f

adapters/modded-common/src/main/java/art/arcane/iris/modded/ModdedEngineBootstrap.java

@@ -104,7 +104,6 @@ public final class ModdedEngineBootstrap {
         ModdedStartup.prepareForStartup();
         IrisModdedChunkGenerator.startGenPool();
         bindWorldGenerators(server);
-        ModdedStartup.runOnce(server);
         services().enableAll();
         ModdedProtocolHandler.start(server);
         ModdedSentry.start(loader());
@@ -125,6 +124,7 @@ public final class ModdedEngineBootstrap {
 
     public static void serverStarted(MinecraftServer server) {
         bindWorldGenerators(server);
+        ModdedStartup.runOnce(server);
         reconcileSpawn(server);
         ModdedWorldCheck.serverStarted(server);
     }
@@ -284,7 +284,8 @@ public final class ModdedEngineBootstrap {
                 IrisPlatforms.bind(created);
                 rollback.add(() -> restorePlatform(previousPlatform));
 
-                ModdedServerAccess previousServerAccess = ModdedDimensionManager.bindAccess(new ModdedServerLevels());
+                ModdedServerAccess previousServerAccess = ModdedDimensionManager.bindAccess(
+                        new ModdedServerLevels(boundLoader::invalidateLevelCache));
                 rollback.add(() -> ModdedDimensionManager.restoreAccess(previousServerAccess));
 
                 IrisObjectRotation.StateRotator previousRotator = IrisObjectRotation.bindPlatformRotator(new ModdedStateRotator());

adapters/modded-common/src/main/java/art/arcane/iris/modded/ModdedLoader.java

@@ -32,6 +32,8 @@ public interface ModdedLoader {
 
     MinecraftServer currentServer();
 
+    void invalidateLevelCache(MinecraftServer server);
+
     boolean clientEnvironment();
 
     Path configDir();

adapters/modded-common/src/main/java/art/arcane/iris/modded/ModdedServerLevels.java

@@ -24,9 +24,17 @@ import net.minecraft.server.level.ServerLevel;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.storage.LevelStorageSource;
 
+import java.util.Objects;
 import java.util.concurrent.Executor;
+import java.util.function.Consumer;
 
 public final class ModdedServerLevels implements ModdedServerAccess {
+    private final Consumer<MinecraftServer> levelCacheInvalidator;
+
+    public ModdedServerLevels(Consumer<MinecraftServer> levelCacheInvalidator) {
+        this.levelCacheInvalidator = Objects.requireNonNull(levelCacheInvalidator);
+    }
+
     @Override
     public Executor levelExecutor(MinecraftServer server) {
         return server.executor;
@@ -39,17 +47,29 @@ public final class ModdedServerLevels implements ModdedServerAccess {
 
     @Override
     public ServerLevel putLevel(MinecraftServer server, ResourceKey<Level> key, ServerLevel level) {
-        return server.levels.put(key, level);
+        ServerLevel previous = server.levels.put(key, level);
+        if (previous != level) {
+            levelCacheInvalidator.accept(server);
+        }
+        return previous;
     }
 
     @Override
     public ServerLevel putLevelIfAbsent(MinecraftServer server, ResourceKey<Level> key, ServerLevel level) {
-        return server.levels.putIfAbsent(key, level);
+        ServerLevel previous = server.levels.putIfAbsent(key, level);
+        if (previous == null) {
+            levelCacheInvalidator.accept(server);
+        }
+        return previous;
     }
 
     @Override
     public ServerLevel removeLevel(MinecraftServer server, ResourceKey<Level> key) {
-        return server.levels.remove(key);
+        ServerLevel removed = server.levels.remove(key);
+        if (removed != null) {
+            levelCacheInvalidator.accept(server);
+        }
+        return removed;
     }
 
     @Override

adapters/modded-common/src/main/java/art/arcane/iris/modded/ModdedStartup.java

@@ -66,7 +66,7 @@ public final class ModdedStartup {
     }
 
     public static void runOnce(MinecraftServer server) {
-        if (server == null) {
+        if (server == null || server.getPlayerList() == null) {
             return;
         }
         prepareForStartup();

adapters/modded-common/src/test/java/art/arcane/iris/modded/ModdedLifecycleFailureContractTest.java

@@ -72,6 +72,44 @@ public class ModdedLifecycleFailureContractTest {
         assertTrue(failure.contains(", e);"));
     }
 
+    @Test
+    public void persistentReinjectionWaitsForPlayerServicesAndServerStarted() throws IOException {
+        String bootstrapSource = source("ModdedEngineBootstrap.java");
+        String start = method(bootstrapSource, "public static void start(");
+        String serverAboutToStart = method(bootstrapSource, "public static void serverAboutToStart(");
+        String serverStarted = method(bootstrapSource, "public static void serverStarted(");
+
+        assertFalse(start.contains("ModdedStartup.runOnce(server);"));
+        assertFalse(serverAboutToStart.contains("ModdedStartup.runOnce(server);"));
+        assertEquals(1, occurrences(serverStarted, "ModdedStartup.runOnce(server);"));
+        assertBefore(serverStarted, "bindWorldGenerators(server);", "ModdedStartup.runOnce(server);");
+        assertBefore(serverStarted, "ModdedStartup.runOnce(server);", "reconcileSpawn(server);");
+
+        String startupSource = source("ModdedStartup.java");
+        String runOnce = method(startupSource, "public static void runOnce(");
+        assertBefore(runOnce, "server.getPlayerList() == null", "STARTED.compareAndSet(false, true)");
+    }
+
+    @Test
+    public void dynamicLevelMutationsInvalidateLoaderTickCaches() throws IOException {
+        String levelsSource = source("ModdedServerLevels.java");
+        String put = method(levelsSource, "public ServerLevel putLevel(");
+        String putIfAbsent = method(levelsSource, "public ServerLevel putLevelIfAbsent(");
+        String remove = method(levelsSource, "public ServerLevel removeLevel(");
+
+        assertBefore(put, "server.levels.put(key, level);", "levelCacheInvalidator.accept(server);");
+        assertTrue(put.contains("if (previous != level)"));
+        assertBefore(putIfAbsent, "server.levels.putIfAbsent(key, level);", "levelCacheInvalidator.accept(server);");
+        assertTrue(putIfAbsent.contains("if (previous == null)"));
+        assertBefore(remove, "server.levels.remove(key);", "levelCacheInvalidator.accept(server);");
+        assertTrue(remove.contains("if (removed != null)"));
+
+        String loaderSource = source("ModdedLoader.java");
+        assertTrue(loaderSource.contains("void invalidateLevelCache(MinecraftServer server);"));
+        String bootstrapSource = source("ModdedEngineBootstrap.java");
+        assertTrue(bootstrapSource.contains("new ModdedServerLevels(boundLoader::invalidateLevelCache)"));
+    }
+
     @Test
     public void packDimensionLoadingNeverSuppressesTheFailureAsNull() throws IOException {
         String source = source("ModdedDimensionManager.java");