Catch IO errors in IO operations

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

@@ -70,6 +70,7 @@ open class VPNTunnelProxy(val packetProxy: PacketProxy,
     private var proxyThreadActive:Boolean = false
     private var cleanupFinalized:Boolean = false
     private val clearLock = ReentrantReadWriteLock()
+    private var ioErrors = 0
 
     constructor(packetProxy: PacketProxy,
                 trafficStats: TrafficStats = TrafficStats(0, 0),
@@ -175,9 +176,9 @@ open class VPNTunnelProxy(val packetProxy: PacketProxy,
                                 logger?.info("Device filed descriptors became invalid")
                                 shouldRun = false
                             } else {
-                                if (pollableAnswers.second.isNotEmpty()) processFutureAnswers(pollableAnswers.second, true)
-                                if (deviceOutputPipe.actualEvent(OsConstants.POLLOUT)) fromLoopbackToDevice(deviceOutput) // There is data in loopback
-                                if (deviceInputPipe.actualEvent(OsConstants.POLLIN)) fromDeviceToPacketProxy(deviceInput)
+                                if (pollableAnswers.second.isNotEmpty()) tryIO { processFutureAnswers(pollableAnswers.second, true) }
+                                if (deviceOutputPipe.actualEvent(OsConstants.POLLOUT)) tryIO {fromLoopbackToDevice(deviceOutput) } // There is data in loopback
+                                if (deviceInputPipe.actualEvent(OsConstants.POLLIN)) tryIO { fromDeviceToPacketProxy(deviceInput) }
                                 Thread.sleep(1)
                             }
                         } else if (shouldRun) {
@@ -236,6 +237,20 @@ open class VPNTunnelProxy(val packetProxy: PacketProxy,
         logger?.info("Done with run().")
     }
 
+    private fun tryIO(block:() -> Unit) {
+        try {
+            block()
+        } catch (ex:IOException) {
+            if(ex is InterruptedIOException) throw ex
+            // Continued errors might indicate an underlying problem.
+            // either way, 100 is a lot and takes a lot of time to reach
+            // (besides, this error is again caught in another try)
+            if(++ioErrors >= 100) {
+                throw ex
+            }
+        }
+    }
+
     private val packetFromDevice = ByteArray(32767)
     fun fromDeviceToPacketProxy(deviceInput:InputStream) {
         val readSize = deviceInput.read(packetFromDevice)