Improve JVM startup time

script/server.sh

@@ -1,10 +1,12 @@
 #!/bin/sh
 
-# The alive checker and Minecraft server is started at the same time. For performance reasons, the
-# OpenJ9 JVM is used instead of Java's default Hotspot JVM.
+# The alive checker and Minecraft server is started at the same time
 
 PATH="$HOME/framework/vendor/java/bin/:$PATH"
 
+# Dump classes
+java -Xshare:dump
+
 # Make sure we're in the server folder, located in the home directory
 cd ~/server/
 
@@ -32,21 +34,9 @@ while true; do
 
 	java \
 		-Xmx1800M \
+		-Xshare:on \
 		-Xss8M \
-		-Xtune:virtualized \
-		-Xaggressive \
-		-Xcompressedrefs \
-		-Xdump:heap+java+snap+system:none \
-		-Xdump:tool:events=throw+systhrow,filter=java/lang/OutOfMemoryError,exec="kill -9 %pid" \
-		-Xgc:concurrentScavenge \
-		-Xgc:dnssExpectedTimeRatioMaximum=3 \
-		-Xgc:scvNoAdaptiveTenure \
-		-Xdisableexplicitgc \
-		-Xshareclasses \
-		-Xshareclasses:noPersistentDiskSpaceCheck \
 		-XX:MaxDirectMemorySize=128M \
-		-XX:+ClassRelationshipVerifier \
-		-XX:+GlobalLockReservation \
 		-XX:+UseContainerSupport \
 		-DPaper.IgnoreJavaVersion=true \
 		-Dpaper.playerconnection.keepalive=360 \

vendor/generate_jre.sh

@@ -1,25 +1,14 @@
 #!/bin/sh
 
-# This script is used as a reference to generate a stripped-down OpenJ9 JRE for the server
+# This script is used as a reference to generate a stripped-down JRE for the server
 
 rm -rf java/
-wget https://github.com/AdoptOpenJDK/openjdk14-binaries/releases/download/jdk-14.0.2%2B12_openj9-0.21.0/OpenJDK14U-jdk_x64_linux_openj9_14.0.2_12_openj9-0.21.0.tar.gz
+wget https://github.com/AdoptOpenJDK/openjdk14-binaries/releases/download/jdk-14.0.2%2B12/OpenJDK14U-jdk_x64_linux_hotspot_14.0.2_12.tar.gz
 tar -zxvf OpenJDK*
 rm OpenJDK*
 mv jdk* jdk/
 jdk/bin/jlink --no-header-files --no-man-pages --compress=2 --strip-debug \
 	--exclude-files=**java_*.properties,**jrunscript,**keytool,**legal/** \
-	--add-modules \
-		java.desktop, \
-		java.logging, \
-		java.management, \
-		java.naming, \
-		java.net.http, \
-		java.scripting, \
-		java.sql, \
-		jdk.crypto.ec, \
-		jdk.unsupported, \
-		jdk.zipfs, \
-		openj9.sharedclasses \
+	--add-modules java.desktop,java.logging,java.management,java.naming,java.net.http,java.scripting,java.sql,jdk.crypto.ec,jdk.unsupported,jdk.zipfs \
 	--output java
 rm -rf jdk/

vendor/java/lib/options.default

@@ -1 +0,0 @@
-"-Xlockword:mode=default,noLockword=java/lang/String,noLockword=java/util/MapEntry,noLockword=java/util/HashMap$Entry,noLockword=org/apache/harmony/luni/util/ModifiedMap$Entry,noLockword=java/util/Hashtable$Entry,noLockword=java/lang/invoke/MethodType,noLockword=java/lang/invoke/MethodHandle,noLockword=java/lang/invoke/CollectHandle,noLockword=java/lang/invoke/ConstructorHandle,noLockword=java/lang/invoke/ConvertHandle,noLockword=java/lang/invoke/ArgumentConversionHandle,noLockword=java/lang/invoke/AsTypeHandle,noLockword=java/lang/invoke/ExplicitCastHandle,noLockword=java/lang/invoke/FilterReturnHandle,noLockword=java/lang/invoke/DirectHandle,noLockword=java/lang/invoke/ReceiverBoundHandle,noLockword=java/lang/invoke/DynamicInvokerHandle,noLockword=java/lang/invoke/FieldHandle,noLockword=java/lang/invoke/FieldGetterHandle,noLockword=java/lang/invoke/FieldSetterHandle,noLockword=java/lang/invoke/StaticFieldGetterHandle,noLockword=java/lang/invoke/StaticFieldSetterHandle,noLockword=java/lang/invoke/IndirectHandle,noLockword=java/lang/invoke/InterfaceHandle,noLockword=java/lang/invoke/VirtualHandle,noLockword=java/lang/invoke/PrimitiveHandle,noLockword=java/lang/invoke/InvokeExactHandle,noLockword=java/lang/invoke/InvokeGenericHandle,noLockword=java/lang/invoke/VarargsCollectorHandle,noLockword=java/lang/invoke/ThunkTuple"

