panic running customtype.go on windows

[tcoopman]

When running customtype.go on windows I get following output:

I just tried running customtype.go on windows and I get an panic...

Text changed...
panic: invalid memory address or nil pointer dereference
fatal error: panic during malloc
[signal 0xc0000005 code=0x0 addr=0x20 pc=0x41b2aa]

runtime stack:
runtime.panic(0x4cf6c0, 0x60c338)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/panic.c:233 +0x2b
runtime: unexpected return pc for runtime.sigpanic called from 0x6fcaef11

goroutine 4 [syscall]:
runtime.cgocall(0x487e4b, 0x3056d4)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/cgocall.c:149 +0x10c fp=0x3056c8
github.com/niemeyer/qml._Cfunc_objectGoAddr(0x25a7660, 0x13120358, 0x4b4240)
        C:/Users/THOMAS~1.PC1/AppData/Local/Temp/go-build936011503/github.com/niemeyer/qml/_obj/_cgo_defun.c:376 +0x33 fp=0x3056d4
github.com/niemeyer/qml.func┬╖016()
        c:/GoExt/src/github.com/niemeyer/qml/qml.go:384 +0x58 fp=0x3056f4github.com/niemeyer/qml.hookIdleTimer()
        c:/GoExt/src/github.com/niemeyer/qml/bridge.go:163 +0x53 fp=0x30570c
----- stack segment boundary -----
runtime.cgocallbackg1()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/cgocall.c:296 +0xb4 fp=0x305770
runtime.cgocallbackg()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/cgocall.c:266 +0x7a fp=0x305778
runtime.cgocallback_gofunc(0x403cb0, 0x48796b, 0x3057c4)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/asm_386.s:676 +0x57 fp=0x305788
runtime.asmcgocall(0x48796b, 0x3057c4)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/asm_386.s:584 +0x22 fp=0x30578c
runtime.cgocall(0x48796b, 0x3057c4)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/cgocall.c:149 +0x120 fp=0x3057b8
github.com/niemeyer/qml._Cfunc_applicationExec(0x6139a0)
        C:/Users/THOMAS~1.PC1/AppData/Local/Temp/go-build936011503/github.com/niemeyer/qml/_obj/_cgo_defun.c:61 +0x33 fp=0x3057c4
github.com/niemeyer/qml.guiLoop()
        c:/GoExt/src/github.com/niemeyer/qml/bridge.go:34 +0x54 fp=0x3057ccruntime.goexit()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/proc.c:1394 fp=0x3057d0
created by github.com/niemeyer/qml.Init
        c:/GoExt/src/github.com/niemeyer/qml/qml.go:58 +0x8c

goroutine 1 [chan receive]:
github.com/niemeyer/qml.gui(0x13129260)
        c:/GoExt/src/github.com/niemeyer/qml/bridge.go:62 +0x94
github.com/niemeyer/qml.(*Common).Interface(0x13120300, 0x0, 0x26c8c8)
        c:/GoExt/src/github.com/niemeyer/qml/qml.go:387 +0x93
main.run(0x0, 0x1)
        c:/Workspace/goqml/qml/examples/customtype/customtype.go:47 +0x120
main.main()
        c:/Workspace/goqml/qml/examples/customtype/customtype.go:10 +0x20

goroutine 3 [syscall]:
runtime.goexit()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist738819395/go/src/pkg/runtime/proc.c:1394
exit status 2

[tcoopman]

I've looked into this issue some more and found that the exact location of the cast is in capi.cpp at objectGoAddr running:

GoValue *goValue = dynamic_cast<GoValue *>(qobject);

As I was running go1.2rc4 before, I've tried running this with go1.2rc1 and I've got a different error:
(it looks like this was changed by this issue: https://code.google.com/p/go/issues/detail?id=6419)

Text changed...
2013/11/14 10:04:18 capi.cpp:489: 0x3aa2dd8 //output of qDebug() << object
2013/11/14 10:04:18 capi.cpp:491: GoType(0x3aa2dd8) //output of qDebug() << qobject
fatal error: malloc/free - deadlock
[signal 0xc0000005 code=0x0 addr=0x10 pc=0x41b30a]

runtime stack:
runtime: unexpected return pc for runtime.sigpanic called from 0x6fcaef11
runtime.throw(0x6101e0)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/panic.c:464 +0x67
runtime.mallocgc(0x8, 0x0, 0x0)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/malloc.goc:51 +0x4f
runtime.mal(0x8)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/malloc.goc:700 +0x3a
copyin(0x4cfba0, 0x18d808, 0x18d814)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/iface.c:153 +0x5c
runtime.convT2E(0x4cfba0, 0x60f36f, 0x31, 0x4cfba0, 0x31)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/iface.c:221 +0x32
runtime.newErrorString(0x60f36f, 0x31, 0x18d830)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/error.go:74 +0x3a
runtime.panicstring(0x60f36f)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/panic.c:477 +0x82
runtime.sigpanic()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/os_windows.c:337 +0xb4
runtime.mallocgc(0x8, 0x0, 0x0)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/malloc.goc:70 +0xca
runtime.mal(0x8)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/malloc.goc:700 +0x3a
copyin(0x4cfba0, 0x18d8d0, 0x18d8dc)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/iface.c:153 +0x5c
runtime.convT2E(0x4cfba0, 0x60f358, 0x16, 0x4cfba0, 0x16)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/iface.c:221 +0x32
runtime.newErrorString(0x60f358, 0x16, 0x18d8f8)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/error.go:74 +0x3a
runtime.panicstring(0x60f358)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/panic.c:477 +0x82
runtime: unexpected return pc for runtime.sigpanic called from 0x6fcaef11
runtime.sigpanic()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/os_windows.c:336 +0xa7

