From 8b8880ee3e1cef2b95e5fb3e67bde4beb4066830 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Sun, 9 Feb 2020 16:40:51 +0100
Subject: [PATCH 01/18] Add prefork util

---
 prefork/prefork.go      | 181 ++++++++++++++++++++++++++++++++++++++++
 prefork/prefork_test.go | 162 +++++++++++++++++++++++++++++++++++
 2 files changed, 343 insertions(+)
 create mode 100644 prefork/prefork.go
 create mode 100644 prefork/prefork_test.go

diff --git a/prefork/prefork.go b/prefork/prefork.go
new file mode 100644
index 0000000000..ad83c98adb
--- /dev/null
+++ b/prefork/prefork.go
@@ -0,0 +1,181 @@
+package prefork
+
+import (
+	"flag"
+	"net"
+	"os"
+	"os/exec"
+	"runtime"
+
+	"github.com/valyala/fasthttp"
+	"github.com/valyala/fasthttp/reuseport"
+)
+
+const preforkChildFlag = "prefork-child"
+const defaultNetwork = "tcp4"
+
+var Child bool
+
+// Prefork implements fasthttp server prefork
+//
+// Preforks master process (with all cores) between several child processes
+// increases performance significantly, because Go doesn't have to share
+// and manage memory between cores
+//
+// WARNING: Does not recommended for servers with in-memory cache,
+// because the cache will be duplicated in each process
+type Prefork struct {
+	Addr string
+
+	// The network must be "tcp", "tcp4" or "tcp6".
+	//
+	// By default is "tcp4"
+	Network string
+
+	// Flag to use a listener with reuseport, if not a File Listener will be used
+	//
+	// It's disabled by default
+	Reuseport bool
+
+	ServeFunc         func(ln net.Listener) error
+	ServeTLSFunc      func(ln net.Listener, certFile, keyFile string) error
+	ServeTLSEmbedFunc func(ln net.Listener, certData, keyData []byte) error
+
+	ln    net.Listener
+	files []*os.File
+}
+
+func init() { // nolint:gochecknoinits
+	flag.BoolVar(&Child, preforkChildFlag, false, "is child proc")
+}
+
+// New wraps the fasthttp server to run with prefork processes
+func New(s *fasthttp.Server) *Prefork {
+	return &Prefork{
+		Network:           defaultNetwork,
+		ServeFunc:         s.Serve,
+		ServeTLSFunc:      s.ServeTLS,
+		ServeTLSEmbedFunc: s.ServeTLSEmbed,
+	}
+}
+
+func (p *Prefork) listen() (net.Listener, error) {
+	runtime.GOMAXPROCS(1)
+
+	if p.Network == "" {
+		p.Network = defaultNetwork
+	}
+
+	if p.Reuseport {
+		return reuseport.Listen(p.Network, p.Addr)
+	}
+
+	return net.FileListener(os.NewFile(3, ""))
+}
+
+func (p *Prefork) setTCPListenerFiles() error {
+	addr, err := net.ResolveTCPAddr(p.Network, p.Addr)
+	if err != nil {
+		return err
+	}
+
+	tcplistener, err := net.ListenTCP(p.Network, addr)
+	if err != nil {
+		return err
+	}
+
+	p.ln = tcplistener
+
+	fl, err := tcplistener.File()
+	if err != nil {
+		return err
+	}
+
+	p.files = []*os.File{fl}
+
+	return nil
+}
+
+func (p *Prefork) prefork() error {
+	strCmd := os.Args[0]
+	chErr := make(chan error, 1)
+
+	if !p.Reuseport {
+		if err := p.setTCPListenerFiles(); err != nil {
+			return err
+		}
+
+		defer p.ln.Close()
+	}
+
+	for i := 0; i < runtime.NumCPU(); i++ {
+		cmd := exec.Command(strCmd, append(os.Args[1:], "-"+preforkChildFlag)...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		cmd.ExtraFiles = p.files
+
+		go func() {
+			chErr <- cmd.Run()
+		}()
+	}
+
+	return <-chErr
+}
+
+// ListenAndServe serves HTTP requests from the given TCP addr
+func (p *Prefork) ListenAndServe(addr string) error {
+	p.Addr = addr
+
+	if Child {
+		ln, err := p.listen()
+		if err != nil {
+			return err
+		}
+
+		p.ln = ln
+
+		return p.ServeFunc(ln)
+	}
+
+	return p.prefork()
+}
+
+// ListenAndServeTLS serves HTTPS requests from the given TCP addr
+//
+// certFile and keyFile are paths to TLS certificate and key files.
+func (p *Prefork) ListenAndServeTLS(addr, certKey, certFile string) error {
+	p.Addr = addr
+
+	if Child {
+		ln, err := p.listen()
+		if err != nil {
+			return err
+		}
+
