runtime panic with last key input update for #517

[simonklee]

6111cef update with gl input keys update causes panic (while
5ce0dd5 works fine).

> pwd
/home/simon/src/engo.io/engo/demos/hud

> go run -tags demo hud.go
2018/03/21 07:06:55 Using standard inputs
fatal error: unexpected signal during runtime execution
[signal SIGSEGV: segmentation violation code=0x1 addr=0x678 pc=0x7fa08d7da729]

runtime stack:
runtime.throw(0x6a9f48, 0x2a)
	/usr/local/go/src/runtime/panic.go:619 +0x81
runtime.sigpanic()
	/usr/local/go/src/runtime/signal_unix.go:372 +0x28e
runtime.asmcgocall(0x11, 0xc420059b98)
	/usr/local/go/src/runtime/asm_amd64.s:692 +0x70

goroutine 1 [syscall]:
runtime.cgocall(0x5c8880, 0xc420059b38, 0x100000000475533)
	/usr/local/go/src/runtime/cgocall.go:128 +0x64 fp=0xc420059af0 sp=0xc420059ab8 pc=0x43f0e4
github.com/go-gl/gl/v2.1/gl._Cfunc_glowClearColor(0x7fa08d7da720, 0x3f8000003f800000, 0x3f8000003f800000)
	_cgo_gotypes.go:7754 +0x45 fp=0xc420059b38 sp=0xc420059af0 pc=0x4f16c5
github.com/go-gl/gl/v2.1/gl.ClearColor(0x3f8000003f800000, 0x3f8000003f800000)
	/home/simon/src/github.com/go-gl/gl/v2.1/gl/package.go:18348 +0x5d fp=0xc420059b60 sp=0xc420059b38 pc=0x4f424d
engo.io/gl.(*Context).ClearColor(0xc4200fe000, 0x3f8000003f800000, 0x3f8000003f800000)
	/home/simon/src/engo.io/gl/gl_gl2.go:918 +0x51 fp=0xc420059b80 sp=0xc420059b60 pc=0x536591
engo.io/engo/common.SetBackground(0x6c3ee0, 0xc4200a60f8)
	/home/simon/src/engo.io/engo/common/render.go:289 +0xba fp=0xc420059ba8 sp=0xc420059b80 pc=0x5ac0aa
main.(*DefaultScene).Setup(0x9d3c20, 0x6c39c0, 0xc42009e100)
	/home/simon/src/engo.io/engo/demos/hud/hud.go:30 +0x7d fp=0xc420059c30 sp=0xc420059ba8 pc=0x5bb4bd
engo.io/engo.SetScene(0x6c4ca0, 0x9d3c20, 0x542f00)
	/home/simon/src/engo.io/engo/scene.go:106 +0x289 fp=0xc420059c78 sp=0xc420059c30 pc=0x543b89
engo.io/engo.RunPreparation(0x6c4ca0, 0x9d3c20)
	/home/simon/src/engo.io/engo/engo_glfw.go:244 +0x54 fp=0xc420059ca0 sp=0xc420059c78 pc=0x542e64
engo.io/engo.runLoop(0x6c4ca0, 0x9d3c20, 0x300)
	/home/simon/src/engo.io/engo/engo_glfw.go:256 +0x121 fp=0xc420059d88 sp=0xc420059ca0 pc=0x542fb1
engo.io/engo.Run(0x0, 0x6959d2, 0x8, 0x0, 0x320, 0x320, 0x0, 0x3c, 0x100, 0x1, ...)
	/home/simon/src/engo.io/engo/engo.go:206 +0x3e6 fp=0xc420059e68 sp=0xc420059d88 pc=0x541d86
main.main()
	/home/simon/src/engo.io/engo/demos/hud/hud.go:62 +0xe0 fp=0xc420059f88 sp=0xc420059e68 pc=0x5bb860
runtime.main()
	/usr/local/go/src/runtime/proc.go:198 +0x212 fp=0xc420059fe0 sp=0xc420059f88 pc=0x4677f2
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:2361 +0x1 fp=0xc420059fe8 sp=0xc420059fe0 pc=0x491df1

goroutine 35 [syscall]:
os/signal.signal_recv(0x0)
	/usr/local/go/src/runtime/sigqueue.go:139 +0xa6
os/signal.loop()
	/usr/local/go/src/os/signal/signal_unix.go:22 +0x22
created by os/signal.init.0
	/usr/local/go/src/os/signal/signal_unix.go:28 +0x41

goroutine 36 [select, locked to thread]:
runtime.gopark(0x6acd10, 0x0, 0x69557e, 0x6, 0x18, 0x1)
	/usr/local/go/src/runtime/proc.go:291 +0x11a
runtime.selectgo(0xc4200af750, 0xc4200800c0)
	/usr/local/go/src/runtime/select.go:392 +0xe50
runtime.ensureSigM.func1()
	/usr/local/go/src/runtime/signal_unix.go:549 +0x1f4
runtime.goexit()
	/usr/local/go/src/runtime/asm_amd64.s:2361 +0x1

goroutine 37 [runnable]:
engo.io/engo.runLoop.func1(0xc4200b4120)
	/home/simon/src/engo.io/engo/engo_glfw.go:251
created by engo.io/engo.runLoop
	/home/simon/src/engo.io/engo/engo_glfw.go:251 +0x103```

[Noofbiz]

Did you press a key before this happened? It looks like it's panicking at gl.ClearColor. I believe go-gl has been having some trouble with the bindings lately, but I thought they were doing it with ogl 4. I'll look into it. Thanks for the report!

[simonklee]

Not that I'm aware of. It panics in less than a second.

[Noofbiz]

Looks like it could be related to go-gl/gl#93, there are a lot of changes to 2.1 in here for some reason. I'll submit an issue there and see. For now, try using go-gl/gl go-gl/gl@eafa86a, it's working for me.

[simonklee]

Thanks for the information. I'll follow your suggestion for now.

[dmitshur]

The original issue report stated:

6111cef update with gl input keys update causes panic (while 5ce0dd5 works fine).

I can reproduce and confirm that. The issue is within this repository, and it's not related to the recent go-gl/gl change.

[dmitshur]

If I add:

func init() {
	runtime.LockOSThread()
}

To engo_glfw.go, the issue seems to be resolved.

[Noofbiz]

Yes, that is exactly right. Right now I've got some weird setup where all my testing is done with gopherjs via Cloud9 so I didn't really look at glfw. Thank you very much!