From b28a418bd9f8885044f48afc5b6c253ad70256e2 Mon Sep 17 00:00:00 2001
From: cpw <cpw+github@weeksfamily.ca>
Date: Sun, 10 Feb 2019 11:44:22 -0500
Subject: [PATCH] Use a configuration value for the thread count, make it
 default to availableProcessors when set to <=0 (default value is -1)

Signed-off-by: cpw <cpw+github@weeksfamily.ca>
---
 .../minecraftforge/fml/loading/FMLConfig.java | 14 +++++++-----
 .../resources/META-INF/defaultfmlconfig.toml  |  2 ++
 .../java/net/minecraftforge/fml/ModList.java  | 22 +++++++++++--------
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/src/fmllauncher/java/net/minecraftforge/fml/loading/FMLConfig.java b/src/fmllauncher/java/net/minecraftforge/fml/loading/FMLConfig.java
index a2b4648f0..5ec8f957d 100644
--- a/src/fmllauncher/java/net/minecraftforge/fml/loading/FMLConfig.java
+++ b/src/fmllauncher/java/net/minecraftforge/fml/loading/FMLConfig.java
@@ -39,9 +39,7 @@ public class FMLConfig
     private static ConfigSpec configSpec = new ConfigSpec();
     static {
         configSpec.define("splashscreen", Boolean.TRUE);
-        configSpec.defineInList("side", Dist.CLIENT.name(), Arrays.stream(Dist.values()).map(Enum::name).collect(Collectors.toList()));
-        configSpec.defineInRange("maxframerate", 60, 10, 120);
-        configSpec.defineInRange("minframerate", 60, 10, 120);
+        configSpec.define("maxThreads", -1);
     }
 
     private CommentedFileConfig configData;
@@ -70,7 +68,13 @@ public class FMLConfig
         LOGGER.debug(CORE, "Splash screen is {}", INSTANCE.splashScreenEnabled());
     }
 
-    public boolean splashScreenEnabled() {
-        return configData.<Boolean>getOptional("splashscreen").orElse(Boolean.FALSE);
+    public static boolean splashScreenEnabled() {
+        return INSTANCE.configData.<Boolean>getOptional("splashscreen").orElse(Boolean.FALSE);
+    }
+
+    public static int loadingThreadCount() {
+        int val = INSTANCE.configData.get("maxThreads");
+        if (val <= 0) return Runtime.getRuntime().availableProcessors();
+        return val;
     }
 }
diff --git a/src/fmllauncher/resources/META-INF/defaultfmlconfig.toml b/src/fmllauncher/resources/META-INF/defaultfmlconfig.toml
index bddded498..dd5a6903d 100644
--- a/src/fmllauncher/resources/META-INF/defaultfmlconfig.toml
+++ b/src/fmllauncher/resources/META-INF/defaultfmlconfig.toml
@@ -1,2 +1,4 @@
 # does the splashscreen run
 splashscreen = true
+# max threads for parallel loading : -1 uses Runtime#availableProcessors
+maxThreads = -1
diff --git a/src/main/java/net/minecraftforge/fml/ModList.java b/src/main/java/net/minecraftforge/fml/ModList.java
index 396e44190..576228928 100644
--- a/src/main/java/net/minecraftforge/fml/ModList.java
+++ b/src/main/java/net/minecraftforge/fml/ModList.java
@@ -19,6 +19,7 @@
 
 package net.minecraftforge.fml;
 
+import net.minecraftforge.fml.loading.FMLConfig;
 import net.minecraftforge.forgespi.language.ModFileScanData;
 import net.minecraftforge.fml.loading.FMLLoader;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
@@ -35,7 +36,6 @@ import java.util.Optional;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ForkJoinPool;
 import java.util.concurrent.ForkJoinWorkerThread;
-import java.util.concurrent.FutureTask;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -56,14 +56,7 @@ public class ModList
     private final Map<String, ModFileInfo> fileById;
     private List<ModContainer> mods;
     private Map<String, ModContainer> indexedMods;
-    private ForkJoinPool modLoadingThreadPool = new ForkJoinPool(Runtime.getRuntime().availableProcessors(), pool ->
-    {
-        ForkJoinWorkerThread thread = ForkJoinPool.defaultForkJoinWorkerThreadFactory.newThread(pool);
-        thread.setName("modloading-worker-" + thread.getPoolIndex());
-        // The default sets it to the SystemClassloader, so copy the current one.
-        thread.setContextClassLoader(Thread.currentThread().getContextClassLoader());
-        return thread;
-    }, null, false);
+    private ForkJoinPool modLoadingThreadPool;
     private List<ModFileScanData> modFileScanData;
 
     private ModList(final List<ModFile> modFiles, final List<ModInfo> sortedList)
@@ -75,6 +68,9 @@ public class ModList
         this.fileById = this.modFiles.stream().map(ModFileInfo::getMods).flatMap(Collection::stream).
                 map(ModInfo.class::cast).
                 collect(Collectors.toMap(ModInfo::getModId, ModInfo::getOwningFile));
+        final int loadingThreadCount = FMLConfig.loadingThreadCount();
+        LOGGER.debug(LOADING, "Using {} threads for parallel mod-loading", loadingThreadCount);
+        modLoadingThreadPool = new ForkJoinPool(loadingThreadCount, ModList::newForkJoinWorkerThread, null, false);
     }
 
     public static ModList of(List<ModFile> modFiles, List<ModInfo> sortedList)
@@ -91,6 +87,14 @@ public class ModList
         return INSTANCE;
     }
 
+    private static ForkJoinWorkerThread newForkJoinWorkerThread(ForkJoinPool pool) {
+        ForkJoinWorkerThread thread = ForkJoinPool.defaultForkJoinWorkerThreadFactory.newThread(pool);
+        thread.setName("modloading-worker-" + thread.getPoolIndex());
+        // The default sets it to the SystemClassloader, so copy the current one.
+        thread.setContextClassLoader(Thread.currentThread().getContextClassLoader());
+        return thread;
+    }
+
     public List<ModFileInfo> getModFiles()
     {
         return modFiles;