+		p.ln = ln
+
+		return p.ServeTLSFunc(ln, certFile, certKey)
+	}
+
+	return p.prefork()
+}
+
+// ListenAndServeTLSEmbed serves HTTPS requests from the given TCP addr
+//
+// certData and keyData must contain valid TLS certificate and key data.
+func (p *Prefork) ListenAndServeTLSEmbed(addr string, certData, keyData []byte) error {
+	p.Addr = addr
+
+	if Child {
+		ln, err := p.listen()
+		if err != nil {
+			return err
+		}
+
+		p.ln = ln
+
+		return p.ServeTLSEmbedFunc(ln, certData, keyData)
+	}
+
+	return p.prefork()
+}
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
new file mode 100644
index 0000000000..1703582fbb
--- /dev/null
+++ b/prefork/prefork_test.go
@@ -0,0 +1,162 @@
+package prefork
+
+import (
+	"fmt"
+	"math/rand"
+	"net"
+	"reflect"
+	"runtime"
+	"testing"
+
+	"github.com/valyala/fasthttp"
+)
+
+func getAddr() string {
+	Child = true
+
+	return fmt.Sprintf(":%d", rand.Intn(9000-3000)+3000)
+}
+
+func Test_New(t *testing.T) {
+	s := &fasthttp.Server{}
+	p := New(s)
+
+	if p.Network != defaultNetwork {
+		t.Errorf("Prefork.Netork == %s, want %s", p.Network, defaultNetwork)
+	}
+
+	if reflect.ValueOf(p.ServeFunc).Pointer() != reflect.ValueOf(s.Serve).Pointer() {
+		t.Errorf("Prefork.ServeFunc == %p, want %p", p.ServeFunc, s.Serve)
+	}
+
+	if reflect.ValueOf(p.ServeTLSFunc).Pointer() != reflect.ValueOf(s.ServeTLS).Pointer() {
+		t.Errorf("Prefork.ServeTLSFunc == %p, want %p", p.ServeTLSFunc, s.ServeTLS)
+	}
+
+	if reflect.ValueOf(p.ServeTLSEmbedFunc).Pointer() != reflect.ValueOf(s.ServeTLSEmbed).Pointer() {
+		t.Errorf("Prefork.ServeTLSFunc == %p, want %p", p.ServeTLSEmbedFunc, s.ServeTLSEmbed)
+	}
+}
+
+func Test_listen(t *testing.T) {
+	p := &Prefork{
+		Addr:      getAddr(),
+		Reuseport: true,
+	}
+	ln, err := p.listen()
+
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	ln.Close()
+
+	if p.Network != defaultNetwork {
+		t.Errorf("Prefork.Network == %s, want %s", p.Network, defaultNetwork)
+	}
+
+	procs := runtime.GOMAXPROCS(0)
+	if procs != 1 {
+		t.Errorf("GOMAXPROCS == %d, want %d", procs, 1)
+	}
+}
+
+func Test_setTCPListenerFiles(t *testing.T) {
+	p := &Prefork{
+		Addr:    getAddr(),
+		Network: defaultNetwork,
+	}
+	err := p.setTCPListenerFiles()
+
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	if p.ln == nil {
+		t.Fatal("Prefork.ln is nil")
+	}
+
+	p.ln.Close()
+
+	if len(p.files) != 1 {
+		t.Errorf("Prefork.files == %d, want %d", len(p.files), 1)
+	}
+}
+
+func Test_ListenAndServe(t *testing.T) {
+	s := &fasthttp.Server{}
+	p := New(s)
+	p.Reuseport = true
+	p.ServeFunc = func(ln net.Listener) error {
+		return nil
+	}
+
+	addr := getAddr()
+
+	err := p.ListenAndServe(addr)
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	p.ln.Close()
+
+	if p.Addr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	}
+
+	if p.ln == nil {
+		t.Error("Prefork.ln is nil")
+	}
+}
+
+func Test_ListenAndServeTLS(t *testing.T) {
+	s := &fasthttp.Server{}
+	p := New(s)
+	p.Reuseport = true
+	p.ServeTLSFunc = func(ln net.Listener, certFile, keyFile string) error {
+		return nil
+	}
+
+	addr := getAddr()
+
+	err := p.ListenAndServeTLS(addr, "./key", "./cert")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	p.ln.Close()
+
+	if p.Addr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	}
+
+	if p.ln == nil {
+		t.Error("Prefork.ln is nil")
+	}
+}
+
+func Test_ListenAndServeTLSEmbed(t *testing.T) {
+	s := &fasthttp.Server{}
+	p := New(s)
+	p.Reuseport = true
+	p.ServeTLSEmbedFunc = func(ln net.Listener, certData, keyData []byte) error {
+		return nil
+	}
+
+	addr := getAddr()
+
+	err := p.ListenAndServeTLSEmbed(addr, []byte("key"), []byte("cert"))
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+
+	p.ln.Close()
+
+	if p.Addr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	}
+
+	if p.ln == nil {
+		t.Error("Prefork.ln is nil")
+	}
+}

