#include "linear_chain.hpp"

#include <tbb/global_control.h>

#include <tbb/flow_graph.h>

// linear_chain_tbb

void linear_chain_tbb(size_t length, unsigned num_threads) {

using namespace tbb;

using namespace tbb::flow;

size_t counter = 0;

tbb::global_control c(

tbb::global_control::max_allowed_parallelism, num_threads

);

graph g;

std::vector<continue_node<continue_msg>*> tasks(length);

for(size_t i=0; i<tasks.size(); i++) {

tasks[i] = new continue_node<continue_msg>(g,

[&]( const continue_msg& ) {

counter++;

}

);

if(i) {

make_edge(*tasks[i-1], *tasks[i]);

}

}

tasks[0]->try_put(continue_msg());

g.wait_for_all();

for(auto& task : tasks) {

delete task;

}

assert(counter == tasks.size());

}

std::chrono::microseconds measure_time_tbb(

size_t length,

unsigned num_threads

) {

auto beg = std::chrono::high_resolution_clock::now();

linear_chain_tbb(length, num_threads);

auto end = std::chrono::high_resolution_clock::now();

return std::chrono::duration_cast<std::chrono::microseconds>(end - beg);

}