+ * Every thread has a priority. Threads with higher priority are
+ * executed in preference to threads with lower priority. Each thread
+ * may or may not also be marked as a daemon. When code running in
+ * some thread creates a new Thread object, the new
+ * thread has its priority initially set equal to the priority of the
+ * creating thread, and is a daemon thread if and only if the
+ * creating thread is a daemon.
+ *
+ * When a Java Virtual Machine starts up, there is usually a single
+ * non-daemon thread (which typically calls the method named
+ * main of some designated class). The Java Virtual
+ * Machine continues to execute threads until either of the following
+ * occurs:
+ *
exit method of class Runtime has been
+ * called and the security manager has permitted the exit operation
+ * to take place.
+ * run method or by
+ * throwing an exception that propagates beyond the run
+ * method.
+ *
+ * There are two ways to create a new thread of execution. One is to
+ * declare a class to be a subclass of Thread. This
+ * subclass should override the run method of class
+ * Thread. An instance of the subclass can then be
+ * allocated and started. For example, a thread that computes primes
+ * larger than a stated value could be written as follows:
+ *
+ * class PrimeThread extends Thread {
+ * long minPrime;
+ * PrimeThread(long minPrime) {
+ * this.minPrime = minPrime;
+ * }
+ *
+ * public void run() {
+ * // compute primes larger than minPrime
+ * . . .
+ * }
+ * }
+ * + * The following code would then create a thread and start it running: + *
+ *+ * PrimeThread p = new PrimeThread(143); + * p.start(); + *
+ * The other way to create a thread is to declare a class that
+ * implements the Runnable interface. That class then
+ * implements the run method. An instance of the class can
+ * then be allocated, passed as an argument when creating
+ * Thread, and started. The same example in this other
+ * style looks like the following:
+ *
+ * class PrimeRun implements Runnable {
+ * long minPrime;
+ * PrimeRun(long minPrime) {
+ * this.minPrime = minPrime;
+ * }
+ *
+ * public void run() {
+ * // compute primes larger than minPrime
+ * . . .
+ * }
+ * }
+ * + * The following code would then create a thread and start it running: + *
+ *+ * PrimeRun p = new PrimeRun(143); + * new Thread(p).start(); + *
+ * Every thread has a name for identification purposes. More than + * one thread may have the same name. If a name is not specified when + * a thread is created, a new name is generated for it. + *
+ * Unless otherwise noted, passing a {@code null} argument to a constructor
+ * or method in this class will cause a {@link NullPointerException} to be
+ * thrown.
+ *
+ * @author unascribed
+ * @see Runnable
+ * @see Runtime#exit(int)
+ * @see #run()
+ * @see #stop()
+ * @since JDK1.0
+ */
+public
+class Thread implements Runnable {
+ /* Make sure registerNatives is the first thing Yield is a heuristic attempt to improve relative progression
+ * between threads that would otherwise over-utilise a CPU. Its use
+ * should be combined with detailed profiling and benchmarking to
+ * ensure that it actually has the desired effect.
+ *
+ * It is rarely appropriate to use this method. It may be useful
+ * for debugging or testing purposes, where it may help to reproduce
+ * bugs due to race conditions. It may also be useful when designing
+ * concurrency control constructs such as the ones in the
+ * {@link java.util.concurrent.locks} package.
+ */
+ public static native void yield();
+
+ /**
+ * Causes the currently executing thread to sleep (temporarily cease
+ * execution) for the specified number of milliseconds, subject to
+ * the precision and accuracy of system timers and schedulers. The thread
+ * does not lose ownership of any monitors.
+ *
+ * @param millis
+ * the length of time to sleep in milliseconds
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * interrupted status of the current thread is
+ * cleared when this exception is thrown.
+ */
+ public static native void sleep(long millis) throws InterruptedException;
+
+ /**
+ * Causes the currently executing thread to sleep (temporarily cease
+ * execution) for the specified number of milliseconds plus the specified
+ * number of nanoseconds, subject to the precision and accuracy of system
+ * timers and schedulers. The thread does not lose ownership of any
+ * monitors.
+ *
+ * @param millis
+ * the length of time to sleep in milliseconds
+ *
+ * @param nanos
+ * {@code 0-999999} additional nanoseconds to sleep
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative, or the value of
+ * {@code nanos} is not in the range {@code 0-999999}
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * interrupted status of the current thread is
+ * cleared when this exception is thrown.
+ */
+ public static void sleep(long millis, int nanos)
+ throws InterruptedException {
+ if (millis < 0) {
+ throw new IllegalArgumentException("timeout value is negative");
+ }
+
+ if (nanos < 0 || nanos > 999999) {
+ throw new IllegalArgumentException(
+ "nanosecond timeout value out of range");
+ }
+
+ if (nanos >= 500000 || (nanos != 0 && millis == 0)) {
+ millis++;
+ }
+
+ sleep(millis);
+ }
+
+ /**
+ * Initializes a Thread.
+ *
+ * @param g the Thread group
+ * @param target the object whose run() method gets called
+ * @param name the name of the new Thread
+ * @param stackSize the desired stack size for the new thread, or
+ * zero to indicate that this parameter is to be ignored.
+ */
+ private void init(ThreadGroup g, Runnable target, String name,
+ long stackSize) {
+ if (name == null) {
+ throw new NullPointerException("name cannot be null");
+ }
+
+ Thread parent = currentThread();
+ SecurityManager security = System.getSecurityManager();
+ if (g == null) {
+ /* Determine if it's an applet or not */
+
+ /* If there is a security manager, ask the security manager
+ what to do. */
+ if (security != null) {
+ g = security.getThreadGroup();
+ }
+
+ /* If the security doesn't have a strong opinion of the matter
+ use the parent thread group. */
+ if (g == null) {
+ g = parent.getThreadGroup();
+ }
+ }
+
+ /* checkAccess regardless of whether or not threadgroup is
+ explicitly passed in. */
+ g.checkAccess();
+
+ /*
+ * Do we have the required permissions?
