View this PageEdit this PageAttachments to this PageHistory of this PageHomeRecent ChangesSearch the SwikiHelp Guide
Hotspots: Admin Pages | Turn-in Site |
Current Links: Cases Final Project Summer 2007

CA3 gtg994h

Garbage Collection:

Reference counting was problematic because if an object pointed to itself or two objects pointed to each other then they would not be deleted. Keeping track of the reference pointing took additional space and performance.

The primary advantages to garbage collection is simplicity to the programmer (it frees the programmer from having to keep track of these things). Secondly, it provides additional security since objects are not deleted by the user. This prevents memory leaks and faults when attempting to free memory that the program does not own.

The primary disadvantage is the performance hit that occurs when implementing garbage collection. Processes have to run that calculate what can be trashed.

History of OO:

It combined data and procedure into one object. Traditionally procedures and data had remained separate. The first of these languages was Simula.

PARC created Ethernet, the mouse, and GUIs.

Usability:

The Gulf of Execution is the difference between a task and what needs to be done to actually accomplish the task. In order for me to create Coweb assignment 3 I must open a web browser, goto my who's who and create a link, and then create and the linked page. Most users would not expect the new page to have to be created from existing page.

The Gulf of Evaluation is how the user interprets the given output or representation. The user must determine whether the output of the system represents the goal at hand. A big red button that says shut down, will probably get interpretted as shutting down the computer. Having it do anything else would be problematic.

Link to this Page