I read this in the tendermint docs :
Note that it is not possible to send transactions to Tendermint during Commit >- if your app tries to send a /broadcast_tx to Tendermint during Commit, it >will deadlock.
Does that mean if my app sends another transaction while a previous one is in commit stage, the app will stop working ?
If the ABCI app logic processing the Commit message sends a broadcast_tx_sync or broadcast_tx_commit and waits for the response before proceeding, it will deadlock.
Executing those broadcast_tx calls involves acquiring a lock that is held during the Commit call, so it's not possible.
If you make the call to the broadcast_tx endpoints concurrently, that's no problem, it just can't be part of the sequential logic of the Commit message