jaroslav@1258: /* jaroslav@1258: * Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved. jaroslav@1258: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. jaroslav@1258: * jaroslav@1258: * This code is free software; you can redistribute it and/or modify it jaroslav@1258: * under the terms of the GNU General Public License version 2 only, as jaroslav@1258: * published by the Free Software Foundation. Oracle designates this jaroslav@1258: * particular file as subject to the "Classpath" exception as provided jaroslav@1258: * by Oracle in the LICENSE file that accompanied this code. jaroslav@1258: * jaroslav@1258: * This code is distributed in the hope that it will be useful, but WITHOUT jaroslav@1258: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or jaroslav@1258: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License jaroslav@1258: * version 2 for more details (a copy is included in the LICENSE file that jaroslav@1258: * accompanied this code). jaroslav@1258: * jaroslav@1258: * You should have received a copy of the GNU General Public License version jaroslav@1258: * 2 along with this work; if not, write to the Free Software Foundation, jaroslav@1258: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. jaroslav@1258: * jaroslav@1258: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA jaroslav@1258: * or visit www.oracle.com if you need additional information or have any jaroslav@1258: * questions. jaroslav@1258: */ jaroslav@1258: jaroslav@1258: package java.lang; jaroslav@1258: jaroslav@1258: import java.util.Map; jaroslav@1258: jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * A thread is a thread of execution in a program. The Java jaroslav@1258: * Virtual Machine allows an application to have multiple threads of jaroslav@1258: * execution running concurrently. jaroslav@1258: *

jaroslav@1258: * Every thread has a priority. Threads with higher priority are jaroslav@1258: * executed in preference to threads with lower priority. Each thread jaroslav@1258: * may or may not also be marked as a daemon. When code running in jaroslav@1258: * some thread creates a new Thread object, the new jaroslav@1258: * thread has its priority initially set equal to the priority of the jaroslav@1258: * creating thread, and is a daemon thread if and only if the jaroslav@1258: * creating thread is a daemon. jaroslav@1258: *

jaroslav@1258: * When a Java Virtual Machine starts up, there is usually a single jaroslav@1258: * non-daemon thread (which typically calls the method named jaroslav@1258: * main of some designated class). The Java Virtual jaroslav@1258: * Machine continues to execute threads until either of the following jaroslav@1258: * occurs: jaroslav@1258: *

jaroslav@1258: *

jaroslav@1258: * There are two ways to create a new thread of execution. One is to jaroslav@1258: * declare a class to be a subclass of Thread. This jaroslav@1258: * subclass should override the run method of class jaroslav@1258: * Thread. An instance of the subclass can then be jaroslav@1258: * allocated and started. For example, a thread that computes primes jaroslav@1258: * larger than a stated value could be written as follows: jaroslav@1258: * 

jaroslav@1258:  *     class PrimeThread extends Thread {
jaroslav@1258:  *         long minPrime;
jaroslav@1258:  *         PrimeThread(long minPrime) {
jaroslav@1258:  *             this.minPrime = minPrime;
jaroslav@1258:  *         }
jaroslav@1258:  *
jaroslav@1258:  *         public void run() {
jaroslav@1258:  *             // compute primes larger than minPrime
jaroslav@1258:  *              . . .
jaroslav@1258:  *         }
jaroslav@1258:  *     }
jaroslav@1258:  *
jaroslav@1258: *

jaroslav@1258: * The following code would then create a thread and start it running: jaroslav@1258: * 

jaroslav@1258:  *     PrimeThread p = new PrimeThread(143);
jaroslav@1258:  *     p.start();
jaroslav@1258:  *
jaroslav@1258: *

jaroslav@1258: * The other way to create a thread is to declare a class that jaroslav@1258: * implements the Runnable interface. That class then jaroslav@1258: * implements the run method. An instance of the class can jaroslav@1258: * then be allocated, passed as an argument when creating jaroslav@1258: * Thread, and started. The same example in this other jaroslav@1258: * style looks like the following: jaroslav@1258: * 

jaroslav@1258:  *     class PrimeRun implements Runnable {
jaroslav@1258:  *         long minPrime;
jaroslav@1258:  *         PrimeRun(long minPrime) {
jaroslav@1258:  *             this.minPrime = minPrime;
jaroslav@1258:  *         }
jaroslav@1258:  *
jaroslav@1258:  *         public void run() {
jaroslav@1258:  *             // compute primes larger than minPrime
jaroslav@1258:  *              . . .
jaroslav@1258:  *         }
jaroslav@1258:  *     }
jaroslav@1258:  *
jaroslav@1258: *

jaroslav@1258: * The following code would then create a thread and start it running: jaroslav@1258: * 

jaroslav@1258:  *     PrimeRun p = new PrimeRun(143);
jaroslav@1258:  *     new Thread(p).start();
jaroslav@1258:  *
jaroslav@1258: *

jaroslav@1258: * Every thread has a name for identification purposes. More than jaroslav@1258: * one thread may have the same name. If a name is not specified when jaroslav@1258: * a thread is created, a new name is generated for it. jaroslav@1258: *

jaroslav@1258: * Unless otherwise noted, passing a {@code null} argument to a constructor jaroslav@1258: * or method in this class will cause a {@link NullPointerException} to be jaroslav@1258: * thrown. jaroslav@1258: * jaroslav@1258: * @author unascribed jaroslav@1258: * @see Runnable jaroslav@1258: * @see Runtime#exit(int) jaroslav@1258: * @see #run() jaroslav@1258: * @see #stop() jaroslav@1258: * @since JDK1.0 jaroslav@1258: */ jaroslav@1258: public jaroslav@1258: class Thread implements Runnable { jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * The minimum priority that a thread can have. jaroslav@1258: */ jaroslav@1258: public final static int MIN_PRIORITY = 1; jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * The default priority that is assigned to a thread. jaroslav@1258: */ jaroslav@1258: public final static int NORM_PRIORITY = 5; jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * The maximum priority that a thread can have. jaroslav@1258: */ jaroslav@1258: public final static int MAX_PRIORITY = 10; jaroslav@1258: jaroslav@1260: private static final Thread ONE = new Thread("main"); jaroslav@1258: /** jaroslav@1258: * Returns a reference to the currently executing thread object. jaroslav@1258: * jaroslav@1258: * @return the currently executing thread. jaroslav@1258: */ jaroslav@1260: public static Thread currentThread() { jaroslav@1260: return ONE; jaroslav@1260: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * A hint to the scheduler that the current thread is willing to yield jaroslav@1258: * its current use of a processor. The scheduler is free to ignore this jaroslav@1258: * hint. jaroslav@1258: * jaroslav@1258: *

Yield is a heuristic attempt to improve relative progression jaroslav@1258: * between threads that would otherwise over-utilise a CPU. Its use jaroslav@1258: * should be combined with detailed profiling and benchmarking to jaroslav@1258: * ensure that it actually has the desired effect. jaroslav@1258: * jaroslav@1258: *

