is the SolrJ call to add collection of documents a blocking function call ?

[ramdev.wudali]

Hi:
   I am trying to index a collection of SolrInputDocs to a Solr server. I was 
wondering if the call I make to add the documents (the 
add(Collection<SolrInputDocument>)  call ) is a blocking function call ?

I would also like to know if the add call is a call that would take longer for 
a larger collection of documents


Thanks

Ramdev