java.lang.Thread Maven / Gradle / Ivy

Neither this file nor any files generated from it describe a complete specification, and they may only be used as described below. For example, no permission is given for you to incorporate this file, in whole or in part, in an implementation of a Java specification.

Sun Microsystems Inc. owns the copyright in this file and it is provided to you for informative, as opposed to normative, use. The file and any files generated from it may be used to generate other informative documentation, such as a unified set of documents of API signatures for a platform that includes technologies expressed as Java APIs. The file may also be used to produce "compilation stubs," which allow applications to be compiled and validated for such platforms.

Any work generated from this file, such as unified javadocs or compiled stub files, must be accompanied by this notice in its entirety.

This work corresponds to the API signatures of JSR 219: Foundation Profile 1.1. In the event of a discrepency between this work and the JSR 219 specification, which is available at http://www.jcp.org/en/jsr/detail?id=219, the latter takes precedence. */ package java.lang; import java.security.AccessController; import java.security.AccessControlContext; import java.util.Map; import java.util.Collections; /** * A thread is a thread of execution in a program. The Java * Virtual Machine allows an application to have multiple threads of * execution running concurrently. *

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

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

*
• The exit method of class Runtime has been * called and the security manager has permitted the exit operation * to take place. *
• All threads that are not daemon threads have died, either by * returning from the call to the run method or by * throwing an exception that propagates beyond the run * method. *

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

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

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

 *     PrimeThread p = new PrimeThread(143);
 *     p.start();
 * 

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

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

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

 *     PrimeRun p = new PrimeRun(143);
 *     new Thread(p).start();
 * 

* Every thread has a name for identification purposes. More than * one thread may have the same name. If a name is not specified when * a thread is created, a new name is generated for it. * * @author unascribed * @version 1.114, 05/17/00 * @see java.lang.Runnable * @see java.lang.Runtime#exit(int) * @see java.lang.Thread#run() * @since JDK1.0 */ public class Thread implements java.lang.Runnable { /** * The minimum priority that a thread can have. */ public static final int MIN_PRIORITY = 1; /** * The default priority that is assigned to a thread. */ public static final int NORM_PRIORITY = 5; /** * The maximum priority that a thread can have. */ public static final int MAX_PRIORITY = 10; /** * Allocates a new Thread object. This constructor has * the same effect as Thread(null, null, * gname), where gname is * a newly generated name. Automatically generated names are of the * form "Thread-"+n, where n is an integer. * * @see java.lang.Thread#Thread(java.lang.ThreadGroup, * java.lang.Runnable, java.lang.String) */ public Thread() { } /** * Allocates a new Thread object. This constructor has * the same effect as Thread(null, target, * gname), where gname is * a newly generated name. Automatically generated names are of the * form "Thread-"+n, where n is an integer. * * @param target the object whose run method is called. * @see java.lang.Thread#Thread(java.lang.ThreadGroup, * java.lang.Runnable, java.lang.String) */ public Thread(java.lang.Runnable target) { } /** * Allocates a new Thread object. This constructor has * the same effect as Thread(group, target, * gname), where gname is * a newly generated name. Automatically generated names are of the * form "Thread-"+n, where n is an integer. * * @param group the thread group. * @param target the object whose run method is called. * @exception SecurityException if the current thread cannot create a * thread in the specified thread group. * @see java.lang.Thread#Thread(java.lang.ThreadGroup, * java.lang.Runnable, java.lang.String) */ public Thread(java.lang.ThreadGroup group, java.lang.Runnable target) { } /** * Allocates a new Thread object. This constructor has * the same effect as Thread(null, null, name). * * @param name the name of the new thread. * @see java.lang.Thread#Thread(java.lang.ThreadGroup, * java.lang.Runnable, java.lang.String) */ public Thread(java.lang.String name) { } /** * Allocates a new Thread object. This constructor has * the same effect as Thread(group, null, name) * * @param group the thread group. * @param name the name of the new thread. * @exception SecurityException if the current thread cannot create a * thread in the specified thread group. * @see java.lang.Thread#Thread(java.lang.ThreadGroup, * java.lang.Runnable, java.lang.String) */ public Thread(java.lang.ThreadGroup group, java.lang.String name) { } /** * Allocates a new Thread object. This constructor has * the same effect as Thread(null, target, name). * * @param target the object whose run method is called. * @param name the name of the new thread. * @see java.lang.Thread#Thread(java.lang.ThreadGroup, * java.lang.Runnable, java.lang.String) */ public Thread(java.lang.Runnable target, java.lang.String name) { } /** * Allocates a new Thread object so that it has * target as its run object, has the specified * name as its name, and belongs to the thread group * referred to by group. *

