# V8js ## V8 JS Attributes Describes V8 JS Engine Runtime related attributes. | Attribute | Type | Description | Examples | Stability | |---|---|---|---|---| | `v8js.gc.type` | string | The type of garbage collection. | `major`; `minor`; `incremental` |  | | `v8js.heap.space.name` | string | The name of the space type of heap memory. [1] | `new_space`; `old_space`; `code_space` |  | **[1]:** Value can be retrieved from value `space_name` of [`v8.getHeapSpaceStatistics()`](https://nodejs.org/api/v8.html#v8getheapspacestatistics) `v8js.gc.type` has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used. | Value | Description | Stability | |---|---|---| | `incremental` | Incremental (Incremental Marking). |  | | `major` | Major (Mark Sweep Compact). |  | | `minor` | Minor (Scavenge). |  | | `weakcb` | Weak Callbacks (Process Weak Callbacks). |  | `v8js.heap.space.name` has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used. | Value | Description | Stability | |---|---|---| | `code_space` | Code memory space. |  | | `large_object_space` | Large object memory space. |  | | `map_space` | Map memory space. |  | | `new_space` | New memory space. |  | | `old_space` | Old memory space. |  |