strategy: avoid data race

proxy/forwarder.go

@@ -13,14 +13,13 @@ import (
 // Forwarder is a forwarder
 type Forwarder struct {
 	Dialer
-	Priority    int
+	addr        string
-	MaxFailures uint32 //maxfailures to set to Disabled
+	priority    uint32
-
+	maxFailures uint32 // maxfailures to set to Disabled
-	addr     string
+	disabled    uint32
-	disabled uint32
+	failures    uint32
-	failures uint32
+	latency     int64
-	latency  int64
+	intface     string // local interface or ip address
-	intface  string // local interface or ip address
 }
 
 // ForwarderFromURL parses `forward=` command value and returns a new forwarder
@@ -67,7 +66,7 @@ func (f *Forwarder) parseOption(option string) error {
 	if p != "" {
 		priority, err = strconv.ParseUint(p, 10, 32)
 	}
-	f.Priority = int(priority)
+	f.SetPriority(uint32(priority))
 
 	f.intface = query.Get("interface")
 
@@ -83,8 +82,8 @@ func (f *Forwarder) Addr() string {
 func (f *Forwarder) Dial(network, addr string) (c net.Conn, err error) {
 	c, err = f.Dialer.Dial(network, addr)
 	if err != nil {
-		atomic.AddUint32(&f.failures, 1)
+		f.IncFailures()
-		if f.Failures() >= f.MaxFailures {
+		if f.Failures() >= f.MaxFailures() {
 			f.Disable()
 			log.F("[forwarder] %s reaches maxfailures, set to disabled", f.addr)
 		}
@@ -98,6 +97,11 @@ func (f *Forwarder) Failures() uint32 {
 	return atomic.LoadUint32(&f.failures)
 }
 
+// IncFailures increase the failuer count by 1
+func (f *Forwarder) IncFailures() {
+	atomic.AddUint32(&f.failures, 1)
+}
+
 // Enable the forwarder
 func (f *Forwarder) Enable() {
 	atomic.StoreUint32(&f.disabled, 0)
@@ -118,6 +122,26 @@ func isTrue(n uint32) bool {
 	return n&1 == 1
 }
 
+// Priority returns the priority of forwarder
+func (f *Forwarder) Priority() uint32 {
+	return atomic.LoadUint32(&f.priority)
+}
+
+// SetPriority sets the priority of forwarder
+func (f *Forwarder) SetPriority(l uint32) {
+	atomic.StoreUint32(&f.priority, l)
+}
+
+// MaxFailures returns the maxFailures of forwarder
+func (f *Forwarder) MaxFailures() uint32 {
+	return atomic.LoadUint32(&f.maxFailures)
+}
+
+// SetMaxFailures sets the maxFailures of forwarder
+func (f *Forwarder) SetMaxFailures(l uint32) {
+	atomic.StoreUint32(&f.maxFailures, l)
+}
+
 // Latency returns the latency of forwarder
 func (f *Forwarder) Latency() int64 {
 	return atomic.LoadInt64(&f.latency)

strategy/ha.go

@@ -0,0 +1,31 @@
+package strategy
+
+import (
+	"net"
+
+	"github.com/nadoo/glider/proxy"
+)
+
+// high availability forwarder
+type haDialer struct{ *rrDialer }
+
+// newHADialer .
+func newHADialer(dialers []*proxy.Forwarder, webhost string, duration int) proxy.Dialer {
+	return &haDialer{rrDialer: newRRDialer(dialers, webhost, duration)}
+}
+
+func (ha *haDialer) nextDialer(dstAddr string) *proxy.Forwarder {
+	d := ha.fwdrs[ha.index]
+	if !d.Enabled() {
+		d = ha.nextDialer(dstAddr)
+	}
+	return d
+}
+
+func (ha *haDialer) Dial(network, addr string) (net.Conn, error) {
+	return ha.nextDialer(addr).Dial(network, addr)
+}
+
+func (ha *haDialer) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
+	return ha.nextDialer(addr).DialUDP(network, addr)
+}

strategy/lha.go

@@ -0,0 +1,46 @@
+package strategy
+
+import (
+	"net"
+
+	"github.com/nadoo/glider/proxy"
+)
+
+// latency based high availability forwarder
+type lhaDialer struct{ *rrDialer }
+
+// newLHADialer .
+func newLHADialer(dialers []*proxy.Forwarder, webhost string, duration int) proxy.Dialer {
+	return &lhaDialer{rrDialer: newRRDialer(dialers, webhost, duration)}
+}
+
+func (lha *lhaDialer) nextDialer(dstAddr string) *proxy.Forwarder {
+	idx := lha.Index()
+	var lowest int64
+	for i, fwder := range lha.fwdrs {
+		if fwder.Enabled() {
+			lha.SetPriority(fwder.Priority())
+			lowest = fwder.Latency()
+			idx = int32(i)
+			break
+		}
+	}
+
+	for i, fwder := range lha.fwdrs {
+		if fwder.Enabled() && fwder.Priority() >= lha.Priority() && fwder.Latency() < lowest {
+			lowest = fwder.Latency()
+			idx = int32(i)
+		}
+	}
+
+	lha.SetIndex(idx)
+	return lha.fwdrs[idx]
+}
+
+func (lha *lhaDialer) Dial(network, addr string) (net.Conn, error) {
+	return lha.nextDialer(addr).Dial(network, addr)
+}
+
+func (lha *lhaDialer) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
+	return lha.nextDialer(addr).DialUDP(network, addr)
+}

