SEQUENCER

2.1 Short circuit

 In a situation where a client performs a 'MIDI-THRU' function by simply forwarding events from one MIDI port to another there is a chance of getting an infinite loop if the just sent event is directly fed into back into the sequencer. This can happen if the synthesizer that is connected to the MIDI port also performs a MIDI THRU function, or if (because of wiring error) the MIDI output is directly connected by a MIDI lead to the MIDI input port.

This scenario can also happen between sequencer clients. Or with a sequencer application that is recording (or even worse: echo-ing) the data it just had played.

This 'short circuit situation' of continuous feedback suffocates the system and can might even hang the system.

How should this situation be prevented???

Perhaps limit the amount of data send/received? (bad idea: with this can't handle bursts of data anymore.)

Or pass all these events, and limit the number of events handled per interrupt. That will at least prevent a 'hanging' operating system. This last option is preferred as it tolerates abuse of the system in case one intentionally want to.
Version 0.036, April 2nd, 1999Usage:
Copyright (c) 1998 by Frank van de Pol, NetherlandsAdvanced Linux Sound Architecture