From 18d765b23b6a4e533db9f40442e91092a08a32dd Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Sun, 9 Feb 2020 16:53:31 +0100
Subject: [PATCH 02/18] Fix

---
 prefork/prefork.go      | 25 +++++++++++--------------
 prefork/prefork_test.go |  9 +++++++--
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index ad83c98adb..8d0990be3a 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -59,7 +59,9 @@ func New(s *fasthttp.Server) *Prefork {
 	}
 }
 
-func (p *Prefork) listen() (net.Listener, error) {
+func (p *Prefork) listen(addr string) (net.Listener, error) {
+	p.Addr = addr
+
 	runtime.GOMAXPROCS(1)
 
 	if p.Network == "" {
@@ -96,7 +98,8 @@ func (p *Prefork) setTCPListenerFiles() error {
 	return nil
 }
 
-func (p *Prefork) prefork() error {
+func (p *Prefork) prefork(addr string) error {
+	p.Addr = addr
 	strCmd := os.Args[0]
 	chErr := make(chan error, 1)
 
@@ -124,10 +127,8 @@ func (p *Prefork) prefork() error {
 
 // ListenAndServe serves HTTP requests from the given TCP addr
 func (p *Prefork) ListenAndServe(addr string) error {
-	p.Addr = addr
-
 	if Child {
-		ln, err := p.listen()
+		ln, err := p.listen(addr)
 		if err != nil {
 			return err
 		}
@@ -137,17 +138,15 @@ func (p *Prefork) ListenAndServe(addr string) error {
 		return p.ServeFunc(ln)
 	}
 
-	return p.prefork()
+	return p.prefork(addr)
 }
 
 // ListenAndServeTLS serves HTTPS requests from the given TCP addr
 //
 // certFile and keyFile are paths to TLS certificate and key files.
 func (p *Prefork) ListenAndServeTLS(addr, certKey, certFile string) error {
-	p.Addr = addr
-
 	if Child {
-		ln, err := p.listen()
+		ln, err := p.listen(addr)
 		if err != nil {
 			return err
 		}
@@ -157,17 +156,15 @@ func (p *Prefork) ListenAndServeTLS(addr, certKey, certFile string) error {
 		return p.ServeTLSFunc(ln, certFile, certKey)
 	}
 
-	return p.prefork()
+	return p.prefork(addr)
 }
 
 // ListenAndServeTLSEmbed serves HTTPS requests from the given TCP addr
 //
 // certData and keyData must contain valid TLS certificate and key data.
 func (p *Prefork) ListenAndServeTLSEmbed(addr string, certData, keyData []byte) error {
-	p.Addr = addr
-
 	if Child {
-		ln, err := p.listen()
+		ln, err := p.listen(addr)
 		if err != nil {
 			return err
 		}
@@ -177,5 +174,5 @@ func (p *Prefork) ListenAndServeTLSEmbed(addr string, certData, keyData []byte)
 		return p.ServeTLSEmbedFunc(ln, certData, keyData)
 	}
 
-	return p.prefork()
+	return p.prefork(addr)
 }
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
index 1703582fbb..dfa47d892f 100644
--- a/prefork/prefork_test.go
+++ b/prefork/prefork_test.go
@@ -40,10 +40,11 @@ func Test_New(t *testing.T) {
 
 func Test_listen(t *testing.T) {
 	p := &Prefork{
-		Addr:      getAddr(),
 		Reuseport: true,
 	}
-	ln, err := p.listen()
+	addr := getAddr()
+
+	ln, err := p.listen(addr)
 
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
@@ -51,6 +52,10 @@ func Test_listen(t *testing.T) {
 
 	ln.Close()
 
+	if p.Addr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	}
+
 	if p.Network != defaultNetwork {
 		t.Errorf("Prefork.Network == %s, want %s", p.Network, defaultNetwork)
 	}

From fae1d8e3d733858faafb5f8dffc6ce8c8d89c213 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Sun, 9 Feb 2020 16:59:24 +0100
Subject: [PATCH 03/18] Fix

---
 prefork/prefork.go      | 11 ++++++-----
 prefork/prefork_test.go |  9 +++++++--
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index 8d0990be3a..53461af9a8 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -75,13 +75,15 @@ func (p *Prefork) listen(addr string) (net.Listener, error) {
 	return net.FileListener(os.NewFile(3, ""))
 }
 
-func (p *Prefork) setTCPListenerFiles() error {
-	addr, err := net.ResolveTCPAddr(p.Network, p.Addr)
+func (p *Prefork) setTCPListenerFiles(addr string) error {
+	p.Addr = addr
+
+	tcpAddr, err := net.ResolveTCPAddr(p.Network, p.Addr)
 	if err != nil {
 		return err
 	}
 
-	tcplistener, err := net.ListenTCP(p.Network, addr)
+	tcplistener, err := net.ListenTCP(p.Network, tcpAddr)
 	if err != nil {
 		return err
 	}
@@ -99,12 +101,11 @@ func (p *Prefork) setTCPListenerFiles() error {
 }
 
 func (p *Prefork) prefork(addr string) error {
-	p.Addr = addr
 	strCmd := os.Args[0]
 	chErr := make(chan error, 1)
 
 	if !p.Reuseport {
-		if err := p.setTCPListenerFiles(); err != nil {
+		if err := p.setTCPListenerFiles(addr); err != nil {
 			return err
 		}
 
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
index dfa47d892f..a117de69d8 100644
--- a/prefork/prefork_test.go
+++ b/prefork/prefork_test.go
@@ -68,15 +68,20 @@ func Test_listen(t *testing.T) {
 
 func Test_setTCPListenerFiles(t *testing.T) {
 	p := &Prefork{
-		Addr:    getAddr(),
 		Network: defaultNetwork,
 	}
-	err := p.setTCPListenerFiles()
+	addr := getAddr()
+
+	err := p.setTCPListenerFiles(addr)
 
 	if err != nil {
 		t.Fatalf("Unexpected error: %v", err)
 	}
 
+	if p.Addr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	}
+
 	if p.ln == nil {
 		t.Fatal("Prefork.ln is nil")
 	}

From 77bdaf9fb2251617d0e954db067d305dd99db927 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Mon, 10 Feb 2020 09:45:30 +0100
Subject: [PATCH 04/18] Fixes

---
 prefork/prefork.go      | 16 ++++++++--------
 prefork/prefork_test.go |  2 +-
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index 53461af9a8..c38e79d1fc 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -14,7 +14,7 @@ import (
 const preforkChildFlag = "prefork-child"
 const defaultNetwork = "tcp4"
 
