Programming C#

Queues

A queue represents a first-in, first-out (FIFO) collection. The classic analogy is to a line (or queue if you are British) at a ticket window. The first person in line ought to be the first person to come off the line to buy a ticket.

A queue is a good collection to use when you are managing a limited resource. For example, you might want to send messages to a resource which can only handle one message at a time. You would then create a message queue so that you can say to your clients: “Your message is important to us. Messages are handled in the order in which they are received.”

The Queue class has a number of member methods and properties, as shown in Table 9-4.

Table 9-4. Queue methods and properties

Method or Property	Purpose
Synchronized( )	Public static method that returns a Queue wrapper that is thread-safe.
Count	Public property that gets the number of elements in the Queue.
IsReadOnly	Public property to get a value indicating if the Queue is read-only.
IsSynchronized	Public property to get a value indicating if the Queue is synchronized.
SyncRoot	Public property that returns an object that can be used to synchronize access to the Queue.
Clear	Removes all objects from the Queue.
Clone()	Creates a shallow copy.
Contains()	Determines if an element is in the Queue.
CopyTo()	Copies the Queue elements to an existing one-dimensional array.
Dequeue()	Removes and returns the object at the beginning of the Queue.
Enqueue()