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# os_activity_t

An object that represents an activity triggered by the user.

## Discussion

The Activity Tracing APIs provide a mechanism for grouping and labeling work that’s done in response to user interactions or other events, so that you can see all log messages related to the triggering action.

## Topics

### Creating Activities

[`os_activity_initiate`](/documentation/os/os_activity_initiate)

Synchronously executes a new activity using the provided block.

[`os_activity_initiate_f`](/documentation/os/os_activity_initiate_f)

Synchronously executes a new activity using the provided function.

[`os_activity_create`](/documentation/os/os_activity_create)

Creates a new activity object.

[`os_activity_label_useraction`](/documentation/os/os_activity_label_useraction)

Label an activity that is auto-generated by AppKit or UIKit.

[`os_activity_flag_t`](/documentation/os/os_activity_flag_t)

### Executing an Activity

[`os_activity_apply`](/documentation/os/os_activity_apply)

Execute a block using a given activity object.

[`os_activity_apply_f`](/documentation/os/os_activity_apply_f)

Execute a function using a given activity object.

### Retrieving an Activity Identifier

[`os_activity_get_identifier`](/documentation/os/os_activity_get_identifier)

Retrieves the identifier for a given activity object.

[`os_activity_id_t`](/documentation/os/os_activity_id_t)

A number that uniquely identifies an activity.

### Saving and Restoring Activity States

[`os_activity_scope_enter`](/documentation/os/os_activity_scope_enter)

Switches the current activity, saving the existing execution context.

[`os_activity_scope_leave`](/documentation/os/os_activity_scope_leave)

Restores the current activity to a previously saved state.

[`os_activity_scope_state_t`](/documentation/os/os_activity_scope_state_t)

An opaque structure that contains a saved activity-execution context.

### Data Types

[`os_activity_t`](/documentation/os/os_activity_t)

An object that represents an activity triggered by the user.


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