-var Child bool
+var child bool
 
 // Prefork implements fasthttp server prefork
 //
@@ -22,8 +22,8 @@ var Child bool
 // increases performance significantly, because Go doesn't have to share
 // and manage memory between cores
 //
-// WARNING: Does not recommended for servers with in-memory cache,
-// because the cache will be duplicated in each process
+// WARNING: using prefork prevents the use of any global state!
+// Things like in-memory caches won't work.
 type Prefork struct {
 	Addr string
 
@@ -46,7 +46,7 @@ type Prefork struct {
 }
 
 func init() { // nolint:gochecknoinits
-	flag.BoolVar(&Child, preforkChildFlag, false, "is child proc")
+	flag.BoolVar(&child, preforkChildFlag, false, "is child proc")
 }
 
 // New wraps the fasthttp server to run with prefork processes
@@ -112,7 +112,7 @@ func (p *Prefork) prefork(addr string) error {
 		defer p.ln.Close()
 	}
 
-	for i := 0; i < runtime.NumCPU(); i++ {
+	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
 		cmd := exec.Command(strCmd, append(os.Args[1:], "-"+preforkChildFlag)...)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
@@ -128,7 +128,7 @@ func (p *Prefork) prefork(addr string) error {
 
 // ListenAndServe serves HTTP requests from the given TCP addr
 func (p *Prefork) ListenAndServe(addr string) error {
-	if Child {
+	if child {
 		ln, err := p.listen(addr)
 		if err != nil {
 			return err
@@ -146,7 +146,7 @@ func (p *Prefork) ListenAndServe(addr string) error {
 //
 // certFile and keyFile are paths to TLS certificate and key files.
 func (p *Prefork) ListenAndServeTLS(addr, certKey, certFile string) error {
-	if Child {
+	if child {
 		ln, err := p.listen(addr)
 		if err != nil {
 			return err
@@ -164,7 +164,7 @@ func (p *Prefork) ListenAndServeTLS(addr, certKey, certFile string) error {
 //
 // certData and keyData must contain valid TLS certificate and key data.
 func (p *Prefork) ListenAndServeTLSEmbed(addr string, certData, keyData []byte) error {
-	if Child {
+	if child {
 		ln, err := p.listen(addr)
 		if err != nil {
 			return err
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
index a117de69d8..099b1f7116 100644
--- a/prefork/prefork_test.go
+++ b/prefork/prefork_test.go
@@ -12,7 +12,7 @@ import (
 )
 
 func getAddr() string {
-	Child = true
+	child = true
 
 	return fmt.Sprintf(":%d", rand.Intn(9000-3000)+3000)
 }

From 082e7156bae1a5cc9a70c731984b8c2e5bfab283 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Mon, 10 Feb 2020 12:22:35 +0100
Subject: [PATCH 05/18] Add README

---
 prefork/README.md | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 prefork/README.md

diff --git a/prefork/README.md b/prefork/README.md
new file mode 100644
index 0000000000..e18377c81f
--- /dev/null
+++ b/prefork/README.md
@@ -0,0 +1,27 @@
+# Prefork
+
+Server prefork implementation.
+
+Preforks master process between several child processes increases performance, because Go doesn't have to share and manage memory between cores.
+
+**WARNING: using prefork prevents the use of any global state!. Things like in-memory caches won't work.**
+
+- How it works:
+
+```go
+import (
+    "github.com/valyala/fasthttp"
+	"github.com/valyala/fasthttp/prefork"
+)
+
+server := &fasthttp.Server{
+    // Your configuration
+}
+
+// Wraps the server with prefork
+preforkServer := prefork.New(server)
+
+if err := preforkServer.ListenAndServe(":8080"); err != nil {
+    panic(err)
+}
+```

From 6dacc602bb1a3a0f59b7ba8fcdbfaa190b01d31d Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Mon, 10 Feb 2020 12:25:19 +0100
Subject: [PATCH 06/18] Fix typo

---
 prefork/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prefork/README.md b/prefork/README.md
index e18377c81f..b4831c3c81 100644
--- a/prefork/README.md
+++ b/prefork/README.md
@@ -11,7 +11,7 @@ Preforks master process between several child processes increases performance, b
 ```go
 import (
     "github.com/valyala/fasthttp"
-	"github.com/valyala/fasthttp/prefork"
+    "github.com/valyala/fasthttp/prefork"
 )
 
 server := &fasthttp.Server{

From c9f06d0d7ecbe39c06ba3da707e937ca3ea8503b Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Mon, 10 Feb 2020 12:59:55 +0100
Subject: [PATCH 07/18] Update README

---
 prefork/README.md | 49 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/prefork/README.md b/prefork/README.md
index b4831c3c81..38b4148c34 100644
--- a/prefork/README.md
+++ b/prefork/README.md
@@ -25,3 +25,52 @@ if err := preforkServer.ListenAndServe(":8080"); err != nil {
     panic(err)
 }
 ```
+
+## Benchmarks
+
+Environment:
+
+- Machine: MacBook Pro 13-inch, 2017
+- OS: MacOS 10.15.3
+- Go: go1.13.6 darwin/amd64
+
+Handler code:
+
+```go
+func requestHandler(ctx *fasthttp.RequestCtx) {
+    // Simulate some hard work
+	time.Sleep(100 * time.Millisecond)
+}
+```
+
+Results:
+
+- **WITH** prefork
+
+```bash
+$ wrk -c 1000 -t 4 -d 30s http://localhost:8080
+Running 30s test @ http://localhost:8080
+  4 threads and 1000 connections
+  Thread Stats   Avg      Stdev     Max   +/- Stdev
+    Latency   104.35ms    1.81ms 114.01ms   73.68%
+    Req/Sec     2.40k   198.27     2.55k    94.19%
+  286846 requests in 30.03s, 25.44MB read
+  Socket errors: connect 0, read 62, write 0, timeout 0
+Requests/sec:   9551.60
+Transfer/sec:    867.48KB
+```
+
+- **WITHOUT** prefork
+
+```bash
+$ wrk -c 1000 -t 4 -d 30s http://localhost:8080
+Running 30s test @ http://localhost:8080
+  4 threads and 1000 connections
+  Thread Stats   Avg      Stdev     Max   +/- Stdev
+    Latency   104.39ms    2.62ms 119.24ms   66.75%
+    Req/Sec     2.13k   581.16     2.65k    83.23%
+  253666 requests in 30.06s, 22.50MB read
+  Socket errors: connect 0, read 903, write 88, timeout 0
+Requests/sec:   8439.21
+Transfer/sec:    766.45KB
+```

