| /* Thread -- an independent thread of executable code |
| Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 |
| Free Software Foundation |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| 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. */ |
| |
| |
| package java.lang; |
| |
| import gnu.gcj.RawData; |
| import gnu.gcj.RawDataManaged; |
| import gnu.java.util.WeakIdentityHashMap; |
| import java.util.Map; |
| |
| /* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 |
| * "The Java Language Specification", ISBN 0-201-63451-1 |
| * plus online API docs for JDK 1.2 beta from http://www.javasoft.com. |
| * Status: Believed complete to version 1.4, with caveats. We do not |
| * implement the deprecated (and dangerous) stop, suspend, and resume |
| * methods. Security implementation is not complete. |
| */ |
| |
| /** |
| * Thread represents a single thread of execution in the VM. When an |
| * application VM starts up, it creates a non-daemon Thread which calls the |
| * main() method of a particular class. There may be other Threads running, |
| * such as the garbage collection thread. |
| * |
| * <p>Threads have names to identify them. These names are not necessarily |
| * unique. Every Thread has a priority, as well, which tells the VM which |
| * Threads should get more running time. New threads inherit the priority |
| * and daemon status of the parent thread, by default. |
| * |
| * <p>There are two methods of creating a Thread: you may subclass Thread and |
| * implement the <code>run()</code> method, at which point you may start the |
| * Thread by calling its <code>start()</code> method, or you may implement |
| * <code>Runnable</code> in the class you want to use and then call new |
| * <code>Thread(your_obj).start()</code>. |
| * |
| * <p>The virtual machine runs until all non-daemon threads have died (either |
| * by returning from the run() method as invoked by start(), or by throwing |
| * an uncaught exception); or until <code>System.exit</code> is called with |
| * adequate permissions. |
| * |
| * <p>It is unclear at what point a Thread should be added to a ThreadGroup, |
| * and at what point it should be removed. Should it be inserted when it |
| * starts, or when it is created? Should it be removed when it is suspended |
| * or interrupted? The only thing that is clear is that the Thread should be |
| * removed when it is stopped. |
| * |
| * @author Tom Tromey |
| * @author John Keiser |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @see Runnable |
| * @see Runtime#exit(int) |
| * @see #run() |
| * @see #start() |
| * @see ThreadLocal |
| * @since 1.0 |
| * @status updated to 1.4 |
| */ |
| public class Thread implements Runnable |
| { |
| /** The minimum priority for a Thread. */ |
| public static final int MIN_PRIORITY = 1; |
| |
| /** The priority a Thread gets by default. */ |
| public static final int NORM_PRIORITY = 5; |
| |
| /** The maximum priority for a Thread. */ |
| public static final int MAX_PRIORITY = 10; |
| |
| /** |
| * The group this thread belongs to. This is set to null by |
| * ThreadGroup.removeThread when the thread dies. |
| */ |
| ThreadGroup group; |
| |
| /** The object to run(), null if this is the target. */ |
| private Runnable runnable; |
| |
| /** The thread name, non-null. */ |
| String name; |
| |
| /** Whether the thread is a daemon. */ |
| private boolean daemon; |
| |
| /** The thread priority, 1 to 10. */ |
| private int priority; |
| |
| boolean interrupt_flag; |
| private boolean alive_flag; |
| private boolean startable_flag; |
| |
| /** The context classloader for this Thread. */ |
| private ClassLoader contextClassLoader; |
| |
| /** This thread's ID. */ |
| private final long threadId; |
| |
| /** The next thread ID to use. */ |
| private static long nextThreadId; |
| |
| /** The default exception handler. */ |
| private static UncaughtExceptionHandler defaultHandler; |
| |
| /** Thread local storage. Package accessible for use by |
| * InheritableThreadLocal. |
| */ |
| WeakIdentityHashMap locals; |
| |
| /** The uncaught exception handler. */ |
| UncaughtExceptionHandler exceptionHandler; |
| |
| /** The access control state for this thread. Package accessible |
| * for use by java.security.VMAccessControlState's native method. |
| */ |
