diff --git a/Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitWorld.java b/Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitWorld.java index 33c23891b..4858036d7 100644 --- a/Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitWorld.java +++ b/Bukkit/src/main/java/com/plotsquared/bukkit/util/BukkitWorld.java @@ -23,11 +23,15 @@ import com.plotsquared.core.location.World; import org.bukkit.Bukkit; import org.checkerframework.checker.nullness.qual.NonNull; +import java.lang.ref.SoftReference; +import java.lang.ref.WeakReference; import java.util.Map; public class BukkitWorld implements World { - private static final Map worldMap = Maps.newHashMap(); + // Upon world unload we should probably have the P2 BukkitWorld be GCed relatively eagerly, thus freeing the bukkit world. + // We also want to avoid circumstances where a bukkit world has been GCed, but a P2 BukkitWorld has not + private static final Map> worldMap = Maps.newHashMap(); private static final boolean HAS_MIN_Y; static { @@ -41,10 +45,11 @@ public class BukkitWorld implements World { HAS_MIN_Y = temp; } - private final org.bukkit.World world; + // We want to allow GC to remove bukkit worlds, but not too eagerly + private final SoftReference world; private BukkitWorld(final org.bukkit.World world) { - this.world = world; + this.world = new SoftReference<>(world); } /** @@ -68,12 +73,13 @@ public class BukkitWorld implements World { * @return World instance */ public static @NonNull BukkitWorld of(final org.bukkit.World world) { - BukkitWorld bukkitWorld = worldMap.get(world.getName()); - if (bukkitWorld != null && bukkitWorld.getPlatformWorld().equals(world)) { + WeakReference bukkitWorldRef = worldMap.get(world.getName()); + BukkitWorld bukkitWorld; + if ((bukkitWorld = bukkitWorldRef.get()) != null && world.equals(bukkitWorld.world.get())) { return bukkitWorld; } bukkitWorld = new BukkitWorld(world); - worldMap.put(world.getName(), bukkitWorld); + worldMap.put(world.getName(), new WeakReference<>(bukkitWorld)); return bukkitWorld; } @@ -97,22 +103,26 @@ public class BukkitWorld implements World { @Override public org.bukkit.World getPlatformWorld() { - return this.world; + org.bukkit.World world = this.world.get(); + if (world == null) { + throw new IllegalStateException("Bukkit platform world was unloaded from memory"); + } + return world; } @Override public @NonNull String getName() { - return this.world.getName(); + return this.getPlatformWorld().getName(); } @Override public int getMinHeight() { - return getMinWorldHeight(world); + return getMinWorldHeight(getPlatformWorld()); } @Override public int getMaxHeight() { - return getMaxWorldHeight(world) - 1; + return getMaxWorldHeight(getPlatformWorld()) - 1; } @Override