It is rarely appropriate to use this method. It may be useful jaroslav@1258: * for debugging or testing purposes, where it may help to reproduce jaroslav@1258: * bugs due to race conditions. It may also be useful when designing jaroslav@1258: * concurrency control constructs such as the ones in the jaroslav@1258: * {@link java.util.concurrent.locks} package. jaroslav@1258: */ jaroslav@1260: public static void yield() { jaroslav@1260: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Causes the currently executing thread to sleep (temporarily cease jaroslav@1258: * execution) for the specified number of milliseconds, subject to jaroslav@1258: * the precision and accuracy of system timers and schedulers. The thread jaroslav@1258: * does not lose ownership of any monitors. jaroslav@1258: * jaroslav@1258: * @param millis jaroslav@1258: * the length of time to sleep in milliseconds jaroslav@1258: * jaroslav@1258: * @throws IllegalArgumentException jaroslav@1258: * if the value of {@code millis} is negative jaroslav@1258: * jaroslav@1258: * @throws InterruptedException jaroslav@1258: * if any thread has interrupted the current thread. The jaroslav@1258: * interrupted status of the current thread is jaroslav@1258: * cleared when this exception is thrown. jaroslav@1258: */ jaroslav@1258: public static native void sleep(long millis) throws InterruptedException; jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Causes the currently executing thread to sleep (temporarily cease jaroslav@1258: * execution) for the specified number of milliseconds plus the specified jaroslav@1258: * number of nanoseconds, subject to the precision and accuracy of system jaroslav@1258: * timers and schedulers. The thread does not lose ownership of any jaroslav@1258: * monitors. jaroslav@1258: * jaroslav@1258: * @param millis jaroslav@1258: * the length of time to sleep in milliseconds jaroslav@1258: * jaroslav@1258: * @param nanos jaroslav@1258: * {@code 0-999999} additional nanoseconds to sleep jaroslav@1258: * jaroslav@1258: * @throws IllegalArgumentException jaroslav@1258: * if the value of {@code millis} is negative, or the value of jaroslav@1258: * {@code nanos} is not in the range {@code 0-999999} jaroslav@1258: * jaroslav@1258: * @throws InterruptedException jaroslav@1258: * if any thread has interrupted the current thread. The jaroslav@1258: * interrupted status of the current thread is jaroslav@1258: * cleared when this exception is thrown. jaroslav@1258: */ jaroslav@1258: public static void sleep(long millis, int nanos) jaroslav@1258: throws InterruptedException { jaroslav@1258: if (millis < 0) { jaroslav@1258: throw new IllegalArgumentException("timeout value is negative"); jaroslav@1258: } jaroslav@1258: jaroslav@1258: if (nanos < 0 || nanos > 999999) { jaroslav@1258: throw new IllegalArgumentException( jaroslav@1258: "nanosecond timeout value out of range"); jaroslav@1258: } jaroslav@1258: jaroslav@1258: if (nanos >= 500000 || (nanos != 0 && millis == 0)) { jaroslav@1258: millis++; jaroslav@1258: } jaroslav@1258: jaroslav@1258: sleep(millis); jaroslav@1258: } jaroslav@1260: private Runnable target; jaroslav@1260: private String name; jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Throws CloneNotSupportedException as a Thread can not be meaningfully jaroslav@1258: * cloned. Construct a new Thread instead. jaroslav@1258: * jaroslav@1258: * @throws CloneNotSupportedException jaroslav@1258: * always jaroslav@1258: */ jaroslav@1258: @Override jaroslav@1258: protected Object clone() throws CloneNotSupportedException { jaroslav@1258: throw new CloneNotSupportedException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object. This constructor has the same jaroslav@1258: * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread} jaroslav@1258: * {@code (null, null, gname)}, where {@code gname} is a newly generated jaroslav@1258: * name. Automatically generated names are of the form jaroslav@1258: * {@code "Thread-"+}n, where n is an integer. jaroslav@1258: */ jaroslav@1258: public Thread() { jaroslav@1258: init(null, null, "Thread-" + nextThreadNum(), 0); jaroslav@1258: } jaroslav@1260: jaroslav@1260: private static int nextThreadNum() { jaroslav@1260: return -1; jaroslav@1260: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object. This constructor has the same jaroslav@1258: * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread} jaroslav@1258: * {@code (null, target, gname)}, where {@code gname} is a newly generated jaroslav@1258: * name. Automatically generated names are of the form jaroslav@1258: * {@code "Thread-"+}n, where n is an integer. jaroslav@1258: * jaroslav@1258: * @param target jaroslav@1258: * the object whose {@code run} method is invoked when this thread jaroslav@1258: * is started. If {@code null}, this classes {@code run} method does jaroslav@1258: * nothing. jaroslav@1258: */ jaroslav@1258: public Thread(Runnable target) { jaroslav@1258: init(null, target, "Thread-" + nextThreadNum(), 0); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object. This constructor has the same jaroslav@1258: * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread} jaroslav@1258: * {@code (group, target, gname)} ,where {@code gname} is a newly generated jaroslav@1258: * name. Automatically generated names are of the form jaroslav@1258: * {@code "Thread-"+}n, where n is an integer. jaroslav@1258: * jaroslav@1258: * @param group jaroslav@1258: * the thread group. If {@code null} and there is a security jaroslav@1258: * manager, the group is determined by {@linkplain jaroslav@1258: * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}. jaroslav@1258: * If there is not a security manager or {@code jaroslav@1258: * SecurityManager.getThreadGroup()} returns {@code null}, the group jaroslav@1258: * is set to the current thread's thread group. jaroslav@1258: * jaroslav@1258: * @param target jaroslav@1258: * the object whose {@code run} method is invoked when this thread jaroslav@1258: * is started. If {@code null}, this thread's run method is invoked. jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if the current thread cannot create a thread in the specified jaroslav@1258: * thread group jaroslav@1258: */ jaroslav@1260: // public Thread(ThreadGroup group, Runnable target) { jaroslav@1260: // init(group, target, "Thread-" + nextThreadNum(), 0); jaroslav@1260: // } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object. This constructor has the same jaroslav@1258: * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread} jaroslav@1258: * {@code (null, null, name)}. jaroslav@1258: * jaroslav@1258: * @param name jaroslav@1258: * the name of the new thread jaroslav@1258: */ jaroslav@1258: public Thread(String name) { jaroslav@1258: init(null, null, name, 0); jaroslav@1258: } jaroslav@1260: jaroslav@1260: private void init(Object o1, Runnable trgt, String nm, int i4) { jaroslav@1260: this.target = trgt; jaroslav@1260: this.name = nm; jaroslav@1260: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object. This constructor has the same jaroslav@1258: * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread} jaroslav@1258: * {@code (group, null, name)}. jaroslav@1258: * jaroslav@1258: * @param group jaroslav@1258: * the thread group. If {@code null} and there is a security jaroslav@1258: * manager, the group is determined by {@linkplain jaroslav@1258: * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}. jaroslav@1258: * If there is not a security manager or {@code jaroslav@1258: * SecurityManager.getThreadGroup()} returns {@code null}, the group jaroslav@1258: * is set to the current thread's thread group. jaroslav@1258: * jaroslav@1258: * @param name jaroslav@1258: * the name of the new thread jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if the current thread cannot create a thread in the specified jaroslav@1258: * thread group jaroslav@1258: */ jaroslav@1260: // public Thread(ThreadGroup group, String name) { jaroslav@1260: // init(group, null, name, 0); jaroslav@1260: // } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object. This constructor has the same jaroslav@1258: * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread} jaroslav@1258: * {@code (null, target, name)}. jaroslav@1258: * jaroslav@1258: * @param target jaroslav@1258: * the object whose {@code run} method is invoked when this thread jaroslav@1258: * is started. If {@code null}, this thread's run method is invoked. jaroslav@1258: * jaroslav@1258: * @param name jaroslav@1258: * the name of the new thread jaroslav@1258: */ jaroslav@1258: public Thread(Runnable target, String name) { jaroslav@1258: init(null, target, name, 0); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object so that it has {@code target} jaroslav@1258: * as its run object, has the specified {@code name} as its name, jaroslav@1258: * and belongs to the thread group referred to by {@code group}. jaroslav@1258: * jaroslav@1258: *

If there is a security manager, its jaroslav@1258: * {@link SecurityManager#checkAccess(ThreadGroup) checkAccess} jaroslav@1258: * method is invoked with the ThreadGroup as its argument. jaroslav@1258: * jaroslav@1258: *

In addition, its {@code checkPermission} method is invoked with jaroslav@1258: * the {@code RuntimePermission("enableContextClassLoaderOverride")} jaroslav@1258: * permission when invoked directly or indirectly by the constructor jaroslav@1258: * of a subclass which overrides the {@code getContextClassLoader} jaroslav@1258: * or {@code setContextClassLoader} methods. jaroslav@1258: * jaroslav@1258: *

The priority of the newly created thread is set equal to the jaroslav@1258: * priority of the thread creating it, that is, the currently running jaroslav@1258: * thread. The method {@linkplain #setPriority setPriority} may be jaroslav@1258: * used to change the priority to a new value. jaroslav@1258: * jaroslav@1258: *

