From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Aikar Date: Tue, 23 Oct 2018 23:14:38 -0400 Subject: [PATCH] Improve Server Thread Pool and Thread Priorities Use a simple executor since Fork join is a much more complex pool type and we are not using its capabilities. Set thread priorities so main thread has above normal priority over server threads Allow usage of a single thread executor by not using ForkJoin so single core CPU's and reduce worldgen thread worker count for low core count CPUs. == AT == public net.minecraft.Util onThreadException(Ljava/lang/Thread;Ljava/lang/Throwable;)V Co-authored-by: Spottedleaf diff --git a/src/main/java/io/papermc/paper/util/ServerWorkerThread.java b/src/main/java/io/papermc/paper/util/ServerWorkerThread.java new file mode 100644 index 0000000000000000000000000000000000000000..b60f59cf5cc8eb84a6055b7861857dece7f2501b --- /dev/null +++ b/src/main/java/io/papermc/paper/util/ServerWorkerThread.java @@ -0,0 +1,14 @@ +package io.papermc.paper.util; + +import java.util.concurrent.atomic.AtomicInteger; +import net.minecraft.Util; + +public class ServerWorkerThread extends Thread { + private static final AtomicInteger threadId = new AtomicInteger(1); + public ServerWorkerThread(Runnable target, String poolName, int prioritityModifier) { + super(target, "Worker-" + poolName + "-" + threadId.getAndIncrement()); + setPriority(Thread.NORM_PRIORITY+prioritityModifier); // Deprioritize over main + this.setDaemon(true); + this.setUncaughtExceptionHandler(Util::onThreadException); + } +} diff --git a/src/main/java/net/minecraft/Util.java b/src/main/java/net/minecraft/Util.java index aa52b271bd556a29f774fde375b713d0d187521b..90f5e7d36719dc9b464dd6ba0335da035bab29d3 100644 --- a/src/main/java/net/minecraft/Util.java +++ b/src/main/java/net/minecraft/Util.java @@ -86,7 +86,7 @@ public class Util { private static final int DEFAULT_MAX_THREADS = 255; private static final int DEFAULT_SAFE_FILE_OPERATION_RETRIES = 10; private static final String MAX_THREADS_SYSTEM_PROPERTY = "max.bg.threads"; - private static final ExecutorService BACKGROUND_EXECUTOR = makeExecutor("Main"); + private static final ExecutorService BACKGROUND_EXECUTOR = makeExecutor("Main", -1); // Paper - add -1 priority private static final ExecutorService IO_POOL = makeIoExecutor("IO-Worker-", false); private static final ExecutorService DOWNLOAD_POOL = makeIoExecutor("Download-", true); // Paper start - don't submit BLOCKING PROFILE LOOKUPS to the world gen thread @@ -152,15 +152,27 @@ public class Util { return FILENAME_DATE_TIME_FORMATTER.format(ZonedDateTime.now()); } - private static ExecutorService makeExecutor(String name) { - int i = Mth.clamp(Runtime.getRuntime().availableProcessors() - 1, 1, getMaxThreads()); + private static ExecutorService makeExecutor(String s, int priorityModifier) { // Paper - add priority + // Paper start - use simpler thread pool that allows 1 thread and reduce worldgen thread worker count for low core count CPUs + int cpus = Runtime.getRuntime().availableProcessors() / 2; + int i; + if (cpus <= 4) { + i = cpus <= 2 ? 1 : 2; + } else if (cpus <= 8) { + // [5, 8] + i = Math.max(3, cpus - 2); + } else { + i = cpus * 2 / 3; + } + i = Math.min(8, i); + i = Integer.getInteger("Paper.WorkerThreadCount", i); ExecutorService executorService; if (i <= 0) { executorService = MoreExecutors.newDirectExecutorService(); } else { - AtomicInteger atomicInteger = new AtomicInteger(1); - executorService = new ForkJoinPool(i, (pool) -> { - ForkJoinWorkerThread forkJoinWorkerThread = new ForkJoinWorkerThread(pool) { + executorService = new java.util.concurrent.ThreadPoolExecutor(i, i,0L, TimeUnit.MILLISECONDS, new java.util.concurrent.LinkedBlockingQueue<>(), target -> new io.papermc.paper.util.ServerWorkerThread(target, s, priorityModifier)); + } + /* @Override protected void onTermination(Throwable throwable) { if (throwable != null) { @@ -176,6 +188,7 @@ public class Util { return forkJoinWorkerThread; }, Util::onThreadException, true); } + }*/ // Paper end return executorService; } diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java index 79a7f64edcfc750bf2753b5b20e4c2ae322e01ab..7a12c0f5a6cb205e8ae7667b9334efe1999e2a6a 100644 --- a/src/main/java/net/minecraft/server/MinecraftServer.java +++ b/src/main/java/net/minecraft/server/MinecraftServer.java @@ -312,6 +312,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop { MinecraftServer.LOGGER.error("Uncaught exception in server thread", throwable); }); + thread.setPriority(Thread.NORM_PRIORITY+2); // Paper - boost priority if (Runtime.getRuntime().availableProcessors() > 4) { thread.setPriority(8); }