200 2009-08-24 03:46:00 -0700 Feedback on OpenCL C++ bindings 2009-09-10 12:04:13 -0700 1 1 1 Unclassified OpenCL Man Pages, Reference Card & Other Documentation unspecified All All ASSIGNED P3 normal --- 1 thomas7755 bgaster devrel stapostol opencl 646 thomas7755 2009-08-24 03:46:19 -0700 When handling multiple devices it would be handy to be able to maintain a vector of kernel functors, where each functor is associated with a command queue: std::vector<cl::KernelFunctor> kernelFunctors; for (int d = 0 ; d < commandQueues.size() ; d++) { kernelFunctors.push_back(kernel.bind(commandQueues[d], globalNDRange, localNDRange)); } Any ideas for how to implement something like this, given that this won't work without being able to copy KernelFunctors? 647 devrel 2009-08-24 05:07:18 -0700 Reassign to Benedict. 649 bgaster 2009-08-24 23:15:43 -0700 I have updated the C++ bindings to provide copy constructor for KernelFunctor and the following program now compiles without error: #include <CL/cl.hpp> int main(void) { std::vector<cl::CommandQueue> commandQueues; cl::Kernel kernel; cl::NDRange globalNDRange; cl::NDRange localNDRange; std::vector<cl::KernelFunctor> kernelFunctors; for (int d = 0 ; d < commandQueues.size() ; d++) { kernelFunctors.push_back( kernel.bind( commandQueues[d], globalNDRange, localNDRange)); } } Please let me know if you have any problems using it and thanks for feedback. 650 thomas7755 2009-08-28 10:50:56 -0700 This doesn't work as hoped unfortunately. The KernelFunctor has a reference to a Kernel and a CommandQueue, and so strange things start happening when you try reseat the reference in the assignment operator. I can get the original code to execute by changing the copy constructor to: inline KernelFunctor::KernelFunctor(const KernelFunctor& rhs) : kernel_(rhs.kernel_), queue_(rhs.queue_), offset_(rhs.offset_), global_(rhs.global_), local_(rhs.local_), err_(rhs.err_) { //*this = rhs; } (i.e. complete the initializer list and remove the call to the assignment operator) In this case the assignment operator is never called, but it must still be present as stl::vectors mandate it. Perhaps the assignment operator should fail if rhs != lhs. KernelFunctor could maintain a pointer instead of a reference, but that's possibly not as elegant. 651 bgaster 2009-08-28 10:58:57 -0700 Indeed. Let me think about this some more and I will get back with a solution. Might be best to simply remove the reference. I do not what to have pointers. 658 thomas7755 2009-09-10 11:59:32 -0700 (In reply to comment #4) > Indeed. Let me think about this some more and I will get back with a solution. > Might be best to simply remove the reference. I do not what to have pointers. Have you had any thoughts on this? I agree it would be preferable to avoid pointers. My suggestion would be to provide the corrected copy constructor and make the assignment illegal. 659 bgaster 2009-09-10 12:04:13 -0700 I'm working on fix for this, not using ponters, and will update the C++ bindings with some other fixes in the next few days.