+ */
+ if (security != null) {
+ if (isCCLOverridden(getClass())) {
+ security.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
+ }
+ }
+
+ g.addUnstarted();
+
+ this.group = g;
+ this.daemon = parent.isDaemon();
+ this.priority = parent.getPriority();
+ this.name = name.toCharArray();
+ if (security == null || isCCLOverridden(parent.getClass()))
+ this.contextClassLoader = parent.getContextClassLoader();
+ else
+ this.contextClassLoader = parent.contextClassLoader;
+ this.inheritedAccessControlContext = AccessController.getContext();
+ this.target = target;
+ setPriority(priority);
+ if (parent.inheritableThreadLocals != null)
+ this.inheritableThreadLocals =
+ ThreadLocal.createInheritedMap(parent.inheritableThreadLocals);
+ /* Stash the specified stack size in case the VM cares */
+ this.stackSize = stackSize;
+
+ /* Set thread ID */
+ tid = nextThreadID();
+ }
+
+ /**
+ * Throws CloneNotSupportedException as a Thread can not be meaningfully
+ * cloned. Construct a new Thread instead.
+ *
+ * @throws CloneNotSupportedException
+ * always
+ */
+ @Override
+ protected Object clone() throws CloneNotSupportedException {
+ throw new CloneNotSupportedException();
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, null, gname)}, where {@code gname} is a newly generated
+ * name. Automatically generated names are of the form
+ * {@code "Thread-"+}n, where n is an integer.
+ */
+ public Thread() {
+ init(null, null, "Thread-" + nextThreadNum(), 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, target, gname)}, where {@code gname} is a newly generated
+ * name. Automatically generated names are of the form
+ * {@code "Thread-"+}n, where n is an integer.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this classes {@code run} method does
+ * nothing.
+ */
+ public Thread(Runnable target) {
+ init(null, target, "Thread-" + nextThreadNum(), 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (group, target, gname)} ,where {@code gname} is a newly generated
+ * name. Automatically generated names are of the form
+ * {@code "Thread-"+}n, where n is an integer.
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group
+ */
+ public Thread(ThreadGroup group, Runnable target) {
+ init(group, target, "Thread-" + nextThreadNum(), 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, null, name)}.
+ *
+ * @param name
+ * the name of the new thread
+ */
+ public Thread(String name) {
+ init(null, null, name, 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (group, null, name)}.
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param name
+ * the name of the new thread
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group
+ */
+ public Thread(ThreadGroup group, String name) {
+ init(group, null, name, 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object. This constructor has the same
+ * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
+ * {@code (null, target, name)}.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @param name
+ * the name of the new thread
+ */
+ public Thread(Runnable target, String name) {
+ init(null, target, name, 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object so that it has {@code target}
+ * as its run object, has the specified {@code name} as its name,
+ * and belongs to the thread group referred to by {@code group}.
+ *
+ * If there is a security manager, its
+ * {@link SecurityManager#checkAccess(ThreadGroup) checkAccess}
+ * method is invoked with the ThreadGroup as its argument.
+ *
+ * In addition, its {@code checkPermission} method is invoked with
+ * the {@code RuntimePermission("enableContextClassLoaderOverride")}
+ * permission when invoked directly or indirectly by the constructor
+ * of a subclass which overrides the {@code getContextClassLoader}
+ * or {@code setContextClassLoader} methods.
+ *
+ * The priority of the newly created thread is set equal to the
+ * priority of the thread creating it, that is, the currently running
+ * thread. The method {@linkplain #setPriority setPriority} may be
+ * used to change the priority to a new value.
+ *
+ * The newly created thread is initially marked as being a daemon
+ * thread if and only if the thread creating it is currently marked
+ * as a daemon thread. The method {@linkplain #setDaemon setDaemon}
+ * may be used to change whether or not a thread is a daemon.
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @param name
+ * the name of the new thread
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group or cannot override the context class loader methods.
+ */
+ public Thread(ThreadGroup group, Runnable target, String name) {
+ init(group, target, name, 0);
+ }
+
+ /**
+ * Allocates a new {@code Thread} object so that it has {@code target}
+ * as its run object, has the specified {@code name} as its name,
+ * and belongs to the thread group referred to by {@code group}, and has
+ * the specified stack size.
+ *
+ * This constructor is identical to {@link
+ * #Thread(ThreadGroup,Runnable,String)} with the exception of the fact
+ * that it allows the thread stack size to be specified. The stack size
+ * is the approximate number of bytes of address space that the virtual
+ * machine is to allocate for this thread's stack. The effect of the
+ * {@code stackSize} parameter, if any, is highly platform dependent.
+ *
+ * On some platforms, specifying a higher value for the
+ * {@code stackSize} parameter may allow a thread to achieve greater
+ * recursion depth before throwing a {@link StackOverflowError}.
+ * Similarly, specifying a lower value may allow a greater number of
+ * threads to exist concurrently without throwing an {@link
+ * OutOfMemoryError} (or other internal error). The details of
+ * the relationship between the value of the stackSize parameter
+ * and the maximum recursion depth and concurrency level are
+ * platform-dependent. On some platforms, the value of the
+ * {@code stackSize} parameter may have no effect whatsoever.
+ *
+ * The virtual machine is free to treat the {@code stackSize}
+ * parameter as a suggestion. If the specified value is unreasonably low
+ * for the platform, the virtual machine may instead use some
+ * platform-specific minimum value; if the specified value is unreasonably
+ * high, the virtual machine may instead use some platform-specific
+ * maximum. Likewise, the virtual machine is free to round the specified
+ * value up or down as it sees fit (or to ignore it completely).
+ *
+ * Specifying a value of zero for the {@code stackSize} parameter will
+ * cause this constructor to behave exactly like the
+ * {@code Thread(ThreadGroup, Runnable, String)} constructor.
+ *
+ * Due to the platform-dependent nature of the behavior of this
+ * constructor, extreme care should be exercised in its use.
+ * The thread stack size necessary to perform a given computation will
+ * likely vary from one JRE implementation to another. In light of this
+ * variation, careful tuning of the stack size parameter may be required,
+ * and the tuning may need to be repeated for each JRE implementation on
+ * which an application is to run.
+ *
+ * Implementation note: Java platform implementers are encouraged to
+ * document their implementation's behavior with respect to the
+ * {@code stackSize} parameter.
+ *
+ *
+ * @param group
+ * the thread group. If {@code null} and there is a security
+ * manager, the group is determined by {@linkplain
+ * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}.
+ * If there is not a security manager or {@code
+ * SecurityManager.getThreadGroup()} returns {@code null}, the group
+ * is set to the current thread's thread group.
+ *
+ * @param target
+ * the object whose {@code run} method is invoked when this thread
+ * is started. If {@code null}, this thread's run method is invoked.
+ *
+ * @param name
+ * the name of the new thread
+ *
+ * @param stackSize
+ * the desired stack size for the new thread, or zero to indicate
+ * that this parameter is to be ignored.
