On Wed, 6 Dec 2023 09:08:55 GMT, Anton Bobrov <d...@openjdk.org> wrote:

>> This patch adds re-try logic to libpipewire screencast error handling as 
>> discussed in PR #16794 and also brings some additional error handling and 
>> thread safety improvements. Specifically around cleanup order where 
>> incorrect ordering lead to native memory corruption issues, and lock/unlock 
>> accounting that while mostly harmless (with the current libpipewire 
>> implementation) did pollute the stderr on jtreg tests, making some tests 
>> (expecting clean stderr) to fail.
>> 
>> The real major change here however is the throw of the RuntimeException 
>> which can propagate to public 
>> 
>> java.awt.Robot. createMultiResolutionScreenCapture, createScreenCapture, 
>> getPixelColor methods. I'm not sure the plain RuntimeException is the way to 
>> go here so this is just a placeholder of sorts. A separate/specific runtime 
>> exception can be created for this BUT *something* needs to be done here as 
>> the current implementation fails to convey libpipewire failures to those 
>> public API callers and since they have no way of detecting such errors 
>> otherwise they have no way of knowing that the data returned by those API is 
>> in fact invalid (eg black screens etc). The reason for using an unchecked 
>> exception here is driven mainly by the following factors:
>> 
>> 1) Since those are public API, their contracts can potentially make it 
>> difficult to introduce specific additional checked exceptions or return 
>> values (as appropriate) as those could potentially break existing API use.
>> 
>> 2) The libpipewire errors of that kind are rare and usually indicate there 
>> is something wrong with the desktop stack eg some fatal configuration or run 
>> time error that is normally not supposed to happen and given this patch now 
>> goes extra step re-trying on such failures it stands to reason runtime 
>> unchecked exception makes sense when that fails as well.
>> 
>> 3) Creating checked exceptions for such specific native implementation 
>> dependent errors and propagating such exceptions thru the call tree does not 
>> make much sense as most public API users won't even know how to handle them 
>> without knowing native implementation specifics.
>
> Anton Bobrov has updated the pull request incrementally with one additional 
> commit since the last revision:
> 
>   8321176: remove RuntimeException and address review comments

Marked as reviewed by prr (Reviewer).

-------------

PR Review: https://git.openjdk.org/jdk/pull/16978#pullrequestreview-1773235252

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