* If group is null and there is a * security manager, the group is determined by the security manager's * getThreadGroup method. If group is * null and there is not a security manager, or the * security manager's getThreadGroup method returns * null, the group is set to be the same ThreadGroup * as the thread that is creating the new thread. * *

If there is a security manager, its checkAccess * method is called with the ThreadGroup as its argument. * This may result in a SecurityException. *

* If the target argument is not null, the * run method of the target is called when * this thread is started. If the target argument is * null, this thread's run method is called * when this thread is started. *

* The priority of the newly created thread is set equal to the * priority of the thread creating it, that is, the currently running * thread. The method setPriority may be used to * change the priority to a new value. *

* The newly created thread is initially marked as being a daemon * thread if and only if the thread creating it is currently marked * as a daemon thread. The method setDaemon may be used * to change whether or not a thread is a daemon. * * @param group the thread group. * @param target the object whose run method is called. * @param name the name of the new thread. * @exception SecurityException if the current thread cannot create a * thread in the specified thread group. * @see java.lang.Runnable#run() * @see java.lang.Thread#run() * @see java.lang.Thread#setDaemon(boolean) * @see java.lang.Thread#setPriority(int) * @see java.lang.ThreadGroup#checkAccess() * @see SecurityManager#checkAccess */ public Thread(java.lang.ThreadGroup group, java.lang.Runnable target, java.lang.String name) { } /** * Allocates a new Thread object so that it has * target as its run object, has the specified * name as its name, belongs to the thread group referred to * by group, and has the specified stack size. * *

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

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

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

Specifying a value of zero for the stackSize parameter will * cause this constructor to behave exactly like the * Thread(ThreadGroup, Runnable, String) constructor. * *

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

Implementation note: Java platform implementers are encouraged to * document their implementation's behavior with respect to the * stackSize parameter. * * @param group the thread group. * @param target the object whose run method is called. * @param name the name of the new thread. * @param stackSize the desired stack size for the new thread, or * zero to indicate that this parameter is to be ignored. * @exception SecurityException if the current thread cannot create a * thread in the specified thread group. */ public Thread(java.lang.ThreadGroup group, java.lang.Runnable target, java.lang.String name, long stackSize) { } /** * Returns a reference to the currently executing thread object. * * @return the currently executing thread. */ public static java.lang.Thread currentThread() { return null; } /** * Causes the currently executing thread object to temporarily pause * and allow other threads to execute. */ public static void yield() { } /** * Causes the currently executing thread to sleep (temporarily cease * execution) for the specified number of milliseconds. The thread * does not lose ownership of any monitors. * * @param millis the length of time to sleep in milliseconds. * @exception InterruptedException if another thread has interrupted * the current thread. The interrupted status of the * current thread is cleared when this exception is thrown. * @see java.lang.Object#notify() */ public static void sleep(long millis) throws java.lang.InterruptedException { } /** * Causes the currently executing thread to sleep (cease execution) * for the specified number of milliseconds plus the specified number * of nanoseconds. The thread does not lose ownership of any monitors. * * @param millis the length of time to sleep in milliseconds. * @param nanos 0-999999 additional nanoseconds to sleep. * @exception IllegalArgumentException if the value of millis is * negative or the value of nanos is not in the range * 0-999999. * @exception InterruptedException if another thread has interrupted * the current thread. The interrupted status of the * current thread is cleared when this exception is thrown. * @see java.lang.Object#notify() */ public static void sleep(long millis, int nanos) throws java.lang.InterruptedException { } /** * Causes this thread to begin execution; the Java Virtual Machine * calls the run method of this thread. *

