RFR: 8301846: Invalid TargetDataLine after screen lock when using JFileChooser or COM library [v7]

[Renjith Kannath Pariyangad]

On Wed, 2 Aug 2023 12:00:47 GMT, Alexey Ivanov <aivanov at openjdk.org> wrote:

>> Renjith Kannath Pariyangad has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Added DS_unlockCache into failed Coinit case
>
> src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_DirectSound.cpp line 183:
> 
>> 181:     INT32 cacheIndex;
>> 182: 
>> 183:     if (!DS_lockCache() || FAILED(::CoInitialize(NULL))) {
> 
> I believe this is incorrect: `::CoInitialize` may return `S_OK` or `S_FALSE`; the value of `S_FALSE` indicates a success too but flags that COM is already initialised. The only real error is `RPC_E_CHANGED_MODE` which also indicates *COM is already initialised* but with a different threading model.
> 
> Thus, we can proceed in *all* the cases but we need to call `::CoUninitialize` only if `::CoInitialize` returns `S_OK` or `S_FALSE`.

Microsoft recommended to use [SUCCEEDED or FAILED](https://learn.microsoft.com/en-us/windows/win32/learnwin32/error-handling-in-com) macro for error handling. Based on our finding without COM Initialization remaining function call may fail, I thought better not to proceed further in case of failure. 

FAILED macro defined as : #define FAILED(hr) (((HRESULT)(hr)) < 0) 
Constant defined as **S_OK =0x0** and **S_FALSE = 0x1** all other errors are -ve 

I thought this will be covered, let me know your if I missed anything.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14898#discussion_r1282616416