wrote:
>
>> This implements fallback to the OpenGL rendering pipeline if Metal rendering pipeline initialization fails.
>> I have tested this fallback on 10.15.4 by stubbing code. We need real testing on a system where Metal is not available.
> My 2 cents. Me and Ajit discussed this internally adding this info in PR also.
>
> 1) No options - Use OpenGL(Switch to Metal later when we want to make it default)
> 2) opengl == true || metal == false - Use OpenGL
> 3) metal initialization fails print log in verbose- Use OpenGL

Maybe we can make this check version specific (maybe 10.12 for now) so 
that in future version when opengl is removed, then this check will be 
noop and if Metal fails, then it will quit.

Regards
Prasanta
> 4) metal == true || opengl == false - Use Metal
> 5) opengl initialization fails print log in verbose(In initial release when OpenGL is default, i am not 100% sure whether we should try Metal pipeline or just exit) - Use Metal / exit
> 6) Both fails print log and exit
>
> All these things can be handled in this PR or future changes.
>
> -------------
>
> PR: https://git.openjdk.java.net/lanai/pull/147