* The result is that two threads are running concurrently: the * current thread (which returns from the call to the * start method) and the other thread (which executes its * run method). * * @exception IllegalThreadStateException if the thread was already * started. * @see java.lang.Thread#run() */ public void start() { } /** * If this thread was constructed using a separate * Runnable run object, then that * Runnable object's run method is called; * otherwise, this method does nothing and returns. *

* Subclasses of Thread should override this method. * * @see java.lang.Thread#start() * @see java.lang.Thread#Thread(java.lang.ThreadGroup, * java.lang.Runnable, java.lang.String) * @see java.lang.Runnable#run() */ public void run() { } /** * Interrupts this thread. * *

First the {@link #checkAccess() checkAccess} method of this thread * is invoked, which may cause a {@link SecurityException} to be thrown. * *

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

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

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

* Otherwise, the priority of this thread is set to the smaller of * the specified newPriority and the maximum permitted * priority of the thread's thread group. * * @param newPriority priority to set this thread to * @exception IllegalArgumentException If the priority is not in the * range MIN_PRIORITY to * MAX_PRIORITY. * @exception SecurityException if the current thread cannot modify * this thread. * @see #getPriority * @see java.lang.Thread#checkAccess() * @see java.lang.Thread#getPriority() * @see java.lang.Thread#getThreadGroup() * @see java.lang.Thread#MAX_PRIORITY * @see java.lang.Thread#MIN_PRIORITY * @see java.lang.ThreadGroup#getMaxPriority() */ public final void setPriority(int newPriority) { } /** * Returns this thread's priority. * * @return this thread's priority. * @see #setPriority * @see java.lang.Thread#setPriority(int) */ public final int getPriority() { return 0; } /** * Changes the name of this thread to be equal to the argument * name. *

* First the checkAccess method of this thread is called * with no arguments. This may result in throwing a * SecurityException. * * @param name the new name for this thread. * @exception SecurityException if the current thread cannot modify this * thread. * @see #getName * @see java.lang.Thread#checkAccess() * @see java.lang.Thread#getName() */ public final void setName(java.lang.String name) { } /** * Returns this thread's name. * * @return this thread's name. * @see #setName * @see java.lang.Thread#setName(java.lang.String) */ public final java.lang.String getName() { return null; } /** * Returns the thread group to which this thread belongs. * This method returns null if this thread has died * (been stopped). * * @return this thread's thread group. */ public final java.lang.ThreadGroup getThreadGroup() { return null; } /** * Returns the number of active threads in the current thread's thread * group. * * @return the number of active threads in the current thread's thread * group. */ public static int activeCount() { return 0; } /** * Copies into the specified array every active thread in * the current thread's thread group and its subgroups. This method simply * calls the enumerate method of the current thread's thread * group with the array argument. *

* First, if there is a security manager, that enumerate * method calls the security * manager's checkAccess method * with the thread group as its argument. This may result * in throwing a SecurityException. * * @param tarray an array of Thread objects to copy to * @return the number of threads put into the array * @exception SecurityException if a security manager exists and its * checkAccess method doesn't allow the operation. * @see java.lang.ThreadGroup#enumerate(java.lang.Thread[]) * @see java.lang.SecurityManager#checkAccess(java.lang.ThreadGroup) */ public static int enumerate(java.lang.Thread[] tarray) { return 0; } /** * Waits at most millis milliseconds for this thread to * die. A timeout of 0 means to wait forever. * * @param millis the time to wait in milliseconds. * @exception InterruptedException if another thread has interrupted * the current thread. The interrupted status of the * current thread is cleared when this exception is thrown. */ public final void join(long millis) throws java.lang.InterruptedException { } /** * Waits at most millis milliseconds plus * nanos nanoseconds for this thread to die. * * @param millis the time to wait in milliseconds. * @param nanos 0-999999 additional nanoseconds to wait. * @exception IllegalArgumentException if the value of millis is negative * the value of nanos is not in the range 0-999999. * @exception InterruptedException if another thread has interrupted * the current thread. The interrupted status of the * current thread is cleared when this exception is thrown. */ public final void join(long millis, int nanos) throws java.lang.InterruptedException { } /** * Waits for this thread to die. * * @exception InterruptedException if another thread has interrupted * the current thread. The interrupted status of the * current thread is cleared when this exception is thrown. */ public final void join() throws java.lang.InterruptedException { } /** * Prints a stack trace of the current thread. This method is used * only for debugging. * * @see java.lang.Throwable#printStackTrace() */ public static void dumpStack() { } /** * Marks this thread as either a daemon thread or a user thread. The * Java Virtual Machine exits when the only threads running are all * daemon threads. *

