Improve server state logical handling; allow setting state directly on the environment

server/install.go

@@ -63,7 +63,7 @@ func (s *Server) Install(sync bool) error {
 
 	// Ensure that the server is marked as offline at this point, otherwise you end up
 	// with a blank value which is a bit confusing.
-	s.SetState(environment.ProcessOfflineState)
+	s.Environment.SetState(environment.ProcessOfflineState)
 
 	// Push an event to the websocket so we can auto-refresh the information in the panel once
 	// the install is completed.

server/listeners.go

@@ -63,8 +63,8 @@ func (s *Server) StartEventListeners() {
 		if err != nil {
 			// If the process is already stopping, just let it continue with that action rather than attempting
 			// to terminate again.
-			if s.GetState() != environment.ProcessStoppingState {
-				s.SetState(environment.ProcessStoppingState)
+			if s.Environment.State() != environment.ProcessStoppingState {
+				s.Environment.SetState(environment.ProcessStoppingState)
 				go func() {
 					s.Log().Warn("stopping server instance, violating throttle limits")
 					s.PublishConsoleOutputFromDaemon("Your server is being stopped for outputting too much data in a short period of time.")
@@ -73,8 +73,8 @@ func (s *Server) StartEventListeners() {
 					if err := s.Environment.WaitForStop(config.Get().Throttles.StopGracePeriod, true); err != nil {
 						// If there is an error set the process back to running so that this throttler is called
 						// again and hopefully kills the server.
-						if s.GetState() != environment.ProcessOfflineState {
-							s.SetState(environment.ProcessRunningState)
+						if s.Environment.State() != environment.ProcessOfflineState {
+							s.Environment.SetState(environment.ProcessRunningState)
 						}
 
 						s.Log().WithField("error", errors.WithStack(err)).Error("failed to terminate environment after triggering throttle")
@@ -100,7 +100,7 @@ func (s *Server) StartEventListeners() {
 			s.Throttler().Reset()
 		}
 
-		s.SetState(e.Data)
+		s.OnStateChange()
 	}
 
 	stats := func(e events.Event) {
@@ -173,7 +173,7 @@ func (s *Server) onConsoleOutput(data string) {
 			// If the specific line of output is one that would mark the server as started,
 			// set the server to that state. Only do this if the server is not currently stopped
 			// or stopping.
-			_ = s.SetState(environment.ProcessRunningState)
+			s.Environment.SetState(environment.ProcessRunningState)
 			break
 		}
 	}
@@ -185,7 +185,7 @@ func (s *Server) onConsoleOutput(data string) {
 		stop := processConfiguration.Stop
 
 		if stop.Type == api.ProcessStopCommand && data == stop.Value {
-			_ = s.SetState(environment.ProcessOfflineState)
+			s.Environment.SetState(environment.ProcessOfflineState)
 		}
 	}
 }

server/loader.go

@@ -104,6 +104,7 @@ func FromConfiguration(data api.ServerConfigurationResponse) (*Server, error) {
 
 	s.resources = ResourceUsage{}
 	defaults.Set(&s.resources)
+	s.resources.State.Store(environment.ProcessOfflineState)
 
 	s.Archiver = Archiver{Server: s}
 	s.fs = filesystem.New(filepath.Join(config.Get().System.Data, s.Id()), s.DiskSpace())

server/resources.go

@@ -3,7 +3,9 @@ package server
 import (
 	"encoding/json"
 	"github.com/pterodactyl/wings/environment"
+	"github.com/pterodactyl/wings/system"
 	"sync"
+	"sync/atomic"
 )
 
 // Defines the current resource usage for a given server instance. If a server is offline you
@@ -16,7 +18,7 @@ type ResourceUsage struct {
 	environment.Stats
 
 	// The current server status.
-	State string `json:"state" default:"offline"`
+	State system.AtomicString `json:"state"`
 
 	// The current disk space being used by the server. This value is not guaranteed to be accurate
 	// at all times. It is "manually" set whenever server.Proc() is called. This is kind of just a
@@ -24,16 +26,16 @@ type ResourceUsage struct {
 	Disk int64 `json:"disk_bytes"`
 }
 
