Add Cleanupable interface

The Cleanup method is called on actors when they exit

actor.go

@@ -127,3 +127,10 @@ type RunShutdownable interface {
 	// should be shut down.
 	Shutdown(ctx context.Context) error
 }
+
+// Cleanupable is any object that must be cleaned up after it has stopped for
+// good. Actors which implement this interface will be cleaned up after they
+// are deleted from the environment.
+type Cleanupable interface {
+	Cleanup(ctx context.Context) error
+}

environment.go

@@ -19,6 +19,7 @@ const defaultRestartInitialInterval  =  8 * time.Second
 const defaultRestartInitialIncrement =  8 * time.Second
 const defaultRestartInitialMaximum   =  1 * time.Hour
 const defaultResetTimeout            =  8 * time.Minute
+const defaultCleanupTimeout          =  1 * time.Minute
 const defaultTrimInterval            =  1 * time.Minute
 const defaultTrimTimeout             =  1 * time.Minute
 const defaultShutdownTimeout         =  8 * time.Minute
@@ -62,6 +63,7 @@ type environment struct {
 		restartIntervalIncrement atomicDuration
 		restartIntervalMaximum   atomicDuration
 		resetTimeout             atomicDuration
+		cleanupTimeout           atomicDuration
 		trimTimeout              atomicDuration
 		shutdownTimeout          atomicDuration
 	}
@@ -238,11 +240,30 @@ func (this *environment) start(actor Actor) {
 // counter will be decremented. note that this function will never increment the
 // wait group counter, so start should usually be used instead.
 func (this *environment) run(actor Actor) {
+	typ := actor.Type()
+	
 	// clean up when done
-	defer this.group.Done()
+	defer func() {
+		this.group.Done()
+		this.delFromSets(actor)
+		if actor, ok := actor.(Cleanupable); ok {
+			ctx, done := context.WithTimeout(
+				context.Background(),
+				defaul(
+					this.timing.cleanupTimeout.Load(),
+					defaultCleanupTimeout))
+			defer done()
+			err := actor.Cleanup(ctx)
+			if err != nil {
+				log.Printf("XXX [%s] failed to cleanup: %v", typ, err)
+				if this.flags.crashOnError {
+					panic(fmt.Sprint(err))
+				}
+			}
+		}
+	}()
 
 	// logging
-	typ := actor.Type()
 	if this.Verb() { log.Printf("(i) [%s] running", typ) }
 	var stopErr error
 	var exited  bool
@@ -434,6 +455,8 @@ func (this *environment) applyConfig() error {
 	if err != nil { return err }
 	err = parseDuration("reset-timeout", &this.timing.resetTimeout)
 	if err != nil { return err }
+	err = parseDuration("cleanup-timeout", &this.timing.cleanupTimeout)
+	if err != nil { return err }
 	err = parseDuration("trim-timeout", &this.timing.trimTimeout)
 	if err != nil { return err }
 	err = parseDuration("shutdown-timeout", &this.timing.shutdownTimeout)

phases.go

@@ -279,6 +279,7 @@ func (this *environment) phase70_5Trimming() bool {
 }
 
 func (this *environment) phase80Shutdown() bool {
+	logActors(All())
 	ctx, done := context.WithTimeout(
 		context.Background(),
 		defaul(this.timing.shutdownTimeout.Load(), defaultShutdownTimeout))