// Sample code that demonstrates a data race between threads reading and writing
// from the same shared global variable in Static Data.
// Interleaving of reads and writes will sometimes cause printed sum to be less
// than expected.
//
// Remember to compile with -pthread

#include <pthread.h>
#include <iostream>

using std::cout;
using std::cerr;
using std::endl;

static constexpr int kNumThreads = 50;
static constexpr int kLoopNum = 1000;

static int sum_total = 0;


// increment sum_total LOOP_NUM times
void *thread_main(void *arg) {
  for (int i = 0; i < kLoopNum; i++) {
    sum_total++;
  }
  return nullptr;  // return type is a pointer
}


int main(int argc, char** argv) {

  for(int i = 0; i < kNumThreads * kLoopNum; i++){
    sum_total++;
  }

  cout << "Total: " << sum_total << endl;

  return EXIT_SUCCESS;
}