The newly created thread is initially marked as being a daemon jaroslav@1258: * thread if and only if the thread creating it is currently marked jaroslav@1258: * as a daemon thread. The method {@linkplain #setDaemon setDaemon} jaroslav@1258: * may be used to change whether or not a thread is a daemon. jaroslav@1258: * jaroslav@1258: * @param group jaroslav@1258: * the thread group. If {@code null} and there is a security jaroslav@1258: * manager, the group is determined by {@linkplain jaroslav@1258: * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}. jaroslav@1258: * If there is not a security manager or {@code jaroslav@1258: * SecurityManager.getThreadGroup()} returns {@code null}, the group jaroslav@1258: * is set to the current thread's thread group. jaroslav@1258: * jaroslav@1258: * @param target jaroslav@1258: * the object whose {@code run} method is invoked when this thread jaroslav@1258: * is started. If {@code null}, this thread's run method is invoked. jaroslav@1258: * jaroslav@1258: * @param name jaroslav@1258: * the name of the new thread jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if the current thread cannot create a thread in the specified jaroslav@1258: * thread group or cannot override the context class loader methods. jaroslav@1258: */ jaroslav@1260: // public Thread(ThreadGroup group, Runnable target, String name) { jaroslav@1260: // init(group, target, name, 0); jaroslav@1260: // } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Allocates a new {@code Thread} object so that it has {@code target} jaroslav@1258: * as its run object, has the specified {@code name} as its name, jaroslav@1258: * and belongs to the thread group referred to by {@code group}, and has jaroslav@1258: * the specified stack size. jaroslav@1258: * jaroslav@1258: *

This constructor is identical to {@link jaroslav@1258: * #Thread(ThreadGroup,Runnable,String)} with the exception of the fact jaroslav@1258: * that it allows the thread stack size to be specified. The stack size jaroslav@1258: * is the approximate number of bytes of address space that the virtual jaroslav@1258: * machine is to allocate for this thread's stack. The effect of the jaroslav@1258: * {@code stackSize} parameter, if any, is highly platform dependent. jaroslav@1258: * jaroslav@1258: *

On some platforms, specifying a higher value for the jaroslav@1258: * {@code stackSize} parameter may allow a thread to achieve greater jaroslav@1258: * recursion depth before throwing a {@link StackOverflowError}. jaroslav@1258: * Similarly, specifying a lower value may allow a greater number of jaroslav@1258: * threads to exist concurrently without throwing an {@link jaroslav@1258: * OutOfMemoryError} (or other internal error). The details of jaroslav@1258: * the relationship between the value of the stackSize parameter jaroslav@1258: * and the maximum recursion depth and concurrency level are jaroslav@1258: * platform-dependent. On some platforms, the value of the jaroslav@1258: * {@code stackSize} parameter may have no effect whatsoever. jaroslav@1258: * jaroslav@1258: *

The virtual machine is free to treat the {@code stackSize} jaroslav@1258: * parameter as a suggestion. If the specified value is unreasonably low jaroslav@1258: * for the platform, the virtual machine may instead use some jaroslav@1258: * platform-specific minimum value; if the specified value is unreasonably jaroslav@1258: * high, the virtual machine may instead use some platform-specific jaroslav@1258: * maximum. Likewise, the virtual machine is free to round the specified jaroslav@1258: * value up or down as it sees fit (or to ignore it completely). jaroslav@1258: * jaroslav@1258: *

Specifying a value of zero for the {@code stackSize} parameter will jaroslav@1258: * cause this constructor to behave exactly like the jaroslav@1258: * {@code Thread(ThreadGroup, Runnable, String)} constructor. jaroslav@1258: * jaroslav@1258: *

Due to the platform-dependent nature of the behavior of this jaroslav@1258: * constructor, extreme care should be exercised in its use. jaroslav@1258: * The thread stack size necessary to perform a given computation will jaroslav@1258: * likely vary from one JRE implementation to another. In light of this jaroslav@1258: * variation, careful tuning of the stack size parameter may be required, jaroslav@1258: * and the tuning may need to be repeated for each JRE implementation on jaroslav@1258: * which an application is to run. jaroslav@1258: * jaroslav@1258: *

Implementation note: Java platform implementers are encouraged to jaroslav@1258: * document their implementation's behavior with respect to the jaroslav@1258: * {@code stackSize} parameter. jaroslav@1258: * jaroslav@1258: * jaroslav@1258: * @param group jaroslav@1258: * the thread group. If {@code null} and there is a security jaroslav@1258: * manager, the group is determined by {@linkplain jaroslav@1258: * SecurityManager#getThreadGroup SecurityManager.getThreadGroup()}. jaroslav@1258: * If there is not a security manager or {@code jaroslav@1258: * SecurityManager.getThreadGroup()} returns {@code null}, the group jaroslav@1258: * is set to the current thread's thread group. jaroslav@1258: * jaroslav@1258: * @param target jaroslav@1258: * the object whose {@code run} method is invoked when this thread jaroslav@1258: * is started. If {@code null}, this thread's run method is invoked. jaroslav@1258: * jaroslav@1258: * @param name jaroslav@1258: * the name of the new thread jaroslav@1258: * jaroslav@1258: * @param stackSize jaroslav@1258: * the desired stack size for the new thread, or zero to indicate jaroslav@1258: * that this parameter is to be ignored. jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if the current thread cannot create a thread in the specified jaroslav@1258: * thread group jaroslav@1258: * jaroslav@1258: * @since 1.4 jaroslav@1258: */ jaroslav@1260: // public Thread(ThreadGroup group, Runnable target, String name, jaroslav@1260: // long stackSize) { jaroslav@1260: // init(group, target, name, stackSize); jaroslav@1260: // } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Causes this thread to begin execution; the Java Virtual Machine jaroslav@1258: * calls the run method of this thread. jaroslav@1258: *

jaroslav@1258: * The result is that two threads are running concurrently: the jaroslav@1258: * current thread (which returns from the call to the jaroslav@1258: * start method) and the other thread (which executes its jaroslav@1258: * run method). jaroslav@1258: *

jaroslav@1258: * It is never legal to start a thread more than once. jaroslav@1258: * In particular, a thread may not be restarted once it has completed jaroslav@1258: * execution. jaroslav@1258: * jaroslav@1258: * @exception IllegalThreadStateException if the thread was already jaroslav@1258: * started. jaroslav@1258: * @see #run() jaroslav@1258: * @see #stop() jaroslav@1258: */ jaroslav@1260: public void start() { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * If this thread was constructed using a separate jaroslav@1258: * Runnable run object, then that jaroslav@1258: * Runnable object's run method is called; jaroslav@1258: * otherwise, this method does nothing and returns. jaroslav@1258: *

jaroslav@1258: * Subclasses of Thread should override this method. jaroslav@1258: * jaroslav@1258: * @see #start() jaroslav@1258: * @see #stop() jaroslav@1258: * @see #Thread(ThreadGroup, Runnable, String) jaroslav@1258: */ jaroslav@1258: @Override jaroslav@1258: public void run() { jaroslav@1258: if (target != null) { jaroslav@1258: target.run(); jaroslav@1258: } jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Forces the thread to stop executing. jaroslav@1258: *

jaroslav@1258: * If there is a security manager installed, its checkAccess jaroslav@1258: * method is called with this jaroslav@1258: * as its argument. This may result in a jaroslav@1258: * SecurityException being raised (in the current thread). jaroslav@1258: *

jaroslav@1258: * If this thread is different from the current thread (that is, the current jaroslav@1258: * thread is trying to stop a thread other than itself), the jaroslav@1258: * security manager's checkPermission method (with a jaroslav@1258: * RuntimePermission("stopThread") argument) is called in jaroslav@1258: * addition. jaroslav@1258: * Again, this may result in throwing a jaroslav@1258: * SecurityException (in the current thread). jaroslav@1258: *

jaroslav@1258: * The thread represented by this thread is forced to stop whatever jaroslav@1258: * it is doing abnormally and to throw a newly created jaroslav@1258: * ThreadDeath object as an exception. jaroslav@1258: *

jaroslav@1258: * It is permitted to stop a thread that has not yet been started. jaroslav@1258: * If the thread is eventually started, it immediately terminates. jaroslav@1258: *

jaroslav@1258: * An application should not normally try to catch jaroslav@1258: * ThreadDeath unless it must do some extraordinary jaroslav@1258: * cleanup operation (note that the throwing of jaroslav@1258: * ThreadDeath causes finally clauses of jaroslav@1258: * try statements to be executed before the thread jaroslav@1258: * officially dies). If a catch clause catches a jaroslav@1258: * ThreadDeath object, it is important to rethrow the jaroslav@1258: * object so that the thread actually dies. jaroslav@1258: *