From 634c07f47e5431be13aaa7d674e6512586d8d184 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Mon, 10 Feb 2020 13:01:30 +0100
Subject: [PATCH 08/18] Fix typo

---
 prefork/README.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/prefork/README.md b/prefork/README.md
index 38b4148c34..d0744cc1cb 100644
--- a/prefork/README.md
+++ b/prefork/README.md
@@ -38,8 +38,8 @@ Handler code:
 
 ```go
 func requestHandler(ctx *fasthttp.RequestCtx) {
-    // Simulate some hard work
-	time.Sleep(100 * time.Millisecond)
+    // Simulates some hard work
+    time.Sleep(100 * time.Millisecond)
 }
 ```
 

From 5fd2cf7b7f5826a794208a2e3ead54968e19985d Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Tue, 11 Feb 2020 09:24:24 +0100
Subject: [PATCH 09/18] Update README

---
 prefork/README.md | 54 +++++++++++++++++++++++++++++------------------
 1 file changed, 34 insertions(+), 20 deletions(-)

diff --git a/prefork/README.md b/prefork/README.md
index d0744cc1cb..31f2c43c31 100644
--- a/prefork/README.md
+++ b/prefork/README.md
@@ -43,34 +43,48 @@ func requestHandler(ctx *fasthttp.RequestCtx) {
 }
 ```
 
+Test command:
+
+```bash
+$ wrk -H 'Host: localhost' -H 'Accept: text/plain,text/html;q=0.9,application/xhtml+xml;q=0.9,application/xml;q=0.8,*/*;q=0.7' -H 'Connection: keep-alive' --latency -d 15 -c 512 --timeout 8 -t 4 http://localhost:8080
+```
+
 Results:
 
-- **WITH** prefork
+- prefork
 
 ```bash
-$ wrk -c 1000 -t 4 -d 30s http://localhost:8080
-Running 30s test @ http://localhost:8080
-  4 threads and 1000 connections
+Running 15s test @ http://localhost:8080
+  4 threads and 512 connections
   Thread Stats   Avg      Stdev     Max   +/- Stdev
-    Latency   104.35ms    1.81ms 114.01ms   73.68%
-    Req/Sec     2.40k   198.27     2.55k    94.19%
-  286846 requests in 30.03s, 25.44MB read
-  Socket errors: connect 0, read 62, write 0, timeout 0
-Requests/sec:   9551.60
-Transfer/sec:    867.48KB
+    Latency     4.75ms    4.27ms 126.24ms   97.45%
+    Req/Sec    26.46k     4.16k   71.18k    88.72%
+  Latency Distribution
+     50%    4.55ms
+     75%    4.82ms
+     90%    5.46ms
+     99%   15.49ms
+  1581916 requests in 15.09s, 140.30MB read
+  Socket errors: connect 0, read 318, write 0, timeout 0
+Requests/sec: 104861.58
+Transfer/sec:      9.30MB
 ```
 
-- **WITHOUT** prefork
+- **non**-prefork
 
