Instruments Preferences

The Preferences dialog is accessed by selecting Instruments > Preferences. It contains six tabs where you can customize Instruments to best suit your needs.

General Tab

Use the General tab to configure basic Instruments preferences including startup, keyboard shortcuts, and warnings options.

Table 1-1  General tab

Option

Description

Always use deferred mode

Performs data analysis for all traces after data collection is complete.

Automatically time profile spinning applications

Automatically monitors for a spinning process and starts the Time Profiler instrument on a spinning process. This can be a process other than the one being recorded.

Suppress template chooser

Hides the template chooser when Instruments starts up and when a new trace document is created.

Save current run only

Saves only the current data collection run for each individual instrument.

Compress run data

Compresses each saved run into zip format.

Default document location

Determines the default location for data storage.

Global Keyboard Shortcuts

Sets a keyboard shortcut for starting the time profiling instrument.

Reset “Don’t Ask Me” Warnings

Enables or disables dialog warnings. Instruments has several warning dialogs that you can disable by selecting the “Do not show this message again” checkbox in the dialog. To reenable all of these warning dialogs, click the Reset “Don’t Ask Me” Warnings button.

Display Tab

Use the Display tab to configure track display options in a trace document.

Table 1-2  Display tab

Option

Description

Enforce initial deck height

When selected, saves the current deck height of an instrument. When deselected, uses the template’s default deck height.

Sort process lists by identifier

When selected, sorts all processes by their process ID. When deselected, sorts processes alphabetically.

Always snap track to fit at end of run

Always snap track to fit at end of run: Automatically resizes the track in a trace document to fit the current track width.

DTrace Tab

Use the DTrace tab to configure how DTrace-based instruments act. DTrace instruments use dynamic tracing to access low-level kernel operations and user processes running on your device.

Table 1-3  DTrace tab

Option

Description

Buffer size

Sets the size of the DTrace buffer (in megabytes). The default is 25 MB.

Max backtrace depth

Sets the maximum stack depth that is captured when using a DTrace instrument (in megabytes). The default is 25 MB.

Permit zero match probes.

Prevents an error when a specified probe is not found.

Preserve intermediate files

Prevents Instruments from removing intermediate files from the disk.

Flag runtime messages

Adds flags to the timeline for status and error messages encountered during a recording.

Background Profiling Tab

Use the Background Profiling tab to determine how the Time Profiler instrument acts when you access it from the system Dock or from a keyboard shortcut (in these cases, Instruments runs in the background). Set how often information is gathered and the length of automatically captured samples.

Table 1-4  Background Profiling tab

Option

Description

Sampling interval

Specifies how often a sample is taken. Type a numeric value in the field. Choose microsecond, millisecond, or second from the pop-up menu. Defaults to 1 millisecond

Sampling duration

Sets the length of the sample. Type a numeric value in the field. Choose microsecond, millisecond, or second from the pop-up menu. Defaults to 5 seconds.

CPUs Tab

Use the CPUs tab to configure Instruments for the CPU configuration of your device.

Table 1-5  CPUs tab

Option

Description

Active Processor Cores

Determines how many cores of your system are used. Use the slider to set the number of active cores equal to the number of cores on the device that you expect your application to run on.

Hardware Multi-Threading

Allows CPU cores to use a second logical core on supported devices. A system with two physical cores would have a total of four cores to use.

dSYMs and Paths Tab

Use the dSYMs and Paths tab to set global search paths for Instruments. Click the plus (+) button to add a new search path.

Table 1-6  dSYMs and Paths tab

Option

Description

+

Adds a search location. Opens the Open Directory dialog. Navigate to the desired directory and click Open.

_

Removes a search location. Select a path and click the minus (-) button to remove the path.

dSYM Download Script

Provides the option of running a custom script to locate and access the necessary dSYM files. This option is provided for use by large developers with distributed code databases; it is not needed by the majority of developers.

When a run ends

Specifies action to take at the conclusion of the Download Script.