Update suture for data race bug

Godeps/_workspace/src/github.com/thejerf/suture/suture.go

@@ -59,6 +59,7 @@ import (
 	"log"
 	"math"
 	"runtime"
+	"sync"
 	"sync/atomic"
 	"time"
 )
@@ -123,7 +124,6 @@ type Supervisor struct {
 	lastFail         time.Time
 	failures         float64
 	restartQueue     []serviceID
-	state            uint8
 	serviceCounter   serviceID
 	control          chan supervisorMessage
 	resumeTimer      <-chan time.Time
@@ -143,6 +143,9 @@ type Supervisor struct {
 	// a minimal chunk.
 	getNow    func() time.Time
 	getResume func(time.Duration) <-chan time.Time
+
+	sync.Mutex
+	state uint8
 }
 
 // Spec is used to pass arguments to the New function to create a
@@ -373,6 +376,7 @@ func (s *Supervisor) Add(service Service) ServiceToken {
 		supervisor.logBackoff = s.logBackoff
 	}
 
+	s.Lock()
 	if s.state == notRunning {
 		id := s.serviceCounter
 		s.serviceCounter++
@@ -380,8 +384,10 @@ func (s *Supervisor) Add(service Service) ServiceToken {
 		s.services[id] = service
 		s.restartQueue = append(s.restartQueue, id)
 
+		s.Unlock()
 		return ServiceToken{uint64(s.id)<<32 | uint64(id)}
 	}
+	s.Unlock()
 
 	response := make(chan serviceID)
 	s.control <- addService{service, response}
@@ -408,16 +414,19 @@ func (s *Supervisor) Serve() {
 	}
 
 	defer func() {
+		s.Lock()
 		s.state = notRunning
+		s.Unlock()
 	}()
 
+	s.Lock()
 	if s.state != notRunning {
-		// FIXME: Don't explain why I don't need a semaphore, just use one
-		// This doesn't use a semaphore because it's just a sanity check.
+		s.Unlock()
 		panic("Running a supervisor while it is already running?")
 	}
 
 	s.state = normal
+	s.Unlock()
 
 	// for all the services I currently know about, start them
 	for _, id := range s.restartQueue {
@@ -472,7 +481,9 @@ func (s *Supervisor) Serve() {
 			// excessive thrashing
 			// FIXME: Ought to permit some spacing of these functions, rather
 			// than simply hammering through them
+			s.Lock()
 			s.state = normal
+			s.Unlock()
 			s.failures = 0
 			s.logBackoff(s, false)
 			for _, id := range s.restartQueue {
@@ -499,7 +510,9 @@ func (s *Supervisor) handleFailedService(id serviceID, err interface{}, stacktra
 	}
 
 	if s.failures > s.failureThreshold {
+		s.Lock()
 		s.state = paused
+		s.Unlock()
 		s.logBackoff(s, true)
 		s.resumeTimer = s.getResume(s.failureBackoff)
 	}
@@ -511,7 +524,13 @@ func (s *Supervisor) handleFailedService(id serviceID, err interface{}, stacktra
 	// It is possible for a service to be no longer monitored
 	// by the time we get here. In that case, just ignore it.
 	if monitored {
-		if s.state == normal {
+		// this may look dangerous because the state could change, but this
+		// code is only ever run in the one goroutine that is permitted to
+		// change the state, so nothing else will.
+		s.Lock()
+		curState := s.state
+		s.Unlock()
+		if curState == normal {
 			s.runService(failedService, id)
 			s.logFailure(s, failedService, s.failures, s.failureThreshold, true, err, stacktrace)
 		} else {