question about Synchronous API

[calvin2021y]

Synchronous API will block os native thread ?

Or it only block erlang actor, the os native thread will use a event loop to handle io ?

[silviucpp]

No API is blocking the native thread. The SYNC API will only block the erlang actor.

If you look to the code:

query(Q) ->
    case query_async(Q) of
        {ok, Tag} ->
            receive_response(Tag);
        Error ->
            Error
    end.

It will send the query message async and then wait for the response. The wait will block only the erlang calling process.

receive_response(Tag) ->
    receive
        {execute_statement_result, Tag, Result} ->
            Result

    after ?RESPONSE_TIMEOUT ->
        {error, timeout}
    end.

Silviu