+ *
+ * @throws SecurityException
+ * if the current thread cannot create a thread in the specified
+ * thread group
+ *
+ * @since 1.4
+ */
+ public Thread(ThreadGroup group, Runnable target, String name,
+ long stackSize) {
+ init(group, target, name, stackSize);
+ }
+
+ /**
+ * Causes this thread to begin execution; the Java Virtual Machine
+ * calls the
+ * The result is that two threads are running concurrently: the
+ * current thread (which returns from the call to the
+ *
+ * It is never legal to start a thread more than once.
+ * In particular, a thread may not be restarted once it has completed
+ * execution.
+ *
+ * @exception IllegalThreadStateException if the thread was already
+ * started.
+ * @see #run()
+ * @see #stop()
+ */
+ public synchronized void start() {
+ /**
+ * This method is not invoked for the main method thread or "system"
+ * group threads created/set up by the VM. Any new functionality added
+ * to this method in the future may have to also be added to the VM.
+ *
+ * A zero status value corresponds to state "NEW".
+ */
+ if (threadStatus != 0)
+ throw new IllegalThreadStateException();
+
+ /* Notify the group that this thread is about to be started
+ * so that it can be added to the group's list of threads
+ * and the group's unstarted count can be decremented. */
+ group.add(this);
+
+ boolean started = false;
+ try {
+ start0();
+ started = true;
+ } finally {
+ try {
+ if (!started) {
+ group.threadStartFailed(this);
+ }
+ } catch (Throwable ignore) {
+ /* do nothing. If start0 threw a Throwable then
+ it will be passed up the call stack */
+ }
+ }
+ }
+
+ private native void start0();
+
+ /**
+ * If this thread was constructed using a separate
+ *
+ * Subclasses of
+ * If there is a security manager installed, its
+ * If this thread is different from the current thread (that is, the current
+ * thread is trying to stop a thread other than itself), the
+ * security manager's
+ * The thread represented by this thread is forced to stop whatever
+ * it is doing abnormally and to throw a newly created
+ *
+ * It is permitted to stop a thread that has not yet been started.
+ * If the thread is eventually started, it immediately terminates.
+ *
+ * An application should not normally try to catch
+ *
+ * The top-level error handler that reacts to otherwise uncaught
+ * exceptions does not print out a message or otherwise notify the
+ * application if the uncaught exception is an instance of
+ *
+ * If there is a security manager installed, the
+ * If this thread is different from the current thread (that is, the current
+ * thread is trying to stop a thread other than itself) or
+ *
+ * If the argument
+ * The thread represented by this thread is forced to stop
+ * whatever it is doing abnormally and to throw the
+ *
+ * It is permitted to stop a thread that has not yet been started.
+ * If the thread is eventually started, it immediately terminates.
+ *
+ * @param obj the Throwable object to be thrown.
+ * @exception SecurityException if the current thread cannot modify
+ * this thread.
+ * @throws NullPointerException if obj is null.
+ * @see #interrupt()
+ * @see #checkAccess()
+ * @see #run()
+ * @see #start()
+ * @see #stop()
+ * @see SecurityManager#checkAccess(Thread)
+ * @see SecurityManager#checkPermission
+ * @deprecated This method is inherently unsafe. See {@link #stop()}
+ * for details. An additional danger of this
+ * method is that it may be used to generate exceptions that the
+ * target thread is unprepared to handle (including checked
+ * exceptions that the thread could not possibly throw, were it
+ * not for this method).
+ * For more information, see
+ * Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
+ */
+ @Deprecated
+ public final synchronized void stop(Throwable obj) {
+ if (obj == null)
+ throw new NullPointerException();
+
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ checkAccess();
+ if ((this != Thread.currentThread()) ||
+ (!(obj instanceof ThreadDeath))) {
+ security.checkPermission(SecurityConstants.STOP_THREAD_PERMISSION);
+ }
+ }
+ // A zero status value corresponds to "NEW", it can't change to
+ // not-NEW because we hold the lock.
+ if (threadStatus != 0) {
+ resume(); // Wake up thread if it was suspended; no-op otherwise
+ }
+
+ // The VM can handle all thread states
+ stop0(obj);
+ }
+
+ /**
+ * Interrupts this thread.
+ *
+ * Unless the current thread is interrupting itself, which is
+ * always permitted, the {@link #checkAccess() checkAccess} method
+ * of this thread is invoked, which may cause a {@link
+ * SecurityException} to be thrown.
+ *
+ * If this thread is blocked in an invocation of the {@link
+ * Object#wait() wait()}, {@link Object#wait(long) wait(long)}, or {@link
+ * Object#wait(long, int) wait(long, int)} methods of the {@link Object}
+ * class, or of the {@link #join()}, {@link #join(long)}, {@link
+ * #join(long, int)}, {@link #sleep(long)}, or {@link #sleep(long, int)},
+ * methods of this class, then its interrupt status will be cleared and it
+ * will receive an {@link InterruptedException}.
+ *
+ * If this thread is blocked in an I/O operation upon an {@link
+ * java.nio.channels.InterruptibleChannel interruptible
+ * channel If this thread is blocked in a {@link java.nio.channels.Selector}
+ * then the thread's interrupt status will be set and it will return
+ * immediately from the selection operation, possibly with a non-zero
+ * value, just as if the selector's {@link
+ * java.nio.channels.Selector#wakeup wakeup} method were invoked.
+ *
+ * If none of the previous conditions hold then this thread's interrupt
+ * status will be set. Interrupting a thread that is not alive need not have any effect.
+ *
+ * @throws SecurityException
+ * if the current thread cannot modify this thread
+ *
+ * @revised 6.0
+ * @spec JSR-51
+ */
+ public void interrupt() {
+ if (this != Thread.currentThread())
+ checkAccess();
+
+ synchronized (blockerLock) {
+ Interruptible b = blocker;
+ if (b != null) {
+ interrupt0(); // Just to set the interrupt flag
+ b.interrupt(this);
+ return;
+ }
+ }
+ interrupt0();
+ }
+
+ /**
+ * Tests whether the current thread has been interrupted. The
+ * interrupted status of the thread is cleared by this method. In
+ * other words, if this method were to be called twice in succession, the
+ * second call would return false (unless the current thread were
+ * interrupted again, after the first call had cleared its interrupted
+ * status and before the second call had examined it).
+ *
+ * A thread interruption ignored because a thread was not alive
+ * at the time of the interrupt will be reflected by this method
+ * returning false.
+ *
+ * @return A thread interruption ignored because a thread was not alive
+ * at the time of the interrupt will be reflected by this method
+ * returning false.
