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.