Button Responsiveness in MidCast

 

Summary

MidCast v2.99 allows a user to click multiple times on a button while the program is processing the request for the first click on that same button. Doing so causes the application to become unstable and either crash MidCast or crash both the operating system and MidCast.

Application Description

HillCast Technologies' MidCast is a real-time stock market watching application for palm pilots. A user can keep a list of watched stocks, which will update continuously, allowing the user to follow their value throughout the day.

         

Test Design

This example demonstrates the use of Interference testing. One of the most unstable times of using any program is when canceling a function that is already in progress. Interfering with the process tells the program to discontinue what it is doing and revert back to its previous state. A task like this might involve coordinating the processor, RAM, CD/Hard drives, and other software, all during which the computer itself will still need to continue performing other tasks.

Since MidCast works over a wireless network, the response time of each operation can depend on the network connection. Due to network lag, it appears sometimes as if clicking on a button did not register with the program, which might cause a user to click on the button again a few more times. Since MidCast accepts and tries to process each of these clicks, the program will attempt to run an operation in the middle of running the same operation in the middle of running the same operation... etc.

Interference testing is where many bugs are found simply because these types of processes are tightly tied in with the uniqueness of a hardware setup and the way that hardware is being utilized by other running software.

Performing the Test

  1. Start MidCast.
  2. Once MidCast has connected and loaded, tap on the button until the or button appears.
  3. Tap on either the or multiple times until the program crashes.

Results/Relevance

After tapping on either button multiple times, just before the program closed you may have seen an error message similar to the ones below:

Or you may have observed the following errors:

Whether you received an error message like the one above or Palm OS locked up, both are critical to the useability of the program and are errors that users should not experience. Error messages that are highly technical and refer to the internal code structure are frightening to the common user because it gives the appearance that major damage has been done to the program or the operating system.

Similar Tests/Additional Notes

Clicking on buttons multiple times can cause a lot of damage to programs if not handled correctly, as the program will attempt to do many things with the same piece of data (or sometimes no data at all) and eventually damage its on memory. Either on a palm pilot or a computer, try finding some other programs that allow you to click on buttons more than once and observe what effect that has on the program's stability.

Configuration Notes

Testing HillCast Technologies' MidCast v2.99 on:

Created 2 June 2004 for the CSTER

All images and written material ©Copyright Sam Oswald 2004

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