<AWT Dev> [9] RFR: 6477756: GraphicsDevice.getConfigurations() is slow taking 3 or more seconds

Vadim Pakhnushev vadim.pakhnushev at oracle.com
Tue May 17 18:24:09 UTC 2016

On 17.05.2016 21:07, Vadim Pakhnushev wrote:
> On 17.05.2016 19:01, Sergey Bylokhov wrote:
>> On 17.05.16 18:54, Vadim Pakhnushev wrote:
>>> For me this bug reproduces only when running through the RDP and with
>>> -Dsun.java2d.d3d=false flag.
>>> Basically each DescribePixelFormat takes about 40-60 ms when running
>>> without hardware acceleration because it calls LoadLibrary/FreeLibrary
>>> for opengl32.dll every time.
>>> So the fix is to cache the handle to the dll.
>> It is needed even in case of d3d=true?
>> (D3DGraphicsDevice extends Win32GraphicsDevice)
> Not really. Although I don't see any harm to it.
> Anyway, I think that this fix could be made even more concise provided 
> that we don't free the handle.
> So I moved this code to the 
> Java_sun_awt_Win32GraphicsDevice_getMaxConfigsImpl which is not called 
> in case of d3d:
> http://cr.openjdk.java.net/~vadim/6477756/webrev.01/
Actually this is wrong as this function could potentially be called many 
times resulting in the handle leak.
I think the first fix is better even if it loads the dll in case of d3d=true


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