Add Thread.onSpinWait MCR

Author: Gaming32

src/main/java/net/raphimc/javadowngrader/transformer/j8/Java9ToJava8.java

@@ -38,6 +38,7 @@
 import net.raphimc.javadowngrader.transformer.j8.methodcallreplacer.OptionalStreamMCR;
 import net.raphimc.javadowngrader.transformer.j8.methodcallreplacer.RuntimeVersionMCR;
 import net.raphimc.javadowngrader.transformer.j8.methodcallreplacer.SetOfMCR;
+import net.raphimc.javadowngrader.transformer.j8.methodcallreplacer.ThreadOnSpinWaitMCR;
 import net.raphimc.javadowngrader.transformer.j8.methodinserter.PathEndsWithMI;
 import net.raphimc.javadowngrader.transformer.j8.methodinserter.PathResolveMI;
 import net.raphimc.javadowngrader.transformer.j8.methodinserter.PathStartsWithMI;
@@ -109,6 +110,8 @@ public Java9ToJava8() {
 
         this.addMethodCallReplacer(Opcodes.INVOKESTATIC, "java/lang/Integer", "parseInt", "(Ljava/lang/CharSequence;III)I", new IntegerParseIntMCR());
         this.addMethodCallReplacer(Opcodes.INVOKESTATIC, "java/lang/Integer", "parseUnsignedInt", "(Ljava/lang/CharSequence;III)I", new IntegerParseIntMCR());
+
+        this.addMethodCallReplacer(Opcodes.INVOKESTATIC, "java/lang/Thread", "onSpinWait", new ThreadOnSpinWaitMCR());
     }
 
     @Override

src/main/java/net/raphimc/javadowngrader/transformer/j8/methodcallreplacer/ThreadOnSpinWaitMCR.java

@@ -0,0 +1,36 @@
+/*
+ * This file is part of JavaDowngrader - https://github.com/RaphiMC/JavaDowngrader
+ * Copyright (C) 2023-2024 RK_01/RaphiMC and contributors
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package net.raphimc.javadowngrader.transformer.j8.methodcallreplacer;
+
+import net.raphimc.javadowngrader.RuntimeDepCollector;
+import net.raphimc.javadowngrader.transformer.DowngradeResult;
+import net.raphimc.javadowngrader.transformer.MethodCallReplacer;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.MethodInsnNode;
+import org.objectweb.asm.tree.MethodNode;
+
+public class ThreadOnSpinWaitMCR implements MethodCallReplacer {
+    @Override
+    public InsnList getReplacement(ClassNode classNode, MethodNode method, String originalName, String originalDesc, RuntimeDepCollector depCollector, DowngradeResult result) {
+        final InsnList replacement = new InsnList();
+        replacement.add(new MethodInsnNode(Opcodes.INVOKESTATIC, "java/lang/Thread", "yield", "()V"));
+        return replacement;
+    }
+}