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Fig. 5.
Searching through the tree to get all intervals intersecting t = 280
Although the traces may be arbitrarily long, the current state normally does
not grow with the trace size. The state history, however, grows linearly with the
trace size. In other words, the current state contains the state values for a given
time, like a snapshot, while the history encompasses all of the previous snapshots.
Keeping separate the
current state
and the
history
makes the proposed method
usable for live trace mode, where the method just keeps track the current state
system and may not keep any history, or possibly a fraction of that (e.g. the
last 10 seconds).
4.3 Visualization
The proposed modeled state system is contributed to TMF (Tracing and Moni-
toring Framework), the Eclipse plugin of Linux Tools)
4
and is accessible under
the terms of Eclispe Public License
5
.
The implementation has actually two parts: a plugin that implements the
library to handle the state provider, attribute tree, history tree and other struc-
tures, and a visualization part named the State System Explorer, which enables
browsing and exploring the state system data directly (Figure 6). The viewer
firstly displays the hierarchical organization of the resources and their attributes,
extracted from the attribute tree, and then shows the state values of any selected
attribute, at any given time. Using this view, users can directly browse the state
values of the resources/attributes, which can help to study its overall behav-
ior. This is interesting because users may not need to look at the trace events
anymore and can directly analyze the state values gathered previously from the
trace. For example, to study the behavior of a particular CPU or a process during
the system execution.
Furthermore, there are other graphical views in TMF that allow analyzing a
system from different aspects using the state values stored in the modeled state
system. For instance, as shown in Figure 7, the Control Flow and Resources views