jaroslav@1258: * The top-level error handler that reacts to otherwise uncaught jaroslav@1258: * exceptions does not print out a message or otherwise notify the jaroslav@1258: * application if the uncaught exception is an instance of jaroslav@1258: * ThreadDeath. jaroslav@1258: * jaroslav@1258: * @exception SecurityException if the current thread cannot jaroslav@1258: * modify this thread. jaroslav@1258: * @see #interrupt() jaroslav@1258: * @see #checkAccess() jaroslav@1258: * @see #run() jaroslav@1258: * @see #start() jaroslav@1258: * @see ThreadDeath jaroslav@1258: * @see ThreadGroup#uncaughtException(Thread,Throwable) jaroslav@1258: * @see SecurityManager#checkAccess(Thread) jaroslav@1258: * @see SecurityManager#checkPermission jaroslav@1258: * @deprecated This method is inherently unsafe. Stopping a thread with jaroslav@1258: * Thread.stop causes it to unlock all of the monitors that it jaroslav@1258: * has locked (as a natural consequence of the unchecked jaroslav@1258: * ThreadDeath exception propagating up the stack). If jaroslav@1258: * any of the objects previously protected by these monitors were in jaroslav@1258: * an inconsistent state, the damaged objects become visible to jaroslav@1258: * other threads, potentially resulting in arbitrary behavior. Many jaroslav@1258: * uses of stop should be replaced by code that simply jaroslav@1258: * modifies some variable to indicate that the target thread should jaroslav@1258: * stop running. The target thread should check this variable jaroslav@1258: * regularly, and return from its run method in an orderly fashion jaroslav@1258: * if the variable indicates that it is to stop running. If the jaroslav@1258: * target thread waits for long periods (on a condition variable, jaroslav@1258: * for example), the interrupt method should be used to jaroslav@1258: * interrupt the wait. jaroslav@1258: * For more information, see jaroslav@1258: * Why jaroslav@1258: * are Thread.stop, Thread.suspend and Thread.resume Deprecated?. jaroslav@1258: */ jaroslav@1258: @Deprecated jaroslav@1258: public final void stop() { jaroslav@1260: stop(null); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Forces the thread to stop executing. jaroslav@1258: *

jaroslav@1258: * If there is a security manager installed, the checkAccess jaroslav@1258: * method of this thread is called, which may result in a jaroslav@1258: * SecurityException being raised (in the current thread). jaroslav@1258: *

jaroslav@1258: * If this thread is different from the current thread (that is, the current jaroslav@1258: * thread is trying to stop a thread other than itself) or jaroslav@1258: * obj is not an instance of ThreadDeath, the jaroslav@1258: * security manager's checkPermission method (with the jaroslav@1258: * RuntimePermission("stopThread") argument) is called in jaroslav@1258: * addition. jaroslav@1258: * Again, this may result in throwing a jaroslav@1258: * SecurityException (in the current thread). jaroslav@1258: *

jaroslav@1258: * If the argument obj is null, a jaroslav@1258: * NullPointerException is thrown (in the current thread). jaroslav@1258: *

jaroslav@1258: * The thread represented by this thread is forced to stop jaroslav@1258: * whatever it is doing abnormally and to throw the jaroslav@1258: * Throwable object obj as an exception. This jaroslav@1258: * is an unusual action to take; normally, the stop method jaroslav@1258: * that takes no arguments should be used. jaroslav@1258: *

jaroslav@1258: * It is permitted to stop a thread that has not yet been started. jaroslav@1258: * If the thread is eventually started, it immediately terminates. jaroslav@1258: * jaroslav@1258: * @param obj the Throwable object to be thrown. jaroslav@1258: * @exception SecurityException if the current thread cannot modify jaroslav@1258: * this thread. jaroslav@1258: * @throws NullPointerException if obj is null. jaroslav@1258: * @see #interrupt() jaroslav@1258: * @see #checkAccess() jaroslav@1258: * @see #run() jaroslav@1258: * @see #start() jaroslav@1258: * @see #stop() jaroslav@1258: * @see SecurityManager#checkAccess(Thread) jaroslav@1258: * @see SecurityManager#checkPermission jaroslav@1258: * @deprecated This method is inherently unsafe. See {@link #stop()} jaroslav@1258: * for details. An additional danger of this jaroslav@1258: * method is that it may be used to generate exceptions that the jaroslav@1258: * target thread is unprepared to handle (including checked jaroslav@1258: * exceptions that the thread could not possibly throw, were it jaroslav@1258: * not for this method). jaroslav@1258: * For more information, see jaroslav@1258: * Why jaroslav@1258: * are Thread.stop, Thread.suspend and Thread.resume Deprecated?. jaroslav@1258: */ jaroslav@1258: @Deprecated jaroslav@1258: public final synchronized void stop(Throwable obj) { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Interrupts this thread. jaroslav@1258: * jaroslav@1258: *

Unless the current thread is interrupting itself, which is jaroslav@1258: * always permitted, the {@link #checkAccess() checkAccess} method jaroslav@1258: * of this thread is invoked, which may cause a {@link jaroslav@1258: * SecurityException} to be thrown. jaroslav@1258: * jaroslav@1258: *

If this thread is blocked in an invocation of the {@link jaroslav@1258: * Object#wait() wait()}, {@link Object#wait(long) wait(long)}, or {@link jaroslav@1258: * Object#wait(long, int) wait(long, int)} methods of the {@link Object} jaroslav@1258: * class, or of the {@link #join()}, {@link #join(long)}, {@link jaroslav@1258: * #join(long, int)}, {@link #sleep(long)}, or {@link #sleep(long, int)}, jaroslav@1258: * methods of this class, then its interrupt status will be cleared and it jaroslav@1258: * will receive an {@link InterruptedException}. jaroslav@1258: * jaroslav@1258: *

If this thread is blocked in an I/O operation upon an {@link jaroslav@1258: * java.nio.channels.InterruptibleChannel interruptible jaroslav@1258: * channel} then the channel will be closed, the thread's interrupt jaroslav@1258: * status will be set, and the thread will receive a {@link jaroslav@1258: * java.nio.channels.ClosedByInterruptException}. jaroslav@1258: * jaroslav@1258: *

If this thread is blocked in a {@link java.nio.channels.Selector} jaroslav@1258: * then the thread's interrupt status will be set and it will return jaroslav@1258: * immediately from the selection operation, possibly with a non-zero jaroslav@1258: * value, just as if the selector's {@link jaroslav@1258: * java.nio.channels.Selector#wakeup wakeup} method were invoked. jaroslav@1258: * jaroslav@1258: *

If none of the previous conditions hold then this thread's interrupt jaroslav@1258: * status will be set.

jaroslav@1258: * jaroslav@1258: *

Interrupting a thread that is not alive need not have any effect. jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if the current thread cannot modify this thread jaroslav@1258: * jaroslav@1258: * @revised 6.0 jaroslav@1258: * @spec JSR-51 jaroslav@1258: */ jaroslav@1258: public void interrupt() { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Tests whether the current thread has been interrupted. The jaroslav@1258: * interrupted status of the thread is cleared by this method. In jaroslav@1258: * other words, if this method were to be called twice in succession, the jaroslav@1258: * second call would return false (unless the current thread were jaroslav@1258: * interrupted again, after the first call had cleared its interrupted jaroslav@1258: * status and before the second call had examined it). jaroslav@1258: * jaroslav@1258: *

A thread interruption ignored because a thread was not alive jaroslav@1258: * at the time of the interrupt will be reflected by this method jaroslav@1258: * returning false. jaroslav@1258: * jaroslav@1258: * @return true if the current thread has been interrupted; jaroslav@1258: * false otherwise. jaroslav@1258: * @see #isInterrupted() jaroslav@1258: * @revised 6.0 jaroslav@1258: */ jaroslav@1258: public static boolean interrupted() { jaroslav@1260: return currentThread().isInterrupted(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Tests whether this thread has been interrupted. The interrupted jaroslav@1258: * status of the thread is unaffected by this method. jaroslav@1258: * jaroslav@1258: *

