Panic on server shutdown #1504
Description
I encounter this panic when shutting down the server.
The steps are:
- start server
- get index page with firefox
- send sigint (invalidates the context)
- see panic
Server setup/shutdown:
lis, err := net.Listen("tcp", "localhost:8080")
if err != nil {
glog.Errorf("failed to listen on %s: %v", ":8080", err)
return
}
srv := &fasthttp.Server{
Handler: handler.RootHandler,
MaxConnsPerIP: 1,
MaxRequestBodySize: 260 * 1024 * 1024,
DisablePreParseMultipartForm: true,
StreamRequestBody: true,
TLSConfig: &tls.Config{},
}
httpErr := make(chan error)
go func() {
httpErr <- srv.Serve(lis)
}()
select {
case err = <-httpErr:
if err != nil {
glog.Errorf("server encoutered an error. not good: %v", err) // TODO: might want to rephrase this
}
errchan <- err
fmt.Println(err)
case <-ctx.Done():
ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
srv.ShutdownWithContext(ctx)
cancel()
return
}The panic I get is:
panic: BUG: negative per-ip counter=-1 for ip=2130706433
goroutine 6 [running]:
github.com/valyala/fasthttp.(*perIPConnCounter).Unregister(0xc0001660e8, 0x68cd0?)
github.com/valyala/fasthttp@v1.44.0/peripconn.go:35 +0x179
github.com/valyala/fasthttp.(*perIPConn).Close(0xc00030e000)
github.com/valyala/fasthttp@v1.44.0/peripconn.go:70 +0x4d
github.com/valyala/fasthttp.(*Server).closeIdleConns(0xc000166000)
github.com/valyala/fasthttp@v1.44.0/server.go:2904 +0x10f
github.com/valyala/fasthttp.(*Server).ShutdownWithContext(0xc000166000, {0x673328, 0xc00011a600})
github.com/valyala/fasthttp@v1.44.0/server.go:1907 +0x272
main.httpListener({0x6732b8, 0xc000090140}, 0x0?, 0xc00010e000)
mpldr.codes/tarbash/main.go:71 +0x408
main.main.func1()
mpldr.codes/tarbash/main.go:32 +0xcd
created by main.main
mpldr.codes/tarbash/main.go:30 +0x111
At times I also get this:
^Cpanic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x5ae6c4]
goroutine 22 [running]:
github.com/valyala/fasthttp.(*perIPConn).Close(0xc000110080)
github.com/valyala/fasthttp@v1.44.0/peripconn.go:69 +0x24
github.com/valyala/fasthttp.(*workerPool).workerFunc(0xc000120140, 0xc0001100c0)
github.com/valyala/fasthttp@v1.44.0/workerpool.go:238 +0x374
github.com/valyala/fasthttp.(*workerPool).getCh.func1()
github.com/valyala/fasthttp@v1.44.0/workerpool.go:196 +0x38
created by github.com/valyala/fasthttp.(*workerPool).getCh
github.com/valyala/fasthttp@v1.44.0/workerpool.go:195 +0x1b0
But the latter is only sometimes.