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.ThreadDeathWatcher
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: io.netty.util.ThreadDeathWatcher
  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 final java.util.concurrent.ThreadFactory threadFactory;
    descriptor: Ljava/util/concurrent/ThreadFactory;
    flags: (0x0018) ACC_STATIC, ACC_FINAL

  private static final java.util.Queue<io.netty.util.ThreadDeathWatcher$Entry> pendingEntries;
    descriptor: Ljava/util/Queue;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    Signature: Ljava/util/Queue<Lio/netty/util/ThreadDeathWatcher$Entry;>;

  private static final io.netty.util.ThreadDeathWatcher$Watcher watcher;
    descriptor: Lio/netty/util/ThreadDeathWatcher$Watcher;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  private static final java.util.concurrent.atomic.AtomicBoolean started;
    descriptor: Ljava/util/concurrent/atomic/AtomicBoolean;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  private static volatile java.lang.Thread watcherThread;
    descriptor: Ljava/lang/Thread;
    flags: (0x004a) ACC_PRIVATE, ACC_STATIC, ACC_VOLATILE

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=6, locals=2, args_size=0
         0: .line 48
            ldc Lio/netty/util/ThreadDeathWatcher;
            invokestatic io.netty.util.internal.logging.InternalLoggerFactory.getInstance:(Ljava/lang/Class;)Lio/netty/util/internal/logging/InternalLogger;
            putstatic io.netty.util.ThreadDeathWatcher.logger:Lio/netty/util/internal/logging/InternalLogger;
         1: .line 54
            new java.util.concurrent.ConcurrentLinkedQueue
            dup
            invokespecial java.util.concurrent.ConcurrentLinkedQueue.<init>:()V
            putstatic io.netty.util.ThreadDeathWatcher.pendingEntries:Ljava/util/Queue;
         2: .line 55
            new io.netty.util.ThreadDeathWatcher$Watcher
            dup
            invokespecial io.netty.util.ThreadDeathWatcher$Watcher.<init>:()V
            putstatic io.netty.util.ThreadDeathWatcher.watcher:Lio/netty/util/ThreadDeathWatcher$Watcher;
         3: .line 56
            new java.util.concurrent.atomic.AtomicBoolean
            dup
            invokespecial java.util.concurrent.atomic.AtomicBoolean.<init>:()V
            putstatic io.netty.util.ThreadDeathWatcher.started:Ljava/util/concurrent/atomic/AtomicBoolean;
         4: .line 60
            ldc "threadDeathWatcher"
            astore 0 /* poolName */
        start local 0 // java.lang.String poolName
         5: .line 61
            ldc "io.netty.serviceThreadPrefix"
            invokestatic io.netty.util.internal.SystemPropertyUtil.get:(Ljava/lang/String;)Ljava/lang/String;
            astore 1 /* serviceThreadPrefix */
        start local 1 // java.lang.String serviceThreadPrefix
         6: .line 62
            aload 1 /* serviceThreadPrefix */
            invokestatic io.netty.util.internal.StringUtil.isNullOrEmpty:(Ljava/lang/String;)Z
            ifne 8
         7: .line 63
            new java.lang.StringBuilder
            dup
            aload 1 /* serviceThreadPrefix */
            invokestatic java.lang.String.valueOf:(Ljava/lang/Object;)Ljava/lang/String;
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 0 /* poolName */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            astore 0 /* poolName */
         8: .line 68
      StackMap locals: java.lang.String java.lang.String
      StackMap stack:
            new io.netty.util.concurrent.DefaultThreadFactory
            dup
            aload 0 /* poolName */
            iconst_1
            iconst_1
            aconst_null
            invokespecial io.netty.util.concurrent.DefaultThreadFactory.<init>:(Ljava/lang/String;ZILjava/lang/ThreadGroup;)V
            putstatic io.netty.util.ThreadDeathWatcher.threadFactory:Ljava/util/concurrent/ThreadFactory;
        end local 1 // java.lang.String serviceThreadPrefix
        end local 0 // java.lang.String poolName
         9: .line 69
            return
      LocalVariableTable:
        Start  End  Slot                 Name  Signature
            5    9     0             poolName  Ljava/lang/String;
            6    9     1  serviceThreadPrefix  Ljava/lang/String;

