C++ - basic thread question

Answer 1

Insert code that is appropriate for your platform where I have added comments below:

{
   // Create event visible by second thread to be signalled on completion
   Launch_Secondary_Thread();

   // Wait for event to be signalled
}

{
   Do_Something_Once();
   // set the event state to signalled so that 1st thread knows to continue working

   while (not_important_condition) {
      Do_Something_Inside_Loop();
   }
}

Make sure that the event DOES get signalled, even if 2nd thread exits abnormally after an exception or other error. If not, your 1st thread will never wake up. Unless you can put a timeout on the wait.

Answer 2

You're free to go with mutex locks!

Do_Something_Once()
{
   boost::mutex::scoped_lock(mutex);
   // ...
}

Update:

For your particular case I would go with condition variable, as others suggested.

Answer 3

This is a job for condition variables.

Check out the Condition Variables section of the boost docs - the example there is almost exactly what you're doing.

Whatever you do, don't do a busy-wait loop with sleep

Answer 4

You could consider using boost's condition variable mechanism. It is designed for this scenario.