+ *
+ * @return
+ * First, the
+ * If the thread is alive, it is suspended and makes no further
+ * progress unless and until it is resumed.
+ *
+ * @exception SecurityException if the current thread cannot modify
+ * this thread.
+ * @see #checkAccess
+ * @deprecated This method has been deprecated, as it is
+ * inherently deadlock-prone. If the target thread holds a lock on the
+ * monitor protecting a critical system resource when it is suspended, no
+ * thread can access this resource until the target thread is resumed. If
+ * the thread that would resume the target thread attempts to lock this
+ * monitor prior to calling
+ * First, the
+ * If the thread is alive but suspended, it is resumed and is
+ * permitted to make progress in its execution.
+ *
+ * @exception SecurityException if the current thread cannot modify this
+ * thread.
+ * @see #checkAccess
+ * @see #suspend()
+ * @deprecated This method exists solely for use with {@link #suspend},
+ * which has been deprecated because it is deadlock-prone.
+ * For more information, see
+ * Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
+ */
+ @Deprecated
+ public final void resume() {
+ checkAccess();
+ resume0();
+ }
+
+ /**
+ * Changes the priority of this thread.
+ *
+ * First the
+ * Otherwise, the priority of this thread is set to the smaller of
+ * the specified
+ * First the The value returned is only an estimate because the number of
+ * threads may change dynamically while this method traverses internal
+ * data structures, and might be affected by the presence of certain
+ * system threads. This method is intended primarily for debugging
+ * and monitoring purposes.
+ *
+ * @return an estimate of the number of active threads in the current
+ * thread's thread group and in any other thread group that
+ * has the current thread's thread group as an ancestor
+ */
+ public static int activeCount() {
+ return currentThread().getThreadGroup().activeCount();
+ }
+
+ /**
+ * Copies into the specified array every active thread in the current
+ * thread's thread group and its subgroups. This method simply
+ * invokes the {@link java.lang.ThreadGroup#enumerate(Thread[])}
+ * method of the current thread's thread group.
+ *
+ * An application might use the {@linkplain #activeCount activeCount}
+ * method to get an estimate of how big the array should be, however
+ * if the array is too short to hold all the threads, the extra threads
+ * are silently ignored. If it is critical to obtain every active
+ * thread in the current thread's thread group and its subgroups, the
+ * invoker should verify that the returned int value is strictly less
+ * than the length of {@code tarray}.
+ *
+ * Due to the inherent race condition in this method, it is recommended
+ * that the method only be used for debugging and monitoring purposes.
+ *
+ * @param tarray
+ * an array into which to put the list of threads
+ *
+ * @return the number of threads put into the array
+ *
+ * @throws SecurityException
+ * if {@link java.lang.ThreadGroup#checkAccess} determines that
+ * the current thread cannot access its thread group
+ */
+ public static int enumerate(Thread tarray[]) {
+ return currentThread().getThreadGroup().enumerate(tarray);
+ }
+
+ /**
+ * Counts the number of stack frames in this thread. The thread must
+ * be suspended.
+ *
+ * @return the number of stack frames in this thread.
+ * @exception IllegalThreadStateException if this thread is not
+ * suspended.
+ * @deprecated The definition of this call depends on {@link #suspend},
+ * which is deprecated. Further, the results of this call
+ * were never well-defined.
+ */
+ @Deprecated
+ public native int countStackFrames();
+
+ /**
+ * Waits at most {@code millis} milliseconds for this thread to
+ * die. A timeout of {@code 0} means to wait forever.
+ *
+ * This implementation uses a loop of {@code this.wait} calls
+ * conditioned on {@code this.isAlive}. As a thread terminates the
+ * {@code this.notifyAll} method is invoked. It is recommended that
+ * applications not use {@code wait}, {@code notify}, or
+ * {@code notifyAll} on {@code Thread} instances.
+ *
+ * @param millis
+ * the time to wait in milliseconds
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * interrupted status of the current thread is
+ * cleared when this exception is thrown.
+ */
+ public final synchronized void join(long millis)
+ throws InterruptedException {
+ long base = System.currentTimeMillis();
+ long now = 0;
+
+ if (millis < 0) {
+ throw new IllegalArgumentException("timeout value is negative");
+ }
+
+ if (millis == 0) {
+ while (isAlive()) {
+ wait(0);
+ }
+ } else {
+ while (isAlive()) {
+ long delay = millis - now;
+ if (delay <= 0) {
+ break;
+ }
+ wait(delay);
+ now = System.currentTimeMillis() - base;
+ }
+ }
+ }
+
+ /**
+ * Waits at most {@code millis} milliseconds plus
+ * {@code nanos} nanoseconds for this thread to die.
+ *
+ * This implementation uses a loop of {@code this.wait} calls
+ * conditioned on {@code this.isAlive}. As a thread terminates the
+ * {@code this.notifyAll} method is invoked. It is recommended that
+ * applications not use {@code wait}, {@code notify}, or
+ * {@code notifyAll} on {@code Thread} instances.
+ *
+ * @param millis
+ * the time to wait in milliseconds
+ *
+ * @param nanos
+ * {@code 0-999999} additional nanoseconds to wait
+ *
+ * @throws IllegalArgumentException
+ * if the value of {@code millis} is negative, or the value
+ * of {@code nanos} is not in the range {@code 0-999999}
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * interrupted status of the current thread is
+ * cleared when this exception is thrown.
+ */
+ public final synchronized void join(long millis, int nanos)
+ throws InterruptedException {
+
+ if (millis < 0) {
+ throw new IllegalArgumentException("timeout value is negative");
+ }
+
+ if (nanos < 0 || nanos > 999999) {
+ throw new IllegalArgumentException(
+ "nanosecond timeout value out of range");
+ }
+
+ if (nanos >= 500000 || (nanos != 0 && millis == 0)) {
+ millis++;
+ }
+
+ join(millis);
+ }
+
+ /**
+ * Waits for this thread to die.
+ *
+ * An invocation of this method behaves in exactly the same
+ * way as the invocation
+ *
+ * This method must be invoked before the thread is started.
+ *
+ * @param on
+ * if {@code true}, marks this thread as a daemon thread
+ *
+ * @throws IllegalThreadStateException
+ * if this thread is {@linkplain #isAlive alive}
+ *
+ * @throws SecurityException
+ * if {@link #checkAccess} determines that the current
+ * thread cannot modify this thread
+ */
+ public final void setDaemon(boolean on) {
+ checkAccess();
+ if (isAlive()) {
+ throw new IllegalThreadStateException();
+ }
+ daemon = on;
+ }
+
+ /**
+ * Tests if this thread is a daemon thread.
