A multi-thread process in C++ returns tensors and I want to concatenate them into one tensor in order.
In C++ I have a single function which returns a single 1x8 tensor.
I call this function multiple times simultaneously with std::thread and I want to concatenate the tensors it returns into one large tensor. For example, I call it 12 times I expect to have a 12x8 tensor when it’s finished.
I’m aware I could just have the function return a 12x8 tensor, but I need to solve the problem of how to grab the tensors produced during the multithreading process.
In my attempt below I try to concatenate the tensors into the all_episode_steps tensor but this returns an error.
If you comment out the all_episode_steps line and put std::cout << one; in the get_tensors function above the return statement you see it appears to be using multithreading to create the tensors with no problems.
#include <torch/torch.h>
torch::Tensor get_tensors(int id) {
torch::Tensor one = torch::rand({8});
return one.unsqueeze(0);
}
torch::Tensor all_episode_steps;
int main() {
std::thread ths[100];
for (int id=0; id<12; id++) {
ths[id] = std::thread(get_tensors, id);
all_episode_steps = torch::cat({ths[id], all_episode_steps});
}
for (int id=0; id<12; id++) {
ths[id].join();
}
}