Class EDU.gac.max.flipserver.FlipServer 
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Class EDU.gac.max.flipserver.FlipServer 

java.lang.Object
   |
   +----EDU.gac.max.flipserver.FlipServer
public class FlipServer
extends Object
This class is the main class for a server daemon program called FlipServer that is used by the multi-user networked puzzle program NetFlip. Each NetFlip communicates with the FlipServer through its NetInterface. The communication protocol is very simple: the NetInterface sends the number of a "key" (i.e., colored button) to be flipped to the FlipServer, which turns around and sends it back to all the NetInterfaces (including the originating one). The only exception from this "echoing" style of operation is that the FlipServer keeps track of the board state (which keys are flipped) and if a new client connects, immediately sends it the key numbers to flip so that the new client's board looks like the others. One ClientConnectionThread is used to listen on each client's connection.

Warning: this FlipServer class is missing some "synchronized" keywords on some methods. This is intentional as part of a lab assignment on race conditions and monitors for the MC78 course. The students are supposed to find the race conditions and predict the buggy behavior that can result, then verify by inserting appropriate sleeps, then fix the problem by adding the needed synchronized keywords. So, this class is known to be buggy.

Written 17 Aug 1996 by Max Hailperin <max@gac.edu>

See Also:
NetFlip, NetInterface, ClientConnectionThread

Method Index

o addOut(OutputStream)
The addOut method is used to add another output stream that should receive the flip notifications (key numbers); this is used when a new client connects.
o flip(int)
The flip method is used to record and transmit a flip; it is used by a client connection thread that has received a flip number
o main(String[])
o removeOut(OutputStream)
The removeOut method is used to remove one of the output streams to which flip notifications (key numbers) are being sent; this is used when the thread tending a particular client connection notices that the client has closed the connection

Methods

o addOut 
  public void addOut(OutputStream newOut)
The addOut method is used to add another output stream that should receive the flip notifications (key numbers); this is used when a new client connects. Keys that were already flipped earlier are also sent to the new stream.
o removeOut 
  public void removeOut(OutputStream oldOut)
The removeOut method is used to remove one of the output streams to which flip notifications (key numbers) are being sent; this is used when the thread tending a particular client connection notices that the client has closed the connection
o flip 
  public void flip(int key)
The flip method is used to record and transmit a flip; it is used by a client connection thread that has received a flip number
o main 
  public static void main(String args[])

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