Jetpack Compose Slot Table and Composition Tree

Gambling Oct 4, 2025

slot

A narrow, elongated depression, groove, notch, or slit, especially one for receiving or admitting something, as a coin or a letter. Also: a position, as in an assignment or job opening. The interior opening in a copy desk, occupied by the chief copy editor. A scheduled time and place for an aircraft to take off or land, as authorized by an airport or air-traffic authority.

The slot table and the Composition Tree are the core data structures that make Jetpack Compose fast, smart, and reactive — without requiring real View objects in memory. Let’s explore them in depth.

In computing, a slot is the operation issue and data path machinery surrounding a set of functional units (FUs) that execute instructions in a single basic instruction cycle. Each FU in a pipeline can only be assigned to a single slot in a given cycle. Modern conventional central processing units have several compute pipelines, each with one or more FUs. Each pipeline can have several slots, allowing multiple operations to be issued in a cycle.

The refill policy for PT stipended and PT Ed Award Only slots are applied jointly, not separately. A refilled slot will not appear on the program information profile page until all stipended and Ed Award Only slots for this grant year are filled, and an FT member who was awarded a PT stipended or PT Ed Award Only slot has exited with less than 15% of their hours completed.