thread.java

轻量嵌入JVM,可用于掌上设备手机等手持消息设备．

/************************************************************************
This file is part of java core libraries for the simpleRTJ virtual machine.

This file is covered by the GNU GPL with the following exception:
  As a special exception, the copyright holders of this library give you permission
  to link this library with independent modules to produce an executable, regardless
  of the license terms of these independent modules, and to copy and distribute the
  resulting executable under terms of your choice, provided that you also meet, for
  each linked independent module, the terms and conditions of the license of that
  module. An independent module is a module which is not derived from or based on
  this library. If you modify this library, you may extend this exception to your
  version of the library, but you are not obligated to do so. If you do not wish
  to do so, delete this exception statement from your version.


THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL RTJ COMPUTING BE LIABLE FOR ANY CLAIM, DAMAGES
OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Created/modified by:
    RTJ Computing
***********************************************************************/
package java.lang;

/**
 * Class that will run in a separate thread must subclass Thread.
 *
 * For detailed description of this class see the Java language documentation.
 */
public class Thread implements Runnable
{
    private Runnable target;
    private boolean interrupting;
    private boolean daemon = false;

    /**
     * Creates a Thread object.
     */
    public Thread()
    {
        this(null);
    }

    /**
     * Creates a Thread object with specified target.
     */
    public Thread(Runnable target)
    {
        this.target = target;
        this.interrupting = false;

        setDaemon(currentThread().isDaemon());
    }

    public static void sleep(int millis, int nanos) throws InterruptedException
    {
        sleep(millis);
    }

    /**
     * Currently running thread sleeps for the specified number of
     * milliseconds.
     */
    public static void sleep(int millis) throws InterruptedException
    {
        sleep0(millis);
        if (Thread.interrupted())
            throw new InterruptedException();
    }

    public void interrupt()
    {
        interrupting = true;
        interrupt0();
    }

    public static boolean interrupted()
    {
        boolean intr = Thread.currentThread().interrupting;
        Thread.currentThread().interrupting = false;
        return intr;
    }

    public boolean isInterrupted()
    {
        return interrupting;
    }

    /**
     * Currently executing thread pauses and allow other threads to run.
     */
    public static native void yield();

    /**
     * Calling this method will cause the thread to begin execution
     */
    public synchronized native void start();

    /**
     * Makes the thread to stop running.
     */
    public native final void stop();

    /**
     * Thread execution method.
     * Subclasses must override this method to implement required functionality.
     */
    public void run()
    {
        if (target != null)
            target.run();
    }

    /**
     * Sets/clears the daemon flag for this thread.
     */
    public final void setDaemon(boolean set)
    {
            daemon = set;
        setDaemon0(set);
    }

    /**
     * Returns true if this thread is daemon.
     */
    public final boolean isDaemon()
    {
            return daemon;
    }

    /**
     * Waits for this thread to die.
     */
    public final void join() throws InterruptedException
    {
        join(0);
    }

    /**
     * Waits specified number of milliseconds for this thread to die.
     */
    public final void join(int millis) throws InterruptedException
    {
        int timeout = System.currentTimeMillis() + millis;
        while (isAlive() && (millis == 0 || System.currentTimeMillis() < timeout))
            yield();
    }

    /**
     * Checks if this thread is alive
     */
    public native boolean isAlive();

    /**
     * Suspends this thread.
     */
    public native final void suspend();

    /**
     * Resumes a suspended thread.
     */
    public native final void resume();

    /**
     * Returns reference to current thread.
     */
    public static native Thread currentThread();

    private static native void sleep0(int millis);
    private native void interrupt0();
    private native void setDaemon0(boolean set);
}