This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
Leave a local root scope, transferring the result value to the next enclosing root scope.
||Pointer to the context. This must be the same context that was passed to
||The result value that should remain protected from garbage collection.|
JS_EnterLocalRootScope for an explanation of local root scopes.
The protection this function affords to
rval is tenuous. If there is an enclosing local root scope, then
rval is transferred to it. Otherwise, the value is stored in an internal per-
JSContext slot. This slot is rooted, but the value will eventually be overwritten by some other operation, and it is very difficult to figure out exactly when this will happen—or more to the point, guarantee that it won't happen in the time it takes some specific chunk of code to run.
In any case, all other newborn values protected by the local root scope, aside from
rval, become subject to garbage collection.