+ *
+ * @return
+ * If there is a security manager, its If a security manager is present, and the invoker's class loader is not
+ * {@code null} and is not the same as or an ancestor of the context class
+ * loader, then this method invokes the security manager's {@link
+ * SecurityManager#checkPermission(java.security.Permission) checkPermission}
+ * method with a {@link RuntimePermission RuntimePermission}{@code
+ * ("getClassLoader")} permission to verify that retrieval of the context
+ * class loader is permitted.
+ *
+ * @return the context ClassLoader for this Thread, or {@code null}
+ * indicating the system class loader (or, failing that, the
+ * bootstrap class loader)
+ *
+ * @throws SecurityException
+ * if the current thread cannot get the context ClassLoader
+ *
+ * @since 1.2
+ */
+ public ClassLoader getContextClassLoader() {
+ if (contextClassLoader == null)
+ return null;
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ ClassLoader ccl = ClassLoader.getCallerClassLoader();
+ if (ccl != null && ccl != contextClassLoader &&
+ !contextClassLoader.isAncestor(ccl)) {
+ sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
+ }
+ }
+ return contextClassLoader;
+ }
+
+ /**
+ * Sets the context ClassLoader for this Thread. The context
+ * ClassLoader can be set when a thread is created, and allows
+ * the creator of the thread to provide the appropriate class loader,
+ * through {@code getContextClassLoader}, to code running in the thread
+ * when loading classes and resources.
+ *
+ * If a security manager is present, its {@link
+ * SecurityManager#checkPermission(java.security.Permission) checkPermission}
+ * method is invoked with a {@link RuntimePermission RuntimePermission}{@code
+ * ("setContextClassLoader")} permission to see if setting the context
+ * ClassLoader is permitted.
+ *
+ * @param cl
+ * the context ClassLoader for this Thread, or null indicating the
+ * system class loader (or, failing that, the bootstrap class loader)
+ *
+ * @throws SecurityException
+ * if the current thread cannot set the context ClassLoader
+ *
+ * @since 1.2
+ */
+ public void setContextClassLoader(ClassLoader cl) {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(new RuntimePermission("setContextClassLoader"));
+ }
+ contextClassLoader = cl;
+ }
+
+ /**
+ * Returns true if and only if the current thread holds the
+ * monitor lock on the specified object.
+ *
+ * This method is designed to allow a program to assert that
+ * the current thread already holds a specified lock:
+ * If there is a security manager, and this thread is not
+ * the current thread, then the security manager's
+ * checkPermission method is called with a
+ * RuntimePermission("getStackTrace") permission
+ * to see if it's ok to get the stack trace.
+ *
+ * Some virtual machines may, under some circumstances, omit one
+ * or more stack frames from the stack trace. In the extreme case,
+ * a virtual machine that has no stack trace information concerning
+ * this thread is permitted to return a zero-length array from this
+ * method.
+ *
+ * @return an array of StackTraceElement,
+ * each represents one stack frame.
+ *
+ * @throws SecurityException
+ * if a security manager exists and its
+ * checkPermission method doesn't allow
+ * getting the stack trace of thread.
+ * @see SecurityManager#checkPermission
+ * @see RuntimePermission
+ * @see Throwable#getStackTrace
+ *
+ * @since 1.5
+ */
+ public StackTraceElement[] getStackTrace() {
+ if (this != Thread.currentThread()) {
+ // check for getStackTrace permission
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkPermission(
+ SecurityConstants.GET_STACK_TRACE_PERMISSION);
+ }
+ // optimization so we do not call into the vm for threads that
+ // have not yet started or have terminated
+ if (!isAlive()) {
+ return EMPTY_STACK_TRACE;
+ }
+ StackTraceElement[][] stackTraceArray = dumpThreads(new Thread[] {this});
+ StackTraceElement[] stackTrace = stackTraceArray[0];
+ // a thread that was alive during the previous isAlive call may have
+ // since terminated, therefore not having a stacktrace.
+ if (stackTrace == null) {
+ stackTrace = EMPTY_STACK_TRACE;
+ }
+ return stackTrace;
+ } else {
+ // Don't need JVM help for current thread
+ return (new Exception()).getStackTrace();
+ }
+ }
+
+ /**
+ * Returns a map of stack traces for all live threads.
+ * The map keys are threads and each map value is an array of
+ * StackTraceElement that represents the stack dump
+ * of the corresponding Thread.
+ * The returned stack traces are in the format specified for
+ * the {@link #getStackTrace getStackTrace} method.
+ *
+ * The threads may be executing while this method is called.
+ * The stack trace of each thread only represents a snapshot and
+ * each stack trace may be obtained at different time. A zero-length
+ * array will be returned in the map value if the virtual machine has
+ * no stack trace information about a thread.
+ *
+ * If there is a security manager, then the security manager's
+ * checkPermission method is called with a
+ * RuntimePermission("getStackTrace") permission as well as
+ * RuntimePermission("modifyThreadGroup") permission
+ * to see if it is ok to get the stack trace of all threads.
+ *
+ * @return a Map from Thread to an array of
+ * StackTraceElement that represents the stack trace of
+ * the corresponding thread.
+ *
+ * @throws SecurityException
+ * if a security manager exists and its
+ * checkPermission method doesn't allow
+ * getting the stack trace of thread.
+ * @see #getStackTrace
+ * @see SecurityManager#checkPermission
+ * @see RuntimePermission
+ * @see Throwable#getStackTrace
+ *
+ * @since 1.5
+ */
+ public static Map
+ * A thread can be in only one state at a given point in time.
+ * These states are virtual machine states which do not reflect
+ * any operating system thread states.
+ *
+ * @since 1.5
+ * @see #getState
+ */
+ public enum State {
+ /**
+ * Thread state for a thread which has not yet started.
+ */
+ NEW,
+
+ /**
+ * Thread state for a runnable thread. A thread in the runnable
+ * state is executing in the Java virtual machine but it may
+ * be waiting for other resources from the operating system
+ * such as processor.
+ */
+ RUNNABLE,
+
+ /**
+ * Thread state for a thread blocked waiting for a monitor lock.
+ * A thread in the blocked state is waiting for a monitor lock
+ * to enter a synchronized block/method or
+ * reenter a synchronized block/method after calling
+ * {@link Object#wait() Object.wait}.
