More safety in Acquired + doc

Signed-off-by: TheMode <themode@outlook.fr>

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

@@ -6,28 +6,39 @@ import org.jetbrains.annotations.NotNull;
 
 import java.util.concurrent.locks.ReentrantLock;
 
+/**
+ * Represents an object that has been safely acquired and can be freed again.
+ * <p>
+ * This class should not be shared, and it is recommended to call {@link #unlock()}
+ * once the acquisition goal has been fulfilled to limit blocking time.
+ *
+ * @param <T> the type of the acquired object
+ */
 public final class Acquired<T> {
     private final T value;
+    private final Thread owner;
     private final ReentrantLock lock;
     private boolean unlocked;
 
     Acquired(T value, TickThread tickThread) {
         this.value = value;
-        this.lock = AcquirableImpl.enter(Thread.currentThread(), tickThread);
+        this.owner = Thread.currentThread();
+        this.lock = AcquirableImpl.enter(owner, tickThread);
     }
 
     public @NotNull T get() {
-        checkLock();
+        safeCheck();
         return value;
     }
 
     public void unlock() {
-        checkLock();
+        safeCheck();
         this.unlocked = true;
         AcquirableImpl.leave(lock);
     }
 
-    private void checkLock() {
+    private void safeCheck() {
+        Check.stateCondition(Thread.currentThread() != owner, "Acquired object is owned by the thread {0}", owner);
         Check.stateCondition(unlocked, "The acquired element has already been unlocked!");
     }
 }