* This method must be called before the thread is started. *

* This method first calls the checkAccess method * of this thread * with no arguments. This may result in throwing a * SecurityException (in the current thread). *

* If process model exists, Thread.setDaemon() should be used * as it is defined in J2SE specification. *

* If process model does not exist, Thread.setDaemon() should be * used to set threads as daemon threads if the programmer uses * good coding techniques to a) guarantee that the daemon thread will * exit and clean up its resources before either a System.exit() is * called and/or all the user threads have exited, and b) override the * security manager's default behavior to throw SecurityException * when System.exit() is called. *

* @param on if true, marks this thread as a * daemon thread. * @exception IllegalThreadStateException if this thread is active. * @exception SecurityException if the current thread cannot modify * this thread. * @see java.lang.Thread#isDaemon() * @see #checkAccess */ public final void setDaemon(boolean on) { } /** * Tests if this thread is a daemon thread. * * @return true if this thread is a daemon thread; * false otherwise. * @see java.lang.Thread#setDaemon(boolean) */ public final boolean isDaemon() { return false; } /** * Determines if the currently running thread has permission to * modify this thread. *

* If there is a security manager, its checkAccess method * is called with this thread as its argument. This may result in * throwing a SecurityException. *

* Note: This method was mistakenly non-final in JDK 1.1. * It has been made final in the Java 2 Platform. * * @exception SecurityException if the current thread is not allowed to * access this thread. * @see java.lang.SecurityManager#checkAccess(java.lang.Thread) */ public final void checkAccess() { } /** * Returns a string representation of this thread, including the * thread's name, priority, and thread group. * * @return a string representation of this thread. */ public java.lang.String toString() { return null; } /** * Returns the context ClassLoader for this Thread. The context * ClassLoader is provided by the creator of the thread for use * by code running in this thread when loading classes and resources. * If not set, the default is the ClassLoader context of the parent * Thread. The context ClassLoader of the primordial thread is * typically set to the class loader used to load the application. * *

First, if there is a security manager, and the caller's class * loader is not null and the caller's class loader is not the same as or * an ancestor of the context class loader for the thread whose * context class loader is being requested, then the security manager's * checkPermission * method is called with a * RuntimePermission("getClassLoader") permission * to see if it's ok to get the context ClassLoader.. * * @return the context ClassLoader for this Thread * * @throws SecurityException * if a security manager exists and its * checkPermission method doesn't allow * getting the context ClassLoader. * @see #setContextClassLoader * @see SecurityManager#checkPermission * @see java.lang.RuntimePermission * * @since 1.2 */ public java.lang.ClassLoader getContextClassLoader() { return null; } /** * Sets the context ClassLoader for this Thread. The context * ClassLoader can be set when a thread is created, and allows * the creator of the thread to provide the appropriate class loader * to code running in the thread when loading classes and resources. * *

First, if there is a security manager, its checkPermission * method is called with a * RuntimePermission("setContextClassLoader") permission * to see if it's ok to set the context ClassLoader.. * * @param cl the context ClassLoader for this Thread * * @exception SecurityException if the current thread cannot set the * context ClassLoader. * @see #getContextClassLoader * @see SecurityManager#checkPermission * @see java.lang.RuntimePermission * * @since 1.2 */ public void setContextClassLoader(java.lang.ClassLoader cl) { } /** * Returns true if and only if the current thread holds the * monitor lock on the specified object. * *

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

     *     assert Thread.holdsLock(obj);
     *