Guides and Sample Code

Developer

Instruments User Guide

Glossary

deferred mode

Running Instruments in deferred mode delays the analysis of data until the data collection is done, either after your app has finished running or after you click Stop. While in deferred mode, you are blocked from interacting with the instruments that are collecting data.

DTrace

A dynamic tracing facility originally created by Sun and ported to OS X. DTrace taps into the operating system kernel, providing access to low-level information about the kernel and the user processes running on your computer. Many of the built-in instruments are already based on DTrace. DTrace is itself a complex tool, but Instruments provides a simple interface that lets you access the power of DTrace without the complexity. To learn about DTrace and the D scripting language, see the Solaris Dynamic Tracing Guide, available from the Oracle Technology Network.

instrument

Monitors different aspects of your app, process, or device over time. It collects data and presents it to you in detail for analysis. A trace document contains one or more instruments.

library

A window that displays a list of available instruments, which may be inserted into a trace document.

playhead

Denotes the current position in the timeline pane of a trace document. Drag the playhead around to view recorded data at different points in time.

profile

The act of monitoring your running app and capturing data about it.

profiling template

Contains a collection of instruments that are commonly used together to analyze an app and gather useful information in order to help identify problems or make your app more efficient.

run

A session during which your app ran and was profiled. A profiling trace document can capture data over a series of runs, allowing you to compare the results.

snapshot

A set of captured profiling results that represent your app at a specific point in time. Some instruments, such as Allocations and Leaks, allow you to take snapshots at timed intervals, rather than constantly recording data.

strategy

Types of data that may be viewed in the timeline pane of a trace document. Options include CPU usage, instrument data, and thread utilization.

target

A device and app or process that you want to profile with Instruments.

timeline

A pane in a trace document that graphically represents data collected over time. You can move the playhead in the timeline pane to view data collected at a specific point in time.

trace

A recording session, or the act of recording, by a trace document. During a trace, your app is monitored and information is gathered for analysis.

trace document

Used to organize and configure instruments for profiling, initiate data collection, and view and analyze the results.