Panic

[captncraig]

I am getting a really odd panic:

fatal error: unexpected signal during runtime execution
[signal 0xc0000005 code=0x0 addr=0xb69709e590 pc=0x425875]

goroutine 25 [running]:
runtime.throw(0xa18620)
c:/go/src/pkg/runtime/panic.c:520 +0x7e fp=0x3cf6f0 sp=0x3cf6d8
runtime.sigpanic()
c:/go/src/pkg/runtime/os_windows.c:352 +0x4b fp=0x3cf708 sp=0x3cf6f0
runtime.mallocgc(0x50, 0x6892c1, 0x1)
c:/go/src/pkg/runtime/malloc.goc:154 +0x365 fp=0x3cf770 sp=0x3cf708
cnew(0x6892c0, 0x12, 0x1)
c:/go/src/pkg/runtime/malloc.goc:836 +0xc8 fp=0x3cf790 sp=0x3cf770
runtime.cnewarray(0x6892c0, 0x12)
c:/go/src/pkg/runtime/malloc.goc:849 +0x41 fp=0x3cf7b0 sp=0x3cf790
makeslice1(0x67a320, 0x12, 0x12, 0x3cf810)
c:/go/src/pkg/runtime/slice.goc:55 +0x54 fp=0x3cf7c8 sp=0x3cf7b0
runtime.makeslice(0x67a320, 0x12, 0x12, 0x0, 0x12, 0x12)
c:/go/src/pkg/runtime/slice.goc:36 +0xba fp=0x3cf7f8 sp=0x3cf7c8
unicode/utf16.Decode(0xc082122510, 0x12, 0x12, 0x0, 0x0, 0x0)
c:/go/src/pkg/unicode/utf16/utf16.go:87 +0x5d fp=0x3cf858 sp=0x3cf7f8
github.com/denisenkom/go-mssqldb.ucs22str(0xc0820109c0, 0x24, 0xc8, 0x0, 0x0, 0x0, 0x0)
D:/GoPath/src/github.com/denisenkom/go-mssqldb/tds.go:315 +0x3cb fp=0x3cf9c8 sp=0x3cf858
github.com/denisenkom/go-mssqldb.decodeUcs2(0xc0820109c0, 0x24, 0xc8, 0x0, 0x0)
D:/GoPath/src/github.com/denisenkom/go-mssqldb/types.go:767 +0x6b fp=0x3cfa68 sp=0x3cf9c8
github.com/denisenkom/go-mssqldb.decodeNChar(0xc0820109c0, 0x24, 0xc8, 0x0, 0x0)
D:/GoPath/src/github.com/denisenkom/go-mssqldb/types.go:775 +0x54 fp=0x3cfa98 sp=0x3cfa68
github.com/denisenkom/go-mssqldb.readShortLenType(0xc08212d818, 0xc082006840, 0x0, 0x0)
D:/GoPath/src/github.com/denisenkom/go-mssqldb/types.go:352 +0x2b3 fp=0x3cfb70 sp=0x3cfa98
github.com/denisenkom/go-mssqldb.parseRow(0xc082006840, 0xc0821a6240, 0x2, 0x2, 0xc082067760, 0x2, 0x2)
D:/GoPath/src/github.com/denisenkom/go-mssqldb/token.go:254 +0xd9 fp=0x3cfc38 sp=0x3cfb70
github.com/denisenkom/go-mssqldb.processResponse(0xc08200c660, 0xc08202e6e0)
D:/GoPath/src/github.com/denisenkom/go-mssqldb/token.go:362 +0x857 fp=0x3cff98 sp=0x3cfc38
runtime.goexit()
c:/go/src/pkg/runtime/proc.c:1445 fp=0x3cffa0 sp=0x3cff98
created by github.com/denisenkom/go-mssqldb.(*MssqlStmt).Query
D:/GoPath/src/github.com/denisenkom/go-mssqldb/mssql.go:212 +0x104
.... My code....

goroutine 16 [runnable]:
github.com/denisenkom/go-mssqldb.(_MssqlRows).Next(0xc082122180, 0xc08211e4a0, 0x2, 0x2, 0x0, 0x0)
D:/GoPath/src/github.com/denisenkom/go-mssqldb/mssql.go:275 +0x8d
database/sql.(_Rows).Next(0xc08200d5c0, 0x2)
c:/go/src/pkg/database/sql/sql.go:1542 +0xec
.... My code....

goroutine 19 [finalizer wait]:
runtime.park(0x416380, 0xa214d0, 0xa1f629)
c:/go/src/pkg/runtime/proc.c:1369 +0xac
runtime.parkunlock(0xa214d0, 0xa1f629)
c:/go/src/pkg/runtime/proc.c:1385 +0x42
runfinq()
c:/go/src/pkg/runtime/mgc0.c:2644 +0xdd
runtime.goexit()
c:/go/src/pkg/runtime/proc.c:1445

goroutine 20 [chan receive]:
database/sql.(*DB).connectionOpener(0xc082046400)
c:/go/src/pkg/database/sql/sql.go:583 +0x4f
created by database/sql.Open
c:/go/src/pkg/database/sql/sql.go:442 +0x283

It is a bit hard to replicate as it appears to be somewhat dependant on data, although I can't find a pattern to trigger it.

My query is "Select top(100) name,value from MyTable" where name is nvarchar(100) and value is int. I am scanning the columns into a string and int. It will work for some number of rows, and then panic.

[dimdin]

Please post the stack trace to the go-nuts list with your go version.

[captncraig]

I did. They think it is heap corruption. I have a pretty simple replication, that hopefully you can reproduce.

https://gist.github.com/captncraig/dfb0224ff4dfab1022e6

Basically tries to read invalid columns from a table, and then it panics in fmt.Println while trying to print the error that Query returns.

Go 1.3.1 on Windows 8.1 to Sql server 2012.

[dimdin]

The heap corruption might be from the single-sign-on code. Can you try using SQL server authentication?

[captncraig]

That seems reasonable. It does not occur with sql authentication, nor does it occur if I set

GODEBUG=efence=1

[dimdin]

@captncraig Please try with the latest version.