Patch.txt

diff --git a/src/main/java/io/vertx/core/file/impl/AsyncFileImpl.java b/src/main/java/io/vertx/core/file/impl/AsyncFileImpl.java
index c9f8992..301bde9 100644
--- a/src/main/java/io/vertx/core/file/impl/AsyncFileImpl.java
+++ b/src/main/java/io/vertx/core/file/impl/AsyncFileImpl.java
@@ -43,6 +43,7 @@ import java.util.HashSet;
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
 
 /**
  *
@@ -65,7 +66,7 @@ public class AsyncFileImpl implements AsyncFile {
   private final ContextImpl context;
   private boolean closed;
   private Runnable closedDeferred;
-  private long writesOutstanding;
+  private AtomicLong writesOutstanding = new AtomicLong();
   private Handler<Throwable> exceptionHandler;
   private Handler<Void> drainHandler;
   private long writePos;
@@ -148,7 +149,7 @@ public class AsyncFileImpl implements AsyncFile {
     Handler<AsyncResult<Void>> wrapped = ar -> {
       if (ar.succeeded()) {
         checkContext();
-        if (writesOutstanding == 0 && closedDeferred != null) {
+        if (writesOutstanding.get() == 0 && closedDeferred != null) {
           closedDeferred.run();
         } else {
           checkDrained();
@@ -200,7 +201,7 @@ public class AsyncFileImpl implements AsyncFile {
   @Override
   public synchronized boolean writeQueueFull() {
     check();
-    return writesOutstanding >= maxWrites;
+    return writesOutstanding.get() >= maxWrites;
   }
 
   @Override
@@ -280,7 +281,7 @@ public class AsyncFileImpl implements AsyncFile {
   }
 
   private synchronized void checkDrained() {
-    if (drainHandler != null && writesOutstanding <= lwm) {
+    if (drainHandler != null && writesOutstanding.get() <= lwm) {
       Handler<Void> handler = drainHandler;
       drainHandler = null;
       handler.handle(null);
@@ -371,7 +372,7 @@ public class AsyncFileImpl implements AsyncFile {
     if (toWrite == 0) {
       throw new IllegalStateException("Cannot save zero bytes");
     }
-    writesOutstanding += toWrite;
+    writesOutstanding.addAndGet(toWrite);
     writeInternal(buff, position, handler);
   }
 
@@ -391,7 +392,7 @@ public class AsyncFileImpl implements AsyncFile {
         } else {
           // It's been fully written
           context.runOnContext((v) -> {
-            writesOutstanding -= buff.limit();
+            writesOutstanding.addAndGet(-buff.limit());
             handler.handle(Future.succeededFuture());
           });
         }
@@ -476,7 +477,7 @@ public class AsyncFileImpl implements AsyncFile {
 
     closed = true;
 
-    if (writesOutstanding == 0) {
+    if (writesOutstanding.get() == 0) {
       doClose(handler);
     } else {
       closedDeferred = () -> doClose(handler);