From d08c612b4059f0ffa0dc97b5df45a5d7e4b2de8a Mon Sep 17 00:00:00 2001
From: Andrey Turbanov <turbanoff@gmail.com>
Date: Fri, 4 Dec 2020 06:32:14 +0000
Subject: [PATCH] 8257708: Remove redundant unmodifiableSet wrapper from
 already immutable set returned by Collections.singleton

Reviewed-by: shade, sspitsyn
---
 .../DefaultPlatformMBeanProvider.java         | 32 +++++++------------
 .../internal/PlatformMBeanProviderImpl.java   |  8 ++---
 2 files changed, 14 insertions(+), 26 deletions(-)

diff --git a/src/java.management/share/classes/java/lang/management/DefaultPlatformMBeanProvider.java b/src/java.management/share/classes/java/lang/management/DefaultPlatformMBeanProvider.java
index ba8661c5bcb..7e928227e57 100644
--- a/src/java.management/share/classes/java/lang/management/DefaultPlatformMBeanProvider.java
+++ b/src/java.management/share/classes/java/lang/management/DefaultPlatformMBeanProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -56,8 +56,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<ClassLoadingMXBean>() {
             private final Set<String> classLoadingInterfaceNames =
-                    Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.ClassLoadingMXBean"));
+                    Collections.singleton("java.lang.management.ClassLoadingMXBean");
 
             @Override
             public Set<Class<? extends ClassLoadingMXBean>> mbeanInterfaces() {
@@ -87,8 +86,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<CompilationMXBean>() {
             private final Set<String> compilationMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.CompilationMXBean"));
+                    = Collections.singleton("java.lang.management.CompilationMXBean");
 
             @Override
             public Set<Class<? extends CompilationMXBean>> mbeanInterfaces() {
@@ -123,8 +121,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<MemoryMXBean>() {
             private final Set<String> memoryMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.MemoryMXBean"));
+                    = Collections.singleton("java.lang.management.MemoryMXBean");
 
             @Override
             public Set<Class<? extends MemoryMXBean>> mbeanInterfaces() {
@@ -203,8 +200,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<MemoryManagerMXBean>() {
             private final Set<String> memoryManagerMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.MemoryManagerMXBean"));
+                    = Collections.singleton("java.lang.management.MemoryManagerMXBean");
 
             @Override
             public Set<Class<? extends MemoryManagerMXBean>> mbeanInterfaces() {
@@ -252,8 +248,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<MemoryPoolMXBean>() {
             private final Set<String> memoryPoolMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.MemoryPoolMXBean"));
+                    = Collections.singleton("java.lang.management.MemoryPoolMXBean");
 
             @Override
             public Set<Class<? extends MemoryPoolMXBean>> mbeanInterfaces() {
@@ -298,8 +293,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<RuntimeMXBean>() {
             private final Set<String> runtimeMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.RuntimeMXBean"));
+                    = Collections.singleton("java.lang.management.RuntimeMXBean");
 
             @Override
             public Set<Class<? extends RuntimeMXBean>> mbeanInterfaces() {
@@ -329,8 +323,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<ThreadMXBean>() {
             private final Set<String> threadMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.ThreadMXBean"));
+                    = Collections.singleton("java.lang.management.ThreadMXBean");
 
             @Override
             public Set<Class<? extends ThreadMXBean>> mbeanInterfaces() {
@@ -361,8 +354,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
              */
             initMBeanList.add(new PlatformComponent<PlatformLoggingMXBean>() {
                 private final Set<String> platformLoggingMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.PlatformLoggingMXBean"));
+                    = Collections.singleton("java.lang.management.PlatformLoggingMXBean");
 
                 @Override
                 public Set<Class<? extends PlatformLoggingMXBean>> mbeanInterfaces() {
@@ -393,8 +385,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<BufferPoolMXBean>() {
             private final Set<String> bufferPoolMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.BufferPoolMXBean"));
+                    = Collections.singleton("java.lang.management.BufferPoolMXBean");
 
             @Override
             public Set<Class<? extends BufferPoolMXBean>> mbeanInterfaces() {
@@ -437,8 +428,7 @@ class DefaultPlatformMBeanProvider extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<OperatingSystemMXBean>() {
             private final Set<String> operatingSystemMXBeanInterfaceNames
-                    = Collections.unmodifiableSet(Collections.singleton(
-                            "java.lang.management.OperatingSystemMXBean"));
+                    = Collections.singleton("java.lang.management.OperatingSystemMXBean");
 
             @Override
             public Set<Class<? extends OperatingSystemMXBean>> mbeanInterfaces() {
diff --git a/src/jdk.management/share/classes/com/sun/management/internal/PlatformMBeanProviderImpl.java b/src/jdk.management/share/classes/com/sun/management/internal/PlatformMBeanProviderImpl.java
index 24fbbb54c93..da1558f59a8 100644
--- a/src/jdk.management/share/classes/com/sun/management/internal/PlatformMBeanProviderImpl.java
+++ b/src/jdk.management/share/classes/com/sun/management/internal/PlatformMBeanProviderImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -204,8 +204,7 @@ public final class PlatformMBeanProviderImpl extends PlatformMBeanProvider {
          */
         initMBeanList.add(new PlatformComponent<com.sun.management.HotSpotDiagnosticMXBean>() {
             private final Set<String> hotSpotDiagnosticMXBeanInterfaceNames =
-                    Collections.unmodifiableSet(Collections.<String>singleton(
-                            "com.sun.management.HotSpotDiagnosticMXBean"));
+                    Collections.singleton("com.sun.management.HotSpotDiagnosticMXBean");
 
             @Override
             public Set<Class<? extends com.sun.management.HotSpotDiagnosticMXBean>> mbeanInterfaces() {
@@ -237,8 +236,7 @@ public final class PlatformMBeanProviderImpl extends PlatformMBeanProvider {
         if (diagMBean != null) {
             initMBeanList.add(new PlatformComponent<DynamicMBean>() {
                 final Set<String> dynamicMBeanInterfaceNames
-                        = Collections.unmodifiableSet(Collections.<String>singleton(
-                                "javax.management.DynamicMBean"));
+                        = Collections.singleton("javax.management.DynamicMBean");
 
                 @Override
                 public Set<String> mbeanInterfaceNames() {