A thread interruption ignored because a thread was not alive jaroslav@1258: * at the time of the interrupt will be reflected by this method jaroslav@1258: * returning false. jaroslav@1258: * jaroslav@1258: * @return true if this thread has been interrupted; jaroslav@1258: * false otherwise. jaroslav@1258: * @see #interrupted() jaroslav@1258: * @revised 6.0 jaroslav@1258: */ jaroslav@1258: public boolean isInterrupted() { jaroslav@1260: return false; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Throws {@link NoSuchMethodError}. jaroslav@1258: * jaroslav@1258: * @deprecated This method was originally designed to destroy this jaroslav@1258: * thread without any cleanup. Any monitors it held would have jaroslav@1258: * remained locked. However, the method was never implemented. jaroslav@1258: * If if were to be implemented, it would be deadlock-prone in jaroslav@1258: * much the manner of {@link #suspend}. If the target thread held jaroslav@1258: * a lock protecting a critical system resource when it was jaroslav@1258: * destroyed, no thread could ever access this resource again. jaroslav@1258: * If another thread ever attempted to lock this resource, deadlock jaroslav@1258: * would result. Such deadlocks typically manifest themselves as jaroslav@1258: * "frozen" processes. For more information, see jaroslav@1258: * jaroslav@1258: * Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?. jaroslav@1258: * @throws NoSuchMethodError always jaroslav@1258: */ jaroslav@1258: @Deprecated jaroslav@1258: public void destroy() { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Tests if this thread is alive. A thread is alive if it has jaroslav@1258: * been started and has not yet died. jaroslav@1258: * jaroslav@1258: * @return true if this thread is alive; jaroslav@1258: * false otherwise. jaroslav@1258: */ jaroslav@1260: public final boolean isAlive() { jaroslav@1260: return true; jaroslav@1260: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Suspends this thread. jaroslav@1258: *

jaroslav@1258: * First, the checkAccess method of this thread is called jaroslav@1258: * with no arguments. This may result in throwing a jaroslav@1258: * SecurityException (in the current thread). jaroslav@1258: *

jaroslav@1258: * If the thread is alive, it is suspended and makes no further jaroslav@1258: * progress unless and until it is resumed. jaroslav@1258: * jaroslav@1258: * @exception SecurityException if the current thread cannot modify jaroslav@1258: * this thread. jaroslav@1258: * @see #checkAccess jaroslav@1258: * @deprecated This method has been deprecated, as it is jaroslav@1258: * inherently deadlock-prone. If the target thread holds a lock on the jaroslav@1258: * monitor protecting a critical system resource when it is suspended, no jaroslav@1258: * thread can access this resource until the target thread is resumed. If jaroslav@1258: * the thread that would resume the target thread attempts to lock this jaroslav@1258: * monitor prior to calling resume, deadlock results. Such jaroslav@1258: * deadlocks typically manifest themselves as "frozen" processes. jaroslav@1258: * For more information, see jaroslav@1258: * Why jaroslav@1258: * are Thread.stop, Thread.suspend and Thread.resume Deprecated?. jaroslav@1258: */ jaroslav@1258: @Deprecated jaroslav@1258: public final void suspend() { jaroslav@1258: checkAccess(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Resumes a suspended thread. jaroslav@1258: *

jaroslav@1258: * First, the checkAccess method of this thread is called jaroslav@1258: * with no arguments. This may result in throwing a jaroslav@1258: * SecurityException (in the current thread). jaroslav@1258: *

jaroslav@1258: * If the thread is alive but suspended, it is resumed and is jaroslav@1258: * permitted to make progress in its execution. jaroslav@1258: * jaroslav@1258: * @exception SecurityException if the current thread cannot modify this jaroslav@1258: * thread. jaroslav@1258: * @see #checkAccess jaroslav@1258: * @see #suspend() jaroslav@1258: * @deprecated This method exists solely for use with {@link #suspend}, jaroslav@1258: * which has been deprecated because it is deadlock-prone. jaroslav@1258: * For more information, see jaroslav@1258: * Why jaroslav@1258: * are Thread.stop, Thread.suspend and Thread.resume Deprecated?. jaroslav@1258: */ jaroslav@1258: @Deprecated jaroslav@1258: public final void resume() { jaroslav@1258: checkAccess(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Changes the priority of this thread. jaroslav@1258: *

jaroslav@1258: * First the checkAccess method of this thread is called jaroslav@1258: * with no arguments. This may result in throwing a jaroslav@1258: * SecurityException. jaroslav@1258: *

jaroslav@1258: * Otherwise, the priority of this thread is set to the smaller of jaroslav@1258: * the specified newPriority and the maximum permitted jaroslav@1258: * priority of the thread's thread group. jaroslav@1258: * jaroslav@1258: * @param newPriority priority to set this thread to jaroslav@1258: * @exception IllegalArgumentException If the priority is not in the jaroslav@1258: * range MIN_PRIORITY to jaroslav@1258: * MAX_PRIORITY. jaroslav@1258: * @exception SecurityException if the current thread cannot modify jaroslav@1258: * this thread. jaroslav@1258: * @see #getPriority jaroslav@1258: * @see #checkAccess() jaroslav@1258: * @see #getThreadGroup() jaroslav@1258: * @see #MAX_PRIORITY jaroslav@1258: * @see #MIN_PRIORITY jaroslav@1258: * @see ThreadGroup#getMaxPriority() jaroslav@1258: */ jaroslav@1258: public final void setPriority(int newPriority) { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns this thread's priority. jaroslav@1258: * jaroslav@1258: * @return this thread's priority. jaroslav@1258: * @see #setPriority jaroslav@1258: */ jaroslav@1258: public final int getPriority() { jaroslav@1260: return Thread.NORM_PRIORITY; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Changes the name of this thread to be equal to the argument jaroslav@1258: * name. jaroslav@1258: *

jaroslav@1258: * First the checkAccess method of this thread is called jaroslav@1258: * with no arguments. This may result in throwing a jaroslav@1258: * SecurityException. jaroslav@1258: * jaroslav@1258: * @param name the new name for this thread. jaroslav@1258: * @exception SecurityException if the current thread cannot modify this jaroslav@1258: * thread. jaroslav@1258: * @see #getName jaroslav@1258: * @see #checkAccess() jaroslav@1258: */ jaroslav@1258: public final void setName(String name) { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns this thread's name. jaroslav@1258: * jaroslav@1258: * @return this thread's name. jaroslav@1258: * @see #setName(String) jaroslav@1258: */ jaroslav@1258: public final String getName() { jaroslav@1258: return String.valueOf(name); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns the thread group to which this thread belongs. jaroslav@1258: * This method returns null if this thread has died jaroslav@1258: * (been stopped). jaroslav@1258: * jaroslav@1258: * @return this thread's thread group. jaroslav@1258: */ jaroslav@1260: // public final ThreadGroup getThreadGroup() { jaroslav@1260: // return group; jaroslav@1260: // } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns an estimate of the number of active threads in the current jaroslav@1258: * thread's {@linkplain java.lang.ThreadGroup thread group} and its jaroslav@1258: * subgroups. Recursively iterates over all subgroups in the current jaroslav@1258: * thread's thread group. jaroslav@1258: * jaroslav@1258: *

The value returned is only an estimate because the number of jaroslav@1258: * threads may change dynamically while this method traverses internal jaroslav@1258: * data structures, and might be affected by the presence of certain jaroslav@1258: * system threads. This method is intended primarily for debugging jaroslav@1258: * and monitoring purposes. jaroslav@1258: * jaroslav@1258: * @return an estimate of the number of active threads in the current jaroslav@1258: * thread's thread group and in any other thread group that jaroslav@1258: * has the current thread's thread group as an ancestor jaroslav@1258: */ jaroslav@1258: public static int activeCount() { jaroslav@1260: return 1; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Copies into the specified array every active thread in the current jaroslav@1258: * thread's thread group and its subgroups. This method simply jaroslav@1258: * invokes the {@link java.lang.ThreadGroup#enumerate(Thread[])} jaroslav@1258: * method of the current thread's thread group. jaroslav@1258: * jaroslav@1258: *