  public static void watch(java.lang.Thread, java.lang.Runnable);
    descriptor: (Ljava/lang/Thread;Ljava/lang/Runnable;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // java.lang.Thread thread
        start local 1 // java.lang.Runnable task
         0: .line 80
            aload 0 /* thread */
            ifnonnull 2
         1: .line 81
            new java.lang.NullPointerException
            dup
            ldc "thread"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 83
      StackMap locals:
      StackMap stack:
            aload 1 /* task */
            ifnonnull 4
         3: .line 84
            new java.lang.NullPointerException
            dup
            ldc "task"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         4: .line 86
      StackMap locals:
      StackMap stack:
            aload 0 /* thread */
            invokevirtual java.lang.Thread.isAlive:()Z
            ifne 6
         5: .line 87
            new java.lang.IllegalArgumentException
            dup
            ldc "thread must be alive."
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;)V
            athrow
         6: .line 90
      StackMap locals:
      StackMap stack:
            aload 0 /* thread */
            aload 1 /* task */
            iconst_1
            invokestatic io.netty.util.ThreadDeathWatcher.schedule:(Ljava/lang/Thread;Ljava/lang/Runnable;Z)V
         7: .line 91
            return
        end local 1 // java.lang.Runnable task
        end local 0 // java.lang.Thread thread
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    8     0  thread  Ljava/lang/Thread;
            0    8     1    task  Ljava/lang/Runnable;
    MethodParameters:
        Name  Flags
      thread  
      task    

  public static void unwatch(java.lang.Thread, java.lang.Runnable);
    descriptor: (Ljava/lang/Thread;Ljava/lang/Runnable;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // java.lang.Thread thread
        start local 1 // java.lang.Runnable task
         0: .line 97
            aload 0 /* thread */
            ifnonnull 2
         1: .line 98
            new java.lang.NullPointerException
            dup
            ldc "thread"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 100
      StackMap locals:
      StackMap stack:
            aload 1 /* task */
            ifnonnull 4
         3: .line 101
            new java.lang.NullPointerException
            dup
            ldc "task"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         4: .line 104
      StackMap locals:
      StackMap stack:
            aload 0 /* thread */
            aload 1 /* task */
            iconst_0
            invokestatic io.netty.util.ThreadDeathWatcher.schedule:(Ljava/lang/Thread;Ljava/lang/Runnable;Z)V
         5: .line 105
            return
        end local 1 // java.lang.Runnable task
        end local 0 // java.lang.Thread thread
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    6     0  thread  Ljava/lang/Thread;
            0    6     1    task  Ljava/lang/Runnable;
    MethodParameters:
        Name  Flags
      thread  
      task    

