bitcoind sendfrom method - is it atomic?

[miso]

sendfrom <fromaccount> <tobitcoinaddress> <amount> [minconf=1] [comment] [comment-to]

Will send the given amount to the given address, ensuring the account has a valid balance using [minconf] confirmations. Returns the transaction ID if successful (not in JSON object).

But is this function atomic? Is bitcoind / bitcoin-qt multi threaded?
If the server receives many sendfrom requests at the same time, is it safe to use?
Thank you.

edit: hope they do not use bitcoin-qt http://www.coindesk.com/poloniex-loses-12-3-bitcoins-latest-bitcoin-exchange-hack/

[gmaxwell]

All updates to the wallet single thread through a common lock, so yes, it's atomic.

Though no one should be using the accounts functionality for this sort of thing, as there is no safe way to back up that data (among other issues).

[miso]

Thanks for reply. What is the problems with bitcoin-qt accounts?
There is no warning except "Account Weaknesses" https://en.bitcoin.it/wiki/Accounts_explained
The only feature I am waiting for is watching only mode without workarounds.