strategy/rr.go

@@ -0,0 +1,161 @@
+package strategy
+
+import (
+	"bytes"
+	"io"
+	"net"
+	"sort"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"github.com/nadoo/glider/common/log"
+	"github.com/nadoo/glider/proxy"
+)
+
+// forwarder slice orderd by priority
+type priSlice []*proxy.Forwarder
+
+func (p priSlice) Len() int           { return len(p) }
+func (p priSlice) Less(i, j int) bool { return p[i].Priority() > p[j].Priority() }
+func (p priSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// rrDialer is a round robin dialer
+type rrDialer struct {
+	fwdrs    priSlice
+	index    int32
+	priority uint32
+	website  string
+	interval int
+}
+
+// newRRDialer returns a new rrDialer
+func newRRDialer(fwdrs []*proxy.Forwarder, website string, interval int) *rrDialer {
+	rr := &rrDialer{fwdrs: fwdrs}
+	sort.Sort(rr.fwdrs)
+
+	rr.website = website
+	if strings.IndexByte(rr.website, ':') == -1 {
+		rr.website += ":80"
+	}
+
+	rr.interval = interval
+	return rr
+}
+
+func (rr *rrDialer) Addr() string { return "STRATEGY" }
+
+func (rr *rrDialer) Dial(network, addr string) (net.Conn, error) {
+	return rr.nextDialer(addr).Dial(network, addr)
+}
+
+func (rr *rrDialer) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
+	return rr.nextDialer(addr).DialUDP(network, addr)
+}
+
+func (rr *rrDialer) NextDialer(dstAddr string) proxy.Dialer { return rr.nextDialer(dstAddr) }
+
+func (rr *rrDialer) nextDialer(dstAddr string) *proxy.Forwarder {
+	n := int32(len(rr.fwdrs))
+	if n == 1 {
+		return rr.fwdrs[0]
+	}
+
+	for _, fwder := range rr.fwdrs {
+		if fwder.Enabled() {
+			rr.SetPriority(fwder.Priority())
+			break
+		}
+	}
+
+	idx := rr.Index()
+	if rr.fwdrs[idx].Priority() < rr.Priority() {
+		idx = 0
+	}
+
+	found := false
+	var i int32
+	for i = 0; i < n; i++ {
+		idx = (idx + 1) % n
+		if rr.fwdrs[idx].Enabled() &&
+			rr.fwdrs[idx].Priority() >= rr.Priority() {
+			found = true
+			rr.SetPriority(rr.fwdrs[idx].Priority())
+			break
+		}
+	}
+
+	if !found {
+		rr.SetPriority(0)
+		log.F("NO AVAILABLE PROXY FOUND! please check your network or proxy server settings.")
+	}
+
+	rr.SetIndex(idx)
+
+	return rr.fwdrs[idx]
+}
+
+// Check implements the Checker interface
+func (rr *rrDialer) Check() {
+	for i := 0; i < len(rr.fwdrs); i++ {
+		go rr.check(i)
+	}
+}
+
+func (rr *rrDialer) check(i int) {
+	f := rr.fwdrs[i]
+	retry := 1
+	buf := make([]byte, 4)
+
+	for {
+		time.Sleep(time.Duration(rr.interval) * time.Second * time.Duration(retry>>1))
+
+		retry <<= 1
+		if retry > 16 {
+			retry = 16
+		}
+
+		if f.Priority() < rr.Priority() {
+			continue
+		}
+
+		startTime := time.Now()
+		rc, err := f.Dial("tcp", rr.website)
+		if err != nil {
+			f.Disable()
+			log.F("[check] %s(%d) -> %s, DISABLED. error in dial: %s", f.Addr(), f.Priority(), rr.website, err)
+			continue
+		}
+
+		rc.Write([]byte("GET / HTTP/1.0\r\n\r\n"))
+
+		_, err = io.ReadFull(rc, buf)
+		if err != nil {
+			f.Disable()
+			log.F("[check] %s(%d) -> %s, DISABLED. error in read: %s", f.Addr(), f.Priority(), rr.website, err)
+		} else if bytes.Equal([]byte("HTTP"), buf) {
+			f.Enable()
+			retry = 2
+			readTime := time.Since(startTime)
+			f.SetLatency(int64(readTime))
+			log.F("[check] %s(%d) -> %s, ENABLED. connect time: %s", f.Addr(), f.Priority(), rr.website, readTime.String())
+		} else {
+			f.Disable()
+			log.F("[check] %s(%d) -> %s, DISABLED. server response: %s", f.Addr(), f.Priority(), rr.website, buf)
+		}
+
+		rc.Close()
+	}
+}
+
+// Index returns the active forwarder's Index of rrDialer
+func (rr *rrDialer) Index() int32 { return atomic.LoadInt32(&rr.index) }
+
+// SetIndex sets the active forwarder's Index of rrDialer
+func (rr *rrDialer) SetIndex(p int32) { atomic.StoreInt32(&rr.index, p) }
+
+// Priority returns the active priority of rrDialer
+func (rr *rrDialer) Priority() uint32 { return atomic.LoadUint32(&rr.priority) }
+
+// SetPriority sets the active priority of rrDialer
+func (rr *rrDialer) SetPriority(p uint32) { atomic.StoreUint32(&rr.priority, p) }

