【发布时间】：2021-07-13 23:43:27
【问题描述】：
我正在努力让 GL+CL 协同工作。
我一直在关注this tutorial。在我的代码中，我首先调用clGetPlatformIDs 并检索第一个（也是唯一一个）平台。我还从 SDL2 获得了我的 gl_context。然后我想在clGetGLContextInfoKHR的帮助下查询OpenGL使用的设备。我使用clGetExtensionFunctionAddressForPlatform(platform_id, "clGetGLContextInfoKHR") 成功获得了这个函数，但不幸的是，当我调用它时，我遇到了分段错误。我的代码是用 Rust 编写的，但我使用 low level OpenCL binding，所以它看起来几乎像它的 C 对应部分。
pub fn new(gl_context: &GLContext) -> Result<Self, ClGlError> {
println!("Initialising OpenCL context");
let raw = unsafe { gl_context.raw() };
println!("Getting default opencl platform");
let platform_id = Self::default_platform()?; // this is valid and not null
let mut props:[cl_sys::cl_context_properties;5] = [
//OpenCL platform
cl_sys::CL_CONTEXT_PLATFORM as cl_sys::cl_context_properties, platform_id as cl_sys::cl_context_properties,
//OpenGL context
cl_sys::CL_GL_CONTEXT_KHR, raw as cl_sys::cl_context_properties,
0
];
let mut device: cl_device_id = std::ptr::null_mut();
let p: *mut cl_device_id = (&mut device) as *mut cl_device_id;
let fn_name = b"clGetGLContextInfoKHR\0" as *const u8 as *const i8;
println!("Getting clGetGLContextInfoKHR");
let clGetGLContextInfoKHR = unsafe{clGetExtensionFunctionAddressForPlatform(platform_id, fn_name ) as cl_sys::clGetGLContextInfoKHR_fn};
if clGetGLContextInfoKHR.is_null(){
// error handling here
}
println!("Getting device"); // this is the last thing I see before segfault
unsafe{
(*clGetGLContextInfoKHR)(props.as_mut_ptr(),cl_sys::CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR,std::mem::size_of::<cl_device_id>(),device as *mut c_void,std::ptr::null_mut());
}
panic!("All good") // this is never reached
}
我有一个相当新的显卡，它支持cl_khr_gl_sharing。
这里是clinfo
Number of platforms 1
Platform Name NVIDIA CUDA
Platform Vendor NVIDIA Corporation
Platform Version OpenCL 1.2 CUDA 11.2.162
Platform Profile FULL_PROFILE
Platform Extensions cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_fp64 cl_khr_byte_addressable_store cl_khr_icd cl_khr_gl_sharing cl_nv_compiler_options cl_nv_device_attribute_query cl_nv_pragma_unroll cl_nv_copy_opts cl_nv_create_buffer cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_device_uuid
Platform Extensions function suffix NV
Platform Name NVIDIA CUDA
Number of devices 1
Device Name GeForce GTX 960
Device Vendor NVIDIA Corporation
Device Vendor ID 0x10de
Device Version OpenCL 1.2 CUDA
Driver Version 460.80
Device OpenCL C Version OpenCL C 1.2
Device Type GPU
Device Extensions cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_fp64 cl_khr_byte_addressable_store cl_khr_icd cl_khr_gl_sharing cl_nv_compiler_options cl_nv_device_attribute_query cl_nv_pragma_unroll cl_nv_copy_opts cl_nv_create_buffer cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_device_uuid
也许最重要的线索可能是我尝试了一堆其他构建在 opencl 之上的库，并且在所有这些库中，每当我调用 clGetGLContextInfoKHR（包装在更安全和更高级别的 API 中）时，它都会崩溃。我认为所有这些库的代码中不太可能都有错误，所以这可能是我的环境中的一些问题。但是，如您所见，我的显卡显然支持所有必要的扩展。
【问题讨论】：