Remove use of semaphore while restarting; covered by changed power actions handling

server/environment_docker.go

@@ -16,7 +16,6 @@ import (
 	"github.com/pkg/errors"
 	"github.com/pterodactyl/wings/api"
 	"github.com/pterodactyl/wings/config"
-	"golang.org/x/sync/semaphore"
 	"io"
 	"os"
 	"path/filepath"
@@ -47,10 +46,6 @@ type DockerEnvironment struct {
 	// Holds the stats stream used by the polling commands so that we can easily close
 	// it out.
 	stats io.ReadCloser
-
-	// Locks when we're performing a restart to avoid trying to restart a process that is already
-	// being restarted.
-	restartSem *semaphore.Weighted
 }
 
 // Set if this process is currently attached to the process.
@@ -325,60 +320,19 @@ func (d *DockerEnvironment) Stop() error {
 	return nil
 }
 
-// Try to acquire a lock to restart the server. If one cannot be obtained within 5 seconds return
-// an error to the caller. You should ideally be checking IsRestarting() before calling this function
-// to avoid unnecessary delays since you can respond immediately from that.
-func (d *DockerEnvironment) acquireRestartLock() error {
-	if d.restartSem == nil {
-		d.restartSem = semaphore.NewWeighted(1)
-	}
-
-	ctx, _ := context.WithTimeout(context.Background(), time.Second*5)
-
-	return d.restartSem.Acquire(ctx, 1)
-}
-
 // Restarts the server process by waiting for the process to gracefully stop and then triggering a
 // start command. This will return an error if there is already a restart process executing for the
 // server. The lock is released when the process is stopped and a start has begun.
 func (d *DockerEnvironment) Restart() error {
-	d.Server.Log().Debug("acquiring process restart lock...")
-	if err := d.acquireRestartLock(); err != nil {
-		d.Server.Log().Warn("failed to acquire restart lock; already acquired by a different process")
-		return err
-	}
-
-	d.Server.Log().Info("acquired process lock; beginning restart process...")
-
 	err := d.WaitForStop(60, false)
 	if err != nil {
-		d.restartSem.Release(1)
 		return err
 	}
 
-	// Release the restart lock, it is now safe for someone to attempt restarting the server again.
-	d.restartSem.Release(1)
-
 	// Start the process.
 	return d.Start()
 }
 
-// Check if the server is currently running the restart process by checking if there is a semaphore
-// allocated, and if so, if we can acquire a lock on it.
-func (d *DockerEnvironment) IsRestarting() bool {
-	if d.restartSem == nil {
-		return false
-	}
-
-	if d.restartSem.TryAcquire(1) {
-		d.restartSem.Release(1)
-
-		return false
-	}
-
-	return true
-}
-
 // Attempts to gracefully stop a server using the defined stop command. If the server
 // does not stop after seconds have passed, an error will be returned, or the instance
 // will be terminated forcefully depending on the value of the second argument.