  private static void schedule(java.lang.Thread, java.lang.Runnable, boolean);
    descriptor: (Ljava/lang/Thread;Ljava/lang/Runnable;Z)V
    flags: (0x000a) ACC_PRIVATE, ACC_STATIC
    Code:
      stack=6, locals=4, args_size=3
        start local 0 // java.lang.Thread thread
        start local 1 // java.lang.Runnable task
        start local 2 // boolean isWatch
         0: .line 108
            getstatic io.netty.util.ThreadDeathWatcher.pendingEntries:Ljava/util/Queue;
            new io.netty.util.ThreadDeathWatcher$Entry
            dup
            aload 0 /* thread */
            aload 1 /* task */
            iload 2 /* isWatch */
            invokespecial io.netty.util.ThreadDeathWatcher$Entry.<init>:(Ljava/lang/Thread;Ljava/lang/Runnable;Z)V
            invokeinterface java.util.Queue.add:(Ljava/lang/Object;)Z
            pop
         1: .line 110
            getstatic io.netty.util.ThreadDeathWatcher.started:Ljava/util/concurrent/atomic/AtomicBoolean;
            iconst_0
            iconst_1
            invokevirtual java.util.concurrent.atomic.AtomicBoolean.compareAndSet:(ZZ)Z
            ifeq 6
         2: .line 111
            getstatic io.netty.util.ThreadDeathWatcher.threadFactory:Ljava/util/concurrent/ThreadFactory;
            getstatic io.netty.util.ThreadDeathWatcher.watcher:Lio/netty/util/ThreadDeathWatcher$Watcher;
            invokeinterface java.util.concurrent.ThreadFactory.newThread:(Ljava/lang/Runnable;)Ljava/lang/Thread;
            astore 3 /* watcherThread */
        start local 3 // java.lang.Thread watcherThread
         3: .line 117
            new io.netty.util.ThreadDeathWatcher$1
            dup
            aload 3 /* watcherThread */
            invokespecial io.netty.util.ThreadDeathWatcher$1.<init>:(Ljava/lang/Thread;)V
            invokestatic java.security.AccessController.doPrivileged:(Ljava/security/PrivilegedAction;)Ljava/lang/Object;
            pop
         4: .line 125
            aload 3 /* watcherThread */
            invokevirtual java.lang.Thread.start:()V
         5: .line 126
            aload 3 /* watcherThread */
            putstatic io.netty.util.ThreadDeathWatcher.watcherThread:Ljava/lang/Thread;
        end local 3 // java.lang.Thread watcherThread
         6: .line 128
      StackMap locals:
      StackMap stack:
            return
        end local 2 // boolean isWatch
        end local 1 // java.lang.Runnable task
        end local 0 // java.lang.Thread thread
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    7     0         thread  Ljava/lang/Thread;
            0    7     1           task  Ljava/lang/Runnable;
            0    7     2        isWatch  Z
            3    6     3  watcherThread  Ljava/lang/Thread;
    MethodParameters:
         Name  Flags
      thread   
      task     
      isWatch  

  public static boolean awaitInactivity(long, java.util.concurrent.TimeUnit);
    descriptor: (JLjava/util/concurrent/TimeUnit;)Z
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=4, args_size=2
        start local 0 // long timeout
        start local 2 // java.util.concurrent.TimeUnit unit
         0: .line 140
            aload 2 /* unit */
            ifnonnull 2
         1: .line 141
            new java.lang.NullPointerException
            dup
            ldc "unit"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 144
      StackMap locals:
      StackMap stack:
            getstatic io.netty.util.ThreadDeathWatcher.watcherThread:Ljava/lang/Thread;
            astore 3 /* watcherThread */
        start local 3 // java.lang.Thread watcherThread
         3: .line 145
            aload 3 /* watcherThread */
            ifnull 8
         4: .line 146
            aload 3 /* watcherThread */
            aload 2 /* unit */
            lload 0 /* timeout */
            invokevirtual java.util.concurrent.TimeUnit.toMillis:(J)J
            invokevirtual java.lang.Thread.join:(J)V
         5: .line 147
            aload 3 /* watcherThread */
            invokevirtual java.lang.Thread.isAlive:()Z
            ifeq 6
            iconst_0
            goto 7
      StackMap locals: java.lang.Thread
      StackMap stack:
         6: iconst_1
      StackMap locals:
      StackMap stack: int
         7: ireturn
         8: .line 149
      StackMap locals:
      StackMap stack:
            iconst_1
            ireturn
        end local 3 // java.lang.Thread watcherThread
        end local 2 // java.util.concurrent.TimeUnit unit
        end local 0 // long timeout
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    9     0        timeout  J
            0    9     2           unit  Ljava/util/concurrent/TimeUnit;
            3    9     3  watcherThread  Ljava/lang/Thread;
    Exceptions:
      throws java.lang.InterruptedException
    MethodParameters:
         Name  Flags
      timeout  
      unit     

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.util.ThreadDeathWatcher this
         0: .line 153
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // io.netty.util.ThreadDeathWatcher this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/util/ThreadDeathWatcher;
}
SourceFile: "ThreadDeathWatcher.java"
NestMembers:
  io.netty.util.ThreadDeathWatcher$1  io.netty.util.ThreadDeathWatcher$Entry  io.netty.util.ThreadDeathWatcher$Watcher
InnerClasses:
  io.netty.util.ThreadDeathWatcher$1
  private final Entry = io.netty.util.ThreadDeathWatcher$Entry of io.netty.util.ThreadDeathWatcher
  private final Watcher = io.netty.util.ThreadDeathWatcher$Watcher of io.netty.util.ThreadDeathWatcher
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()