Information Technology Reference
In-Depth Information
For this example, select the Leaks template. Click Profile. Wait while Instruments launches and initializes.
Eventually, you see the display in Figure 16.11. The Leaks template includes two instruments: Allocations and
Leaks.
FIGURE 16.11
A first look at the Leaks template
Understanding the time line
After the display is updating regularly, you can begin reviewing the output to see how it offers insights into the
behavior of the app.
There are two areas of activity. The time line area shows an initial flurry of allocation events when the app
launches and a steadily increasing series of events in the Leaks lane. The statistics show a much more compre-
hensive—and difficult to understand—list of information, which is described in more detail later.
The Leaks graph provides a clear indication that the app is leaking. But note that the graph doesn't exactly mir-
ror the leak activity. You might expect the leak count to grow steadily, but by default, the graph is sampled every
10 seconds, so the leaks time line displays a summary view.
TIP
In fact, you can change the sampling time to force the graph to update more frequently. For smaller apps the cost
is a small performance hit. Select the Leaks instrument, and change the value in the box in the Sampling Options