| Object accessControlState = null; |
| |
| // This describes the top-most interpreter frame for this thread. |
| RawData interp_frame; |
| |
| // Our native data - points to an instance of struct natThread. |
| private RawDataManaged data; |
| |
| /** |
| * Allocates a new <code>Thread</code> object. This constructor has |
| * the same effect as <code>Thread(null, null,</code> |
| * <i>gname</i><code>)</code>, where <b><i>gname</i></b> is |
| * a newly generated name. Automatically generated names are of the |
| * form <code>"Thread-"+</code><i>n</i>, where <i>n</i> is an integer. |
| * <p> |
| * Threads created this way must have overridden their |
| * <code>run()</code> method to actually do anything. An example |
| * illustrating this method being used follows: |
| * <p><blockquote><pre> |
| * import java.lang.*; |
| * |
| * class plain01 implements Runnable { |
| * String name; |
| * plain01() { |
| * name = null; |
| * } |
| * plain01(String s) { |
| * name = s; |
| * } |
| * public void run() { |
| * if (name == null) |
| * System.out.println("A new thread created"); |
| * else |
| * System.out.println("A new thread with name " + name + |
| * " created"); |
| * } |
| * } |
| * class threadtest01 { |
| * public static void main(String args[] ) { |
| * int failed = 0 ; |
| * |
| * <b>Thread t1 = new Thread();</b> |
| * if (t1 != null) |
| * System.out.println("new Thread() succeed"); |
| * else { |
| * System.out.println("new Thread() failed"); |
| * failed++; |
| * } |
| * } |
| * } |
| * </pre></blockquote> |
| * |
| * @see java.lang.Thread#Thread(java.lang.ThreadGroup, |
| * java.lang.Runnable, java.lang.String) |
| */ |
| public Thread() |
| { |
| this(null, null, gen_name()); |
| } |
| |
| /** |
| * Allocates a new <code>Thread</code> object. This constructor has |
| * the same effect as <code>Thread(null, target,</code> |
| * <i>gname</i><code>)</code>, where <i>gname</i> is |
| * a newly generated name. Automatically generated names are of the |
| * form <code>"Thread-"+</code><i>n</i>, where <i>n</i> is an integer. |
| * |
| * @param target the object whose <code>run</code> method is called. |
| * @see java.lang.Thread#Thread(java.lang.ThreadGroup, |
| * java.lang.Runnable, java.lang.String) |
| */ |
| public Thread(Runnable target) |
| { |
| this(null, target, gen_name()); |
| } |
| |
| /** |
| * Allocates a new <code>Thread</code> object. This constructor has |
| * the same effect as <code>Thread(null, null, name)</code>. |
| * |
| * @param name the name of the new thread. |
| * @see java.lang.Thread#Thread(java.lang.ThreadGroup, |
| * java.lang.Runnable, java.lang.String) |
| */ |
| public Thread(String name) |
| { |
| this(null, null, name); |
| } |
| |
| /** |
| * Allocates a new <code>Thread</code> object. This constructor has |
| * the same effect as <code>Thread(group, target,</code> |
| * <i>gname</i><code>)</code>, where <i>gname</i> is |
| * a newly generated name. Automatically generated names are of the |
| * form <code>"Thread-"+</code><i>n</i>, where <i>n</i> is an integer. |
| * |
| * @param group the group to put the Thread into |
| * @param target the Runnable object to execute |
| * @throws SecurityException if this thread cannot access <code>group</code> |
| * @throws IllegalThreadStateException if group is destroyed |
| * @see #Thread(ThreadGroup, Runnable, String) |
| */ |
| public Thread(ThreadGroup group, Runnable target) |
| { |
| this(group, target, gen_name()); |
| } |
| |
| /** |
| * Allocates a new <code>Thread</code> object. This constructor has |
| * the same effect as <code>Thread(group, null, name)</code> |
| * |
| * @param group the group to put the Thread into |
| * @param name the name for the Thread |
| * @throws NullPointerException if name is null |
| * @throws SecurityException if this thread cannot access <code>group</code> |
| * @throws IllegalThreadStateException if group is destroyed |
| * @see #Thread(ThreadGroup, Runnable, String) |
| */ |
| public Thread(ThreadGroup group, String name) |
| { |
| this(group, null, name); |
| } |
| |
| /** |
| * Allocates a new <code>Thread</code> object. This constructor has |
| * the same effect as <code>Thread(null, target, name)</code>. |
| * |
| * @param target the Runnable object to execute |
| * @param name the name for the Thread |