-// Alias the resource usage so that we don't infinitely recurse when marshaling the struct.
-type IResourceUsage ResourceUsage
-
 // Custom marshaler to ensure that the object is locked when we're converting it to JSON in
 // order to avoid race conditions.
 func (ru *ResourceUsage) MarshalJSON() ([]byte, error) {
 	ru.mu.Lock()
 	defer ru.mu.Unlock()
 
-	return json.Marshal(IResourceUsage(*ru))
+	// Alias the resource usage so that we don't infinitely recurse when marshaling the struct.
+	type alias ResourceUsage
+
+	return json.Marshal(alias(*ru))
 }
 
 // Returns the resource usage stats for the server instance. If the server is not running, only the
@@ -42,10 +44,10 @@ func (ru *ResourceUsage) MarshalJSON() ([]byte, error) {
 //
 // When a process is stopped all of the stats are zeroed out except for the disk.
 func (s *Server) Proc() *ResourceUsage {
-	s.resources.SetDisk(s.Filesystem().CachedUsage())
+	// Store the updated disk usage when requesting process usage.
+	atomic.StoreInt64(&s.resources.Disk, s.Filesystem().CachedUsage())
 
-	// Get a read lock on the resources at this point. Don't do this before setting
-	// the disk, otherwise you'll cause a deadlock.
+	// Acquire a lock before attempting to return the value of resources.
 	s.resources.mu.RLock()
 	defer s.resources.mu.RUnlock()
 
@@ -57,24 +59,3 @@ func (s *Server) emitProcUsage() {
 		s.Log().WithField("error", err).Warn("error while emitting server resource usage to listeners")
 	}
 }
-
-// Returns the servers current state.
-func (ru *ResourceUsage) getInternalState() string {
-	ru.mu.RLock()
-	defer ru.mu.RUnlock()
-
-	return ru.State
-}
-
-// Sets the new state for the server.
-func (ru *ResourceUsage) setInternalState(state string) {
-	ru.mu.Lock()
-	ru.State = state
-	ru.mu.Unlock()
-}
-
-func (ru *ResourceUsage) SetDisk(i int64) {
-	ru.mu.Lock()
-	ru.Disk = i
-	ru.mu.Unlock()
-}

server/state.go

@@ -2,7 +2,6 @@ package server
 
 import (
 	"encoding/json"
-	"fmt"
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/config"
 	"github.com/pterodactyl/wings/environment"
@@ -63,23 +62,17 @@ func saveServerStates() error {
 
 // Sets the state of the server internally. This function handles crash detection as
 // well as reporting to event listeners for the server.
-func (s *Server) SetState(state string) error {
-	if state != environment.ProcessOfflineState &&
-		state != environment.ProcessStartingState &&
-		state != environment.ProcessRunningState &&
-		state != environment.ProcessStoppingState {
-		return errors.New(fmt.Sprintf("invalid server state received: %s", state))
-	}
-
-	prevState := s.GetState()
+func (s *Server) OnStateChange() {
+	prevState := s.Proc().State.Load()
 
+	st := s.Environment.State()
 	// Update the currently tracked state for the server.
-	s.Proc().setInternalState(state)
+	s.Proc().State.Store(st)
 
 	// Emit the event to any listeners that are currently registered.
-	if prevState != state {
-		s.Log().WithField("status", s.Proc().getInternalState()).Debug("saw server status change event")
-		s.Events().Publish(StatusEvent, s.Proc().getInternalState())
+	if prevState != s.Environment.State() {
+		s.Log().WithField("status", st).Debug("saw server status change event")
+		s.Events().Publish(StatusEvent, st)
 	}
 
 	// Persist this change to the disk immediately so that should the Daemon be stopped or
@@ -98,7 +91,7 @@ func (s *Server) SetState(state string) error {
 
 	// Reset the resource usage to 0 when the process fully stops so that all of the UI
 	// views in the Panel correctly display 0.
-	if state == environment.ProcessOfflineState {
+	if st == environment.ProcessOfflineState {
 		s.resources.mu.Lock()
 		s.resources.Empty()
 		s.resources.mu.Unlock()
@@ -127,13 +120,13 @@ func (s *Server) SetState(state string) error {
 			}
 		}(s)
 	}
-
-	return nil
 }
 
 // Returns the current state of the server in a race-safe manner.
+// Deprecated
+// use Environment.State()
 func (s *Server) GetState() string {
-	return s.Proc().getInternalState()
+	return s.Environment.State()
 }
 
 // Determines if the server state is running or not. This is different than the