+ */
+ BLOCKED,
+
+ /**
+ * Thread state for a waiting thread.
+ * A thread is in the waiting state due to calling one of the
+ * following methods:
+ * A thread in the waiting state is waiting for another thread to
+ * perform a particular action.
+ *
+ * For example, a thread that has called Object.wait()
+ * on an object is waiting for another thread to call
+ * Object.notify() or Object.notifyAll() on
+ * that object. A thread that has called Thread.join()
+ * is waiting for a specified thread to terminate.
+ */
+ WAITING,
+
+ /**
+ * Thread state for a waiting thread with a specified waiting time.
+ * A thread is in the timed waiting state due to calling one of
+ * the following methods with a specified positive waiting time:
+ * When a thread is about to terminate due to an uncaught exception
+ * the Java Virtual Machine will query the thread for its
+ * UncaughtExceptionHandler using
+ * {@link #getUncaughtExceptionHandler} and will invoke the handler's
+ * uncaughtException method, passing the thread and the
+ * exception as arguments.
+ * If a thread has not had its UncaughtExceptionHandler
+ * explicitly set, then its ThreadGroup object acts as its
+ * UncaughtExceptionHandler. If the ThreadGroup object
+ * has no
+ * special requirements for dealing with the exception, it can forward
+ * the invocation to the {@linkplain #getDefaultUncaughtExceptionHandler
+ * default uncaught exception handler}.
+ *
+ * @see #setDefaultUncaughtExceptionHandler
+ * @see #setUncaughtExceptionHandler
+ * @see ThreadGroup#uncaughtException
+ * @since 1.5
+ */
+ public interface UncaughtExceptionHandler {
+ /**
+ * Method invoked when the given thread terminates due to the
+ * given uncaught exception.
+ * Any exception thrown by this method will be ignored by the
+ * Java Virtual Machine.
+ * @param t the thread
+ * @param e the exception
+ */
+ void uncaughtException(Thread t, Throwable e);
+ }
+
+ // null unless explicitly set
+ private volatile UncaughtExceptionHandler uncaughtExceptionHandler;
+
+ // null unless explicitly set
+ private static volatile UncaughtExceptionHandler defaultUncaughtExceptionHandler;
+
+ /**
+ * Set the default handler invoked when a thread abruptly terminates
+ * due to an uncaught exception, and no other handler has been defined
+ * for that thread.
+ *
+ * Uncaught exception handling is controlled first by the thread, then
+ * by the thread's {@link ThreadGroup} object and finally by the default
+ * uncaught exception handler. If the thread does not have an explicit
+ * uncaught exception handler set, and the thread's thread group
+ * (including parent thread groups) does not specialize its
+ * uncaughtException method, then the default handler's
+ * uncaughtException method will be invoked.
+ * By setting the default uncaught exception handler, an application
+ * can change the way in which uncaught exceptions are handled (such as
+ * logging to a specific device, or file) for those threads that would
+ * already accept whatever "default" behavior the system
+ * provided.
+ *
+ * Note that the default uncaught exception handler should not usually
+ * defer to the thread's ThreadGroup object, as that could cause
+ * infinite recursion.
+ *
+ * @param eh the object to use as the default uncaught exception handler.
+ * If null then there is no default handler.
+ *
+ * @throws SecurityException if a security manager is present and it
+ * denies {@link RuntimePermission}
+ * ("setDefaultUncaughtExceptionHandler")
+ *
+ * @see #setUncaughtExceptionHandler
+ * @see #getUncaughtExceptionHandler
+ * @see ThreadGroup#uncaughtException
+ * @since 1.5
+ */
+ public static void setDefaultUncaughtExceptionHandler(UncaughtExceptionHandler eh) {
+ SecurityManager sm = System.getSecurityManager();
+ if (sm != null) {
+ sm.checkPermission(
+ new RuntimePermission("setDefaultUncaughtExceptionHandler")
+ );
+ }
+
+ defaultUncaughtExceptionHandler = eh;
+ }
+
+ /**
+ * Returns the default handler invoked when a thread abruptly terminates
+ * due to an uncaught exception. If the returned value is null,
+ * there is no default.
+ * @since 1.5
+ * @see #setDefaultUncaughtExceptionHandler
+ */
+ public static UncaughtExceptionHandler getDefaultUncaughtExceptionHandler(){
+ return defaultUncaughtExceptionHandler;
+ }
+
+ /**
+ * Returns the handler invoked when this thread abruptly terminates
+ * due to an uncaught exception. If this thread has not had an
+ * uncaught exception handler explicitly set then this thread's
+ * ThreadGroup object is returned, unless this thread
+ * has terminated, in which case null is returned.
+ * @since 1.5
+ */
+ public UncaughtExceptionHandler getUncaughtExceptionHandler() {
+ return uncaughtExceptionHandler != null ?
+ uncaughtExceptionHandler : group;
+ }
+
+ /**
+ * Set the handler invoked when this thread abruptly terminates
+ * due to an uncaught exception.
+ * A thread can take full control of how it responds to uncaught
+ * exceptions by having its uncaught exception handler explicitly set.
+ * If no such handler is set then the thread's ThreadGroup
+ * object acts as its handler.
+ * @param eh the object to use as this thread's uncaught exception
+ * handler. If null then this thread has no explicit handler.
+ * @throws SecurityException if the current thread is not allowed to
+ * modify this thread.
+ * @see #setDefaultUncaughtExceptionHandler
+ * @see ThreadGroup#uncaughtException
+ * @since 1.5
+ */
+ public void setUncaughtExceptionHandler(UncaughtExceptionHandler eh) {
+ checkAccess();
+ uncaughtExceptionHandler = eh;
+ }
+
+ /**
+ * Dispatch an uncaught exception to the handler. This method is
+ * intended to be called only by the JVM.
+ */
+ private void dispatchUncaughtException(Throwable e) {
+ getUncaughtExceptionHandler().uncaughtException(this, e);
+ }
+
+ /**
+ * Removes from the specified map any keys that have been enqueued
+ * on the specified reference queue.
+ */
+ static void processQueue(ReferenceQueuerun method of this thread.
+ * start method) and the other thread (which executes its
+ * run method).
+ * Runnable run object, then that
+ * Runnable object's run method is called;
+ * otherwise, this method does nothing and returns.
+ * Thread should override this method.
+ *
+ * @see #start()
+ * @see #stop()
+ * @see #Thread(ThreadGroup, Runnable, String)
+ */
+ @Override
+ public void run() {
+ if (target != null) {
+ target.run();
+ }
+ }
+
+ /**
+ * This method is called by the system to give a Thread
+ * a chance to clean up before it actually exits.
