Allow Vert.x to use other Context implementations than EventLoopConte…

…xt and WorkerContext.

The Context and its related classes/intefaces have been refactored to pull up code as much as possible in Context and ContextInternal in order to ease new implementations, consequently the AbstractContext class has been removed.

The ContextImpl class has been renamed ContextBase and provides a base class for implementing context.

fixes #4425

src/main/java/io/vertx/core/Context.java

@@ -16,6 +16,7 @@
 import io.vertx.codegen.annotations.Nullable;
 import io.vertx.codegen.annotations.VertxGen;
 import io.vertx.core.impl.VertxThread;
+import io.vertx.core.impl.launcher.VertxCommandLauncher;
 import io.vertx.core.json.JsonObject;
 
 import java.util.List;
@@ -135,7 +136,9 @@ static boolean isOnVertxThread() {
    * @param resultHandler  handler that will be called when the blocking code is complete
    * @param <T> the type of the result
    */
-  <T> void executeBlocking(Handler<Promise<T>> blockingCodeHandler, Handler<AsyncResult<@Nullable T>> resultHandler);
+  default <T> void executeBlocking(Handler<Promise<T>> blockingCodeHandler, Handler<AsyncResult<@Nullable T>> resultHandler) {
+    executeBlocking(blockingCodeHandler, true, resultHandler);
+  }
 
   /**
    * Same as {@link #executeBlocking(Handler, boolean, Handler)} but with an {@code handler} called when the operation completes
@@ -145,7 +148,9 @@ static boolean isOnVertxThread() {
   /**
    * Same as {@link #executeBlocking(Handler, Handler)} but with an {@code handler} called when the operation completes
    */
-  <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler);
+  default <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler) {
+    return executeBlocking(blockingCodeHandler, true);
+  }
 
   /**
    * If the context is associated with a Verticle deployment, this returns the deployment ID of that deployment.
@@ -165,7 +170,9 @@ static boolean isOnVertxThread() {
   /**
    * The process args
    */
-  List<String> processArgs();
+  default List<String> processArgs() {
+    return VertxCommandLauncher.getProcessArguments();
+  }
 
   /**
    * Is the current context an event loop context?

src/main/java/io/vertx/core/file/impl/AsyncFileImpl.java

@@ -99,9 +99,9 @@ public class AsyncFileImpl implements AsyncFile {
     try {
       if (options.getPerms() != null) {
         FileAttribute<?> attrs = PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString(options.getPerms()));
-        ch = AsynchronousFileChannel.open(file, opts, vertx.getWorkerPool(), attrs);
+        ch = AsynchronousFileChannel.open(file, opts, vertx.getWorkerPool().executor(), attrs);
       } else {
-        ch = AsynchronousFileChannel.open(file, opts, vertx.getWorkerPool());
+        ch = AsynchronousFileChannel.open(file, opts, vertx.getWorkerPool().executor());
       }
       if (options.isAppend()) writePos = ch.size();
     } catch (IOException e) {

src/main/java/io/vertx/core/http/impl/Http1xServerRequest.java

@@ -123,7 +123,7 @@ void setRequest(HttpRequest request) {
 
   private InboundBuffer<Object> pendingQueue() {
     if (pending == null) {
-      pending = new InboundBuffer<>(conn.getContext(), 8);
+      pending = new InboundBuffer<>(context, 8);
       pending.drainHandler(v -> conn.doResume());
       pending.handler(buffer -> {
         if (buffer == InboundBuffer.END_SENTINEL) {