| * @throws NullPointerException if name is null |
| * @see #Thread(ThreadGroup, Runnable, String) |
| */ |
| public Thread(Runnable target, String name) |
| { |
| this(null, target, name); |
| } |
| |
| /** |
| * Allocate a new Thread object, with the specified ThreadGroup and name, and |
| * using the specified Runnable object's <code>run()</code> method to |
| * execute. If the Runnable object is null, <code>this</code> (which is |
| * a Runnable) is used instead. |
| * |
| * <p>If the ThreadGroup is null, the security manager is checked. If a |
| * manager exists and returns a non-null object for |
| * <code>getThreadGroup</code>, that group is used; otherwise the group |
| * of the creating thread is used. Note that the security manager calls |
| * <code>checkAccess</code> if the ThreadGroup is not null. |
| * |
| * <p>The new Thread will inherit its creator's priority and daemon status. |
| * These can be changed with <code>setPriority</code> and |
| * <code>setDaemon</code>. |
| * |
| * @param group the group to put the Thread into |
| * @param target the Runnable object to execute |
| * @param name the name for the Thread |
| * @throws NullPointerException if name is null |
| * @throws SecurityException if this thread cannot access <code>group</code> |
| * @throws IllegalThreadStateException if group is destroyed |
| * @see Runnable#run() |
| * @see #run() |
| * @see #setDaemon(boolean) |
| * @see #setPriority(int) |
| * @see SecurityManager#checkAccess(ThreadGroup) |
| * @see ThreadGroup#checkAccess() |
| */ |
| public Thread(ThreadGroup group, Runnable target, String name) |
| { |
| this(currentThread(), group, target, name); |
| } |
| |
| /** |
| * Allocate a new Thread object, as if by |
| * <code>Thread(group, null, name)</code>, and give it the specified stack |
| * size, in bytes. The stack size is <b>highly platform independent</b>, |
| * and the virtual machine is free to round up or down, or ignore it |
| * completely. A higher value might let you go longer before a |
| * <code>StackOverflowError</code>, while a lower value might let you go |
| * longer before an <code>OutOfMemoryError</code>. Or, it may do absolutely |
| * nothing! So be careful, and expect to need to tune this value if your |
| * virtual machine even supports it. |
| * |
| * @param group the group to put the Thread into |
| * @param target the Runnable object to execute |
| * @param name the name for the Thread |
| * @param size the stack size, in bytes; 0 to be ignored |
| * @throws NullPointerException if name is null |
| * @throws SecurityException if this thread cannot access <code>group</code> |
| * @throws IllegalThreadStateException if group is destroyed |
| * @since 1.4 |
| */ |
| public Thread(ThreadGroup group, Runnable target, String name, long size) |
| { |
| // Just ignore stackSize for now. |
| this(currentThread(), group, target, name); |
| } |
| |
| private Thread (Thread current, ThreadGroup g, Runnable r, String n) |
| { |
| // Make sure the current thread may create a new thread. |
| checkAccess(); |
| |
| // The Class Libraries book says ``threadName cannot be null''. I |
| // take this to mean NullPointerException. |
| if (n == null) |
| throw new NullPointerException (); |
| |
| if (g == null) |
| { |
| // If CURRENT is null, then we are bootstrapping the first thread. |
| // Use ThreadGroup.root, the main threadgroup. |
| if (current == null) |
| group = ThreadGroup.root; |
| else |
| group = current.getThreadGroup(); |
| } |
| else |
| group = g; |
| |
| data = null; |
| interrupt_flag = false; |
| alive_flag = false; |
| startable_flag = true; |
| |
| synchronized (Thread.class) |
| { |
| this.threadId = nextThreadId++; |
| } |
| |
| if (current != null) |
| { |
| group.checkAccess(); |
| |
| daemon = current.isDaemon(); |
| int gmax = group.getMaxPriority(); |
| int pri = current.getPriority(); |
| priority = (gmax < pri ? gmax : pri); |
| contextClassLoader = current.contextClassLoader; |
| InheritableThreadLocal.newChildThread(this); |
| } |
| else |
| { |
| daemon = false; |
| priority = NORM_PRIORITY; |
| } |
| |
| name = n; |
| group.addThread(this); |
| runnable = r; |
| |
| initialize_native (); |
| } |
| |
| /** |
| * Get the number of active threads in the current Thread's ThreadGroup. |
| * This implementation calls |
