vibed_test2/vtest2/source/test1.d

// todo test   https://dlang.org/phobos/std_parallelism.html


alias uint8  = ubyte;
alias uint64 = ulong;


import std.stdio;
import std.concurrency : spawn;
import core.time : Duration, dur;
import core.thread : Thread;



uint64 fact(uint64 n){
  return fact(n, 1);
}

uint64 fact(uint64 n, uint64 a){
  if(n == 0){
    return a;
  }else{
    return fact(n - 1, n * a);
  }
}


//void test1_worker(uint8 n){
void test1_worker(int n){
  writeln("started worker = ", n);
  
  while(true){
    //Thread.sleep(dur!"seconds"(120));
    Thread.sleep(dur!"seconds"(3));
    
    auto v20 = fact(20);
    writeln("worker = ", n, " fact 20 = ", v20);
  }
  
  Thread.sleep(dur!"seconds"(3));
  
  writeln("stopped worker = ", n);
}


void test1_spawner(){
  //uint8 i = 10; // 10 = 1.8 Mb RAM // 255 = 2.9 Mb RAM // 1000 = 6.1 Mb RAM // 10_000 = 47.9 Mb RAM // 100_000 = 180.3 -> 434.4 Mb RAM ,, 161.8 -> 607.7 Mb RAM
  //int i = 100_000; // fails
  int i = 30_000;
  
  /**/
  while(i > 0){
    spawn(&test1_worker, i);
    
    i--;
  }
  /**/
  
}


/*

> make run
./vtest2
...
// core.thread.threadbase.ThreadError@core/thread/threadbase.d(1297): Error creating thread

*/