thread.java

linux下编程用 编译软件

  public void run()
  {
    if (runnable != null)
      runnable.run();
  }

  /**
   * Set the daemon status of this Thread.  If this is a daemon Thread, then
   * the VM may exit even if it is still running.  This may only be called
   * before the Thread starts running. There may be a security check,
   * <code>checkAccess</code>.
   *
   * @param daemon whether this should be a daemon thread or not
   * @throws SecurityException if you cannot modify this Thread
   * @throws IllegalThreadStateException if the Thread is active
   * @see #isDaemon()
   * @see #checkAccess()
   */
  public final synchronized void setDaemon(boolean daemon)
  {
    if (vmThread != null)
      throw new IllegalThreadStateException();
    checkAccess();
    this.daemon = daemon;
  }

  /**
   * Returns the context classloader of this Thread. The context
   * classloader can be used by code that want to load classes depending
   * on the current thread. Normally classes are loaded depending on
   * the classloader of the current class. There may be a security check
   * for <code>RuntimePermission("getClassLoader")</code> if the caller's
   * class loader is not null or an ancestor of this thread's context class
   * loader.
   *
   * @return the context class loader
   * @throws SecurityException when permission is denied
   * @see #setContextClassLoader(ClassLoader)
   * @since 1.2
   */
  public synchronized ClassLoader getContextClassLoader()
  {
    // Bypass System.getSecurityManager, for bootstrap efficiency.
    SecurityManager sm = SecurityManager.current;
    if (sm != null)
      // XXX Don't check this if the caller's class loader is an ancestor.
      sm.checkPermission(new RuntimePermission("getClassLoader"));
    return contextClassLoader;
  }

  /**
   * Sets the context classloader for this Thread. When not explicitly set,
   * the context classloader for a thread is the same as the context
   * classloader of the thread that created this thread. The first thread has
   * as context classloader the system classloader. There may be a security
   * check for <code>RuntimePermission("setContextClassLoader")</code>.
   *
   * @param classloader the new context class loader
   * @throws SecurityException when permission is denied
   * @see #getContextClassLoader()
   * @since 1.2
   */
  public synchronized void setContextClassLoader(ClassLoader classloader)
  {
    SecurityManager sm = SecurityManager.current;
    if (sm != null)
      sm.checkPermission(new RuntimePermission("setContextClassLoader"));
    this.contextClassLoader = classloader;
  }

  /**
   * Set this Thread's name.  There may be a security check,
   * <code>checkAccess</code>.
   *
   * @param name the new name for this Thread
   * @throws NullPointerException if name is null
   * @throws SecurityException if you cannot modify this Thread
   */
  public final synchronized void setName(String name)
  {
    checkAccess();
    // The Class Libraries book says ``threadName cannot be null''.  I
    // take this to mean NullPointerException.
    if (name == null)
      throw new NullPointerException();
    VMThread t = vmThread;
    if (t != null)
	t.setName(name);
    else
	this.name = name;
  }

  /**
   * Yield to another thread. The Thread will not lose any locks it holds
   * during this time. There are no guarantees which thread will be
   * next to run, and it could even be this one, but most VMs will choose
   * the highest priority thread that has been waiting longest.
   */
  public static void yield()
  {
    VMThread.yield();
  }

  /**
   * Suspend the current Thread's execution for the specified amount of
   * time. The Thread will not lose any locks it has during this time. There
   * are no guarantees which thread will be next to run, but most VMs will
   * choose the highest priority thread that has been waiting longest.
   *
   * @param ms the number of milliseconds to sleep.
   * @throws InterruptedException if the Thread is (or was) interrupted;
   *         it's <i>interrupted status</i> will be cleared
   * @throws IllegalArgumentException if ms is negative
   * @see #interrupt()
   */
  public static void sleep(long ms) throws InterruptedException
  {
    sleep(ms, 0);
  }

  /**
   * Suspend the current Thread's execution for the specified amount of
   * time. The Thread will not lose any locks it has during this time. There
   * are no guarantees which thread will be next to run, but most VMs will
   * choose the highest priority thread that has been waiting longest.
   * <p>
   * Note that 1,000,000 nanoseconds == 1 millisecond, but most VMs
   * do not offer that fine a grain of timing resolution. When ms is
   * zero and ns is non-zero the Thread will sleep for at least one
   * milli second. There is no guarantee that this thread can start up
   * immediately when time expires, because some other thread may be
   * active.  So don't expect real-time performance.
   *
   * @param ms the number of milliseconds to sleep
   * @param ns the number of extra nanoseconds to sleep (0-999999)
   * @throws InterruptedException if the Thread is (or was) interrupted;
   *         it's <i>interrupted status</i> will be cleared
   * @throws IllegalArgumentException if ms or ns is negative
   *         or ns is larger than 999999.
   * @see #interrupt()
   */
  public static void sleep(long ms, int ns) throws InterruptedException
  {

    // Check parameters
    if (ms < 0 )
      throw new IllegalArgumentException("Negative milliseconds: " + ms);

    if (ns < 0 || ns > 999999)
      throw new IllegalArgumentException("Nanoseconds ouf of range: " + ns);

    // Really sleep
    VMThread.sleep(ms, ns);
  }

  /**
   * Start this Thread, calling the run() method of the Runnable this Thread
   * was created with, or else the run() method of the Thread itself. This
   * is the only way to start a new thread; calling run by yourself will just
   * stay in the same thread. The virtual machine will remove the thread from
   * its thread group when the run() method completes.
   *
   * @throws IllegalThreadStateException if the thread has already started
   * @see #run()
   */
  public synchronized void start()
  {
    if (vmThread != null || group == null)
	throw new IllegalThreadStateException();