| * <code>currentThread().getThreadGroup().activeCount()</code>. |
| * |
| * @return the number of active threads in the current ThreadGroup |
| * @see ThreadGroup#activeCount() |
| */ |
| public static int activeCount() |
| { |
| return currentThread().group.activeCount(); |
| } |
| |
| /** |
| * Check whether the current Thread is allowed to modify this Thread. This |
| * passes the check on to <code>SecurityManager.checkAccess(this)</code>. |
| * |
| * @throws SecurityException if the current Thread cannot modify this Thread |
| * @see SecurityManager#checkAccess(Thread) |
| */ |
| public final void checkAccess() |
| { |
| SecurityManager sm = System.getSecurityManager(); |
| if (sm != null) |
| sm.checkAccess(this); |
| } |
| |
| /** |
| * Count the number of stack frames in this Thread. The Thread in question |
| * must be suspended when this occurs. |
| * |
| * @return the number of stack frames in this Thread |
| * @throws IllegalThreadStateException if this Thread is not suspended |
| * @deprecated pointless, since suspend is deprecated |
| */ |
| public native int countStackFrames(); |
| |
| /** |
| * Get the currently executing Thread. |
| * |
| * @return the currently executing Thread |
| */ |
| public static native Thread currentThread(); |
| |
| /** |
| * Originally intended to destroy this thread, this method was never |
| * implemented by Sun, and is hence a no-op. |
| */ |
| public void destroy() |
| { |
| throw new NoSuchMethodError(); |
| } |
| |
| /** |
| * Print a stack trace of the current thread to stderr using the same |
| * format as Throwable's printStackTrace() method. |
| * |
| * @see Throwable#printStackTrace() |
| */ |
| public static void dumpStack() |
| { |
| (new Exception("Stack trace")).printStackTrace(); |
| } |
| |
| /** |
| * Copy every active thread in the current Thread's ThreadGroup into the |
| * array. Extra threads are silently ignored. This implementation calls |
| * <code>getThreadGroup().enumerate(array)</code>, which may have a |
| * security check, <code>checkAccess(group)</code>. |
| * |
| * @param array the array to place the Threads into |
| * @return the number of Threads placed into the array |
| * @throws NullPointerException if array is null |
| * @throws SecurityException if you cannot access the ThreadGroup |
| * @see ThreadGroup#enumerate(Thread[]) |
| * @see #activeCount() |
| * @see SecurityManager#checkAccess(ThreadGroup) |
| */ |
| public static int enumerate(Thread[] array) |
| { |
| return currentThread().group.enumerate(array); |
| } |
| |
| /** |
| * Get this Thread's name. |
| * |
| * @return this Thread's name |
| */ |
| public final String getName() |
| { |
| return name; |
| } |
| |
| /** |
| * Get this Thread's priority. |
| * |
| * @return the Thread's priority |
| */ |
| public final int getPriority() |
| { |
| return priority; |
| } |
| |
| /** |
| * Get the ThreadGroup this Thread belongs to. If the thread has died, this |
| * returns null. |
| * |
| * @return this Thread's ThreadGroup |
| */ |
| public final ThreadGroup getThreadGroup() |
| { |
| return group; |
| } |
| |
| /** |
| * Checks whether the current thread holds the monitor on a given object. |
| * This allows you to do <code>assert Thread.holdsLock(obj)</code>. |
| * |
| * @param obj the object to test lock ownership on. |
| * @return true if the current thread is currently synchronized on obj |
| * @throws NullPointerException if obj is null |
| * @since 1.4 |
| */ |
| public static native boolean holdsLock(Object obj); |
| |
| /** |
| * Interrupt this Thread. First, there is a security check, |
| * <code>checkAccess</code>. Then, depending on the current state of the |
| * thread, various actions take place: |
| * |
| * <p>If the thread is waiting because of {@link #wait()}, |
| * {@link #sleep(long)}, or {@link #join()}, its <i>interrupt status</i> |
| * will be cleared, and an InterruptedException will be thrown. Notice that |
| * this case is only possible if an external thread called interrupt(). |
| * |
| * <p>If the thread is blocked in an interruptible I/O operation, in |
| * {@link java.nio.channels.InterruptibleChannel}, the <i>interrupt |
| * status</i> will be set, and ClosedByInterruptException will be thrown. |
| * |
| * <p>If the thread is blocked on a {@link java.nio.channels.Selector}, the |