 ```bash
-$ wrk -c 1000 -t 4 -d 30s http://localhost:8080
-Running 30s test @ http://localhost:8080
-  4 threads and 1000 connections
+Running 15s test @ http://localhost:8080
+  4 threads and 512 connections
   Thread Stats   Avg      Stdev     Max   +/- Stdev
-    Latency   104.39ms    2.62ms 119.24ms   66.75%
-    Req/Sec     2.13k   581.16     2.65k    83.23%
-  253666 requests in 30.06s, 22.50MB read
-  Socket errors: connect 0, read 903, write 88, timeout 0
-Requests/sec:   8439.21
-Transfer/sec:    766.45KB
+    Latency     6.42ms   11.83ms 177.19ms   96.42%
+    Req/Sec    24.96k     5.83k   56.83k    82.93%
+  Latency Distribution
+     50%    4.53ms
+     75%    4.93ms
+     90%    6.94ms
+     99%   74.54ms
+  1472441 requests in 15.09s, 130.59MB read
+  Socket errors: connect 0, read 265, write 0, timeout 0
+Requests/sec:  97553.34
+Transfer/sec:      8.65MB
 ```

From 5dc4c2b896e7608c1366f5b26c2e7c7e1e862877 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 11:49:18 +0100
Subject: [PATCH 10/18] Check if is a child from os.Args

---
 prefork/prefork.go      | 27 ++++++++++++++++++---------
 prefork/prefork_test.go | 31 +++++++++++++++++++++++++++++--
 2 files changed, 47 insertions(+), 11 deletions(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index c38e79d1fc..9eb446e2f9 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -11,11 +11,9 @@ import (
 	"github.com/valyala/fasthttp/reuseport"
 )
 
-const preforkChildFlag = "prefork-child"
+const preforkChildFlag = "-prefork-child"
 const defaultNetwork = "tcp4"
 
-var child bool
-
 // Prefork implements fasthttp server prefork
 //
 // Preforks master process (with all cores) between several child processes
@@ -45,8 +43,19 @@ type Prefork struct {
 	files []*os.File
 }
 
-func init() { // nolint:gochecknoinits
-	flag.BoolVar(&child, preforkChildFlag, false, "is child proc")
+func init() { //nolint:gochecknoinits
+	flag.Bool(preforkChildFlag[1:], false, "is a child process")
+}
+
+// IsChild checks if the current thread/process is a child
+func IsChild() bool {
+	for _, arg := range os.Args[1:] {
+		if arg == preforkChildFlag {
+			return true
+		}
+	}
+
+	return false
 }
 
 // New wraps the fasthttp server to run with prefork processes
@@ -113,7 +122,7 @@ func (p *Prefork) prefork(addr string) error {
 	}
 
 	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
-		cmd := exec.Command(strCmd, append(os.Args[1:], "-"+preforkChildFlag)...)
+		cmd := exec.Command(strCmd, append(os.Args[1:], preforkChildFlag)...)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
 		cmd.ExtraFiles = p.files
@@ -128,7 +137,7 @@ func (p *Prefork) prefork(addr string) error {
 
 // ListenAndServe serves HTTP requests from the given TCP addr
 func (p *Prefork) ListenAndServe(addr string) error {
-	if child {
+	if IsChild() {
 		ln, err := p.listen(addr)
 		if err != nil {
 			return err
@@ -146,7 +155,7 @@ func (p *Prefork) ListenAndServe(addr string) error {
 //
 // certFile and keyFile are paths to TLS certificate and key files.
 func (p *Prefork) ListenAndServeTLS(addr, certKey, certFile string) error {
-	if child {
+	if IsChild() {
 		ln, err := p.listen(addr)
 		if err != nil {
 			return err
@@ -164,7 +173,7 @@ func (p *Prefork) ListenAndServeTLS(addr, certKey, certFile string) error {
 //
 // certData and keyData must contain valid TLS certificate and key data.
 func (p *Prefork) ListenAndServeTLSEmbed(addr string, certData, keyData []byte) error {
-	if child {
+	if IsChild() {
 		ln, err := p.listen(addr)
 		if err != nil {
 			return err
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
index 099b1f7116..9a70b7abcb 100644
--- a/prefork/prefork_test.go
+++ b/prefork/prefork_test.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"math/rand"
 	"net"
+	"os"
 	"reflect"
 	"runtime"
 	"testing"
@@ -11,12 +12,38 @@ import (
 	"github.com/valyala/fasthttp"
 )
 
-func getAddr() string {
-	child = true
+func init() { //nolint:gochecknoinits
+	setUp()
+}
+
+func setUp() {
+	os.Args = append(os.Args, preforkChildFlag)
+}
 
+func tearDown() {
+	os.Args = os.Args[:len(os.Args)-1]
+}
+
+func getAddr() string {
 	return fmt.Sprintf(":%d", rand.Intn(9000-3000)+3000)
 }
 
+func Test_IsChild(t *testing.T) {
+	v := IsChild()
+	if !v {
+		t.Errorf("IsChild() == %v, want %v", v, true)
+	}
+
+	tearDown()
+
+	v = IsChild()
+	if v {
+		t.Errorf("IsChild() == %v, want %v", v, false)
+	}
+
+	setUp()
+}
+
 func Test_New(t *testing.T) {
 	s := &fasthttp.Server{}
 	p := New(s)

From 7e62e07d0d0128ca2e5a0a30caf4e7b0acbe930b Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:04:00 +0100
Subject: [PATCH 11/18] Remove Addr field

---
 prefork/prefork.go      | 10 ++--------
 prefork/prefork_test.go | 31 ++++++++++++++++++-------------
 2 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index 9eb446e2f9..bb3f7ea2f8 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -23,8 +23,6 @@ const defaultNetwork = "tcp4"
 // WARNING: using prefork prevents the use of any global state!
 // Things like in-memory caches won't work.
