litho-core/com.facebook.litho/ComponentTreeRegistry

ComponentTreeRegistry

Thread-safe singleton registry that holds weak references to all ComponentTree instances that are still in memory, including released ones that have not been garbage collected yet.

Gated by enabled so it is zero-cost when disabled. The flag is set by com.facebook.litho.hotreload.LithoHotReloadHandler.install and by Litho Observability in debug and perf builds.

Types

StateCounts

class StateCounts(val attached: Int, val detached: Int, val released: Int)

TreeInfo

class TreeInfo(val id: Int, val rootName: String, val isAttached: Boolean, val createdAtMs: Long, val releasedAtMs: Long?)

State of one registered tree.

Properties

enabled

@JvmField

@Volatile

var enabled: Boolean

Functions

countByState

fun countByState(): ComponentTreeRegistry.StateCounts

Counts registered trees by state. Takes no ComponentTree lock, so it is cheap to sample.

forceResolveAll

fun forceResolveAll(): Int

Forces a re-resolve on every registered ComponentTree by setting a new root with a fresh component ID via Component.makeShallowCopyWithNewId. This causes every component's render() to be called again (picking up hot-swapped bytecode) while preserving hook state.

forEach

fun forEach(action: (ComponentTree) -> Unit)

Iterates over a snapshot of all unreleased ComponentTree instances.

markReleased

fun markReleased(tree: ComponentTree)

Marks tree as released. The tree stays in the registry until it is garbage collected, so a released tree that is still reachable can be reported as a leak.

fun register(tree: ComponentTree)

Adds tree to the registry if enabled is true.

snapshot

fun snapshot(): List<ComponentTreeRegistry.TreeInfo>

Returns the state of every registered tree. Reads root names under each tree's lock, so use countByState for frequent sampling.