| * <i>interrupt status</i> will be set, and the selection will return, with |
| * a possible non-zero value, as though by the wakeup() method. |
| * |
| * <p>Otherwise, the interrupt status will be set. |
| * |
| * @throws SecurityException if you cannot modify this Thread |
| */ |
| public native void interrupt(); |
| |
| /** |
| * Determine whether the current Thread has been interrupted, and clear |
| * the <i>interrupted status</i> in the process. |
| * |
| * @return whether the current Thread has been interrupted |
| * @see #isInterrupted() |
| */ |
| public static boolean interrupted() |
| { |
| return currentThread().isInterrupted(true); |
| } |
| |
| /** |
| * Determine whether the given Thread has been interrupted, but leave |
| * the <i>interrupted status</i> alone in the process. |
| * |
| * @return whether the Thread has been interrupted |
| * @see #interrupted() |
| */ |
| public boolean isInterrupted() |
| { |
| return interrupt_flag; |
| } |
| |
| /** |
| * Determine whether this Thread is alive. A thread which is alive has |
| * started and not yet died. |
| * |
| * @return whether this Thread is alive |
| */ |
| public final synchronized boolean isAlive() |
| { |
| return alive_flag; |
| } |
| |
| /** |
| * Tell whether this is a daemon Thread or not. |
| * |
| * @return whether this is a daemon Thread or not |
| * @see #setDaemon(boolean) |
| */ |
| public final boolean isDaemon() |
| { |
| return daemon; |
| } |
| |
| /** |
| * Wait forever for the Thread in question to die. |
| * |
| * @throws InterruptedException if the Thread is interrupted; it's |
| * <i>interrupted status</i> will be cleared |
| */ |
| public final void join() throws InterruptedException |
| { |
| join(0, 0); |
| } |
| |
| /** |
| * Wait the specified amount of time for the Thread in question to die. |
| * |
| * @param ms the number of milliseconds to wait, or 0 for forever |
| * @throws InterruptedException if the Thread is interrupted; it's |
| * <i>interrupted status</i> will be cleared |
| */ |
| public final void join(long ms) throws InterruptedException |
| { |
| join(ms, 0); |
| } |
| |
| /** |
| * Wait the specified amount of time for the Thread in question to die. |
| * |
| * <p>Note that 1,000,000 nanoseconds == 1 millisecond, but most VMs do |
| * not offer that fine a grain of timing resolution. Besides, 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 wait, or 0 for forever |
| * @param ns the number of extra nanoseconds to sleep (0-999999) |
| * @throws InterruptedException if the Thread is interrupted; it's |
| * <i>interrupted status</i> will be cleared |
| * @throws IllegalArgumentException if ns is invalid |
| * @XXX A ThreadListener would be nice, to make this efficient. |
| */ |
| public final native void join(long ms, int ns) |
| throws InterruptedException; |
| |
| /** |
| * Resume a suspended thread. |
| * |
| * @throws SecurityException if you cannot resume the Thread |
| * @see #checkAccess() |
| * @see #suspend() |
| * @deprecated pointless, since suspend is deprecated |
| */ |
| public final native void resume(); |
| |
| private final native void finish_(); |
| |
| /** |
| * Determine whether the given Thread has been interrupted, but leave |
| * the <i>interrupted status</i> alone in the process. |
| * |
| * @return whether the current Thread has been interrupted |
| * @see #interrupted() |
| */ |
| private boolean isInterrupted(boolean clear_flag) |
| { |
| boolean r = interrupt_flag; |
| if (clear_flag && r) |
| { |
| // Only clear the flag if we saw it as set. Otherwise this could |
| // potentially cause us to miss an interrupt in a race condition, |
| // because this method is not synchronized. |
| interrupt_flag = false; |
| } |
| return r; |
| } |
| |
| /** |
| * The method of Thread that will be run if there is no Runnable object |
| * associated with the Thread. Thread's implementation does nothing at all. |
| * |
| * @see #start() |
| * @see #Thread(ThreadGroup, Runnable, String) |
| */ |
| 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 void setDaemon(boolean daemon) |
| { |
| if (!startable_flag) |
| 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() |
| { |
| if (contextClassLoader == null) |
| contextClassLoader = ClassLoader.getSystemClassLoader(); |
| |