 type Prefork struct {
-	Addr string
-
 	// The network must be "tcp", "tcp4" or "tcp6".
 	//
 	// By default is "tcp4"
@@ -69,8 +67,6 @@ func New(s *fasthttp.Server) *Prefork {
 }
 
 func (p *Prefork) listen(addr string) (net.Listener, error) {
-	p.Addr = addr
-
 	runtime.GOMAXPROCS(1)
 
 	if p.Network == "" {
@@ -78,16 +74,14 @@ func (p *Prefork) listen(addr string) (net.Listener, error) {
 	}
 
 	if p.Reuseport {
-		return reuseport.Listen(p.Network, p.Addr)
+		return reuseport.Listen(p.Network, addr)
 	}
 
 	return net.FileListener(os.NewFile(3, ""))
 }
 
 func (p *Prefork) setTCPListenerFiles(addr string) error {
-	p.Addr = addr
-
-	tcpAddr, err := net.ResolveTCPAddr(p.Network, p.Addr)
+	tcpAddr, err := net.ResolveTCPAddr(p.Network, addr)
 	if err != nil {
 		return err
 	}
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
index 9a70b7abcb..89329ae595 100644
--- a/prefork/prefork_test.go
+++ b/prefork/prefork_test.go
@@ -25,7 +25,7 @@ func tearDown() {
 }
 
 func getAddr() string {
-	return fmt.Sprintf(":%d", rand.Intn(9000-3000)+3000)
+	return fmt.Sprintf("0.0.0.0:%d", rand.Intn(9000-3000)+3000)
 }
 
 func Test_IsChild(t *testing.T) {
@@ -79,8 +79,9 @@ func Test_listen(t *testing.T) {
 
 	ln.Close()
 
-	if p.Addr != addr {
-		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	lnAddr := ln.Addr().String()
+	if lnAddr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", lnAddr, addr)
 	}
 
 	if p.Network != defaultNetwork {
@@ -105,14 +106,15 @@ func Test_setTCPListenerFiles(t *testing.T) {
 		t.Fatalf("Unexpected error: %v", err)
 	}
 
-	if p.Addr != addr {
-		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
-	}
-
 	if p.ln == nil {
 		t.Fatal("Prefork.ln is nil")
 	}
 
+	lnAddr := p.ln.Addr().String()
+	if lnAddr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", lnAddr, addr)
+	}
+
 	p.ln.Close()
 
 	if len(p.files) != 1 {
@@ -137,8 +139,9 @@ func Test_ListenAndServe(t *testing.T) {
 
 	p.ln.Close()
 
-	if p.Addr != addr {
-		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	lnAddr := p.ln.Addr().String()
+	if lnAddr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", lnAddr, addr)
 	}
 
 	if p.ln == nil {
@@ -163,8 +166,9 @@ func Test_ListenAndServeTLS(t *testing.T) {
 
 	p.ln.Close()
 
-	if p.Addr != addr {
-		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	lnAddr := p.ln.Addr().String()
+	if lnAddr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", lnAddr, addr)
 	}
 
 	if p.ln == nil {
@@ -189,8 +193,9 @@ func Test_ListenAndServeTLSEmbed(t *testing.T) {
 
 	p.ln.Close()
 
-	if p.Addr != addr {
-		t.Errorf("Prefork.Addr == %s, want %s", p.Addr, addr)
+	lnAddr := p.ln.Addr().String()
+	if lnAddr != addr {
+		t.Errorf("Prefork.Addr == %s, want %s", lnAddr, addr)
 	}
 
 	if p.ln == nil {

From 0b63ce96acee9a80976c605f86d5b1f3024ef415 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:16:31 +0100
Subject: [PATCH 12/18] Set default network

---
 prefork/prefork.go      |  4 ++++
 prefork/prefork_test.go | 10 ++++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index bb3f7ea2f8..d67a21e8ae 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -81,6 +81,10 @@ func (p *Prefork) listen(addr string) (net.Listener, error) {
 }
 
 func (p *Prefork) setTCPListenerFiles(addr string) error {
+	if p.Network == "" {
+		p.Network = defaultNetwork
+	}
+
 	tcpAddr, err := net.ResolveTCPAddr(p.Network, addr)
 	if err != nil {
 		return err
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
index 89329ae595..4f359dbbf7 100644
--- a/prefork/prefork_test.go
+++ b/prefork/prefork_test.go
@@ -95,9 +95,7 @@ func Test_listen(t *testing.T) {
 }
 
 func Test_setTCPListenerFiles(t *testing.T) {
-	p := &Prefork{
-		Network: defaultNetwork,
-	}
+	p := &Prefork{}
 	addr := getAddr()
 
 	err := p.setTCPListenerFiles(addr)
@@ -110,12 +108,16 @@ func Test_setTCPListenerFiles(t *testing.T) {
 		t.Fatal("Prefork.ln is nil")
 	}
 
+	p.ln.Close()
+
 	lnAddr := p.ln.Addr().String()
 	if lnAddr != addr {
 		t.Errorf("Prefork.Addr == %s, want %s", lnAddr, addr)
 	}
 
-	p.ln.Close()
+	if p.Network != defaultNetwork {
+		t.Errorf("Prefork.Network == %s, want %s", p.Network, defaultNetwork)
+	}
 
 	if len(p.files) != 1 {
 		t.Errorf("Prefork.files == %d, want %d", len(p.files), 1)

From 6a430e80d2eb807ce5259d7fe35b9027d80e671d Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:24:30 +0100
Subject: [PATCH 13/18] Fix typo

---
 prefork/prefork.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index d67a21e8ae..5ee8b1d6ef 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -42,7 +42,7 @@ type Prefork struct {
 }
 
 func init() { //nolint:gochecknoinits
-	flag.Bool(preforkChildFlag[1:], false, "is a child process")
+	flag.Bool(preforkChildFlag[1:], false, "Is a child process")
 }
 
 // IsChild checks if the current thread/process is a child

From a8c75433d1d5b0888c3a2604ef72f4737eeda83a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sergio=20Andr=C3=A9s=20Virviescas=20Santana?=
