On Mon, 24 Jul 2023 09:58:09 GMT, Alexey Ivanov <aiva...@openjdk.org> wrote:
>> Renjith Kannath Pariyangad has updated the pull request incrementally with
>> one additional commit since the last revision:
>>
>> Disabled OLE1 from CoInit
>
> src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_DirectSound.cpp
> line 482:
>
>> 480: DWORD WINAPI __stdcall DS_StartBufferHelper::ThreadProc(void *param)
>> 481: {
>> 482: ::CoInitializeEx(NULL, COINIT_MULTITHREADED |
>> COINIT_DISABLE_OLE1DDE);
>
> You're changing the COM for this thread from `COINIT_APARTMENTTHREADED` to
> `COINIT_MULTITHREADED`.
>
> Do DirectSound objects support multi-threading? I couldn't find anything
> quickly.
>
> A Microsoft sample for [Creating the Device
> Object](https://learn.microsoft.com/en-us/previous-versions/windows/desktop/ee416365(v=vs.85))
> uses `CoInitializeEx(NULL, 0)`.
>
> The documentation for
> [`CoInitializeEx`](https://learn.microsoft.com/en-us/windows/win32/api/combaseapi/nf-combaseapi-coinitializeex)
> says, “You need to initialize the COM library on a thread before you call
> any of the library functions…”
>
> This implies that any thread which creates DirectSound objects must
> initialise COM first. I can't see it happening. Do I miss anything?
@aivanov-jdk, Thank you for your time and reviews,
`CoInitializeEx(NULL, 0)` also resolving this problem because as per document
**The default is COINIT_MULTITHREADED**.
In my debug session noticed `DirectSoundCaptureEnumerate` getting called ahead
of thread call or ::CoInitialize and that was the root cause this failure.
For resolving this found 3 ways and all works:
1 . Use COM multi-threading :- Simplest approach with respect to other
solutions
2. Hold the call till CoInitialize : - Can end up in deadlock situation so
that need to be taken care.
3. Do another CoInitialize before call :- not a good approach
_This implies that any thread which creates DirectSound objects must initialise
COM first. I can't see it happening. Do I miss anything?_
`DS_StartBufferHelper` class initializing COM in thread and all member
functions checking initialization status before making any calls. So another
solution may be restructure the code for accessing `isInitialized()` method
from outer methods and proceed. (approach 2 in better way)
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/14898#discussion_r1273063731
