cudaFlow Algorithms » Single Task

Contents

• Include the Header
• Run a Task with a Single Thread
• Miscellaneous Items

tf::cudaFlow provides a template method, tf::cudaFlow::single_task, for creating a task to run the given callable using a single kernel thread.

Include the Header

You need to include the header file, taskflow/cuda/algorithm/for_each.hpp, for creating a single-threaded task.

#include <taskflow/cuda/algorithm/for_each.hpp>

Run a Task with a Single Thread

You can create a task to run a kernel function just once, i.e., using one GPU thread. This is handy when you want to set up a single or a few global variables that do not need multiple threads and will be used by multiple kernels afterwards. The following example creates a single-task kernel that sets a device variable to 1.

int* gpu_variable;
cudaMalloc(&gpu_variable, sizeof(int));

tf::cudaFlow cf;
cf.single_task([gpu_variable] __device__ () {
  *gpu_Variable = 1;
});

tf::cudaStream stream;
cf.run(stream);
stream.synchronize();

Since the callable runs on GPU, it must be declared with a __device__ specifier.

Miscellaneous Items

The single-task algorithm is also available in tf::cudaFlowCapturer::single_task.