fix(Android): Remove use of AsyncTask.THREAD_POOL_EXECUTOR (#46)

Author: Rapsssito

android/src/main/java/com/asterinet/react/tcpsocket/TcpReceiverTask.java

@@ -14,7 +14,7 @@
  * notifies it's listener when data is received.  This is not threadsafe, the listener
  * should handle synchronicity.
  */
-public class TcpReceiverTask extends AsyncTask<Pair<TcpSocketClient, TcpReceiverTask.OnDataReceivedListener>, Void, Void> {
+class TcpReceiverTask extends AsyncTask<Pair<TcpSocketClient, TcpReceiverTask.OnDataReceivedListener>, Void, Void> {
     /**
      * An infinite loop to block and read data from the socket.
      */

android/src/main/java/com/asterinet/react/tcpsocket/TcpSocketClient.java

@@ -2,17 +2,18 @@
 
 import android.content.Context;
 import android.net.Network;
-import android.os.AsyncTask;
 import android.util.Pair;
 
 import com.facebook.react.bridge.ReadableMap;
 
-import java.io.OutputStream;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.security.GeneralSecurityException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import javax.net.SocketFactory;
 import javax.net.ssl.SSLSocket;
@@ -23,12 +24,14 @@
 
 class TcpSocketClient {
     private final int id;
+    private final ExecutorService executorService;
     private TcpReceiverTask receiverTask;
     private Socket socket;
     private TcpReceiverTask.OnDataReceivedListener mReceiverListener;
 
     TcpSocketClient(final int id) {
         this.id = id;
+        this.executorService = Executors.newFixedThreadPool(1);
     }
 
     TcpSocketClient(@NonNull final TcpReceiverTask.OnDataReceivedListener receiverListener, @NonNull final Integer id, @Nullable final Socket socket) {
@@ -38,6 +41,9 @@ class TcpSocketClient {
         mReceiverListener = receiverListener;
     }
 
+    ExecutorService getExecutorService() {
+        return this.executorService;
+    }
 
     public int getId() {
         return id;
@@ -52,7 +58,7 @@ public void connect(@NonNull final Context context, @NonNull final String addres
         final boolean isTls = options.hasKey("tls") && options.getBoolean("tls");
         if (isTls) {
             SocketFactory sf;
-            if (options.hasKey("tlsCheckValidity") && !options.getBoolean("tlsCheckValidity")){
+            if (options.hasKey("tlsCheckValidity") && !options.getBoolean("tlsCheckValidity")) {
                 sf = SSLCertificateHelper.createBlindSocketFactory();
             } else {
                 final String customTlsCert = options.hasKey("tlsCert") ? options.getString("tlsCert") : null;
@@ -89,7 +95,7 @@ public void connect(@NonNull final Context context, @NonNull final String addres
     @SuppressWarnings("WeakerAccess")
     public void startListening() {
         //noinspection unchecked
-        receiverTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, new Pair<>(this, mReceiverListener));
+        receiverTask.executeOnExecutor(getExecutorService(), new Pair<>(this, mReceiverListener));
     }
 
     /**
@@ -113,6 +119,7 @@ public void close() {
             if (receiverTask != null && !receiverTask.isCancelled()) {
                 // stop the receiving task
                 receiverTask.cancel(true);
+                getExecutorService().shutdown();
             }
             // close the socket
             if (socket != null && !socket.isClosed()) {

android/src/main/java/com/asterinet/react/tcpsocket/TcpSocketModule.java

@@ -6,7 +6,6 @@
 import android.net.ConnectivityManager;
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
-import android.os.AsyncTask;
 import android.util.Base64;
 import android.net.Network;
 
@@ -26,6 +25,8 @@
 import java.net.InetSocketAddress;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 
@@ -34,10 +35,12 @@
 
 public class TcpSocketModule extends ReactContextBaseJavaModule implements TcpReceiverTask.OnDataReceivedListener {
     private static final String TAG = "TcpSockets";
+    private static final int N_THREADS = 2;
     private final ReactApplicationContext mReactContext;
     private final ConcurrentHashMap<Integer, TcpSocketClient> socketClients = new ConcurrentHashMap<>();
     private final ConcurrentHashMap<String, Network> mNetworkMap = new ConcurrentHashMap<>();
     private final CurrentNetwork currentNetwork = new CurrentNetwork();
+    private final ExecutorService executorService = Executors.newFixedThreadPool(N_THREADS);
 
     public TcpSocketModule(ReactApplicationContext reactContext) {
         super(reactContext);
@@ -89,7 +92,7 @@ protected void doInBackgroundGuarded(Void... params) {
                     onError(cId, e.getMessage());
                 }
             }
-        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        }.executeOnExecutor(executorService);
     }
 
     @SuppressLint("StaticFieldLeak")
@@ -115,7 +118,7 @@ protected void doInBackgroundGuarded(Void... params) {
                     onError(cId, e.toString());
                 }
             }
-        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        }.executeOnExecutor(executorService);
     }
 
     @SuppressLint("StaticFieldLeak")
@@ -132,7 +135,7 @@ protected void doInBackgroundGuarded(Void... params) {
                 socketClient.close();
                 socketClients.remove(cId);
             }
-        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        }.executeOnExecutor(executorService);
     }
 
     @SuppressWarnings("unused")
@@ -158,7 +161,7 @@ protected void doInBackgroundGuarded(Void... params) {
                     onError(cId, uhe.getMessage());
                 }
             }
-        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        }.executeOnExecutor(executorService);
     }
 
     private void requestNetwork(final int transportType) throws InterruptedException {

android/src/main/java/com/asterinet/react/tcpsocket/TcpSocketServer.java

@@ -11,6 +11,7 @@
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
 
 public final class TcpSocketServer extends TcpSocketClient {
     private ServerSocket serverSocket;
@@ -76,7 +77,7 @@ private int getClientId() {
 
     private void listen() {
         //noinspection unchecked
-        listening.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        listening.executeOnExecutor(getExecutorService());
     }
 
     @Override
@@ -90,6 +91,7 @@ public void close() {
             if (!listening.isCancelled()) {
                 // stop the receiving task
                 listening.cancel(true);
+                getExecutorService().shutdown();
             }
 
             // close the socket