Method create_queue

src/device/opencl/opencl_context.cpp:739–797

}

std::shared_ptr<device_queue> opencl_context::create_queue(const device& dev) const {
	// has a default queue already been created for this device?
	bool has_default_queue = false;
	std::shared_ptr<device_queue> dev_default_queue;
	for (auto&& default_queue : default_queues) {
		if(default_queue.first == &dev) {
			has_default_queue = true;
			dev_default_queue = default_queue.second;
			break;
		}
	}
	
	// has the user already created a queue for this device (i.e. accessed the default queue)?
	bool user_accessed = false;
	if(has_default_queue) {
		const auto iter = default_queues_user_accessed.find(&dev);
		if(iter != std::end(default_queues_user_accessed)) {
			user_accessed = iter->second;
		}
		
		// default queue exists and the user is creating a queue for this device for the first time
		// -> return the default queue
		if(!user_accessed) {
			// signal that the user has accessed the default queue, any subsequent create_queue calls will actually create a new queue
			default_queues_user_accessed.emplace(&dev, 1u);
			floor_return_no_nrvo(dev_default_queue);
		}
	}
	
	// create the queue
	cl_int create_err = CL_SUCCESS;
#if /*defined(CL_VERSION_2_0) ||*/ 0 // TODO: should only be enabled if platform (and device?) support OpenCL 2.0+
	const cl_queue_properties properties[] { 0 };
	cl_command_queue cl_queue = clCreateCommandQueueWithProperties(ctx, ((const opencl_device&)dev).device_id,
																   properties, &create_err);
#else
	
FLOOR_PUSH_WARNINGS() // silence "clCreateCommandQueue" is deprecated warning
FLOOR_IGNORE_WARNING(deprecated-declarations)
	
	cl_command_queue cl_queue = clCreateCommandQueue(ctx, ((const opencl_device&)dev).device_id, 0, &create_err);
	
FLOOR_POP_WARNINGS()
#endif
	if(create_err != CL_SUCCESS) {
		log_error("failed to create command queue: $: $", create_err, cl_error_to_string(create_err));
		return {};
	}
	
	auto ret = std::make_shared<opencl_queue>(dev, cl_queue);
	queues.push_back(ret);
	
	// set the default queue if it hasn't been set yet
	if(!has_default_queue) {
		default_queues.emplace(&dev, ret);
	}
	
	return ret;