The Synchronization package includes the synchronization classes and the guard classes.

The synchronization classes include mutual exclusion and condition synchronization mechanisms. The classes are shown in Figure 21.

The RWSynchObject base class has a common interface for enabling and disabling automatic cancellation detection. All of the classes that derive from RWSynchObject can test for runnable cancellation prior to performing any synchronization operation that might result in a blocking wait. For more information, see “Canceling a Runnable.”

To simplify the acquisition and release of synchronization resources and to make these operations safe in the presence of exceptions, the Synchronization package has a set of helper classes called guards. They are shown in Figure 22.

Guards are used for exception-safe mutex acquisition and release.