Dont allow gradle to run game/genSources tasks in parallel (#901)

* Dont allow gradle to run game/genSources tasks in parallel

* Fix build

src/main/java/net/fabricmc/loom/task/AbstractRunTask.java

@@ -38,18 +38,25 @@ import java.util.stream.Collectors;
 import org.gradle.api.Project;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.FileCollection;
+import org.gradle.api.provider.Property;
+import org.gradle.api.services.ServiceReference;
 import org.gradle.api.specs.Spec;
 import org.gradle.api.tasks.JavaExec;
 import org.jetbrains.annotations.NotNull;
 
 import net.fabricmc.loom.configuration.ide.RunConfig;
 import net.fabricmc.loom.util.Constants;
+import net.fabricmc.loom.util.gradle.SyncTaskBuildService;
 
 public abstract class AbstractRunTask extends JavaExec {
 	private final RunConfig config;
 	// We control the classpath, as we use a ArgFile to pass it over the command line: https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javac.html#commandlineargfile
 	private final ConfigurableFileCollection classpath = getProject().getObjects().fileCollection();
 
+	// Prevent Gradle from running two run tasks in parallel
+	@ServiceReference(SyncTaskBuildService.NAME)
+	abstract Property<SyncTaskBuildService> getSyncTask();
+
 	public AbstractRunTask(Function<Project, RunConfig> configProvider) {
 		super();
 		setGroup(Constants.TaskGroup.FABRIC);

src/main/java/net/fabricmc/loom/task/GenerateSourcesTask.java

@@ -48,6 +48,7 @@ import javax.inject.Inject;
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.RegularFileProperty;
 import org.gradle.api.provider.Property;
+import org.gradle.api.services.ServiceReference;
 import org.gradle.api.tasks.InputFile;
 import org.gradle.api.tasks.InputFiles;
 import org.gradle.api.tasks.OutputFile;
@@ -72,6 +73,7 @@ import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.FileSystemUtil;
 import net.fabricmc.loom.util.IOStringConsumer;
 import net.fabricmc.loom.util.Platform;
+import net.fabricmc.loom.util.gradle.SyncTaskBuildService;
 import net.fabricmc.loom.util.gradle.ThreadedProgressLoggerConsumer;
 import net.fabricmc.loom.util.gradle.ThreadedSimpleProgressLogger;
 import net.fabricmc.loom.util.gradle.WorkerDaemonClientsManagerHelper;
@@ -111,6 +113,10 @@ public abstract class GenerateSourcesTask extends AbstractLoomTask {
 	@Inject
 	public abstract WorkerDaemonClientsManager getWorkerDaemonClientsManager();
 
+	// Prevent Gradle from running two gen sources tasks in parallel
+	@ServiceReference(SyncTaskBuildService.NAME)
+	abstract Property<SyncTaskBuildService> getSyncTask();
+
 	@Inject
 	public GenerateSourcesTask(DecompilerOptions decompilerOptions) {
 		this.decompilerOptions = decompilerOptions;

src/main/java/net/fabricmc/loom/task/RemapTaskConfiguration.java

@@ -44,6 +44,7 @@ import net.fabricmc.loom.LoomGradleExtension;
 import net.fabricmc.loom.util.Constants;
 import net.fabricmc.loom.util.gradle.GradleUtils;
 import net.fabricmc.loom.util.gradle.SourceSetHelper;
+import net.fabricmc.loom.util.gradle.SyncTaskBuildService;
 
 public abstract class RemapTaskConfiguration implements Runnable {
 	public static final String REMAP_JAR_TASK_NAME = "remapJar";
@@ -64,6 +65,8 @@ public abstract class RemapTaskConfiguration implements Runnable {
 	public void run() {
 		final LoomGradleExtension extension = LoomGradleExtension.get(getProject());
 
+		SyncTaskBuildService.register(getProject());
+
 		if (GradleUtils.getBooleanProperty(getProject(), Constants.Properties.DONT_REMAP)) {
 			extension.getUnmappedModCollection().from(getTasks().getByName(JavaPlugin.JAR_TASK_NAME));
 			return;

src/main/java/net/fabricmc/loom/task/RunGameTask.java

@@ -29,7 +29,7 @@ import javax.inject.Inject;
 import net.fabricmc.loom.configuration.ide.RunConfig;
 import net.fabricmc.loom.configuration.ide.RunConfigSettings;
 
-public class RunGameTask extends AbstractRunTask {
+public abstract class RunGameTask extends AbstractRunTask {
 	@Inject
 	public RunGameTask(RunConfigSettings settings) {
 		super(proj -> RunConfig.runConfig(proj, settings));

src/main/java/net/fabricmc/loom/util/gradle/SyncTaskBuildService.java

@@ -0,0 +1,52 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2018-2021 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.util.gradle;
+
+import org.gradle.api.Project;
+import org.gradle.api.services.BuildService;
+import org.gradle.api.services.BuildServiceParameters;
+
+/**
+ * Add the following snippet to task to prevent tasks running asynchronously with any other task with the same build service.
+ *
+ * <pre>{@code
+ * @ServiceReference(SyncTaskBuildService.NAME)
+ * abstract Property<SyncTaskBuildService> getSyncTask();
+ * }</pre>
+ */
+public abstract class SyncTaskBuildService implements BuildService<SyncTaskBuildService.Params> {
+	public static final String NAME = "loomSyncTask";
+
+	public static void register(Project project) {
+		project.getGradle().getSharedServices().registerIfAbsent(
+					NAME,
+					SyncTaskBuildService.class,
+					spec -> spec.getMaxParallelUsages().set(1)
+		);
+	}
+
+	public interface Params extends BuildServiceParameters {
+	}
+}