Message Buffering

Often, when writing an application to read and process messages, your program may at times be doing other things when messages arrive. Rather than ignore the messages, TIBCO SmartSockets provides a very flexible buffering mechanism such that the messages are stored until they are ready to be processed.

Step 21

Copy the receive3.c and send3.c files

To illustrate this important concept, copy the files receive3.c and send3.c into your working directory. Under Windows copy the makefiles rcv3w32m.mak and snd3w32m.mak into your current directory.

The receive3.c file contains a new while loop that causes the program to read and process messages for two seconds, and then sleep for ten seconds. While sleeping, any messages that arrive are buffered. The difference between the receive2.c and receive3.c program is this while loop in receive3.c:

/* Read and Process all incoming messages */ 
while (1) { 
  TipcSrvMainLoop(2.0); 
  TutOut("Sleeping...\n"); 
  TutSleep(10.0); 
  TutOut("...Done Sleeping!\n"); 
} 

Step 22

Compile, link, and start the receiving program

To see the TIBCO SmartSockets message buffering in action, first compile and link the receive3.c program. Then start the receiving program:

 $ receive3.x 

$ run receive3 

$ receive3 

Step 23

Compile, link, and start the sending program

Now, in a different window, do the same for the send3.c program. Compile and link it the send3.c program. Then start the sending program:

$ send3.x 

$ run send3 

$ send3 

The sending program is sending messages once a second. The receiving program is reading and processing messages for two seconds and then sleeping for 10 seconds. This output displays in the window where the receiving program is running:

Sleeping... 
...Done Sleeping! 
Message Count = 1 
Message Count = 2 
Message Count = 3 
Message Count = 4 
Message Count = 5 
Message Count = 6 
Message Count = 7 
Message Count = 8 
Message Count = 9 
Sleeping... 
...Done Sleeping! 
Message Count = 10 
Message Count = 11 
Message Count = 12 
Message Count = 13 
Message Count = 14 
Message Count = 15 
Message Count = 16 
Message Count = 17 
Message Count = 18 
Message Count = 19 
Message Count = 20 
Sleeping... 

As you watch the receiving program run, notice that while sleeping, it does not read or process any messages. When it is finished sleeping, it reads and processes all the messages it has in its buffer. This is why you see the messages output in quick bursts.

Step 24

Stop all RTclients

Before proceeding to the next section, stop the RTserver and its RTclients with this command:

$ rtserver -stop_clients