//! [0]
QSystemSemaphore sem("market", 3, QSystemSemaphore::Create);
                             // resources available == 3
sem.acquire();               // resources available == 2
sem.acquire();               // resources available == 1
sem.acquire();               // resources available == 0
sem.release();               // resources available == 1
sem.release(2);              // resources available == 3
//! [0]


//! [1]
QSystemSemaphore sem("market", 5, QSystemSemaphore::Create);
sem.acquire(5);           // acquire all 5 resources
sem.release(5);           // release the 5 resources
//! [1]


//! [2]
sem.release(10);          // "create" 10 new resources
//! [2]
