sendSysEx() on Mac OSX

[denisgottardello]

Hi, my program works well in Linux and Windows. It goes to crash on Mac OS X. After a debug session I can't find the bug. I can send not more than one or two midi massage (on Mac OS X). My opinion is that MIDISendSysex() function is async. Does anyone had the same problem?

[LeStahL]

Could you provide some information on your problem? Useful would be

• steps to reproduce / minimal example
• what did you try?

[waddlesplash]

CC @CodeforEvolution.

[denisgottardello]

Please try it http://www.denisgottardello.it/Test01.zip On windows and Linux no problem. On Mac OS X sometimes works, sometimes goes to crash.

[LeStahL]

You might be right - the request is made with a reference to a temporary (from your functions on_pushButton_clicked and on_pushButton_2_clicked), which is likely the cause for the crash. Those will return and the result of HexStringToByteArray(ui->lineEditNoteOn->text()) becomes invalid - and so does request.data.

Possible options:

• Don't call sendSysEx on temporaries in your non-QMidi code.
• Change QMidi_CoreMidi.cpp to alloc and copy the bytes, then use the completionProc of the request to free them again.

I do not have OS X available for testing, so I'm not the right person to implement such a thing ;)

[denisgottardello]

Solved by changing the code ` MIDISysexSendRequest request; request.bytesToSend = data.length(); request.complete = false; request.completionProc = nullptr; request.completionRefCon = nullptr; request.data = (Byte *)data.constData(); request.destination = fMidiPtrs->destinationId;

MIDISendSysex(&request);`

to ` MIDISysexSendRequest *request= new MIDISysexSendRequest(); request->bytesToSend = data.length(); request->complete = false; request->completionProc = nullptr; request->completionRefCon = nullptr; request->data = (Byte *)data.constData(); request->destination = fMidiPtrs->destinationId;

MIDISendSysex(request);`

When can I delete the object request ? On compile time I have a lot of warnings. Can I add as developer or there is anyone that will improve the code?

[LeStahL]

request->completionProc can be used to delete request again, after passing the pointer there with request->completionRefCon

refer to https://developer.apple.com/documentation/coremidi/midisysexsendrequest

completionProc will be called when you can delete the request.

[LeStahL]

Can I add as developer

@waddlesplash would have to answer that. :)

[waddlesplash]

You can submit a pull request with this, sure. It would be best if the warnings were fixed, and of course you need to write the callback to delete the request.