ThreadGroup

ThreadGroup

java.lang

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Java 1.0

This class represents a group of threads and allows that group to be manipulated as a whole. A ThreadGroup can contain THRead objects, as well as other child ThreadGroup objects. All ThreadGroup objects are created as children of some other THReadGroup , and thus there is a parent/child hierarchy of ThreadGroup objects. Use getParent( ) to obtain the parent ThreadGroup , and use activeCount( ) , activeGroupCount( ) , and the various enumerate( ) methods to list the child Thread and THReadGroup objects. Most applications can simply rely on the default system thread group. System-level code and applications such as servers that need to create a large number of threads may find it convenient to create their own THReadGroup objects, however.

interrupt( ) interrupts all threads in the group at once. setMaxPriority( ) specifies the maximum priority any thread in the group can have. checkAccess( ) checks whether the calling thread has permission to modify the given thread group. The method throws a SecurityException if the current thread does not have access. uncaughtException( ) contains the code that is run when a thread terminates because of an uncaught exception or error. You can customize this method by subclassing ThreadGroup .

Figure 10-65. java.lang.ThreadGroup

 public class  ThreadGroup  implements Thread.UncaughtExceptionHandler {  // Public Constructors  public  ThreadGroup  (String  name  );        public  ThreadGroup  (ThreadGroup  parent  , String  name  );  // Public Instance Methods  public int  activeCount  ( );        public int  activeGroupCount  ( );        public final void  checkAccess  ( );        public final void  destroy  ( );        public int  enumerate  (ThreadGroup[ ]  list  );        public int  enumerate  (Thread[ ]  list  );        public int  enumerate  (Thread[ ]  list  , boolean  recurse  );        public int  enumerate  (ThreadGroup[ ]  list  , boolean  recurse  );        public final int  getMaxPriority  ( );        public final String  getName  ( );        public final ThreadGroup  getParent  ( );  1.2  public final void  interrupt  ( );        public final boolean  isDaemon  ( );  1.1  public boolean  isDestroyed  ( );  synchronized  public void  list  ( );        public final boolean  parentOf  (ThreadGroup  g  );        public final void  setDaemon  (boolean  daemon  );        public final void  setMaxPriority  (int  pri  );        public void  uncaughtException  (Thread  t  , Throwable  e  );  Implements:  Thread.UncaughtExceptionHandler  // Methods Implementing Thread.UncaughtExceptionHandler  public void  uncaughtException  (Thread  t  , Throwable  e  );  // Public Methods Overriding Object  public String  toString  ( );  // Deprecated Public Methods   1.1#  public boolean  allowThreadSuspension  (boolean  b  );  #  public final void  resume  ( );  #  public final void  stop  ( );  #  public final void  suspend  ( );   } 

Passed To

SecurityManager.checkAccess( ) , THRead.Thread( )

Returned By

SecurityManager.getThreadGroup( ) , THRead.getThreadGroup( )