goroutine 4 [syscall]:
runtime.cgocallbackg()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/cgocall.c:267 +0x7f fp=0x344e2c
runtime.cgocallback_gofunc(0x403af0, 0x4882eb, 0x344e78)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/asm_386.s:676 +0x57 fp=0x344e3c
runtime.asmcgocall(0x4882eb, 0x344e78)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/asm_386.s:584 +0x22 fp=0x344e40
runtime.cgocall(0x4882eb, 0x344e78)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/cgocall.c:149 +0x120 fp=0x344e6c
github.com/niemeyer/qml._Cfunc_objectGoAddr(0x3aa2dd8, 0x14450358, 0x1)
        C:/Users/THOMAS~1.PC1/AppData/Local/Temp/go-build007705559/github.com/niemeyer/qml/_obj/_cgo_defun.c:376 +0x33 fp=0x344e78
github.com/niemeyer/qml.func┬╖016()
        c:/Workspace/goqml/src/github.com/niemeyer/qml/qml.go:387 +0x19d fp=0x344ef4
github.com/niemeyer/qml.hookIdleTimer()
        c:/Workspace/goqml/src/github.com/niemeyer/qml/bridge.go:163 +0x53 fp=0x344f0c
----- stack segment boundary -----
runtime.cgocallbackg1()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/cgocall.c:296 +0xb4 fp=0x344f70
runtime.cgocallbackg()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/cgocall.c:266 +0x7a fp=0x344f78
runtime.cgocallback_gofunc(0x403af0, 0x487e0b, 0x344fc4)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/asm_386.s:676 +0x57 fp=0x344f88
runtime.asmcgocall(0x487e0b, 0x344fc4)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/asm_386.s:584 +0x22 fp=0x344f8c
runtime.cgocall(0x487e0b, 0x344fc4)
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/cgocall.c:149 +0x120 fp=0x344fb8
github.com/niemeyer/qml._Cfunc_applicationExec(0x616960)
        C:/Users/THOMAS~1.PC1/AppData/Local/Temp/go-build007705559/github.com/niemeyer/qml/_obj/_cgo_defun.c:61 +0x33 fp=0x344fc4
github.com/niemeyer/qml.guiLoop()
        c:/Workspace/goqml/src/github.com/niemeyer/qml/bridge.go:33 +0x54 fp=0x344fcc
runtime.goexit()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runtime/proc.c:1389 fp=0x344fd0
created by github.com/niemeyer/qml.Init
        c:/Workspace/goqml/src/github.com/niemeyer/qml/qml.go:58 +0x8c

goroutine 1 [chan receive]:
github.com/niemeyer/qml.gui(0x14452270)
        c:/Workspace/goqml/src/github.com/niemeyer/qml/bridge.go:62 +0x94
github.com/niemeyer/qml.(*Common).Interface(0x14450300, 0x0, 0x26c188)
        c:/Workspace/goqml/src/github.com/niemeyer/qml/qml.go:395 +0x93
main.run(0x0, 0x1)
        c:/Workspace/goqml/src/github.com/niemeyer/qml/examples/customtype/customtype.go:47 +0x120
main.main()
        c:/Workspace/goqml/src/github.com/niemeyer/qml/examples/customtype/customtype.go:10 +0x20

goroutine 3 [syscall]:
runtime.goexit()
        C:/Users/ADMINI~1/AppData/Local/Temp/2/bindist351444495/go/src/pkg/runti
me/proc.c:1389
exit status 2

[niemeyer]

Can you still reproduce this issue after the recent changes?

[niemeyer]

I'm closing this for the time being. Please reopen if you can reproduce the issue with Go 1.2 final.

[niemeyer]

Reopening as there was another report for this same bug:

https://groups.google.com/d/msg/go-qml/j-5Zdb7Lo7g/Q9RNRI2Atm0J

[niemeyer]

The fix on adf30a8 was confirmed to solve the problem.

[xlab]

Reproduced... https://groups.google.com/d/msg/go-qml/jwgVTL3TFzU/jEeTndgCV2wJ

[niemeyer]

Thanks, I'll review the bug and see if there's something I can identify in that code path.

[xlab]

https://github.com/xlab/goqml-customtype-fail here is a minimal PoC. Works as expected under go1.2.1 OSX, but fails under Windows mingw 4.8.1 go 1.2.1.
After a bit of experimenting, it can be clearly seen that these methods failing in cgo backend: objectGetProperty, objectFindChild, and in case like original Interface() call - objectGoAddr. Hope this helps.

[niemeyer]

Can you please provide the failure traceback for that specific example?

Thanks!

On Wed, Apr 30, 2014 at 4:28 PM, Maxim Kouprianov
notifications@github.comwrote:

https://github.com/xlab/goqml-customtype-fail here is a minimal PoC.
Works as expected under go1.2.1 OSX, but fails under Windows mingw 4.8.1 go
1.2.1.
After a bit of experimenting, it can be clearly seen that these methods
failing in cgo backend: objectGetProperty, objectFindChild, and in
case like original Interface() call - objectGoAddr. Hope this helps.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/19#issuecomment-41863928
.

gustavo @ http://niemeyer.net