| SecurityManager sm = System.getSecurityManager(); |
| // FIXME: we can't currently find the caller's class loader. |
| ClassLoader callers = null; |
| if (sm != null && callers != null) |
| { |
| // See if the caller's class loader is the same as or an |
| // ancestor of this thread's class loader. |
| while (callers != null && callers != contextClassLoader) |
| { |
| // FIXME: should use some internal version of getParent |
| // that avoids security checks. |
| callers = callers.getParent(); |
| } |
| |
| if (callers != contextClassLoader) |
| 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 = System.getSecurityManager(); |
| 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 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(); |
| this.name = name; |
| } |
| |
| /** |
| * Causes the currently executing thread object to temporarily pause |
| * and allow other threads to execute. |
| */ |
| public static native void 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, or 0 for forever |
| * @throws InterruptedException if the Thread is interrupted; it's |
| * <i>interrupted status</i> will be cleared |
| * @see #notify() |
| * @see #wait(long) |
| */ |
| 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. Besides, 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, or 0 for forever |
| * @param ns the number of extra nanoseconds to sleep (0-999999) |
| * @throws InterruptedException if the Thread is interrupted; it's |
| * <i>interrupted status</i> will be cleared |
| * @throws IllegalArgumentException if ns is invalid |
| * @see #notify() |
| * @see #wait(long, int) |
| */ |
| public static native void sleep(long timeout, int nanos) |
| throws InterruptedException; |
| |
| /** |
| * 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 native void start(); |
| |
| /** |
| * 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() |
| { |
| // Argument doesn't matter, because this is no longer |
| // supported. |
| stop(null); |
| } |
| |
| /** |
| * Cause this Thread to stop abnormally and throw the specified exception. |
| * If you stop a Thread that has not yet started, it will stop immediately |
| * when it is actually started. <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 native void stop(Throwable 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 native void 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 native void setPriority(int newPriority); |
| |
| /** |
| * 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()) + "]"); |
| } |
| |
| private final native void initialize_native(); |
| |
| private final native static String gen_name(); |
| |
| /** |
| * 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 WeakIdentityHashMap(); |
| } |
| return locals; |
| } |
| |
| /** |
| * Assigns the given <code>UncaughtExceptionHandler</code> to this |
| * thread. This will then be called if the thread terminates due |
| * to an uncaught exception, pre-empting that of the |
| * <code>ThreadGroup</code>. |
| * |
| * @param h the handler to use for this thread. |
| * @throws SecurityException if the current thread can't modify this thread. |
| * @since 1.5 |
| */ |
| public void setUncaughtExceptionHandler(UncaughtExceptionHandler h) |
| { |
| SecurityManager sm = SecurityManager.current; // Be thread-safe. |
| if (sm != null) |
| sm.checkAccess(this); |
| exceptionHandler = h; |
| } |
| |
| /** |
| * <p> |
| * Returns the handler used when this thread terminates due to an |
| * uncaught exception. The handler used is determined by the following: |
| * </p> |
| * <ul> |
| * <li>If this thread has its own handler, this is returned.</li> |
| * <li>If not, then the handler of the thread's <code>ThreadGroup</code> |
| * object is returned.</li> |
| * <li>If both are unavailable, then <code>null</code> is returned |
| * (which can only happen when the thread was terminated since |
| * then it won't have an associated thread group anymore).</li> |
| * </ul> |
| * |
| * @return the appropriate <code>UncaughtExceptionHandler</code> or |
| * <code>null</code> if one can't be obtained. |
| * @since 1.5 |
| */ |
| public UncaughtExceptionHandler getUncaughtExceptionHandler() |
| { |
| return exceptionHandler != null ? exceptionHandler : group; |
| } |
| |
| /** |
| * <p> |
| * Sets the default uncaught exception handler used when one isn't |
