http://netty.io/netty-all/: Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers and clients. (The Netty Project) 
public final class io.netty.util.ReferenceCountUtil
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: io.netty.util.ReferenceCountUtil
  super_class: java.lang.Object
{
  private static final io.netty.util.internal.logging.InternalLogger logger;
    descriptor: Lio/netty/util/internal/logging/InternalLogger;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=5, locals=0, args_size=0
         0: .line 27
            ldc Lio/netty/util/ReferenceCountUtil;
            invokestatic io.netty.util.internal.logging.InternalLoggerFactory.getInstance:(Ljava/lang/Class;)Lio/netty/util/internal/logging/InternalLogger;
            putstatic io.netty.util.ReferenceCountUtil.logger:Lio/netty/util/internal/logging/InternalLogger;
         1: .line 30
            ldc Lio/netty/util/ReferenceCountUtil;
            iconst_1
            anewarray java.lang.String
            dup
            iconst_0
            ldc "touch"
            aastore
            invokestatic io.netty.util.ResourceLeakDetector.addExclusions:(Ljava/lang/Class;[Ljava/lang/String;)V
         2: .line 31
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public static <T> T retain();
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // java.lang.Object msg
         0: .line 39
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 2
         1: .line 40
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            invokeinterface io.netty.util.ReferenceCounted.retain:()Lio/netty/util/ReferenceCounted;
            areturn
         2: .line 42
      StackMap locals:
      StackMap stack:
            aload 0 /* msg */
            areturn
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0   msg  TT;
    Signature: <T:Ljava/lang/Object;>(TT;)TT;
    MethodParameters:
      Name  Flags
      msg   

  public static <T> T retain(T, );
    descriptor: (Ljava/lang/Object;I)Ljava/lang/Object;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.lang.Object msg
        start local 1 // int increment
         0: .line 51
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 2
         1: .line 52
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            iload 1 /* increment */
            invokeinterface io.netty.util.ReferenceCounted.retain:(I)Lio/netty/util/ReferenceCounted;
            areturn
         2: .line 54
      StackMap locals:
      StackMap stack:
            aload 0 /* msg */
            areturn
        end local 1 // int increment
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    3     0        msg  TT;
            0    3     1  increment  I
    Signature: <T:Ljava/lang/Object;>(TT;I)TT;
    MethodParameters:
           Name  Flags
      msg        
      increment  

  public static <T> T touch();
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // java.lang.Object msg
         0: .line 63
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 2
         1: .line 64
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            invokeinterface io.netty.util.ReferenceCounted.touch:()Lio/netty/util/ReferenceCounted;
            areturn
         2: .line 66
      StackMap locals:
      StackMap stack:
            aload 0 /* msg */
            areturn
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0   msg  TT;
    Signature: <T:Ljava/lang/Object;>(TT;)TT;
    MethodParameters:
      Name  Flags
      msg   

  public static <T> T touch(T, );
    descriptor: (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.lang.Object msg
        start local 1 // java.lang.Object hint
         0: .line 76
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 2
         1: .line 77
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            aload 1 /* hint */
            invokeinterface io.netty.util.ReferenceCounted.touch:(Ljava/lang/Object;)Lio/netty/util/ReferenceCounted;
            areturn
         2: .line 79
      StackMap locals:
      StackMap stack:
            aload 0 /* msg */
            areturn
        end local 1 // java.lang.Object hint
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0   msg  TT;
            0    3     1  hint  Ljava/lang/Object;
    Signature: <T:Ljava/lang/Object;>(TT;Ljava/lang/Object;)TT;
    MethodParameters:
      Name  Flags
      msg   
      hint  

  public static boolean release(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // java.lang.Object msg
         0: .line 87
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 2
         1: .line 88
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            invokeinterface io.netty.util.ReferenceCounted.release:()Z
            ireturn
         2: .line 90
      StackMap locals:
      StackMap stack:
            iconst_0
            ireturn
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0   msg  Ljava/lang/Object;
    MethodParameters:
      Name  Flags
      msg   

  public static boolean release(java.lang.Object, int);
    descriptor: (Ljava/lang/Object;I)Z
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.lang.Object msg
        start local 1 // int decrement
         0: .line 98
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 2
         1: .line 99
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            iload 1 /* decrement */
            invokeinterface io.netty.util.ReferenceCounted.release:(I)Z
            ireturn
         2: .line 101
      StackMap locals:
      StackMap stack:
            iconst_0
            ireturn
        end local 1 // int decrement
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    3     0        msg  Ljava/lang/Object;
            0    3     1  decrement  I
    MethodParameters:
           Name  Flags
      msg        
      decrement  

