The &xcenter; "Sentinel" widget shows you a graph of the current memory consumption on your system.

The sentinel takes a bit of getting used to, but it comes in quite handy after a while. Not unlike the "Pulse" widget, it shows you a graph of how memory usage has evolved on your system over time. This graph is updated every two seconds.

However, the sentinel shows you several graphs at the same time, in different colors, with the current measurements (in MB) painted in the same colors on the left:

The graphs represent the following:

  1. The top value (in green) is the currently free physical RAM. This is the same value as with the "Memory" widget. So if you have 128 MB of RAM on your system, this will never go above that value (and most likely never reach it, of course).

  2. The middle value (in blue) is the currently used physical RAM. If you add this value to the top value, you should get your total RAM.

  3. If you have a recent win32k.sys driver from Odin (March 2001 or newer) installed, the size of your swap file is represented by two more colors, as in the screenshot above. The third value (in purple) then shows you the the amount of space in your swap file that is currently in use. The bottom value (in red) then represents the free space in the swap file. The two values added represent the size of your swap file.

    As you can see in the above screenshot, more and more memory was allocated until the free memory (in green) was used up. &os2; then started using free space in the swap file (in red) until that was used up too. Then &os2; started growing the swap file, which is represented by the purple graph growing. Finally, the memory was gradually released, which was shown by the blue and purple graphs shrinking again. Finally, &os2; started shrinking the swap file again since there was plenty of free space in it.

    If you do not have a recent win32k.sys driver installed, you will only see a purple color, simply representing the size of your swap file.

The gray area above the colored graphs really has no meaning. It is only the result of the scaling that the sentinel performs on the display. When time passes, you will see that as soon as the "bump" in the middle leaves the screen, the display is rescaled and the gray area is then used for the display as well.

Note that you can drag and drop fonts and colors onto the sentinel widget. Presently, you can only change the background color though. Besides, it is sizeable.

Implementation Details

The source of the information that is displayed by the sentinel widget depends on whether a recent version of Odin's win32k.sys driver is installed.