topic check context property in OpenCL* for CPU

check context property

Sajjadul — Thu, 19 Sep 2013 22:34:26 GMT

Hi forum,

I have created an opencl context with the gl-cl interoperability. The context creation was fine and it did not give me any cl error string . But i am getting some trouble while making opencl image buffer from 2D gl texture object. I am getting the cl error string "CL_OUT_OF_RESOURCES"

I suspect that i have problem with context creation. Since i am not getting any cl error string other than CL_SUCCESS, i do not know how else to validate the successful opencl context creation with gl-cl interoperability.

To find the context info i am doing the following :

[cpp]

//now pull out the context infor from the recently created context

size_t contextPropertySize = 0; cl_context_properties *properties = NULL;

//now extract the context information that we have created

errNum = clGetContextInfo(_m_clContext,CL_CONTEXT_PROPERTIES,0,NULL,&contextPropertySize);

if(errNum != CL_SUCCESS) { osg::notify(osg::FATAL) << __FUNCTION__ << ": " << __LINE__ << ": " << "Error while clGetContextInfo(..)" << getErrorString(errNum) << std::endl; }
properties = new cl_context_properties[contextPropertySize];
errNum = clGetContextInfo(_m_clContext,CL_CONTEXT_PROPERTIES,contextPropertySize,properties,NULL);
if(errNum != CL_SUCCESS) { osg::notify(osg::FATAL) << __FUNCTION__ << ": " << __LINE__ << ": " << "Error while clGetContextInfo(..)" << getErrorString(errNum) << std::endl; }

[/cpp]

So i have all the information inside properties array . How do i confirm that content of the properties array contain the context properties for gl-cl interoperability ?

Regards

Sajjadul

How are you creating the

Raghupathi_M_Intel — Fri, 20 Sep 2013 21:52:29 GMT

How are you creating the context? Your snippet shows code querrying the context but not the creation. You should create the context by setting the properties to enable CL/GL sharing. Also make sure to get the gl device associated with the gl context

[cpp]

cl_context_properties properties[] =
{
    CL_CONTEXT_PLATFORM, (cl_context_properties) platform,
    CL_GL_CONTEXT_KHR, (cl_context_properties) g_hRC,
    CL_WGL_HDC_KHR, (cl_context_properties) g_hDC,
    0
};

....
cl_int res = pclGetGLContextInfoKHR(properties, CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR, 0, NULL, &devSize);
res = pclGetGLContextInfoKHR( properties, CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR, sizeof(cl_device_id), &device, NULL);

.....
context = clCreateContext(properties,1,&device,0,0,&res);

[/cpp]

Of course, you should do the proper error checking at each step.

Raghu

Thanks for the hint!

Sajjadul — Sat, 21 Sep 2013 11:48:39 GMT

Thanks for the hint!

I saw many examples where they have not used the function "clGetGLContextInfoKHR(...)" and their context creation is successful. I am confused if it mandatory to use it or not. I am creating the context as follows:

[cpp]

cl_context_properties contextProperties[] = { #ifdef defined(_WIN32) CL_CONTEXT_PLATFORM, (cl_context_properties) _m_clPlatform, CL_GL_CONTEXT_KHR, (cl_context_properties) windowsContext->getWGLContext(), CL_WGL_HDC_KHR, (cl_context_properties) windowsContext->getHDC(), #elif defined(__GNUC__) CL_CONTEXT_PLATFORM, (cl_context_properties) _m_clPlatform, CL_GL_CONTEXT_KHR, (cl_context_properties) linuxContext->getContext(), CL_GLX_DISPLAY_KHR, (cl_context_properties) linuxContext->getDisplay(), #elif defined(__APPLE__) CGLContextObj glContext = CGLGetCurrentContext(); // get the current GL context CGLShareGroupObj shareGroup = CGLGetShareGroup(glContext); // share group
CL_CONTEXT_PROPERTY_USE_CGL_SHAREGROUP_APPLE, (cl_context_properties) shareGroup, #endif 0 };
_m_clContext = clCreateContext(contextProperties,1,&clDevices[clDevUsed],NULL,NULL,&errNum);
if(errNum != CL_SUCCESS) { osg::notify(osg::FATAL) << __FUNCTION__ << ": " << __LINE__ << ": " << " OpenCL Context Creation with GL-CL interoperability was not successful :" << getErrorString(errNum) << std::endl; return false; }

[/cpp]

I am getting CL_SUCCESS with the context creation. But later if i try to create 2D opencl image buffer from the valid opengl texture object i get the opencl error "CL_OUT_OF_RESOURCES". Any idea what might have caused it ?

It will be nice to know some scenarios that cause this type of error.

Thanks

Sajjadul

You get CL_OUT_OF_RESOURCES

Raghupathi_M_Intel — Mon, 07 Oct 2013 18:19:08 GMT

You get CL_OUT_OF_RESOURCES if for some reason the allocation failed (sorry dont have specifics). But I think the reason your call is failing is because you are creating a shared buffer without a shared context. You need to create the context using a device that is associated with both cl and gl.

Thanks,
Raghu