Re-added acquired to support manual locking

src/main/java/net/minestom/server/acquirable/Acquirable.java

@@ -53,6 +53,18 @@ public interface Acquirable<T> {
         AsyncUtils.runAsync(() -> sync(consumer));
     }
 
+    default @NotNull Acquired<T> lock() {
+        var optional = optional();
+        if (optional.isPresent()) {
+            return new Acquired<>(optional.get(), false, null);
+        } else {
+            final Thread currentThread = Thread.currentThread();
+            final TickThread tickThread = getHandler().getTickThread();
+            var lock = Acquisition.acquireEnter(currentThread, tickThread);
+            return new Acquired<>(unwrap(), true, lock);
+        }
+    }
+
     default @NotNull Optional<T> optional() {
         final Thread currentThread = Thread.currentThread();
         final TickThread tickThread = getHandler().getTickThread();

src/main/java/net/minestom/server/acquirable/Acquired.java

@@ -0,0 +1,32 @@
+package net.minestom.server.acquirable;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+public class Acquired<T> {
+
+    private final T value;
+
+    private final boolean locked;
+    private final ReentrantLock lock;
+
+    protected Acquired(@NotNull T value,
+                       boolean locked, @Nullable ReentrantLock lock) {
+        this.value = value;
+        this.locked = locked;
+        this.lock = lock;
+    }
+
+    public @NotNull T get() {
+        return value;
+    }
+
+    public void unlock() {
+        if (!locked)
+            return;
+        Acquisition.acquireLeave(lock);
+    }
+
+}