golang http server panic recover //StateHijacked, https://launchdarkly.com/blog/golang-pearl-its-dangerous-to-go-alone

GoSafe.go

import (
  "github.com/launchdarkly/foundation/logger"
  "runtime"
)
 
func GoSafely(fn func()) {
  go func() {
 
    defer func() {
      if err := recover(); err != nil {
        stack := make([]byte, 1024*8)
        stack = stack[:runtime.Stack(stack, false)]
 
        f := "PANIC: %s\n%s"
        logger.Logger.Error().Printf(f, err, stack)
      }
    }()
 
    fn()
  }()
}

recover.go

	defer func() {
		if err := recover(); err != nil {
			const size = 64 << 10
			buf := make([]byte, size)
			buf = buf[:runtime.Stack(buf, false)]
			c.server.logf("http: panic serving %v: %v\n%s", c.remoteAddr, err, buf)
		}
		if !c.hijacked() {
			c.close()
			c.setState(origConn, StateClosed)
		}
	}()

statedef.go

type ConnState int

const (
	// StateNew represents a new connection that is expected to
	// send a request immediately. Connections begin at this
	// state and then transition to either StateActive or
	// StateClosed.
	StateNew ConnState = iota

	// StateActive represents a connection that has read 1 or more
	// bytes of a request. The Server.ConnState hook for
	// StateActive fires before the request has entered a handler
	// and doesn't fire again until the request has been
	// handled. After the request is handled, the state
	// transitions to StateClosed, StateHijacked, or StateIdle.
	StateActive

	// StateIdle represents a connection that has finished
	// handling a request and is in the keep-alive state, waiting
	// for a new request. Connections transition from StateIdle
	// to either StateActive or StateClosed.
	StateIdle

	// StateHijacked represents a hijacked connection.
	// This is a terminal state. It does not transition to StateClosed.
	StateHijacked

	// StateClosed represents a closed connection.
	// This is a terminal state. Hijacked connections do not
	// transition to StateClosed.
	StateClosed
)