| * provided by the thread or its associated <code>ThreadGroup</code>. |
| * This exception handler is used when the thread itself does not |
| * have an exception handler, and the thread's <code>ThreadGroup</code> |
| * does not override this default mechanism with its own. As the group |
| * calls this handler by default, this exception handler should not defer |
| * to that of the group, as it may lead to infinite recursion. |
| * </p> |
| * <p> |
| * Uncaught exception handlers are used when a thread terminates due to |
| * an uncaught exception. Replacing this handler allows default code to |
| * be put in place for all threads in order to handle this eventuality. |
| * </p> |
| * |
| * @param h the new default uncaught exception handler to use. |
| * @throws SecurityException if a security manager is present and |
| * disallows the runtime permission |
| * "setDefaultUncaughtExceptionHandler". |
| * @since 1.5 |
| */ |
| public static void |
| setDefaultUncaughtExceptionHandler(UncaughtExceptionHandler h) |
| { |
| SecurityManager sm = SecurityManager.current; // Be thread-safe. |
| if (sm != null) |
| sm.checkPermission(new RuntimePermission("setDefaultUncaughtExceptionHandler")); |
| defaultHandler = h; |
| } |
| |
| /** |
| * Returns the handler used by default when a thread terminates |
| * unexpectedly due to an exception, or <code>null</code> if one doesn't |
| * exist. |
| * |
| * @return the default uncaught exception handler. |
| * @since 1.5 |
| */ |
| public static UncaughtExceptionHandler getDefaultUncaughtExceptionHandler() |
| { |
| return defaultHandler; |
| } |
| |
| /** |
| * Returns the unique identifier for this thread. This ID is generated |
| * on thread creation, and may be re-used on its death. |
| * |
| * @return a positive long number representing the thread's ID. |
| * @since 1.5 |
| */ |
| public long getId() |
| { |
| return threadId; |
| } |
| |
| /** |
| * <p> |
| * This interface is used to handle uncaught exceptions |
| * which cause a <code>Thread</code> to terminate. When |
| * a thread, t, is about to terminate due to an uncaught |
| * exception, the virtual machine looks for a class which |
| * implements this interface, in order to supply it with |
| * the dying thread and its uncaught exception. |
| * </p> |
| * <p> |
| * The virtual machine makes two attempts to find an |
| * appropriate handler for the uncaught exception, in |
| * the following order: |
| * </p> |
| * <ol> |
| * <li> |
| * <code>t.getUncaughtExceptionHandler()</code> -- |
| * the dying thread is queried first for a handler |
| * specific to that thread. |
| * </li> |
| * <li> |
| * <code>t.getThreadGroup()</code> -- |
| * the thread group of the dying thread is used to |
| * handle the exception. If the thread group has |
| * no special requirements for handling the exception, |
| * it may simply forward it on to |
| * <code>Thread.getDefaultUncaughtExceptionHandler()</code>, |
| * the default handler, which is used as a last resort. |
| * </li> |
| * </ol> |
| * <p> |
| * The first handler found is the one used to handle |
| * the uncaught exception. |
| * </p> |
| * |
| * @author Tom Tromey <tromey@redhat.com> |
| * @author Andrew John Hughes <gnu_andrew@member.fsf.org> |
| * @since 1.5 |
| * @see Thread#getUncaughtExceptionHandler() |
| * @see Thread#setUncaughtExceptionHander(java.lang.Thread.UncaughtExceptionHandler) |
| * @see Thread#getDefaultUncaughtExceptionHandler() |
| * @see |
| * Thread#setDefaultUncaughtExceptionHandler(java.lang.Thread.UncaughtExceptionHandler) |
| */ |
| public interface UncaughtExceptionHandler |
| { |
| /** |
| * Invoked by the virtual machine with the dying thread |
| * and the uncaught exception. Any exceptions thrown |
| * by this method are simply ignored by the virtual |
| * machine. |
| * |
| * @param thr the dying thread. |
| * @param exc the uncaught exception. |
| */ |
| void uncaughtException(Thread thr, Throwable exc); |
| } |
| |
| /** |
| * Returns the current state of the thread. This |
| * is designed for monitoring thread behaviour, rather |
| * than for synchronization control. |
| * |
| * @return the current thread state. |
| */ |
| public String getState() |
| { |
| // FIXME - Provide real implementation. |
| return "NEW"; |
| } |
| } |