C++ thread 02

Table of contents

void func_1()
{
  fmt::print( "hello from method {}\n", __FUNCTION__ );
}

void func_2()
{
  fmt::print( "hello from method {}\n", __FUNCTION__ );
}

int main()
{
  std::thread thread_1( func_1 );
  std::thread thread_2( func_2 );

  // This program is unsafe
  // I intentionally forgot to join or detach here to produce an error
  // thread_1.join();

  thread_2.join();

  if( thread_1.joinable() ) {
    fmt::print( "thread_1 is joinable thread\n" );
  }

  if( thread_2.joinable() ) {
    fmt::print( "thread_2 is joinable thread\n" );
  }
  else {
    fmt::print( "after calling join, thread_2 is not a joinable thread\n" );
  }

  fmt::print( "hello from main thread\n" );

  // give time for all threads execute their functions
  std::this_thread::sleep_for( std::chrono::seconds( 1 ) );
  std::fflush( nullptr );

  // An exception std::terminate should be throwed for thread_1
  return 0;
}

Possible output

hello from method func_1
hello from method func_2
thread_1 is joinable thread
after calling join, thread_2 is not a joinable thread
hello from main thread

Possible error output

terminate called without an active exception

References

• Udemy Modern C++ Concurrency in Depth