Re-add locking

library/src/main/java/com/frostnerd/vpntunnelproxy/ForwardedPacketStore.kt

@@ -11,7 +11,9 @@ import java.net.DatagramSocket
 import java.net.Socket
 import java.net.SocketException
 import java.util.*
+import java.util.concurrent.locks.ReentrantLock
 import kotlin.collections.ArrayList
+import kotlin.concurrent.withLock
 
 /*
  * Copyright (C) 2019 Daniel Wolf (Ch4t4r)
@@ -41,6 +43,7 @@ class ForwardedPacketStore(var logger: Logger?) {
     private val _nonPollableForwardedPackets:LinkedList<FutureAnswer> = LinkedList()
     private val newlyForwardedPackets: ArrayList<FutureAnswer> = ArrayList()
     private val newlyForwardedNonPollablePackets: ArrayList<FutureAnswer> = ArrayList()
+    private val newPacketsLock = ReentrantLock()
     val nonPollableForwardedPackets:List<FutureAnswer> = _nonPollableForwardedPackets
     val forwardedPollablePackets:List<FutureAnswer> = _forwardedPollablePackets
     var hasMixedAnswerType:Boolean = true
@@ -63,27 +66,33 @@ class ForwardedPacketStore(var logger: Logger?) {
 
     @Throws(IOException::class)
     fun addForwardedQuestion(futureAnswer: FutureAnswer) {
-        if(futureAnswer.isPollable()) newlyForwardedPackets.add(futureAnswer)
-        else newlyForwardedNonPollablePackets.add(futureAnswer)
+        newPacketsLock.withLock {
+            if(futureAnswer.isPollable()) newlyForwardedPackets.add(futureAnswer)
+            else newlyForwardedNonPollablePackets.add(futureAnswer)
+        }
     }
 
     fun processNewAnswers(pollable:Boolean) {
         if(pollable && newlyForwardedPackets.isNotEmpty()) {
             hasMixedAnswerType = newlyForwardedNonPollablePackets.isNotEmpty()
-            for (packet in newlyForwardedPackets) {
-                packet.index = _forwardedPollablePackets.size
-                if(packet.isPollable()) _forwardedPollablePackets.add(packet)
-                else _forwardedPollablePackets.add(packet)
+            newPacketsLock.withLock {
+                for (packet in newlyForwardedPackets) {
+                    packet.index = _forwardedPollablePackets.size
+                    if(packet.isPollable()) _forwardedPollablePackets.add(packet)
+                    else _forwardedPollablePackets.add(packet)
+                }
+                newlyForwardedPackets.clear()
             }
-            newlyForwardedPackets.clear()
         } else if(!pollable && newlyForwardedNonPollablePackets.isNotEmpty()) {
-            hasMixedAnswerType = newlyForwardedPackets.isNotEmpty()
-            for (packet in newlyForwardedNonPollablePackets) {
-                packet.index = _nonPollableForwardedPackets.size
-                if(packet.isPollable()) _nonPollableForwardedPackets.add(packet)
-                else _nonPollableForwardedPackets.add(packet)
+            newPacketsLock.withLock {
+                hasMixedAnswerType = newlyForwardedPackets.isNotEmpty()
+                for (packet in newlyForwardedNonPollablePackets) {
+                    packet.index = _nonPollableForwardedPackets.size
+                    if(packet.isPollable()) _nonPollableForwardedPackets.add(packet)
+                    else _nonPollableForwardedPackets.add(packet)
+                }
+                newlyForwardedNonPollablePackets.clear()
             }
-            newlyForwardedNonPollablePackets.clear()
         }
     }
 
@@ -97,22 +106,24 @@ class ForwardedPacketStore(var logger: Logger?) {
         if(clearing) return
         clearing = true
         logger?.fine("Clearing ForwardedPacketStore")
+        newPacketsLock.withLock {
+            newlyForwardedPackets.forEach {
+                cleanup(it)
+            }
+            newlyForwardedNonPollablePackets.forEach {
+                cleanup(it)
+            }
+            newlyForwardedPackets.clear()
+            newlyForwardedNonPollablePackets.clear()
+        }
         forwardedPollablePackets.forEach {
             cleanup(it)
         }
         _nonPollableForwardedPackets.forEach {
             cleanup(it)
         }
-        newlyForwardedPackets.forEach {
-            cleanup(it)
-        }
-        newlyForwardedNonPollablePackets.forEach {
-            cleanup(it)
-        }
         _nonPollableForwardedPackets.clear()
         _forwardedPollablePackets.clear()
-        newlyForwardedPackets.clear()
-        newlyForwardedNonPollablePackets.clear()
         clearing = false
         if(completely) logger = null
     }