+ */
+ private void exit() {
+ if (group != null) {
+ group.threadTerminated(this);
+ group = null;
+ }
+ /* Aggressively null out all reference fields: see bug 4006245 */
+ target = null;
+ /* Speed the release of some of these resources */
+ threadLocals = null;
+ inheritableThreadLocals = null;
+ inheritedAccessControlContext = null;
+ blocker = null;
+ uncaughtExceptionHandler = null;
+ }
+
+ /**
+ * Forces the thread to stop executing.
+ * checkAccess
+ * method is called with this
+ * as its argument. This may result in a
+ * SecurityException being raised (in the current thread).
+ * checkPermission method (with a
+ * RuntimePermission("stopThread") argument) is called in
+ * addition.
+ * Again, this may result in throwing a
+ * SecurityException (in the current thread).
+ * ThreadDeath object as an exception.
+ * ThreadDeath unless it must do some extraordinary
+ * cleanup operation (note that the throwing of
+ * ThreadDeath causes finally clauses of
+ * try statements to be executed before the thread
+ * officially dies). If a catch clause catches a
+ * ThreadDeath object, it is important to rethrow the
+ * object so that the thread actually dies.
+ * ThreadDeath.
+ *
+ * @exception SecurityException if the current thread cannot
+ * modify this thread.
+ * @see #interrupt()
+ * @see #checkAccess()
+ * @see #run()
+ * @see #start()
+ * @see ThreadDeath
+ * @see ThreadGroup#uncaughtException(Thread,Throwable)
+ * @see SecurityManager#checkAccess(Thread)
+ * @see SecurityManager#checkPermission
+ * @deprecated This method is inherently unsafe. Stopping a thread with
+ * Thread.stop causes it to unlock all of the monitors that it
+ * has locked (as a natural consequence of the unchecked
+ * ThreadDeath exception propagating up the stack). If
+ * any of the objects previously protected by these monitors were in
+ * an inconsistent state, the damaged objects become visible to
+ * other threads, potentially resulting in arbitrary behavior. Many
+ * uses of stop should be replaced by code that simply
+ * modifies some variable to indicate that the target thread should
+ * stop running. The target thread should check this variable
+ * regularly, and return from its run method in an orderly fashion
+ * if the variable indicates that it is to stop running. If the
+ * target thread waits for long periods (on a condition variable,
+ * for example), the interrupt method should be used to
+ * interrupt the wait.
+ * For more information, see
+ * Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
+ */
+ @Deprecated
+ public final void stop() {
+ stop(new ThreadDeath());
+ }
+
+ /**
+ * Forces the thread to stop executing.
+ * checkAccess
+ * method of this thread is called, which may result in a
+ * SecurityException being raised (in the current thread).
+ * obj is not an instance of ThreadDeath, the
+ * security manager's checkPermission method (with the
+ * RuntimePermission("stopThread") argument) is called in
+ * addition.
+ * Again, this may result in throwing a
+ * SecurityException (in the current thread).
+ * obj is null, a
+ * NullPointerException is thrown (in the current thread).
+ * Throwable object obj as an exception. This
+ * is an unusual action to take; normally, the stop method
+ * that takes no arguments should be used.
+ * } then the channel will be closed, the thread's interrupt
+ * status will be set, and the thread will receive a {@link
+ * java.nio.channels.ClosedByInterruptException}.
+ *
+ * true if the current thread has been interrupted;
+ * false otherwise.
+ * @see #isInterrupted()
+ * @revised 6.0
+ */
+ public static boolean interrupted() {
+ return currentThread().isInterrupted(true);
+ }
+
+ /**
+ * Tests whether this thread has been interrupted. The interrupted
+ * status of the thread is unaffected by this method.
+ *
+ * true if this thread has been interrupted;
+ * false otherwise.
+ * @see #interrupted()
+ * @revised 6.0
+ */
+ public boolean isInterrupted() {
+ return isInterrupted(false);
+ }
+
+ /**
+ * Tests if some Thread has been interrupted. The interrupted state
+ * is reset or not based on the value of ClearInterrupted that is
+ * passed.
+ */
+ private native boolean isInterrupted(boolean ClearInterrupted);
+
+ /**
+ * Throws {@link NoSuchMethodError}.
+ *
+ * @deprecated This method was originally designed to destroy this
+ * thread without any cleanup. Any monitors it held would have
+ * remained locked. However, the method was never implemented.
+ * If if were to be implemented, it would be deadlock-prone in
+ * much the manner of {@link #suspend}. If the target thread held
+ * a lock protecting a critical system resource when it was
+ * destroyed, no thread could ever access this resource again.
+ * If another thread ever attempted to lock this resource, deadlock
+ * would result. Such deadlocks typically manifest themselves as
+ * "frozen" processes. For more information, see
+ *
+ * Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
+ * @throws NoSuchMethodError always
+ */
+ @Deprecated
+ public void destroy() {
+ throw new NoSuchMethodError();
+ }
+
+ /**
+ * Tests if this thread is alive. A thread is alive if it has
+ * been started and has not yet died.
+ *
+ * @return true if this thread is alive;
+ * false otherwise.
+ */
+ public final native boolean isAlive();
+
+ /**
+ * Suspends this thread.
+ * checkAccess method of this thread is called
+ * with no arguments. This may result in throwing a
+ * SecurityException (in the current thread).
+ * resume, deadlock results. Such
+ * deadlocks typically manifest themselves as "frozen" processes.
+ * For more information, see
+ * Why
+ * are Thread.stop, Thread.suspend and Thread.resume Deprecated?.
+ */
+ @Deprecated
+ public final void suspend() {
+ checkAccess();
+ suspend0();
+ }
+
+ /**
+ * Resumes a suspended thread.
+ * checkAccess method of this thread is called
+ * with no arguments. This may result in throwing a
+ * SecurityException (in the current thread).
+ * checkAccess method of this thread is called
+ * with no arguments. This may result in throwing a
+ * SecurityException.
+ * newPriority and the maximum permitted
+ * priority of the thread's thread group.
+ *
+ * @param newPriority priority to set this thread to
+ * @exception IllegalArgumentException If the priority is not in the
+ * range MIN_PRIORITY to
+ * MAX_PRIORITY.
+ * @exception SecurityException if the current thread cannot modify
+ * this thread.
