From 1f0914e2df98226a78f655943bf28d06f46c9106 Mon Sep 17 00:00:00 2001
From: Tim Beatham <tcb1@st-andrews.ac.uk>
Date: Thu, 4 Jan 2024 00:23:20 +0000
Subject: [PATCH] bugfix-node-not-leaving

- Add lock when perform synchronisation on concurrent access
---
 pkg/conn/cluster.go | 5 ++---
 pkg/mesh/manager.go | 3 ++-
 pkg/sync/syncer.go  | 3 +++
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/pkg/conn/cluster.go b/pkg/conn/cluster.go
index d3d241b..5a08f70 100644
--- a/pkg/conn/cluster.go
+++ b/pkg/conn/cluster.go
@@ -23,9 +23,10 @@ func binarySearch(global []string, selfId string, groupSize int) (int, int) {
 
 	lower := 0
 	higher := len(global) - 1
-	mid := (lower + higher) / 2
 
 	for (higher+1)-lower > groupSize {
+		mid := (lower + higher) / 2
+
 		if global[mid] < selfId {
 			lower = mid + 1
 		} else if global[mid] > selfId {
@@ -33,8 +34,6 @@ func binarySearch(global []string, selfId string, groupSize int) (int, int) {
 		} else {
 			break
 		}
-
-		mid = (lower + higher) / 2
 	}
 
 	return lower, int(math.Min(float64(lower+groupSize), float64(len(global))))
diff --git a/pkg/mesh/manager.go b/pkg/mesh/manager.go
index 226706f..59c9132 100644
--- a/pkg/mesh/manager.go
+++ b/pkg/mesh/manager.go
@@ -10,6 +10,7 @@ import (
 	"github.com/tim-beatham/smegmesh/pkg/conf"
 	"github.com/tim-beatham/smegmesh/pkg/ip"
 	"github.com/tim-beatham/smegmesh/pkg/lib"
+	logging "github.com/tim-beatham/smegmesh/pkg/log"
 	"github.com/tim-beatham/smegmesh/pkg/wg"
 	"golang.zx2c4.com/wireguard/wgctrl"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
@@ -355,7 +356,7 @@ func (s *MeshManagerImpl) LeaveMesh(meshId string) error {
 	err := mesh.RemoveNode(s.HostParameters.GetPublicKey())
 
 	if err != nil {
-		return err
+		logging.Log.WriteErrorf(err.Error())
 	}
 
 	if s.OnDelete != nil {
diff --git a/pkg/sync/syncer.go b/pkg/sync/syncer.go
index 359abc7..c14e10a 100644
--- a/pkg/sync/syncer.go
+++ b/pkg/sync/syncer.go
@@ -28,6 +28,7 @@ type SyncerImpl struct {
 	cluster        conn.ConnCluster
 	conf           *conf.DaemonConfiguration
 	lastSync       map[string]int64
+	lock           sync.RWMutex
 }
 
 // Sync: Sync with random nodes
@@ -134,7 +135,9 @@ func (s *SyncerImpl) Sync(correspondingMesh mesh.MeshProvider) error {
 
 	correspondingMesh.SaveChanges()
 
+	s.lock.Lock()
 	s.lastSync[correspondingMesh.GetMeshId()] = time.Now().Unix()
+	s.lock.Unlock()
 	return nil
 }