Call runtime.LockOSThread automatically in NewQApplication

[mappu]

Wow. Indeed, calling runtime.LockOSThread() before NewQApplication seems to make it always work.

Originally posted by @ilius in #68 (reply in thread)

[ilius]

Although if NewQApplication itself is called in another function which is called in main(), this may not fix the problem (I had that issue in FreeBSD).
I think runtime.LockOSThread() should be called directly inside main().

[mappu]

@ilius Are you sure?

The documentation for LockOSThread says it should affect the entire goroutine indefinitely. It doesn't stop taking effect when returning from the function, it only stops taking effect when explicitly unlocking with UnlockOSThread.

But, real experience beats documentation.

Sorry to bother you but since I can't currently reproduce this, would you be able to remove your own calls to LockOSThread and try the branch from #83 ?

[ilius]

I got this error with #84 on FreeBSD.
https://gist.github.com/ilius/48a96df3d4acd5cb06757f77dcbb7ceb

Then I ran sudo rm -rf $GOPATH/pkg/mod/github.com/mappu/miqt\@v0.* and go build again, but it finished quickly.
So I ran rm -rf ~/.cache/go-build/ and go build again, and I got the same error as above.

[ilius]

I get this error on master as well.
I might have updated my Qt since last build.
How to fix it?

[mappu]

Cannot mix incompatible Qt library (6.7.3) with this library (6.7.2)

I think this is caused by a mismatched version of your qt6 and qt6-multimedia packages. Really they should have the same version. Can you check in your package manager if there are more updates?

[ilius]

They are both 6.7.3, the latest version in FreeBSD repo.

[ilius]

Oh, qt6-base was older.

[ilius]

FreeBSD's pkg is not as clever as Linux's apt or dnf I guess!

[ilius]

Moving runtime.LockOSThread out of main() func to before qt.NewQMainWindow works now.
Maybe I was doing something wrong before!

Also #83 without runtime.LockOSThread works.

Next I reverted back miqt to master (still no runtime.LockOSThread), compiled and ran, this time with no error! But the app window does not show up! Did they change something in Qt 4.7.3 that caused this (it sounds worse!).
Edit: tried for 3rd time and got the old Cannot create children for a parent that is in a different thread error.

Anyway, #83 fixes it.

[mappu]

Thank you @ilius for the extra testing. It is difficult to reproduce this intermittent issue, so I'm really glad to hear that #83 solved the issue for you.