Common Thread Types
Much of the functionality of threads is provided through the classes
in the System.Threading namespace. The most basic
thread class to understand is the Monitor class,
which is explained next.
The Monitor Class
The System.Threading.Monitor class
provides an implementation of
Hoare’s Monitor that allows you to use any
reference-type instance as a monitor.
The Enter and Exit Methods
The Enter( ) and Exit( )
methods
respectively obtain and release a lock
on an object. If the object is already held by another thread,
Enter( ) waits until the lock is released, or the
thread is interrupted by a
ThreadInterruptedException. Every call to
Enter( ) for a given object on a thread should be
matched with a call to Exit( ) for the same object
on the same thread.
The TryEnter Methods
The TryEnter( ) methods
are similar to the Enter( ) method, but they don’t require a lock on
the object to proceed. These methods return true
if the lock is obtained, and false if it
isn’t, optionally passing in a timeout parameter
that specifies the maximum time to wait for the other threads to
relinquish the lock.
The Wait Methods
The thread holding a
lock
on an object may call one of the
Wait( ) methods to temporarily release the lock
and block itself, while it waits for another thread to notify it by
executing a pulse on the monitor. This approach can tell a worker
thread there is work to perform on that object. The overloaded
versions of Wait( ) allow you to specify a timeout that reactivates ...