strategy/strategy.go

@@ -1,17 +1,15 @@
 package strategy
 
 import (
-	"bytes"
-	"io"
-	"net"
-	"sort"
-	"strings"
-	"time"
-
 	"github.com/nadoo/glider/common/log"
 	"github.com/nadoo/glider/proxy"
 )
 
+// Checker is an interface of forwarder checker
+type Checker interface {
+	Check()
+}
+
 // Config of strategy
 type Config struct {
 	Strategy      string
@@ -21,11 +19,6 @@ type Config struct {
 	IntFace       string
 }
 
-// Checker is an interface of forwarder checker
-type Checker interface {
-	Check()
-}
-
 // NewDialer returns a new strategy dialer
 func NewDialer(s []string, c *Config) proxy.Dialer {
 	var fwdrs []*proxy.Forwarder
@@ -34,7 +27,7 @@ func NewDialer(s []string, c *Config) proxy.Dialer {
 		if err != nil {
 			log.Fatal(err)
 		}
-		fwdr.MaxFailures = uint32(c.MaxFailures)
+		fwdr.SetMaxFailures(uint32(c.MaxFailures))
 		fwdrs = append(fwdrs, fwdr)
 	}
 
@@ -68,217 +61,3 @@ func NewDialer(s []string, c *Config) proxy.Dialer {
 
 	return dialer
 }
-
-// slice orderd by priority
-type priSlice []*proxy.Forwarder
-
-func (p priSlice) Len() int           { return len(p) }
-func (p priSlice) Less(i, j int) bool { return p[i].Priority > p[j].Priority }
-func (p priSlice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
-
-// rrDialer is a round robin dialer
-// 1. find the highest priority which there's at least 1 dialer is enabled
-// 2. choose a enabled dialer in that priority using round robin mode
-type rrDialer struct {
-	fwdrs priSlice
-
-	// may have data races, but doesn't matter
-	idx      int
-	priority int
-
-	// for checking
-	website  string
-	interval int
-}
-
-// newRRDialer returns a new rrDialer
-func newRRDialer(fs []*proxy.Forwarder, website string, interval int) *rrDialer {
-	rr := &rrDialer{fwdrs: fs}
-	sort.Sort(rr.fwdrs)
-
-	rr.website = website
-	if strings.IndexByte(rr.website, ':') == -1 {
-		rr.website += ":80"
-	}
-
-	rr.interval = interval
-
-	return rr
-}
-
-func (rr *rrDialer) Addr() string { return "STRATEGY" }
-func (rr *rrDialer) Dial(network, addr string) (net.Conn, error) {
-	return rr.NextDialer(addr).Dial(network, addr)
-}
-
-func (rr *rrDialer) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
-	return rr.NextDialer(addr).DialUDP(network, addr)
-}
-
-func (rr *rrDialer) nextDialer(dstAddr string) *proxy.Forwarder {
-	n := len(rr.fwdrs)
-	if n == 1 {
-		rr.idx = 0
-	}
-
-	for _, fwder := range rr.fwdrs {
-		if fwder.Enabled() {
-			rr.priority = fwder.Priority
-			break
-		}
-	}
-
-	if rr.fwdrs[rr.idx].Priority < rr.priority {
-		rr.idx = 0
-	}
-
-	found := false
-	for i := 0; i < n; i++ {
-		rr.idx = (rr.idx + 1) % n
-		if rr.fwdrs[rr.idx].Enabled() &&
-			rr.fwdrs[rr.idx].Priority >= rr.priority {
-			found = true
-			rr.priority = rr.fwdrs[rr.idx].Priority
-			break
-		}
-	}
-
-	if !found {
-		rr.priority = 0
-		log.F("NO AVAILABLE PROXY FOUND! please check your network or proxy server settings.")
-	}
-
-	return rr.fwdrs[rr.idx]
-}
-
-func (rr *rrDialer) NextDialer(dstAddr string) proxy.Dialer {
-	return rr.nextDialer(dstAddr)
-}
-
-// Check implements the Checker interface
-func (rr *rrDialer) Check() {
-	for _, f := range rr.fwdrs {
-		go rr.checkDialer(f)
-	}
-}
-
-// Check dialer
