Closed
Description
This program should run forever. It crashes quickly, because GoroutineProfile is using
the wrong pc/sp combination for the traceback if the corresponding goroutine has just
come out of a system call.
The only workaround is not to call GoroutineProfile. Possible #go121 candidate.
package main
import (
"runtime"
"syscall"
)
func main() {
runtime.GOMAXPROCS(200)
for i := 0; i < 10; i++ {
go func() {
for {
syscall.Close(-1)
}
}()
}
stk := make([]runtime.StackRecord, 1000)
for n := 0;; n++ {
_, ok := runtime.GoroutineProfile(stk)
if !ok {
panic("GoroutineProfile refused")
}
if n&(n-1) == 0 {
println(n)
}
}
}
panic: invalid memory address or nil pointer dereference
fatal error: panic during gc
[signal 0xb code=0x1 addr=0x0 pc=0x1a7f5]
goroutine 1 [running]:
runtime.throw(0x6b1ac)
/Users/rsc/g/go/src/pkg/runtime/panic.c:462 +0x69 fp=0x2210248d40
runtime.panicstring(0x6b5b9)
/Users/rsc/g/go/src/pkg/runtime/panic.c:477 +0x8d fp=0x2210248d68
runtime.sigpanic()
/Users/rsc/g/go/src/pkg/runtime/os_darwin.c:450 +0x16a fp=0x2210248d80
runtime.gentraceback(0x7850, 0x0, 0x0, 0x2100d8ea0, 0x0, ...)
/Users/rsc/g/go/src/pkg/runtime/traceback_x86.c:101 +0x745 fp=0x2210248e40
saveg(0x7850, 0x0, 0x2100d8ea0, 0x210148600)
/Users/rsc/rscgo/src/pkg/runtime/mprof.goc:531 +0x76 fp=0x2210248ea0
runtime.GoroutineProfile(0x210148000, 0x3e8, 0x3e8, 0xc, 0x301)
/Users/rsc/rscgo/src/pkg/runtime/mprof.goc:559 +0x148 fp=0x2210248ee8
main.main()
/Users/rsc/x.go:19 +0xbd fp=0x2210248f48
runtime.main()
/Users/rsc/g/go/src/pkg/runtime/proc.c:220 +0x11f fp=0x2210248fa0
runtime.goexit()
/Users/rsc/g/go/src/pkg/runtime/proc.c:1394 fp=0x2210248fa8