//!
//! Construct a lock for given semaphore. Wait forever if necessary.
//! numTokens tokens are acquired after the lock construction and
//! will be released when the lock is destructed. Use isOk() to verify
//! proper instantiation (i.e., to verify if tokens were successfully
//! acquired). Locking zero tokens is considered a failure.
//!
Semaphore::Lock::Lock(Semaphore& semaphore, unsigned int numTokens)
{
numTokens_ = numTokens;
semaphore_ = 0;
if (numTokens > 0)
{
bool ok = (numTokens == 1)? semaphore.decrement(): semaphore.decrementBy(numTokens);
if (ok)
{
semaphore_ = &semaphore;
}
}
}
//!
//! Construct a lock for given semaphore. Wait forever if necessary. A
//! token is acquired after the lock construction and will be released
//! when the lock is destructed. Use isOk() to verify proper instantiation
//! (i.e., to verify if a token was successfully acquired).
//!
Semaphore::Lock::Lock(Semaphore& semaphore)
{
numTokens_ = 1;
semaphore_ = semaphore.decrement()? &semaphore: 0;
}
