Q: OpenGL imageAtomicCompSwap mutex, endless loop

Asked Mar 22 '17 at 12:57

Active Mar 22 '17 at 12:57

Viewed 224 times

This shader will run into endless loop because of imageAtomicCompSwap mutex. The code is learn form OpenGL Programming Guide(Eighth Edition)

void takeLock(ivec2 vPos)
{
    uint iLockAvaiable;
    do
    {
        iLockAvaiable = imageAtomicCompSwap(uLockImage, vPos, uint(0),         uint(1)); 
    }while(iLockAvaiable != uint(0));
}

void releaseLock(ivec2 vPos)
{
    //imageStore(uLockImage, vPos, uint(0));
    uint uiValue = imageAtomicExchange(uLockImage, vPos, uint(0));
}


void main()  
{   

    takeLock(ivec2(f2TexCoord));

    float BaseDepth = imageLoad(uDepthTest, ivec2(f2TexCoord)).x;
    if(BaseDepth == 0.0 || refScreenCoord.z < BaseDepth)
        imageStore(uDepthTest, ivec2(f2TexCoord), vec4(refScreenCoord.z));
    releaseLock(ivec2(f2TexCoord));
}

asked Mar 22 '17 at 12:57

youyouyou

So... what's your question? – Nicol Bolas Mar 22 '17 at 13:19
do.. while will cause "A TDR has been detected" – youyouyou Mar 22 '17 at 14:24
Put that in your question. Also, what is a "TDR"? Who is reporting this error? Explain exactly what is going on. – Nicol Bolas Mar 22 '17 at 15:06
The book shows `do {...} while (iLockAvailable == 0)` instead of `!=` as you do. – pleluron Mar 22 '17 at 15:53
I call the takeLock, store value in image, then I releaseLock(), but I run into endless loop in fragment shader, error "TDR" occurs when render time is too long – youyouyou Mar 24 '17 at 09:36
I have asked the same question as you. [link]https://stackoverflow.com/questions/51704683/glsl-per-pixel-spinlock-using-imageatomiccompswap – Zhibo Shen Aug 07 '18 at 01:03

Q: OpenGL imageAtomicCompSwap mutex, endless loop

0 Answers0