An application might use the {@linkplain #activeCount activeCount} jaroslav@1258: * method to get an estimate of how big the array should be, however jaroslav@1258: * if the array is too short to hold all the threads, the extra threads jaroslav@1258: * are silently ignored. If it is critical to obtain every active jaroslav@1258: * thread in the current thread's thread group and its subgroups, the jaroslav@1258: * invoker should verify that the returned int value is strictly less jaroslav@1258: * than the length of {@code tarray}. jaroslav@1258: * jaroslav@1258: *

Due to the inherent race condition in this method, it is recommended jaroslav@1258: * that the method only be used for debugging and monitoring purposes. jaroslav@1258: * jaroslav@1258: * @param tarray jaroslav@1258: * an array into which to put the list of threads jaroslav@1258: * jaroslav@1258: * @return the number of threads put into the array jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if {@link java.lang.ThreadGroup#checkAccess} determines that jaroslav@1258: * the current thread cannot access its thread group jaroslav@1258: */ jaroslav@1258: public static int enumerate(Thread tarray[]) { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Counts the number of stack frames in this thread. The thread must jaroslav@1258: * be suspended. jaroslav@1258: * jaroslav@1258: * @return the number of stack frames in this thread. jaroslav@1258: * @exception IllegalThreadStateException if this thread is not jaroslav@1258: * suspended. jaroslav@1258: * @deprecated The definition of this call depends on {@link #suspend}, jaroslav@1258: * which is deprecated. Further, the results of this call jaroslav@1258: * were never well-defined. jaroslav@1258: */ jaroslav@1258: @Deprecated jaroslav@1258: public native int countStackFrames(); jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Waits at most {@code millis} milliseconds for this thread to jaroslav@1258: * die. A timeout of {@code 0} means to wait forever. jaroslav@1258: * jaroslav@1258: *

This implementation uses a loop of {@code this.wait} calls jaroslav@1258: * conditioned on {@code this.isAlive}. As a thread terminates the jaroslav@1258: * {@code this.notifyAll} method is invoked. It is recommended that jaroslav@1258: * applications not use {@code wait}, {@code notify}, or jaroslav@1258: * {@code notifyAll} on {@code Thread} instances. jaroslav@1258: * jaroslav@1258: * @param millis jaroslav@1258: * the time to wait in milliseconds jaroslav@1258: * jaroslav@1258: * @throws IllegalArgumentException jaroslav@1258: * if the value of {@code millis} is negative jaroslav@1258: * jaroslav@1258: * @throws InterruptedException jaroslav@1258: * if any thread has interrupted the current thread. The jaroslav@1258: * interrupted status of the current thread is jaroslav@1258: * cleared when this exception is thrown. jaroslav@1258: */ jaroslav@1258: public final synchronized void join(long millis) jaroslav@1258: throws InterruptedException { jaroslav@1258: long base = System.currentTimeMillis(); jaroslav@1258: long now = 0; jaroslav@1258: jaroslav@1258: if (millis < 0) { jaroslav@1258: throw new IllegalArgumentException("timeout value is negative"); jaroslav@1258: } jaroslav@1258: jaroslav@1258: if (millis == 0) { jaroslav@1258: while (isAlive()) { jaroslav@1258: wait(0); jaroslav@1258: } jaroslav@1258: } else { jaroslav@1258: while (isAlive()) { jaroslav@1258: long delay = millis - now; jaroslav@1258: if (delay <= 0) { jaroslav@1258: break; jaroslav@1258: } jaroslav@1258: wait(delay); jaroslav@1258: now = System.currentTimeMillis() - base; jaroslav@1258: } jaroslav@1258: } jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Waits at most {@code millis} milliseconds plus jaroslav@1258: * {@code nanos} nanoseconds for this thread to die. jaroslav@1258: * jaroslav@1258: *

This implementation uses a loop of {@code this.wait} calls jaroslav@1258: * conditioned on {@code this.isAlive}. As a thread terminates the jaroslav@1258: * {@code this.notifyAll} method is invoked. It is recommended that jaroslav@1258: * applications not use {@code wait}, {@code notify}, or jaroslav@1258: * {@code notifyAll} on {@code Thread} instances. jaroslav@1258: * jaroslav@1258: * @param millis jaroslav@1258: * the time to wait in milliseconds jaroslav@1258: * jaroslav@1258: * @param nanos jaroslav@1258: * {@code 0-999999} additional nanoseconds to wait jaroslav@1258: * jaroslav@1258: * @throws IllegalArgumentException jaroslav@1258: * if the value of {@code millis} is negative, or the value jaroslav@1258: * of {@code nanos} is not in the range {@code 0-999999} jaroslav@1258: * jaroslav@1258: * @throws InterruptedException jaroslav@1258: * if any thread has interrupted the current thread. The jaroslav@1258: * interrupted status of the current thread is jaroslav@1258: * cleared when this exception is thrown. jaroslav@1258: */ jaroslav@1258: public final synchronized void join(long millis, int nanos) jaroslav@1258: throws InterruptedException { jaroslav@1258: jaroslav@1258: if (millis < 0) { jaroslav@1258: throw new IllegalArgumentException("timeout value is negative"); jaroslav@1258: } jaroslav@1258: jaroslav@1258: if (nanos < 0 || nanos > 999999) { jaroslav@1258: throw new IllegalArgumentException( jaroslav@1258: "nanosecond timeout value out of range"); jaroslav@1258: } jaroslav@1258: jaroslav@1258: if (nanos >= 500000 || (nanos != 0 && millis == 0)) { jaroslav@1258: millis++; jaroslav@1258: } jaroslav@1258: jaroslav@1258: join(millis); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Waits for this thread to die. jaroslav@1258: * jaroslav@1258: *

An invocation of this method behaves in exactly the same jaroslav@1258: * way as the invocation jaroslav@1258: * jaroslav@1258: *

jaroslav@1258: * {@linkplain #join(long) join}{@code (0)} jaroslav@1258: *
jaroslav@1258: * jaroslav@1258: * @throws InterruptedException jaroslav@1258: * if any thread has interrupted the current thread. The jaroslav@1258: * interrupted status of the current thread is jaroslav@1258: * cleared when this exception is thrown. jaroslav@1258: */ jaroslav@1258: public final void join() throws InterruptedException { jaroslav@1258: join(0); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Prints a stack trace of the current thread to the standard error stream. jaroslav@1258: * This method is used only for debugging. jaroslav@1258: * jaroslav@1258: * @see Throwable#printStackTrace() jaroslav@1258: */ jaroslav@1258: public static void dumpStack() { jaroslav@1258: new Exception("Stack trace").printStackTrace(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Marks this thread as either a {@linkplain #isDaemon daemon} thread jaroslav@1258: * or a user thread. The Java Virtual Machine exits when the only jaroslav@1258: * threads running are all daemon threads. jaroslav@1258: * jaroslav@1258: *

This method must be invoked before the thread is started. jaroslav@1258: * jaroslav@1258: * @param on jaroslav@1258: * if {@code true}, marks this thread as a daemon thread jaroslav@1258: * jaroslav@1258: * @throws IllegalThreadStateException jaroslav@1258: * if this thread is {@linkplain #isAlive alive} jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if {@link #checkAccess} determines that the current jaroslav@1258: * thread cannot modify this thread jaroslav@1258: */ jaroslav@1258: public final void setDaemon(boolean on) { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Tests if this thread is a daemon thread. jaroslav@1258: * jaroslav@1258: * @return true if this thread is a daemon thread; jaroslav@1258: * false otherwise. jaroslav@1258: * @see #setDaemon(boolean) jaroslav@1258: */ jaroslav@1258: public final boolean isDaemon() { jaroslav@1260: return false; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Determines if the currently running thread has permission to jaroslav@1258: * modify this thread. jaroslav@1258: *

jaroslav@1258: * If there is a security manager, its checkAccess method jaroslav@1258: * is called with this thread as its argument. This may result in jaroslav@1258: * throwing a SecurityException. jaroslav@1258: * jaroslav@1258: * @exception SecurityException if the current thread is not allowed to jaroslav@1258: * access this thread. jaroslav@1258: * @see SecurityManager#checkAccess(Thread) jaroslav@1258: */ jaroslav@1258: public final void checkAccess() { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns a string representation of this thread, including the jaroslav@1258: * thread's name, priority, and thread group. jaroslav@1258: * jaroslav@1258: * @return a string representation of this thread. jaroslav@1258: */ jaroslav@1258: public String toString() { jaroslav@1260: return "Thread[" + getName() + "," + getPriority() + "," + jaroslav@1260: "" + "]"; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns the context ClassLoader for this Thread. The context jaroslav@1258: * ClassLoader is provided by the creator of the thread for use jaroslav@1258: * by code running in this thread when loading classes and resources. jaroslav@1258: * If not {@linkplain #setContextClassLoader set}, the default is the jaroslav@1258: * ClassLoader context of the parent Thread. The context ClassLoader of the jaroslav@1258: * primordial thread is typically set to the class loader used to load the jaroslav@1258: * application. jaroslav@1258: * jaroslav@1258: *

