Fixes chunk unloading - close #17

sources/src/main/java/net/minecraft/server/PaperLightingQueue.java

@@ -0,0 +1,98 @@
+package net.minecraft.server;
+
+import co.aikar.timings.Timing;
+import it.unimi.dsi.fastutil.objects.ObjectCollection;
+
+import java.util.ArrayDeque;
+
+/**
+ * <b>Akarin Changes Note</b><br>
+ * <br>
+ * 1) Expose private members<br>
+ * @author cakoyo
+ */
+class PaperLightingQueue {
+    private static final long MAX_TIME = (long) (1000000000 / 20 * .95);
+    private static int updatesThisTick;
+
+
+    static void processQueue(long curTime) {
+        updatesThisTick = 0;
+
+        final long startTime = System.nanoTime();
+        final long maxTickTime = MAX_TIME - (startTime - curTime);
+
+        START:
+        for (World world : MinecraftServer.getServer().worlds) {
+            if (!world.paperConfig.queueLightUpdates) {
+                continue;
+            }
+
+            ObjectCollection<Chunk> loadedChunks = ((WorldServer) world).getChunkProviderServer().chunks.values();
+            for (Chunk chunk : loadedChunks.toArray(new Chunk[loadedChunks.size()])) {
+                if (chunk.lightingQueue.processQueue(startTime, maxTickTime)) {
+                    break START;
+                }
+            }
+        }
+    }
+
+    public static class LightingQueue extends ArrayDeque<Runnable> { // Akarin - public
+        final private Chunk chunk;
+
+        LightingQueue(Chunk chunk) {
+            super();
+            this.chunk = chunk;
+        }
+
+        /**
+         * Processes the lighting queue for this chunk
+         *
+         * @param startTime If start Time is 0, we will not limit execution time
+         * @param maxTickTime Maximum time to spend processing lighting updates
+         * @return true to abort processing furthur lighting updates
+         */
+        private boolean processQueue(long startTime, long maxTickTime) {
+            if (this.isEmpty()) {
+                return false;
+            }
+            try (Timing ignored = chunk.world.timings.lightingQueueTimer.startTiming()) {
+                Runnable lightUpdate;
+                while ((lightUpdate = this.poll()) != null) {
+                    lightUpdate.run();
+                    if (startTime > 0 && ++PaperLightingQueue.updatesThisTick % 10 == 0 && PaperLightingQueue.updatesThisTick > 10) {
+                        if (System.nanoTime() - startTime > maxTickTime) {
+                            return true;
+                        }
+                    }
+                }
+            }
+
+            return false;
+        }
+
+        /**
+         * Flushes lighting updates to unload the chunk
+         */
+        public void processUnload() { // Akarin - public
+            if (!chunk.world.paperConfig.queueLightUpdates) {
+                return;
+            }
+            processQueue(0, 0); // No timeout
+
+            final int radius = 1; // TODO: bitflip, why should this ever be 2?
+            for (int x = chunk.locX - radius; x <= chunk.locX + radius; ++x) {
+                for (int z = chunk.locZ - radius; z <= chunk.locZ + radius; ++z) {
+                    if (x == chunk.locX && z == chunk.locZ) {
+                        continue;
+                    }
+
+                    Chunk neighbor = MCUtil.getLoadedChunkWithoutMarkingActive(chunk.world, x, z);
+                    if (neighbor != null) {
+                        neighbor.lightingQueue.processQueue(0, 0); // No timeout
+                    }
+                }
+            }
+        }
+    }
+}