+ * @see #getPriority
+ * @see #checkAccess()
+ * @see #getThreadGroup()
+ * @see #MAX_PRIORITY
+ * @see #MIN_PRIORITY
+ * @see ThreadGroup#getMaxPriority()
+ */
+ public final void setPriority(int newPriority) {
+ ThreadGroup g;
+ checkAccess();
+ if (newPriority > MAX_PRIORITY || newPriority < MIN_PRIORITY) {
+ throw new IllegalArgumentException();
+ }
+ if((g = getThreadGroup()) != null) {
+ if (newPriority > g.getMaxPriority()) {
+ newPriority = g.getMaxPriority();
+ }
+ setPriority0(priority = newPriority);
+ }
+ }
+
+ /**
+ * Returns this thread's priority.
+ *
+ * @return this thread's priority.
+ * @see #setPriority
+ */
+ public final int getPriority() {
+ return priority;
+ }
+
+ /**
+ * Changes the name of this thread to be equal to the argument
+ * name.
+ * checkAccess method of this thread is called
+ * with no arguments. This may result in throwing a
+ * SecurityException.
+ *
+ * @param name the new name for this thread.
+ * @exception SecurityException if the current thread cannot modify this
+ * thread.
+ * @see #getName
+ * @see #checkAccess()
+ */
+ public final void setName(String name) {
+ checkAccess();
+ this.name = name.toCharArray();
+ }
+
+ /**
+ * Returns this thread's name.
+ *
+ * @return this thread's name.
+ * @see #setName(String)
+ */
+ public final String getName() {
+ return String.valueOf(name);
+ }
+
+ /**
+ * Returns the thread group to which this thread belongs.
+ * This method returns null if this thread has died
+ * (been stopped).
+ *
+ * @return this thread's thread group.
+ */
+ public final ThreadGroup getThreadGroup() {
+ return group;
+ }
+
+ /**
+ * Returns an estimate of the number of active threads in the current
+ * thread's {@linkplain java.lang.ThreadGroup thread group} and its
+ * subgroups. Recursively iterates over all subgroups in the current
+ * thread's thread group.
+ *
+ *
+ * {@linkplain #join(long) join}{@code (0)}
+ *
+ *
+ * @throws InterruptedException
+ * if any thread has interrupted the current thread. The
+ * interrupted status of the current thread is
+ * cleared when this exception is thrown.
+ */
+ public final void join() throws InterruptedException {
+ join(0);
+ }
+
+ /**
+ * Prints a stack trace of the current thread to the standard error stream.
+ * This method is used only for debugging.
+ *
+ * @see Throwable#printStackTrace()
+ */
+ public static void dumpStack() {
+ new Exception("Stack trace").printStackTrace();
+ }
+
+ /**
+ * Marks this thread as either a {@linkplain #isDaemon daemon} thread
+ * or a user thread. The Java Virtual Machine exits when the only
+ * threads running are all daemon threads.
+ *
+ * true if this thread is a daemon thread;
+ * false otherwise.
+ * @see #setDaemon(boolean)
+ */
+ public final boolean isDaemon() {
+ return daemon;
+ }
+
+ /**
+ * Determines if the currently running thread has permission to
+ * modify this thread.
+ * checkAccess method
+ * is called with this thread as its argument. This may result in
+ * throwing a SecurityException.
+ *
+ * @exception SecurityException if the current thread is not allowed to
+ * access this thread.
+ * @see SecurityManager#checkAccess(Thread)
+ */
+ public final void checkAccess() {
+ SecurityManager security = System.getSecurityManager();
+ if (security != null) {
+ security.checkAccess(this);
+ }
+ }
+
+ /**
+ * Returns a string representation of this thread, including the
+ * thread's name, priority, and thread group.
+ *
+ * @return a string representation of this thread.
+ */
+ public String toString() {
+ ThreadGroup group = getThreadGroup();
+ if (group != null) {
+ return "Thread[" + getName() + "," + getPriority() + "," +
+ group.getName() + "]";
+ } else {
+ return "Thread[" + getName() + "," + getPriority() + "," +
+ "" + "]";
+ }
+ }
+
+ /**
+ * Returns the context ClassLoader for this Thread. The context
+ * ClassLoader is provided by the creator of the thread for use
+ * by code running in this thread when loading classes and resources.
+ * If not {@linkplain #setContextClassLoader set}, the default is the
+ * ClassLoader context of the parent Thread. The context ClassLoader of the
+ * primordial thread is typically set to the class loader used to load the
+ * application.
+ *
+ *
+ * assert Thread.holdsLock(obj);
+ *
+ *
+ * @param obj the object on which to test lock ownership
+ * @throws NullPointerException if obj is null
+ * @return true if the current thread holds the monitor lock on
+ * the specified object.
+ * @since 1.4
+ */
+ public static native boolean holdsLock(Object obj);
+
+ private static final StackTraceElement[] EMPTY_STACK_TRACE
+ = new StackTraceElement[0];
+
+ /**
+ * Returns an array of stack trace elements representing the stack dump
+ * of this thread. This method will return a zero-length array if
+ * this thread has not started, has started but has not yet been
+ * scheduled to run by the system, or has terminated.
+ * If the returned array is of non-zero length then the first element of
+ * the array represents the top of the stack, which is the most recent
+ * method invocation in the sequence. The last element of the array
+ * represents the bottom of the stack, which is the least recent method
+ * invocation in the sequence.
+ *
+ *
+ *
+ *
+ *
+ * A thread that has not yet started is in this state.
+ *
+ * A thread executing in the Java virtual machine is in this state.
+ *
+ * A thread that is blocked waiting for a monitor lock
+ * is in this state.
+ *
+ * A thread that is waiting indefinitely for another thread to
+ * perform a particular action is in this state.
+ *
+ * A thread that is waiting for another thread to perform an action
+ * for up to a specified waiting time is in this state.
+ *
+ * A thread that has exited is in this state.
+ *
+ *
+ *
+ *
+ *
+ */
+ TIMED_WAITING,
+
+ /**
+ * Thread state for a terminated thread.
+ * The thread has completed execution.
+ */
+ TERMINATED;
+ }
+
+ /**
+ * Returns the state of this thread.
+ * This method is designed for use in monitoring of the system state,
+ * not for synchronization control.
+ *
+ * @return this thread's state.
+ * @since 1.5
+ */
+ public State getState() {
+ // get current thread state
+ return sun.misc.VM.toThreadState(threadStatus);
+ }
+
+ // Added in JSR-166
+
+ /**
+ * Interface for handlers invoked when a Thread abruptly
+ * terminates due to an uncaught exception.
+ *