If a security manager is present, and the invoker's class loader is not jaroslav@1258: * {@code null} and is not the same as or an ancestor of the context class jaroslav@1258: * loader, then this method invokes the security manager's {@link jaroslav@1258: * SecurityManager#checkPermission(java.security.Permission) checkPermission} jaroslav@1258: * method with a {@link RuntimePermission RuntimePermission}{@code jaroslav@1258: * ("getClassLoader")} permission to verify that retrieval of the context jaroslav@1258: * class loader is permitted. jaroslav@1258: * jaroslav@1258: * @return the context ClassLoader for this Thread, or {@code null} jaroslav@1258: * indicating the system class loader (or, failing that, the jaroslav@1258: * bootstrap class loader) jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if the current thread cannot get the context ClassLoader jaroslav@1258: * jaroslav@1258: * @since 1.2 jaroslav@1258: */ jaroslav@1258: public ClassLoader getContextClassLoader() { jaroslav@1403: return ClassLoader.getSystemClassLoader(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Sets the context ClassLoader for this Thread. The context jaroslav@1258: * ClassLoader can be set when a thread is created, and allows jaroslav@1258: * the creator of the thread to provide the appropriate class loader, jaroslav@1258: * through {@code getContextClassLoader}, to code running in the thread jaroslav@1258: * when loading classes and resources. jaroslav@1258: * jaroslav@1258: *

If a security manager is present, its {@link jaroslav@1258: * SecurityManager#checkPermission(java.security.Permission) checkPermission} jaroslav@1258: * method is invoked with a {@link RuntimePermission RuntimePermission}{@code jaroslav@1258: * ("setContextClassLoader")} permission to see if setting the context jaroslav@1258: * ClassLoader is permitted. jaroslav@1258: * jaroslav@1258: * @param cl jaroslav@1258: * the context ClassLoader for this Thread, or null indicating the jaroslav@1258: * system class loader (or, failing that, the bootstrap class loader) jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if the current thread cannot set the context ClassLoader jaroslav@1258: * jaroslav@1258: * @since 1.2 jaroslav@1258: */ jaroslav@1258: public void setContextClassLoader(ClassLoader cl) { jaroslav@1403: if (cl == ClassLoader.getSystemClassLoader()) { jaroslav@1403: return; jaroslav@1403: } jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns true if and only if the current thread holds the jaroslav@1258: * monitor lock on the specified object. jaroslav@1258: * jaroslav@1258: *

This method is designed to allow a program to assert that jaroslav@1258: * the current thread already holds a specified lock: jaroslav@1258: * 

jaroslav@1258:      *     assert Thread.holdsLock(obj);
jaroslav@1258:      *
jaroslav@1258: * jaroslav@1258: * @param obj the object on which to test lock ownership jaroslav@1258: * @throws NullPointerException if obj is null jaroslav@1258: * @return true if the current thread holds the monitor lock on jaroslav@1258: * the specified object. jaroslav@1258: * @since 1.4 jaroslav@1258: */ jaroslav@1260: public static boolean holdsLock(Object obj) { jaroslav@1260: return true; jaroslav@1260: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns an array of stack trace elements representing the stack dump jaroslav@1258: * of this thread. This method will return a zero-length array if jaroslav@1258: * this thread has not started, has started but has not yet been jaroslav@1258: * scheduled to run by the system, or has terminated. jaroslav@1258: * If the returned array is of non-zero length then the first element of jaroslav@1258: * the array represents the top of the stack, which is the most recent jaroslav@1258: * method invocation in the sequence. The last element of the array jaroslav@1258: * represents the bottom of the stack, which is the least recent method jaroslav@1258: * invocation in the sequence. jaroslav@1258: * jaroslav@1258: *

If there is a security manager, and this thread is not jaroslav@1258: * the current thread, then the security manager's jaroslav@1258: * checkPermission method is called with a jaroslav@1258: * RuntimePermission("getStackTrace") permission jaroslav@1258: * to see if it's ok to get the stack trace. jaroslav@1258: * jaroslav@1258: *

Some virtual machines may, under some circumstances, omit one jaroslav@1258: * or more stack frames from the stack trace. In the extreme case, jaroslav@1258: * a virtual machine that has no stack trace information concerning jaroslav@1258: * this thread is permitted to return a zero-length array from this jaroslav@1258: * method. jaroslav@1258: * jaroslav@1258: * @return an array of StackTraceElement, jaroslav@1258: * each represents one stack frame. jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if a security manager exists and its jaroslav@1258: * checkPermission method doesn't allow jaroslav@1258: * getting the stack trace of thread. jaroslav@1258: * @see SecurityManager#checkPermission jaroslav@1258: * @see RuntimePermission jaroslav@1258: * @see Throwable#getStackTrace jaroslav@1258: * jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public StackTraceElement[] getStackTrace() { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns a map of stack traces for all live threads. jaroslav@1258: * The map keys are threads and each map value is an array of jaroslav@1258: * StackTraceElement that represents the stack dump jaroslav@1258: * of the corresponding Thread. jaroslav@1258: * The returned stack traces are in the format specified for jaroslav@1258: * the {@link #getStackTrace getStackTrace} method. jaroslav@1258: * jaroslav@1258: *

The threads may be executing while this method is called. jaroslav@1258: * The stack trace of each thread only represents a snapshot and jaroslav@1258: * each stack trace may be obtained at different time. A zero-length jaroslav@1258: * array will be returned in the map value if the virtual machine has jaroslav@1258: * no stack trace information about a thread. jaroslav@1258: * jaroslav@1258: *

If there is a security manager, then the security manager's jaroslav@1258: * checkPermission method is called with a jaroslav@1258: * RuntimePermission("getStackTrace") permission as well as jaroslav@1258: * RuntimePermission("modifyThreadGroup") permission jaroslav@1258: * to see if it is ok to get the stack trace of all threads. jaroslav@1258: * jaroslav@1258: * @return a Map from Thread to an array of jaroslav@1258: * StackTraceElement that represents the stack trace of jaroslav@1258: * the corresponding thread. jaroslav@1258: * jaroslav@1258: * @throws SecurityException jaroslav@1258: * if a security manager exists and its jaroslav@1258: * checkPermission method doesn't allow jaroslav@1258: * getting the stack trace of thread. jaroslav@1258: * @see #getStackTrace jaroslav@1258: * @see SecurityManager#checkPermission jaroslav@1258: * @see RuntimePermission jaroslav@1258: * @see Throwable#getStackTrace jaroslav@1258: * jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public static Map getAllStackTraces() { jaroslav@1260: throw new SecurityException(); jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns the identifier of this Thread. The thread ID is a positive jaroslav@1258: * long number generated when this thread was created. jaroslav@1258: * The thread ID is unique and remains unchanged during its lifetime. jaroslav@1258: * When a thread is terminated, this thread ID may be reused. jaroslav@1258: * jaroslav@1258: * @return this thread's ID. jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public long getId() { jaroslav@1260: return 0; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * A thread state. A thread can be in one of the following states: jaroslav@1258: *

