When does NestedLoopJoinOperator perform memory management?

[Imagoodboy]

I am learning presto, and in the process of debugging the TestNestedLoopJoinOperator#testNestedLoopJoin() test case under the presto-main module, I found that for buildPages, in the NestedLoopBuildOperator#addInput(..) method, such as localUserMemoryContext.setBytes(..) ) memory management .

but no similar operations were found in the subsequent NestedLoopJoinOperator. Its getOutput(..) method directly uses NestedLoopPageBuilder#next(..) for result output, and the result set is also declared in the construction method. .

I am very confused here. If the Cartesian product of buildPages and probePage is performed, will it occupy a very large memory and cause memory overflow? I would like to ask the experts whether there is memory management here and I don't see it?

Thank you so much!!