修复了开启，关闭，再开启，连不上的问题

app/src/main/java/com/jihe/punchnet/PunchnetService.kt

@@ -37,6 +37,7 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.io.FileInputStream
 import java.io.FileOutputStream
+import java.util.concurrent.atomic.AtomicBoolean
 
 class PunchnetService : VpnService() , IfaceTun {
     private val TAG = "PunchnetService"
@@ -46,6 +47,9 @@ class PunchnetService : VpnService() , IfaceTun {
 
     private var vpnDescriptor: ParcelFileDescriptor? = null
 
+    private val serviceLock = Any()
+    private val isRunning = AtomicBoolean(false)
+
 
     var input: FileInputStream? = null
     var output: FileOutputStream? = null
@@ -125,6 +129,11 @@ class PunchnetService : VpnService() , IfaceTun {
     }
 
     private fun disconnect() {
+        synchronized(serviceLock) {
+            if (!isRunning.get()) {
+                return
+            }
+
             Toast.makeText(this, "stop vpn called", Toast.LENGTH_LONG).show()
             stopForeground(STOP_FOREGROUND_REMOVE)
             input?.close()
@@ -132,13 +141,18 @@ class PunchnetService : VpnService() , IfaceTun {
             vpnDescriptor?.close()
 
             vpnDescriptor = null
-
             stopSelf()
         }
+    }
 
     private fun connect(startArg: PunchnetServiceArgument?) {
-        val iface = this
 
+        synchronized(serviceLock) {
+            if (isRunning.get()) {
+                return
+            }
+
+            val iface = this
             val server = "punchnet.aioe.tech"
 
             Log.d("DIR", "datadir = ${Environment.getDataDirectory().name}")
@@ -175,6 +189,9 @@ class PunchnetService : VpnService() , IfaceTun {
 
             val notification = createNotification()
             startForeground(1, notification)
+
+            isRunning.set(true)
+        }
     }
 
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {