Why does HRegion acquire all needed locks before performing batch put?

[肖之慰]

hi all,

When I read the doMiniBatchPut function in HBase-0.90.1, I find that
it would first acquire as many row locks as it can before performing
updates. If one row is not accessible, all following rows will not be
updated for this batch. So why not update one row at a time so that
every row can be processed?

Thank you.
---
Wade