  public static void safeRelease(java.lang.Object);
    descriptor: (Ljava/lang/Object;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=2, args_size=1
        start local 0 // java.lang.Object msg
         0: .line 113
            aload 0 /* msg */
            invokestatic io.netty.util.ReferenceCountUtil.release:(Ljava/lang/Object;)Z
            pop
         1: .line 114
            goto 4
      StackMap locals:
      StackMap stack: java.lang.Throwable
         2: astore 1 /* t */
        start local 1 // java.lang.Throwable t
         3: .line 115
            getstatic io.netty.util.ReferenceCountUtil.logger:Lio/netty/util/internal/logging/InternalLogger;
            ldc "Failed to release a message: {}"
            aload 0 /* msg */
            aload 1 /* t */
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)V
        end local 1 // java.lang.Throwable t
         4: .line 117
      StackMap locals:
      StackMap stack:
            return
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0   msg  Ljava/lang/Object;
            3    4     1     t  Ljava/lang/Throwable;
      Exception table:
        from    to  target  type
           0     1       2  Class java.lang.Throwable
    MethodParameters:
      Name  Flags
      msg   

  public static void safeRelease(java.lang.Object, int);
    descriptor: (Ljava/lang/Object;I)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=6, locals=3, args_size=2
        start local 0 // java.lang.Object msg
        start local 1 // int decrement
         0: .line 128
            aload 0 /* msg */
            iload 1 /* decrement */
            invokestatic io.netty.util.ReferenceCountUtil.release:(Ljava/lang/Object;I)Z
            pop
         1: .line 129
            goto 5
      StackMap locals:
      StackMap stack: java.lang.Throwable
         2: astore 2 /* t */
        start local 2 // java.lang.Throwable t
         3: .line 130
            getstatic io.netty.util.ReferenceCountUtil.logger:Lio/netty/util/internal/logging/InternalLogger;
            invokeinterface io.netty.util.internal.logging.InternalLogger.isWarnEnabled:()Z
            ifeq 5
         4: .line 131
            getstatic io.netty.util.ReferenceCountUtil.logger:Lio/netty/util/internal/logging/InternalLogger;
            ldc "Failed to release a message: {} (decrement: {})"
            iconst_3
            anewarray java.lang.Object
            dup
            iconst_0
            aload 0 /* msg */
            aastore
            dup
            iconst_1
            iload 1 /* decrement */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            aastore
            dup
            iconst_2
            aload 2 /* t */
            aastore
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;[Ljava/lang/Object;)V
        end local 2 // java.lang.Throwable t
         5: .line 134
      StackMap locals:
      StackMap stack:
            return
        end local 1 // int decrement
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    6     0        msg  Ljava/lang/Object;
            0    6     1  decrement  I
            3    5     2          t  Ljava/lang/Throwable;
      Exception table:
        from    to  target  type
           0     1       2  Class java.lang.Throwable
    MethodParameters:
           Name  Flags
      msg        
      decrement  

  public static <T> T releaseLater();
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // java.lang.Object msg
         0: .line 145
            aload 0 /* msg */
            iconst_1
            invokestatic io.netty.util.ReferenceCountUtil.releaseLater:(Ljava/lang/Object;I)Ljava/lang/Object;
            areturn
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0   msg  TT;
    Signature: <T:Ljava/lang/Object;>(TT;)TT;
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()
    MethodParameters:
      Name  Flags
      msg   

  public static <T> T releaseLater(T, );
    descriptor: (Ljava/lang/Object;I)Ljava/lang/Object;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=5, locals=2, args_size=2
        start local 0 // java.lang.Object msg
        start local 1 // int decrement
         0: .line 157
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 2
         1: .line 158
            invokestatic java.lang.Thread.currentThread:()Ljava/lang/Thread;
            new io.netty.util.ReferenceCountUtil$ReleasingTask
            dup
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            iload 1 /* decrement */
            invokespecial io.netty.util.ReferenceCountUtil$ReleasingTask.<init>:(Lio/netty/util/ReferenceCounted;I)V
            invokestatic io.netty.util.ThreadDeathWatcher.watch:(Ljava/lang/Thread;Ljava/lang/Runnable;)V
         2: .line 160
      StackMap locals:
      StackMap stack:
            aload 0 /* msg */
            areturn
        end local 1 // int decrement
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    3     0        msg  TT;
            0    3     1  decrement  I
    Signature: <T:Ljava/lang/Object;>(TT;I)TT;
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()
    MethodParameters:
           Name  Flags
      msg        
      decrement  

  public static int refCnt(java.lang.Object);
    descriptor: (Ljava/lang/Object;)I
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // java.lang.Object msg
         0: .line 168
            aload 0 /* msg */
            instanceof io.netty.util.ReferenceCounted
            ifeq 1
            aload 0 /* msg */
            checkcast io.netty.util.ReferenceCounted
            invokeinterface io.netty.util.ReferenceCounted.refCnt:()I
            goto 2
      StackMap locals:
      StackMap stack:
         1: iconst_m1
      StackMap locals:
      StackMap stack: int
         2: ireturn
        end local 0 // java.lang.Object msg
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0   msg  Ljava/lang/Object;
    MethodParameters:
      Name  Flags
      msg   

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.util.ReferenceCountUtil this
         0: .line 203
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // io.netty.util.ReferenceCountUtil this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/util/ReferenceCountUtil;
}
SourceFile: "ReferenceCountUtil.java"
NestMembers:
  io.netty.util.ReferenceCountUtil$ReleasingTask
InnerClasses:
  private final ReleasingTask = io.netty.util.ReferenceCountUtil$ReleasingTask of io.netty.util.ReferenceCountUtil