 <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:39:04 +0100
Subject: [PATCH 14/18] Update prefork/prefork.go

Co-Authored-By: Erik Dubbelboer <erik@dubbelboer.com>
---
 prefork/prefork.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index 5ee8b1d6ef..539b81563f 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -120,7 +120,7 @@ func (p *Prefork) prefork(addr string) error {
 	}
 
 	for i := 0; i < runtime.GOMAXPROCS(0); i++ {
-		cmd := exec.Command(strCmd, append(os.Args[1:], preforkChildFlag)...)
+		cmd := exec.Command(os.Args[0], append(os.Args[1:], preforkChildFlag)...)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
 		cmd.ExtraFiles = p.files

From 49fe00b23ccd9429dbf9b35c62e729df86388fbf Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:44:24 +0100
Subject: [PATCH 15/18] Fixes

---
 prefork/prefork.go      |  2 +-
 prefork/prefork_test.go | 28 ++++++++++++++++++----------
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index 539b81563f..c30badbc27 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -29,6 +29,7 @@ type Prefork struct {
 	Network string
 
 	// Flag to use a listener with reuseport, if not a File Listener will be used
+	// See: https://www.nginx.com/blog/socket-sharding-nginx-release-1-9-1/
 	//
 	// It's disabled by default
 	Reuseport bool
@@ -108,7 +109,6 @@ func (p *Prefork) setTCPListenerFiles(addr string) error {
 }
 
 func (p *Prefork) prefork(addr string) error {
-	strCmd := os.Args[0]
 	chErr := make(chan error, 1)
 
 	if !p.Reuseport {
diff --git a/prefork/prefork_test.go b/prefork/prefork_test.go
index 4f359dbbf7..12f84452db 100644
--- a/prefork/prefork_test.go
+++ b/prefork/prefork_test.go
@@ -12,10 +12,6 @@ import (
 	"github.com/valyala/fasthttp"
 )
 
-func init() { //nolint:gochecknoinits
-	setUp()
-}
-
 func setUp() {
 	os.Args = append(os.Args, preforkChildFlag)
 }
@@ -30,18 +26,18 @@ func getAddr() string {
 
 func Test_IsChild(t *testing.T) {
 	v := IsChild()
-	if !v {
-		t.Errorf("IsChild() == %v, want %v", v, true)
+	if v {
+		t.Errorf("IsChild() == %v, want %v", v, false)
 	}
 
-	tearDown()
+	setUp()
 
 	v = IsChild()
-	if v {
-		t.Errorf("IsChild() == %v, want %v", v, false)
+	if !v {
+		t.Errorf("IsChild() == %v, want %v", v, true)
 	}
 
-	setUp()
+	tearDown()
 }
 
 func Test_New(t *testing.T) {
@@ -125,6 +121,8 @@ func Test_setTCPListenerFiles(t *testing.T) {
 }
 
 func Test_ListenAndServe(t *testing.T) {
+	setUp()
+
 	s := &fasthttp.Server{}
 	p := New(s)
 	p.Reuseport = true
@@ -149,9 +147,13 @@ func Test_ListenAndServe(t *testing.T) {
 	if p.ln == nil {
 		t.Error("Prefork.ln is nil")
 	}
+
+	tearDown()
 }
 
 func Test_ListenAndServeTLS(t *testing.T) {
+	setUp()
+
 	s := &fasthttp.Server{}
 	p := New(s)
 	p.Reuseport = true
@@ -176,9 +178,13 @@ func Test_ListenAndServeTLS(t *testing.T) {
 	if p.ln == nil {
 		t.Error("Prefork.ln is nil")
 	}
+
+	tearDown()
 }
 
 func Test_ListenAndServeTLSEmbed(t *testing.T) {
+	setUp()
+
 	s := &fasthttp.Server{}
 	p := New(s)
 	p.Reuseport = true
@@ -203,4 +209,6 @@ func Test_ListenAndServeTLSEmbed(t *testing.T) {
 	if p.ln == nil {
 		t.Error("Prefork.ln is nil")
 	}
+
+	tearDown()
 }

From 769b6454f650dbcdabb04a866615ef98721dd23f Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:52:15 +0100
Subject: [PATCH 16/18] Add comment

---
 prefork/prefork.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index c30badbc27..47ef052e94 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -43,6 +43,8 @@ type Prefork struct {
 }
 
 func init() { //nolint:gochecknoinits
+	// Definition flag to not break the program when the user adds their own flags
+	// and runs `flag.Parse()`
 	flag.Bool(preforkChildFlag[1:], false, "Is a child process")
 }
 

From 5735586908ff8b919ad794af8ad00ff168982a0d Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:55:36 +0100
Subject: [PATCH 17/18] Fix typo

---
 prefork/prefork.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index 47ef052e94..7bdd08e9c3 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -59,7 +59,7 @@ func IsChild() bool {
 	return false
 }
 
-// New wraps the fasthttp server to run with prefork processes
+// New wraps the fasthttp server to run with preforked processes
 func New(s *fasthttp.Server) *Prefork {
 	return &Prefork{
 		Network:           defaultNetwork,

From 69f33616eb291b49e5f183f317761580cd400213 Mon Sep 17 00:00:00 2001
From: Sergio Andres Virviescas Santana <developersavsgio@gmail.com>
Date: Wed, 12 Feb 2020 12:58:59 +0100
Subject: [PATCH 18/18] Fix typo

---
 prefork/prefork.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prefork/prefork.go b/prefork/prefork.go
index 7bdd08e9c3..8fcc842d18 100644
--- a/prefork/prefork.go
+++ b/prefork/prefork.go
@@ -28,7 +28,7 @@ type Prefork struct {
 	// By default is "tcp4"
 	Network string
 
-	// Flag to use a listener with reuseport, if not a File Listener will be used
+	// Flag to use a listener with reuseport, if not a file Listener will be used
 	// See: https://www.nginx.com/blog/socket-sharding-nginx-release-1-9-1/
 	//
 	// It's disabled by default