jaroslav@1258: * jaroslav@1258: *

jaroslav@1258: * A thread can be in only one state at a given point in time. jaroslav@1258: * These states are virtual machine states which do not reflect jaroslav@1258: * any operating system thread states. jaroslav@1258: * jaroslav@1258: * @since 1.5 jaroslav@1258: * @see #getState jaroslav@1258: */ jaroslav@1258: public enum State { jaroslav@1258: /** jaroslav@1258: * Thread state for a thread which has not yet started. jaroslav@1258: */ jaroslav@1258: NEW, jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Thread state for a runnable thread. A thread in the runnable jaroslav@1258: * state is executing in the Java virtual machine but it may jaroslav@1258: * be waiting for other resources from the operating system jaroslav@1258: * such as processor. jaroslav@1258: */ jaroslav@1258: RUNNABLE, jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Thread state for a thread blocked waiting for a monitor lock. jaroslav@1258: * A thread in the blocked state is waiting for a monitor lock jaroslav@1258: * to enter a synchronized block/method or jaroslav@1258: * reenter a synchronized block/method after calling jaroslav@1258: * {@link Object#wait() Object.wait}. jaroslav@1258: */ jaroslav@1258: BLOCKED, jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Thread state for a waiting thread. jaroslav@1258: * A thread is in the waiting state due to calling one of the jaroslav@1258: * following methods: jaroslav@1258: *

jaroslav@1258: * jaroslav@1258: *

A thread in the waiting state is waiting for another thread to jaroslav@1258: * perform a particular action. jaroslav@1258: * jaroslav@1258: * For example, a thread that has called Object.wait() jaroslav@1258: * on an object is waiting for another thread to call jaroslav@1258: * Object.notify() or Object.notifyAll() on jaroslav@1258: * that object. A thread that has called Thread.join() jaroslav@1258: * is waiting for a specified thread to terminate. jaroslav@1258: */ jaroslav@1258: WAITING, jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Thread state for a waiting thread with a specified waiting time. jaroslav@1258: * A thread is in the timed waiting state due to calling one of jaroslav@1258: * the following methods with a specified positive waiting time: jaroslav@1258: *

jaroslav@1258: */ jaroslav@1258: TIMED_WAITING, jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Thread state for a terminated thread. jaroslav@1258: * The thread has completed execution. jaroslav@1258: */ jaroslav@1258: TERMINATED; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns the state of this thread. jaroslav@1258: * This method is designed for use in monitoring of the system state, jaroslav@1258: * not for synchronization control. jaroslav@1258: * jaroslav@1258: * @return this thread's state. jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public State getState() { jaroslav@1258: // get current thread state jaroslav@1260: return State.RUNNABLE; jaroslav@1258: } jaroslav@1258: jaroslav@1258: // Added in JSR-166 jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Interface for handlers invoked when a Thread abruptly jaroslav@1258: * terminates due to an uncaught exception. jaroslav@1258: *

When a thread is about to terminate due to an uncaught exception jaroslav@1258: * the Java Virtual Machine will query the thread for its jaroslav@1258: * UncaughtExceptionHandler using jaroslav@1258: * {@link #getUncaughtExceptionHandler} and will invoke the handler's jaroslav@1258: * uncaughtException method, passing the thread and the jaroslav@1258: * exception as arguments. jaroslav@1258: * If a thread has not had its UncaughtExceptionHandler jaroslav@1258: * explicitly set, then its ThreadGroup object acts as its jaroslav@1258: * UncaughtExceptionHandler. If the ThreadGroup object jaroslav@1258: * has no jaroslav@1258: * special requirements for dealing with the exception, it can forward jaroslav@1258: * the invocation to the {@linkplain #getDefaultUncaughtExceptionHandler jaroslav@1258: * default uncaught exception handler}. jaroslav@1258: * jaroslav@1258: * @see #setDefaultUncaughtExceptionHandler jaroslav@1258: * @see #setUncaughtExceptionHandler jaroslav@1258: * @see ThreadGroup#uncaughtException jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public interface UncaughtExceptionHandler { jaroslav@1258: /** jaroslav@1258: * Method invoked when the given thread terminates due to the jaroslav@1258: * given uncaught exception. jaroslav@1258: *

Any exception thrown by this method will be ignored by the jaroslav@1258: * Java Virtual Machine. jaroslav@1258: * @param t the thread jaroslav@1258: * @param e the exception jaroslav@1258: */ jaroslav@1258: void uncaughtException(Thread t, Throwable e); jaroslav@1258: } jaroslav@1258: jaroslav@1258: // null unless explicitly set jaroslav@1258: private volatile UncaughtExceptionHandler uncaughtExceptionHandler; jaroslav@1258: jaroslav@1258: // null unless explicitly set jaroslav@1258: private static volatile UncaughtExceptionHandler defaultUncaughtExceptionHandler; jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Set the default handler invoked when a thread abruptly terminates jaroslav@1258: * due to an uncaught exception, and no other handler has been defined jaroslav@1258: * for that thread. jaroslav@1258: * jaroslav@1258: *

Uncaught exception handling is controlled first by the thread, then jaroslav@1258: * by the thread's {@link ThreadGroup} object and finally by the default jaroslav@1258: * uncaught exception handler. If the thread does not have an explicit jaroslav@1258: * uncaught exception handler set, and the thread's thread group jaroslav@1258: * (including parent thread groups) does not specialize its jaroslav@1258: * uncaughtException method, then the default handler's jaroslav@1258: * uncaughtException method will be invoked. jaroslav@1258: *

By setting the default uncaught exception handler, an application jaroslav@1258: * can change the way in which uncaught exceptions are handled (such as jaroslav@1258: * logging to a specific device, or file) for those threads that would jaroslav@1258: * already accept whatever "default" behavior the system jaroslav@1258: * provided. jaroslav@1258: * jaroslav@1258: *

Note that the default uncaught exception handler should not usually jaroslav@1258: * defer to the thread's ThreadGroup object, as that could cause jaroslav@1258: * infinite recursion. jaroslav@1258: * jaroslav@1258: * @param eh the object to use as the default uncaught exception handler. jaroslav@1258: * If null then there is no default handler. jaroslav@1258: * jaroslav@1258: * @throws SecurityException if a security manager is present and it jaroslav@1258: * denies {@link RuntimePermission} jaroslav@1258: * ("setDefaultUncaughtExceptionHandler") jaroslav@1258: * jaroslav@1258: * @see #setUncaughtExceptionHandler jaroslav@1258: * @see #getUncaughtExceptionHandler jaroslav@1258: * @see ThreadGroup#uncaughtException jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public static void setDefaultUncaughtExceptionHandler(UncaughtExceptionHandler eh) { jaroslav@1260: throw new SecurityException(); jaroslav@1260: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns the default handler invoked when a thread abruptly terminates jaroslav@1258: * due to an uncaught exception. If the returned value is null, jaroslav@1258: * there is no default. jaroslav@1258: * @since 1.5 jaroslav@1258: * @see #setDefaultUncaughtExceptionHandler jaroslav@1258: */ jaroslav@1258: public static UncaughtExceptionHandler getDefaultUncaughtExceptionHandler(){ jaroslav@1258: return defaultUncaughtExceptionHandler; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Returns the handler invoked when this thread abruptly terminates jaroslav@1258: * due to an uncaught exception. If this thread has not had an jaroslav@1258: * uncaught exception handler explicitly set then this thread's jaroslav@1258: * ThreadGroup object is returned, unless this thread jaroslav@1258: * has terminated, in which case null is returned. jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public UncaughtExceptionHandler getUncaughtExceptionHandler() { jaroslav@1258: return uncaughtExceptionHandler != null ? jaroslav@1260: uncaughtExceptionHandler : null; jaroslav@1258: } jaroslav@1258: jaroslav@1258: /** jaroslav@1258: * Set the handler invoked when this thread abruptly terminates jaroslav@1258: * due to an uncaught exception. jaroslav@1258: *

A thread can take full control of how it responds to uncaught jaroslav@1258: * exceptions by having its uncaught exception handler explicitly set. jaroslav@1258: * If no such handler is set then the thread's ThreadGroup jaroslav@1258: * object acts as its handler. jaroslav@1258: * @param eh the object to use as this thread's uncaught exception jaroslav@1258: * handler. If null then this thread has no explicit handler. jaroslav@1258: * @throws SecurityException if the current thread is not allowed to jaroslav@1258: * modify this thread. jaroslav@1258: * @see #setDefaultUncaughtExceptionHandler jaroslav@1258: * @see ThreadGroup#uncaughtException jaroslav@1258: * @since 1.5 jaroslav@1258: */ jaroslav@1258: public void setUncaughtExceptionHandler(UncaughtExceptionHandler eh) { jaroslav@1258: checkAccess(); jaroslav@1258: uncaughtExceptionHandler = eh; jaroslav@1258: } jaroslav@1258: }