    VMThread.create(this, stacksize);
  }
  
  /**
   * Cause this Thread to stop abnormally because of the throw of a ThreadDeath
   * error. If you stop a Thread that has not yet started, it will stop
   * immediately when it is actually started.
   *
   * <p>This is inherently unsafe, as it can interrupt synchronized blocks and
   * leave data in bad states.  Hence, there is a security check:
   * <code>checkAccess(this)</code>, plus another one if the current thread
   * is not this: <code>RuntimePermission("stopThread")</code>. If you must
   * catch a ThreadDeath, be sure to rethrow it after you have cleaned up.
   * ThreadDeath is the only exception which does not print a stack trace when
   * the thread dies.
   *
   * @throws SecurityException if you cannot stop the Thread
   * @see #interrupt()
   * @see #checkAccess()
   * @see #start()
   * @see ThreadDeath
   * @see ThreadGroup#uncaughtException(Thread, Throwable)
   * @see SecurityManager#checkAccess(Thread)
   * @see SecurityManager#checkPermission(Permission)
   * @deprecated unsafe operation, try not to use
   */
  public final void stop()
  {
    stop(new ThreadDeath());
  }

  /**
   * Cause this Thread to stop abnormally and throw the specified exception.
   * If you stop a Thread that has not yet started, the stop is ignored
   * (contrary to what the JDK documentation says).
   * <b>WARNING</b>This bypasses Java security, and can throw a checked
   * exception which the call stack is unprepared to handle. Do not abuse
   * this power.
   *
   * <p>This is inherently unsafe, as it can interrupt synchronized blocks and
   * leave data in bad states.  Hence, there is a security check:
   * <code>checkAccess(this)</code>, plus another one if the current thread
   * is not this: <code>RuntimePermission("stopThread")</code>. If you must
   * catch a ThreadDeath, be sure to rethrow it after you have cleaned up.
   * ThreadDeath is the only exception which does not print a stack trace when
   * the thread dies.
   *
   * @param t the Throwable to throw when the Thread dies
   * @throws SecurityException if you cannot stop the Thread
   * @throws NullPointerException in the calling thread, if t is null
   * @see #interrupt()
   * @see #checkAccess()
   * @see #start()
   * @see ThreadDeath
   * @see ThreadGroup#uncaughtException(Thread, Throwable)
   * @see SecurityManager#checkAccess(Thread)
   * @see SecurityManager#checkPermission(Permission)
   * @deprecated unsafe operation, try not to use
   */
  public final synchronized void stop(Throwable t)
  {
    if (t == null)
      throw new NullPointerException();
    // Bypass System.getSecurityManager, for bootstrap efficiency.
    SecurityManager sm = SecurityManager.current;
    if (sm != null)
      {
        sm.checkAccess(this);
        if (this != currentThread())
          sm.checkPermission(new RuntimePermission("stopThread"));
      }
    VMThread vt = vmThread;
    if (vt != null)
	vt.stop(t);
    else
	stillborn = t;
  }

  /**
   * Suspend this Thread.  It will not come back, ever, unless it is resumed.
   *
   * <p>This is inherently unsafe, as the suspended thread still holds locks,
   * and can potentially deadlock your program.  Hence, there is a security
   * check: <code>checkAccess</code>.
   *
   * @throws SecurityException if you cannot suspend the Thread
   * @see #checkAccess()
   * @see #resume()
   * @deprecated unsafe operation, try not to use
   */
  public final synchronized void suspend()
  {
    checkAccess();
    VMThread t = vmThread;
    if (t != null)
	t.suspend();
  }

  /**
   * Set this Thread's priority. There may be a security check,
   * <code>checkAccess</code>, then the priority is set to the smaller of
   * priority and the ThreadGroup maximum priority.
   *
   * @param priority the new priority for this Thread
   * @throws IllegalArgumentException if priority exceeds MIN_PRIORITY or
   *         MAX_PRIORITY
   * @throws SecurityException if you cannot modify this Thread
   * @see #getPriority()
   * @see #checkAccess()
   * @see ThreadGroup#getMaxPriority()
   * @see #MIN_PRIORITY
   * @see #MAX_PRIORITY
   */
  public final synchronized void setPriority(int priority)
  {
    checkAccess();
    if (priority < MIN_PRIORITY || priority > MAX_PRIORITY)
      throw new IllegalArgumentException("Invalid thread priority value "
                                         + priority + ".");
    priority = Math.min(priority, group.getMaxPriority());
    VMThread t = vmThread;
    if (t != null)
	t.setPriority(priority);
    else
	this.priority = priority;
  }

  /**
   * Returns a string representation of this thread, including the
   * thread's name, priority, and thread group.
   *
   * @return a human-readable String representing this Thread
   */
  public String toString()
  {
    return ("Thread[" + name + "," + priority + ","
	    + (group == null ? "" : group.getName()) + "]");
  }

  /**
   * Clean up code, called by VMThread when thread dies.
   */
  synchronized void die()
  {
    group.removeThread(this);
    vmThread = null;
    locals = null;
  }

  /**
   * Returns the map used by ThreadLocal to store the thread local values.
   */
  static Map getThreadLocals()
  {
    Thread thread = currentThread();
    Map locals = thread.locals;
    if (locals == null)
      {
        locals = thread.locals = new WeakHashMap();
      }
    return locals;
  }
}