#include <QCoreapplication>
#include <QDebug>
#include <QSystemSemaphore>

int main(int argc, char ** argv)
{
   QCoreApplication app(argc, argv);
   const int nSem = 11;

   for(int i = 0; i < nSem; i++) {
      // creating semaphore
      QSystemSemaphore *s = new QSystemSemaphore(QString("S%1").arg(i), 1);
      // acquiring semaphore
      qDebug("acquiring semaphore %d", i);
      if(!s->acquire()) {
         qWarning("Unable to acquire semaphore: %d,%s",s->error(), qPrintable(s->errorString()));
         break;
      }
   }

  return 0;
}