vendor/java/lib/security/default.policy

@@ -103,19 +103,6 @@ grant codeBase "jrt:/jdk.accessibility" {
     permission java.lang.RuntimePermission "accessClassInPackage.sun.awt";
 };
 
-grant codeBase "jrt:/jdk.attach" {
-    permission java.lang.RuntimePermission "accessClassInPackage.com.ibm.oti.util";
-    permission java.lang.RuntimePermission "accessClassInPackage.openj9.internal.tools.attach.target";
-    permission java.lang.RuntimePermission "accessClassInPackage.openj9.internal.tools.attach.diagnostics.base";
-    permission java.util.PropertyPermission "com.ibm.tools.attach.*", "read";
-    // required by com.ibm.tools.attach.attacher.OpenJ9AttachProvider.listVirtualMachinesImp():commonDir.exists(),
-    // openj9.internal.tools.attach.target.Reply.writeReply():new RandomAccessFile(replyFile, "rw"),
-    // and openj9.internal.tools.attach.target.Reply.deleteReply():replyFile.delete()
-    permission java.io.FilePermission "<<ALL FILES>>", "read,write,delete";
-    // required by com.ibm.tools.attach.attacher.OpenJ9VirtualMachine.tryAttachTarget():targetServer.accept()
-    permission java.net.SocketPermission "localhost:1024-", "accept,resolve";
-};
-
 grant codeBase "jrt:/jdk.charsets" {
     permission java.util.PropertyPermission "os.name", "read";
     permission java.lang.RuntimePermission "charsetProvider";
@@ -219,26 +206,6 @@ grant codeBase "jrt:/jdk.zipfs" {
     permission java.util.PropertyPermission "user.name", "read";
 };
 
-grant codeBase "jrt:/openj9.cuda" {
-    permission java.lang.RuntimePermission "accessClassInPackage.com.ibm.oti.vm";
-    permission java.lang.RuntimePermission "loadLibrary.cuda4j29";
-    permission java.lang.RuntimePermission "modifyThread";
-    permission java.lang.RuntimePermission "modifyThreadGroup";
-    permission java.util.PropertyPermission "com.ibm.oti.vm.library.version", "read";
-};
-
-grant codeBase "jrt:/openj9.gpu" {
-    permission com.ibm.gpu.GPUPermission "access";
-    permission java.lang.RuntimePermission "accessClassInPackage.com.ibm.gpu.spi";
-    permission java.lang.RuntimePermission "accessClassInPackage.com.ibm.oti.vm";
-    permission java.lang.RuntimePermission "modifyThread";
-    permission java.lang.RuntimePermission "modifyThreadGroup";
-    permission java.util.PropertyPermission "com.ibm.gpu.verbose", "read";
-    permission java.util.PropertyPermission "com.ibm.gpu.enforce", "read";
-    permission java.util.PropertyPermission "com.ibm.gpu.enable", "read";
-    permission java.util.PropertyPermission "com.ibm.gpu.disable", "read";
-};
-
 // permissions needed by applications using java.desktop module
 grant {
     permission java.lang.RuntimePermission "accessClassInPackage.com.sun.beans";

vendor/java/release

@@ -1,2 +1,2 @@
 JAVA_VERSION="14.0.2"
-MODULES="java.base java.datatransfer java.xml java.prefs java.desktop java.logging java.management java.security.sasl java.naming java.net.http java.scripting java.transaction.xa java.sql jdk.crypto.ec jdk.unsupported jdk.zipfs openj9.sharedclasses"
+MODULES="java.base java.datatransfer java.xml java.prefs java.desktop java.logging java.management java.security.sasl java.naming java.net.http java.scripting java.transaction.xa java.sql jdk.crypto.ec jdk.unsupported jdk.zipfs"