-func (rr *rrDialer) checkDialer(f *proxy.Forwarder) {
-	retry := 1
-	buf := make([]byte, 4)
-
-	for {
-		time.Sleep(time.Duration(rr.interval) * time.Second * time.Duration(retry>>1))
-
-		retry <<= 1
-		if retry > 16 {
-			retry = 16
-		}
-
-		// check forwarders whose priority not less than current priority only
-		if f.Priority < rr.priority {
-			// log.F("f.Priority:%d, rr.priority:%d", f.Priority, rr.priority)
-			continue
-		}
-
-		startTime := time.Now()
-		rc, err := f.Dial("tcp", rr.website)
-		if err != nil {
-			f.Disable()
-			log.F("[check] %s(%d) -> %s, DISABLED. error in dial: %s", f.Addr(), f.Priority, rr.website, err)
-			continue
-		}
-
-		rc.Write([]byte("GET / HTTP/1.0\r\n\r\n"))
-
-		_, err = io.ReadFull(rc, buf)
-		if err != nil {
-			f.Disable()
-			log.F("[check] %s(%d) -> %s, DISABLED. error in read: %s", f.Addr(), f.Priority, rr.website, err)
-		} else if bytes.Equal([]byte("HTTP"), buf) {
-			f.Enable()
-			retry = 2
-			readTime := time.Since(startTime)
-			f.SetLatency(int64(readTime))
-			log.F("[check] %s(%d) -> %s, ENABLED. connect time: %s", f.Addr(), f.Priority, rr.website, readTime.String())
-		} else {
-			f.Disable()
-			log.F("[check] %s(%d) -> %s, DISABLED. server response: %s", f.Addr(), f.Priority, rr.website, buf)
-		}
-
-		rc.Close()
-	}
-}
-
-// high availability forwarder
-// 1. choose dialer whose priority is the highest
-// 2. choose the first enabled dialer in that priority
-type haDialer struct {
-	*rrDialer
-}
-
-// newHADialer .
-func newHADialer(dialers []*proxy.Forwarder, webhost string, duration int) proxy.Dialer {
-	return &haDialer{rrDialer: newRRDialer(dialers, webhost, duration)}
-}
-
-func (ha *haDialer) nextDialer(dstAddr string) *proxy.Forwarder {
-	d := ha.fwdrs[ha.idx]
-	if !d.Enabled() {
-		d = ha.nextDialer(dstAddr)
-	}
-	return d
-}
-
-func (ha *haDialer) Dial(network, addr string) (net.Conn, error) {
-	d := ha.nextDialer(addr)
-	return d.Dial(network, addr)
-}
-
-func (ha *haDialer) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
-	d := ha.nextDialer(addr)
-	return d.DialUDP(network, addr)
-}
-
-// latency based high availability forwarder
-// 1. choose dialer whose priority is the highest
-// 2. choose dialer with the lowest latency
-type lhaDialer struct {
-	*rrDialer
-}
-
-// newLHADialer .
-func newLHADialer(dialers []*proxy.Forwarder, webhost string, duration int) proxy.Dialer {
-	return &lhaDialer{rrDialer: newRRDialer(dialers, webhost, duration)}
-}
-
-func (lha *lhaDialer) nextDialer(dstAddr string) *proxy.Forwarder {
-	var latency int64
-	for i, fwder := range lha.fwdrs {
-		if fwder.Enabled() {
-			lha.priority = fwder.Priority
-			latency = fwder.Latency()
-			lha.idx = i
-			break
-		}
-	}
-
-	for i, fwder := range lha.fwdrs {
-		if fwder.Enabled() && fwder.Priority >= lha.priority && fwder.Latency() < latency {
-			latency = fwder.Latency()
-			lha.idx = i
-		}
-	}
-
-	return lha.fwdrs[lha.idx]
-}
-
-func (lha *lhaDialer) Dial(network, addr string) (net.Conn, error) {
-	d := lha.nextDialer(addr)
-	return d.Dial(network, addr)
-}
-
-func (lha *lhaDialer) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
-	d := lha.nextDialer(addr)
-	return d.DialUDP(network, addr)
-}